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# August 17

## Very large sets of permutations and their application in contemporary music theory

Twelve-tone music is based on an ordered set of 12, unique, pitch classes notated in music set theory as integers 0 … 11. Therefore there are 479,001,600 possible twelve tone rows (permutations of the ordered set). Even if it took just a millisecond to calculate each permutation it would still take about 326 days to perform that calculation, correct? Is there any hope at all that a searchable database of all twelve-tone rows can be constructed? --50.46.100.76 (talk) 00:31, 17 August 2014 (UTC)

Modern computers can do calculations far quicker than a millisecond. They can do more like millions or billions of calcs per second, depending on the complexity of the calculation and the computer used. But, even using your mere thousand calcs per second, I still get 5 and half days, not 326 (12!/1000/60/60/24). It looks like you forgot to divide by either the 60 seconds in a minute or the 60 minutes in an hour.
Also, I don't see any point in creating such a list. If I understand you correctly, there would be 12 notes in sequence, and the first could be any of the 12 notes, while the next would be any of the remaining 11 notes, etc., giving us 12! possibilities. If you really wanted a list of all those possible sequences, it probably already exists online, but what use would it be ? StuRat (talk) 03:00, 17 August 2014 (UTC)
Thanks for the reply, and sorry for my arithmetic error. My interest in having this kind of collection would be to search and/or sort the resulting database for desirable characteristics such as certain kinds of symmetries in the hexachords, all-interval tetrachords, etc. For students of 20th-century music theory this actually has great importance and practical application. I'm not aware of a readily available tool to do this online. (In addition, it would be a proof of concept that I would want to expand into other, more interesting applications in the study of algorithmic composition.)
I know that finding all the permutations is probably the most brute force of many available approaches, however I would want to allow for very broad flexibility in what the user specified as a search criteria. Could a database of this kind be indexed in some way so as to make the search more speedy than the initial calculation by which it was created? And is there some way to split up a calculation of this kind over a number of computers to speed up the process? Finally, how can one calculate the memory size for a database from the number of sets generated? Thanks! --50.46.100.76 (talk) 04:38, 17 August 2014 (UTC)
I don't understand why you're searching. If every possible permutation of notes is in your hypothetical database, why do you need to search it? Every conceivable combination is in there - so the answer to every search is "YES!" - so why search?!? SteveBaker (talk) 05:05, 17 August 2014 (UTC)
Steve, as a composer myself, I frequently want to see a selection of sets or chords with certain properties. This database would provide an analytical means of reviewing an inhumanly large data set and selecting appropriate musical material. Remember, we're talking about music represented by numbers. Perhaps the twelve-tone example is a bit obscure, but consider the set of all natural harmonics up to the 9th partial in the string section of the classical, western orchestra (also a set with close to half a million members if we only go up to hexachord-size subsets). Generating every combination of these harmonics reveals every possible chord in that set, each with its own expressive properties. That would be incredibly valuable in the field of contemporary sound art and algorithmic music composition. So, --50.46.100.76 (talk) 05:49, 17 August 2014 (UTC)
Yeah - but that list would also contain every possible jarring, grating, iharmoneous squawk. I'm no expert, but I bet there are 10,000 horrible sounds for every good one. If you have an algorithm for making "useful" chords - then just generate those rather than all of them. How are you going to search this list anyway? The point is that STORING a predictable series is pointless when you can generate the Nth element of the series trivially easily. It's kinda like saying: "I need to divide a bunch of number by 3 - so I'm going to generate a database of the first 100,000,000,000 multiples of 3 and search it to find the number I want to divide into." - there is simply no point in making the list.
If you're planning to generate every possible set of (say) 6 notes - then we can write you code that runs in a billionth of a second that'll produce the N'th element of that series. Pre-generating and storing makes NO sense whatever. SteveBaker (talk) 21:22, 17 August 2014 (UTC)
The thing is, twelve-tone rows are not chords. They're never or hardly ever heard in any perceptible form in a final composition. Instead, they are a kind of tool which could be used to construct an infinite number of compositions. The row imparts certain qualities to the resulting work, but is fairly unimportant to the sonic result. In other cases, such as the set of all natural harmonics up to the 9th partial in the string section of the orchestra, remember that the point of music is not to create "nice" sounds. Like all other arts, the point of "art music" is to express something. (That's debatable of course, but certainly the desire is to do SOMETHING beyond creating pleasant sounds.) What one composer finds ugly, another composer will find beautiful. Since the purpose is to make this tool available to all, it must be flexible enough to sort for any quality at all in the resulting sets. --50.46.100.76 (talk) 17:32, 18 August 2014 (UTC)
Sounds to me like what the OP is asking about is more of a sorting algorithm with the database (or else it'd be like assigning keywords or tags to certain combinations, like 'hex' and 'tetra' and so forth...) rather than simply a searchable database. And to add to the mix, s/he is sometimes using the term 'search' above when he seems to mean 'sort' -- or else 'search for the keywords as assigned previously...'. (I know he said 'search and/or sort,' but the conflation of terms after that is perhaps some source of confusion (?) though i can't pretend to know much about the music side of the question. El duderino (abides) 06:08, 17 August 2014 (UTC)
• This sort of thing arises all the time in database programming -- that is, situations where you have a database most of whose index values don't have any entries associated with them. The standard solution is to construct what is called a hash table, which allows the database to be searched efficiently. Looie496 (talk) 14:29, 17 August 2014 (UTC)
• As far as figuring out the size of the database table, take the number of records (479,001,600) and multiply it by the length of each record. To calculate the length of a record, since each of the 12 positions will hold one of 12 values, that takes 4 bits per position, since 2^4 = 16. If the DB system doesn't support 4 bit integers, then hopefully it supports 8 bit integers, or at least 16 bit. So, we have 12 times 4 or 8 or 16, for 48, 96, or 192 bits. Now, you'll probably want to add some more fields to label this record. These could be binary variables, noting whether this record is or isn't a certain type of combo. So, one bit each would do. If you have 8 of those, that's 8 more bits. So, we now have 56, 104, or 200 bits. Using an 8-bit byte, that's 7, 13, or 25 bytes per record. Now we multiple by the number of records, to get 3.4GB, 6.2GB, or 12GB. The lower two would fit on one side of a DVD, while the larger would fit on a two-sided DVD. All would easily fit on modern hard drives, flash drives, etc.
There's also possible index space needed. That's typically much less than the data space, but if you put an index on every field, it could actually be more, considering that each data record is quite short. To index each of 479,001,600 records, you'd need a 29 bit index, since 2^29 is the first multiple of 2 greater than that number. However, you aren't likely to be able to do that, and will need to go to a 32 bit (4 byte) index, instead. So, you multiply that by the number of records, and the number of indexes. If you had an index on all 12 notes and 8 labels, that's 20×4×479,001,600, or over 38GB for the indexes. You probably don't want to do that, but you could, if speeding up the searches is far more important than the space on the hard drive. So, worst case scenario, we're at 50GB total, for data and indices. You could also be more conservative and only put indices on the label fields, which would lower the index size to 15GB, and the worst case total size to 27GB. If you need fewer than 8 labels, you could lower it even more. StuRat (talk) 18:27, 17 August 2014 (UTC)

I want to connect my computer to my TV and be able to watch video/movies on it. I have no idea what connection/wire type I would need to do this or if it's even possible, so I was hoping someone here could be specific and tell me what I need: what type of wire/what type of connection/any adapters and so on.

My TV is a brand new Sony Bravia and it's specs including its ports are here. I want to run to it from my iMac (iMac11,3 Intel Core i5 2.8 GHz). After a bit of research, looking at the back and the searching for what they are, my iMac has four USB 3 ports, an ethernet port, a FireWire port, a mini DisplayPort, an audio out, an audio in and in fact is identical to this.

Thanks much in advance, even if the answer is that I can't.--108.46.97.218 (talk) 01:15, 17 August 2014 (UTC)

Hmm, it looks rather incompatible. The inputs to the TV include HDMI, composite, and component video. Both devices have USB ports, but I don't think you can send streaming video over that, it's used more for displaying stills, playing music, etc. (Although maybe USB 3.0 can handle video, I'm not sure on that.) I'd think your best bet would be to get a device to convert the mini display port output to HDMI format, but let's see what others have to say about it. StuRat (talk) 01:40, 17 August 2014 (UTC)
They could get a mini display to HDMI adaptor. Dismas|(talk) 01:46, 17 August 2014 (UTC)
Cool. So if I got this, and ran an HDMI cable from my TV to it, would it be as simple as (after changing the input on the TV to that HDMI connection) just turning on AVI/Quicktime/Wondershare, and playing the movie?--108.46.97.218 (talk) 02:30, 17 August 2014 (UTC)
There could still be some annoyances. For example, does the movie you are playing match the aspect ratio of the TV ? If not, then you will have letterboxing, stretching, or part of the movie will be off the edge of the screen. You can probably select which option you want using your TV remote. Also, the iMac might not send the full 1920x1080 resolution the TV can display. The TV may then create a smaller pic, or it could try to interpolate to "upscale" the image. Again, the TV remote may have options for which approach it takes.
Also, you will want to switch to a full screen display of the movie on the iMac, or you will get all the window frame and other junk displayed around the edges on the TV. Note that you won't be able to use the iMac for anything else interactive while the movie plays, because anything you do will also display on the TV. (You could run things in background mode, but they might cause the video or audio to pause or get out of sync.) StuRat (talk) 02:47, 17 August 2014 (UTC)
Interesting. Worth a shot considering what a pain it is to burn movies to DVD which take up a lot of time (especially now that I always want 1080p).--108.46.97.218 (talk) 03:56, 17 August 2014 (UTC)
On a side note, you don't have to buy brand name retail, which includes huge markups. There are perfectly good adapters out there for under $5 ([1]) if you don't mind waiting a few days for delivery. Same for the HDMI cables. You can find 25 foot HDMI cables for under$10 ([2]). -- Tom N talk/contrib 06:07, 17 August 2014 (UTC)
The specs for the TV say that it supports WiFi and Ethernet. Why not just network it and watch the videos directly from the TV, rather than via the iMac? --Phil Holmes (talk) 10:16, 17 August 2014 (UTC)
I am pretty sure that screen mirroring on Sony Bravia TVs is using a thing called Miracast which seems incompatible with Macs. ny156uk (talk) 12:29, 17 August 2014 (UTC)
Oh, that's interesting too! I really don't know where to begin though. So, um, it's a mac, so it only broadcasts via bluetooth right? I thought wifi and bluetooth were not compatible? Any suggestions on how I would "ask" the mac to send a movie that I have on it, and in a way a wifi capable tv would understand it--108.46.97.218 (talk) 12:10, 17 August 2014 (UTC)
I think Phil Holmes assumed that everything you want to watch is streaming video from the Internet, such as Hulu, Netflix, YouTube, etc. If that's the case, your TV wouldn't be connected to your Mac but to your router, using WiFi or an Ethernet cable. In other words, your TV would be like another computer in your home network. TVs that have that capability provide a way to connect to the desired site and start the video, using the TV's remote control and on-screen menus. That should all be in the documentation for the TV.
If you're talking about other video sources such as files on your Mac and DVDs, etc., then the TV's networking support is of no value to you. That is, unless there's some kind of Mac app that I'm not aware of, that would allow you to send a stream from your Mac to the TV through your router.
Bravia is a family of television models. If you could provide your TV's model number, we could be referring you to specific pages in specific manual(s) on the Web. 12:41, 17 August 2014 (UTC)
Thanks Mandruss. It's a 48w600b. Yes, I am not thinking of using content from the internet directly, but videos on my computer. I have ordered the adapter and HDMI cable, for a grand total of about 14 (thanks Tom N!); thanks all!--108.46.97.218 (talk) 13:50, 17 August 2014 (UTC) Cool. I'll mark this Q resolved for now, but please come back and tell us if it worked (repost if the Q has been archived by then). StuRat (talk) 17:09, 17 August 2014 (UTC) Resolved Reporting back @User:StuRat], so I got the HDMI cord a few days ago, and the adapter today. Unfortunately, it's the wrong adapter. It does have the exact same symbol on it, but it's not even close to fitting the slot. Apple must have changed the configuration. My slot is sort of the shape of a "D" but the adapter fits a larger, rectangular opening. It was very cheap, Just lamenting that I have to wait for another to arrive. Researching the types of slots now.--108.46.97.218 (talk) 00:58, 22 August 2014 (UTC) Is it a Mini DisplayPort you have?--Salix alba (talk): 02:04, 22 August 2014 (UTC) Okay, after an amazing amount of time looking, I finally located what I have and thus that the seller simply sent me the wrong adapter. Sigh. It's a Mini DVI to HDMI adapter. D'oh.--108.46.97.218 (talk) 03:07, 22 August 2014 (UTC) ## Automated accepting of cookies in EU The EU passed a moronic law requiring each and every goddamned website to ask for permission to store cookies on my computer. I would like to grant permission once and for all - is there some way I can communicate this through a browser mod or user agent or some such thing? 129.215.47.59 (talk) 15:23, 17 August 2014 (UTC) I think P3P does this, but it's not widely implemented.--Shantavira|feed me 06:08, 18 August 2014 (UTC) ## XML support in databases I wonder what FREE databases provide XML support. I know PostgreSQL does. What others are in this league? Thanks, --AboutFace 22 (talk) 16:04, 17 August 2014 (UTC) ## Google Chrome - How to remove the white boxes There are 8 white boxes in Google Chrome that are obstructing the theme I've chosen. Can I remove them and leave everything else the same? I've tried what you can do from Settings and a number of apps. The apps can remove them, but they also remove the background picture. Starfsmanna (talk) 16:53, 17 August 2014 (UTC) I don't think so. However, there is a great extension called "New Tab Redirect". When you click on a new tab, instead of going to the boxes, it goes to the homepage of your choice, which can be a website or even a homemade html page on your hard disk. Mine is an html page with a bunch of links I use all the time. So, it is just like the 8 boxes, but I can choose what is there and what is not. Anna Frodesiak (talk) 16:59, 17 August 2014 (UTC) Thank you, with your help and a continued search for a solution, I managed to come up with a workaround. https://answers.yahoo.com/question/index?qid=20140817094306AAw8dmg Starfsmanna (talk) 18:00, 17 August 2014 (UTC) # August 18 ## Priming/initial charging a lithium-ion battery? Is it even necessary? Some claim that I should give them an initial charge for like six hours to even a day, while others don't. In the case of a just-purchased tablet with a Lithium iron phosphate cell, do I really need to initialise it? Blake Gripling (talk) 01:21, 18 August 2014 (UTC) I've never heard of this and I've been using LiPo batteries with remote controlled helicopters and airplanes for years. Did your device come with instructions? That's usually covered in the manual. As far as I know, Lithium batteries do not suffer from memory effect, but that might not be the only reason to charge a battery for that long. Also, lithium batteries are very sensitive to OVER voltage, so any device that's designed to charge them should STOP charging them when they hit full charge, so I can't see how leaving it plugged in for 6 or 24 hours would make any difference. But, like I said, I'd read what it says in the manual and stick to that. Vespine (talk) 03:35, 18 August 2014 (UTC) It did come with some documentation, but there's nothing in the manual that suggests leaving the device charged for hours to prep a battery for first use. Also, during the time when I bought a Lenovo smartphone, the only advice the saleslady told me (at another store) was not to drain the battery at too low a voltage to curb any damage. Blake Gripling (talk) 04:47, 18 August 2014 (UTC) As Vespine has said, you cannot prime a lithium ion battery by charging it for six hours or a day. Unless there is something seriously wrong with charger, it will completely stop charging once the battery reaches capacity. There is no trickle charging or anything like that for lithium ion batteries, if you keeping trying, there's a good chance you could cause sufficient damage to your batteries to cause the infamous "venting with flames". The good news is that unless you're charging a raw 18650 with a dumb charger or something, it's fairly unlikely you will ever do so. However there is still a good reason not to leave your device plugged in. Because people generally expect their devices to be at fully charge, many will try to keep the battery at full charge when plugged in which has a negative effect on the capacity of the battery over time. There is sometimes a suggestion you should let your battery charge fully without using it first. AFAIK, the only reason to actually do so for a lithium ion battery is that it may help the device more accurately understand charge state faster. In other words, failing to do so doesn't affect the battery negatively, it just means your device may not be very accurate at reporting battery capacity for longer. (Of course many of these warnings are simply an ancient legacy of nickel based rechargable batteries.) Nil Einne (talk) 14:13, 21 August 2014 (UTC) ## Bitmap Header Field - Importance? A while back I made my own image enhancement software (just to tinker with), I was going over it and decided to change the header it uses to the standard windows one (it's just for tinkering, so it assumes a certain structure). At any rate, what actually uses the biXPelsPerMeter and biYPelsPerMeter fields? As in, if I left them 0, would the image display differently anywhere? I understand what the values mean, but I can't find anything indicating if they need be correct - and I know that not all bmp headers have them. Just curious. Thank you:-)Phoenixia1177 (talk) 06:30, 18 August 2014 (UTC) My own, rather limited experience, with generating bitmap (BMP or otherwise) headers from scratch is that physical specifications (DPI, DPM, PPI, etc.) are ignored for all but a few print-ready formats (TIFF, PS, EPS, PDF) and even than any actual print job being done, a designer or operator will still check (print-preview, essentially) what's to be printed before starting a job, to avoid nasty surprises - caused by mad suggested-size values in vector media (like SVG) or page size variances in page-aware formats (A4/letter/legal). Back when BMP had some currency as an interchange format, pretty much "what Windows does" was the nearest you'd get to compliance with its rather hazy specification (given that's it's just an old OS/2 "barf your internals into a file" type format). A corollary of your question is surely "if you don't know the physical dimensions of your bitmap, what values should bi[XY]PelsPerMeter have?". If you can, it's surely better to be silent (to not have the entry at all) than to lie. If you have to lie, it's better to lie with a sensible-ish guess than a definitely wrong value like 0 or NaN or -1 - because if some code somewhere does honour it, it'll surely do something like width_in_metres = width_in_pixels/biXPelsPerMeter - and your 0 value will either make the decode fail silently or with an error. Better, surely, to have a default that shows the image (at a wrong but recognisable size) than have the image not appear at all. These days I'd only add "what does libbmp do" and "what does libmagick do" to "what does windows do". Personally, if I were writing my own graphics software now and I wasn't going to use standard formats like JPEG or PNG, I'd probably use Netpbm format (with any of my own info in comments) as a path-of-least-makework. If I needed fancier features like alpha, gamma, compression, or progressive rendering I'd probably use libpng (with my custom data in PNG custom chunks). -- Finlay McWalterTalk 12:21, 18 August 2014 (UTC) • I'm a strong advocate of following standards in every possible respect, regardless of whether you know why they are written that way. I've never worked with that particular file format, but you can find documentation for the header structure at http://www.herdsoft.com/ti/davincie/davp3xo2.htm, where it states: "biXPelsPerMeter DWORD Specifies the horizontal resolution of the target device in pixels per metre. Applications often use this value to select the resource bitmap that best matches the characteristics of the current device.". In other words, you should specify the device resolution that makes your bitmap look best -- neither too large nor too small. Looie496 (talk) 13:11, 18 August 2014 (UTC) ## Preventing Spam Apparently that advice about ignoring internet trolls and cyber-bullies doesn't always work, since mine is now threatening to send a flood of spam against my twitter account, emails and most likely anywhere else he can find. I am wondering if anyone can recommend some way of blocking him from doing this, pre-emptively protecting myself in case he comes through with his threats? Thank you 82.132.212.22 (talk) 12:04, 18 August 2014 (UTC) As previously advised...ignore trolls. They crave attention - they delight in causing you grief. So, don't react. Don't acknowledge that there is a problem. "Dont Feed the Trolls" is excellent advice. SteveBaker (talk) 02:28, 19 August 2014 (UTC) yes, random trolls feed on attention, but this concrete case seems much more like stalking by someone the OP knows in real life. Maybe this is a case to be reported to the police, if it gets to far.OsmanRF34 (talk) 16:04, 19 August 2014 (UTC) I'd say it's time to change your accounts. Only give the new names to people you trust not to pass them along. StuRat (talk) 16:41, 19 August 2014 (UTC) ISTM that the term "Troll" has changed or extended in popular meaning since the advice of "Do not feed the Trolls" was formulated. Back then it was applied merely to those who tried to provoke arguments – preferably between others rather than with themselves – by subtly provocative comments, and of course derived from the angling term "trolling" (often for "newbies"). For such provocateurs, the advice frequently worked. Latterly the term seems to have been misunderstood as deriving from to the ugly mythological monsters, and is misapplied particularly by the mainstream media to people directing often crude or obscene attacks or continued harassments against other individuals. This sort of behavior is significantly different and the advice will often not work. This has resulted in people who are suffering the latter type of attacks being additionally seriously distressed by the inapplicability of the advice, not realizing that it refers to a different sort of troll. It might be desirable to establish consensus for a different term for the latter behavior – "Cyber-bully" is one possible example – and convince the media to use it appropriately. How this could be achieved, however, is beyond me. Apologies for side-tracking rather than addressing the OP's problem {The poster formerly known as 87.81.230.195} 212.95.237.92 (talk) 13:51, 20 August 2014 (UTC) ## Label printers I'm in need of printing a bunch of shipping labels for my wife's business (http://renm.us) - and it's clear that using our inkjet printer isn't a good option because you have to print an entire sheet of labels at one time. I see that there are a bunch of devices by different manufacturers that take a roll of stickers - so (presumably) I can print to them one at a time. My question is how those devices interface to the PC. Are they (in effect) just tiny inkjet printers as far as the operating system is concerned...or do I have to use some horrible (probably!) software that comes with the printer itself? We use an SQL customer database, with custom web interface software - and I'd like to use our standard query software with a "PRINT ADDRESS LABEL" button. I can write the code to do that if the interface to the label printer isn't something exotic. Does anyone have any experience with these machines? (Also, if you can recommend a good one, that would be nice). TIA SteveBaker (talk) 20:06, 18 August 2014 (UTC) Brother, Seiko and Dymo make affordable thermal label printers but they use special software. Zebra makes higher end printers with a higher price that you can create a print file in ZPL language. -- 01:30, 19 August 2014 (UTC) Are there significant problems with the thermal-printed labels fading in strong sunlight and 100 degree Texas days? They won't experience any of those things when they're in our control - but we ship packages around the world. SteveBaker (talk) 02:32, 19 August 2014 (UTC) For the lengths of time that your packages would see those temps, I don't think you should have an issue. Dismas|(talk) 06:05, 19 August 2014 (UTC) There are basically two types of thermal printing: direct and indirect. Direct thermal uses a print head to essentially burn the label in a controlled way to print. Cash register receipts are often printed this way. They tend to have low operating costs because there's no ribbon or ink, but they do tend to be thermally sensitive. I would definitely request samples and/or specs if you're thinking of going that way. Indirect thermal printing uses a wax/resin ribbon that gets burned onto the label by the print head. They tend to have higher operating costs (but the amount of ribbon you'd need would be negligible) and, IIRC, are somewhat pricier off the shelf as well. In my experience, they do not fade with heat, but you may experience cracking if you print to poly labels (the plastic expands in the heat and cracks the printing). I don't think that would happen if you printed to paper labels. I use a Datamax indirect thermal printer which has done yeoman's work for many years. The software is ridiculously priced, but it can marry up with standard DBF files and so forth. Matt Deres (talk) 17:15, 19 August 2014 (UTC) I have never seen the term "indirect thermal" used— this is thermal transfer (TT) as opposed to direct thermal (DT). If you need durable labels, then you need thermal transfer with coated paper, vinyl or poly labels and a resin ribbon. The more popular label applications are Neat Label, LabelView and BarTender. -- 22:39, 19 August 2014 (UTC) # August 19 ## Hard disc I/O error uTorrent can't download to one of my hard discs. It used to be fine. Now, it downloads for a while, then all the downloads stop and say "Error: WriteToDisk: The request could not be performed because of an I/O device error." The disc works fine otherwise. I'm running and old version of XP. If you have an suggestions, I'd be most grateful. Anna Frodesiak (talk) 02:12, 19 August 2014 (UTC) Try running CHKDSK, run "chkdsk /f". I think you run a command prompt "as administrator" and reboot your computer to start it. It may take a couple of hours. Bubba73 You talkin' to me? 02:31, 19 August 2014 (UTC) Thank you very much. I'll give that a try. One thing I did is close uTorrent and start it again with a lower download speed. This is working. I recently renewed my ISP deal and they gave me much greater speed. Anna Frodesiak (talk) 08:58, 19 August 2014 (UTC) ## Wording: "ID must be numeric" Situation: A website has an admin search menu with several IDs to look for. Some IDs are numbers, others are strings; and some of the strings are with digits only (with leading zeros added by the search function, if necessary), others with mixed characters. If someone looks, say, for a shop and enters letters in the shop ID search function, while a numeric shop ID is required, an error message is helpful. Is "Shop ID must be numeric" a perfect wording? Can it be used both for numbers and purely numeric strings? If it is suboptimal for any reason, what would be better? --KnightMove (talk) 13:46, 19 August 2014 (UTC) I might prefer "ID must contain only numerals" -- that way it doesn't matter if it's considered as a number or a string of numerals. I suppose you could even include something like "(0-9)" to make it more clear what is allowed. SemanticMantis (talk) 15:53, 19 August 2014 (UTC) ## Null Zero Deletion in MS Word How to delete all Null Zeros in Saved MS Word Document?--Tenkasi Subramanian (talk) 14:07, 19 August 2014 (UTC) ## Movie quality What would be better quality for a movie - an itunes download in 1080p or a 1080p "mastered in 4k" blu ray? — Preceding unsigned comment added by 176.251.149.21 (talk) 15:33, 19 August 2014 (UTC) All other factors being equal (bitrate, source), the 4K Blu-ray will be higher quality. Simply because iTunes 1080p uses h264 encoding, while 4K Blu-rays use its successor. However, in the real world, it's really a case-by-case comparison, because the bitrate, source, and what's being encoded all affect quality. --Wirbelwind(ヴィルヴェルヴィント) 18:36, 19 August 2014 (UTC) As I understand it, there's no such thing as a 4k Blu-ray. The format is technically still under development [3] [4] with no one sure what's going to happen with it. What the OP appears to be referring to are Blu-rays where the source material is 4k until it's converted to 1080p for the Blu-ray. In that case, while there are various reasons the mastered in 4k could be better, there's no guarantee it will be. However the blu-ray will frequently be better quality. Even though they spend a fair bit on many different languages (at least one maybe more in lossless multi channel), extras and stuff, the video bitrate tends to be quite a bit higher on the Bluray than most download formats. The compression format is frequently the same h.264 (some still use VC-1, MPEG2 is very rare nowadays and unlikely for a mastered in 4k), I'm not sure if iTunes generally uses a higher profile than that allowed by Blurays, but it wouldn't generally be enough to make up for the bitrate differences. It's also possible the source material will come in to play. While the mastered in 4k isn't that important, download sources don't necessarily get the same level of attention that Blurays get during production. Of course whether you can actually notice the difference during playback on your specific output device is another question. (And some people may prefer the higher compressed version for whatever reason.) It's clear many people don't care hence why streaming and download formats are dominating and Bluray is starting to have problems. Even among copyright violating sources, it's frequently difficult to find material where the video is untouched. Heck even finding Bluray sourced material can be difficult for TV series compared to that taken from the TV stream or deDRMed web downloads (which themselves are not always easy to find in comparison). Nil Einne (talk) 13:51, 21 August 2014 (UTC) ## Did the hardware logic been? Did the hardware logic (instrument logic) been or it been only the program logic?--Alex Sazonov (talk) 17:39, 19 August 2014 (UTC) Could you try rephrasing the question? I'm not really sure what "instrument logic" is. Are you trying to ask about physical logic gates versus software logic, e.g. conditional statements? --Wirbelwind(ヴィルヴェルヴィント) 18:34, 19 August 2014 (UTC) Could the math physical logical of material crystals of chips beening, is it a program (software) logic? I think that, the program (software) logic is simple section of chips, is it right? I seen that, the program (software) logical is been definite of all logical of computers, is it right?--Alex Sazonov (talk) 09:42, 20 August 2014 (UTC) It seems me, that the static memory of structure of materials proves that hardware logic been.--Alex Sazonov (talk) 11:14, 20 August 2014 (UTC) I'm not sure what your asking, but maybe Hardware description language will give you the answer. -- Q Chris (talk) 11:41, 20 August 2014 (UTC) Thanks much. In simply case, I interested in that, did the logic been without program languages?--Alex Sazonov (talk) 14:13, 20 August 2014 (UTC) Alex, can I make a specific request that you go and learn how to conjugate and use the English verb to be, please? You really can't just use the past form ('been') indiscriminately for everything. AlexTiefling (talk) 14:23, 20 August 2014 (UTC) Well. I suppose that, the crystal structure of all materials always is mobile, however it had a static memory, that’s why the simple logic without program language be.--Alex Sazonov (talk) 15:09, 20 August 2014 (UTC) Do you realise that your response has nothing to do with what I said? AlexTiefling (talk) 15:12, 20 August 2014 (UTC) ## When using a VPN, do web-pages know their users are connecting to it through one If yes, do web-sites like online banks or ecommerce sites care or at least raise a red flag due to it being a potential fraud? (in a scenario where a user connect both through a VPN when on public spaces and to the same page without said VPN from home or from the office).OsmanRF34 (talk) 19:51, 19 August 2014 (UTC) ## Silverlight - What Does It Do? What does Silverlight do? The only times I have ever seen anything about it on my computer (ANY of my computers) is when I get a message on my browser saying it has stopped working. What exactly is it supposed to do? KägeTorä - () (Chin Wag) 21:59, 19 August 2014 (UTC) Our article Microsoft Silverlight gives a basic description of what it is and how it is used. --Mark viking (talk) 22:10, 19 August 2014 (UTC) For the most part, it's an Adobe Flash substitute. Netflix, for example, uses Silverlight to stream their content. Without Silverlight, you'd see a blank page. They do have some HTML5 support, but it's in the infancy. --Wirbelwind(ヴィルヴェルヴィント) 22:13, 19 August 2014 (UTC) This site claims that only 0.2% of websites use Silverlight. Other than the very notable example of Netflix, which Wirbelwind mentioned, I can't remember ever finding a site that I wanted to use which needed Silverlight to work. 87.112.89.107 (talk) 22:35, 19 August 2014 (UTC) Microsoft provides a list of Silverlight features. Among these, I find the video streaming technologies to be the most interesting and useful, because the feature-set for streaming video is significantly richer than that available in the HTML5 specification. For example, Silverlight supports adaptive streaming from multiple sources at variable bitrates, using client-side cooperation built into the Silverlight plug-in to monitor streaming performance and adjust the server-side parameters accordingly. This would be very difficult to re-implement using only HTML5 - so there's an immediate value-add for video-streaming providers who want a software solution that already works. Silverlight also provides state-of-the-art security and authentication, assuring integrity from the network layer all the way to the hardware layer - again, by relying on cooperative security provided by the client-side plug-in (addressing a very difficult problem, which is that content is consumed on machines that categorically cannot be controlled by the content-provider). This plug-in solution ranks among the more secure ways to execute digital rights management (digital restrictions management) - for better or for worse, this means that it's more difficult (prohibitively difficult) for users to save, copy, or inspect digital content in ways that the developers and providers do not authorize. Nimur (talk) 23:27, 19 August 2014 (UTC) Basically, Silverlight is only one case where "somebody else is innovative, and Microsoft makes an inferior knock-off product". (This sounds bad, but it isn't always a bad thing. In some cases, the MS product isn't too bad, and actually good enough for 90% of the users.) The bad part is that Silverlight cannot possibly replace Flash, due to the popularity of Flash, which makes Silverlight a solution without a problem. If Silverlight becomes more popular, internet users are in big trouble; both products have quite a record of bad (browser-breaking) updates. - ¡Ouch! (hurt me / more pain) 08:11, 20 August 2014 (UTC) A lot of Microsoft's products are better than the competition's. IE certainly was for a while, mainly because it worked while Netscape was so buggy it was almost unusable. (And don't forget that IE introduced DHTML and Ajax, which everyone else then copied.) I suspect Silverlight is better than Flash for similar reasons, but it's hard to know when no one develops for it. -- BenRG (talk) 19:00, 20 August 2014 (UTC) In my experience, IE, rather than Netscape, was the one with lots of misaligned items. Many other bugs were not in the original NN but popped up with changed API standards, with malice aforethought. From a purely economic POV, the way Microsoft made competing products was the right (and logical) way to go. It is worth noting that in many cases, only when MS offered their product as part of their OS (as they did with DriveSpace) it became popular. Users are more likely to use a feature if it comes with the OS than to pay extra, as they had to with Stacker, before DOS/Windows offered disk compression. - ¡Ouch! (hurt me / more pain) 07:09, 21 August 2014 (UTC) As our article says, Microsoft has basically abandoned Silverlight so whatever they were planning to do, it's largely a moot point now. Nil Einne (talk) 13:35, 21 August 2014 (UTC) ## Replacing RAM with old RAM still in the system I have a set of 2x4GB ram running at 1600mhz. One of these sticks has gone bad, and it has been determined it is not a socket problem. The other one is not, so I'd like to get another stick of 4GB ram to replace the bad one. 2 questions here. Must it be the same model or manufacturer? (they are Patriot Viper 3s) Does it have to be the same speed? I'd run them in dual channel. KonveyorBelt 23:31, 19 August 2014 (UTC) I find it prudent to swap it with the stick of the same speed, i.e. 800Mhz on a board that takes DDR2-800s. Not sure if mixing speeds would be bad but I bet it is. It should be alright to use different brands though. Blake Gripling (talk) 00:43, 20 August 2014 (UTC) I believe the problem with mixing speeds is that they all then work at the lower speed. StuRat (talk) 23:03, 20 August 2014 (UTC) It may be alright to use different brands, but if you can get the same brand and/or model, by all means do. One can occasionally run into serious problems with otherwise identical sticks by different manufacturers; I know I did a few years ago!—Ëzhiki (Igels Hérissonovich Ïzhakoff-Amursky) • (yo?); August 20, 2014; 19:32 (UTC) # August 20 ## McAfee Security Scan Plus Hi there. One day I found this application installed on my computer. I never asked them to install it. I am surprised the application showed up, just like this. Roughly once a month it "runs" which takes about 30 seconds and declares that my computer is free of malware. I googled and found a few websites with mostly negative information. This is one of them. I wonder what people visiting this Reference Desk would say. I decided to ask here before I uninstalled it. Thanks, - --AboutFace 22 (talk) 00:46, 20 August 2014 (UTC) It is offered with Adobe Flash Player- if you update, you have to opt out. I have a low opinion of McAfee security products. -- 01:14, 20 August 2014 (UTC) It's so bad even McAfee himself hates it. Based on personal experience, yes it is indeed no better off than not having antivirus protection, as what I observed with a friend's laptop. Blake Gripling (talk) 01:21, 21 August 2014 (UTC) ## A better way to restore files? I accidentally deleted a directory and wanted to restore it using MozyHome, but I had to choose between restoring a single file and restoring everything. Is this the way it works with all the online backup services? --Halcatalyst (talk) 22:19, 20 August 2014 (UTC) • Well... I discovered the backup Mozy keeps locally on my computer, and it IS organized by directories, and so I'm OK. User education error. --Halcatalyst (talk) 03:15, 21 August 2014 (UTC) # August 21 ## Cannot add or change Chrome search engines It is driving me nuts. It is this thing. But, I cannot add a new one. Also, I cannot change the third column entry with the url. I just keep getting red boxes and no saves. Please help!!! Anna Frodesiak (talk) 08:58, 21 August 2014 (UTC) Ok, it decided to work. Anna Frodesiak (talk) 01:42, 22 August 2014 (UTC) ## Mastered in 4k Do mastered in 4k blu rays really have better quality on a 720 or 1080p HDTV than other blu rays? — Preceding unsigned comment added by 176.251.149.21 (talk) 12:36, 21 August 2014 (UTC) It's marketing hype that you should ignore. As mentioned in the previous thread, a "mastered in 4k" Blu-Ray disc is still only 1080p. It probably just means they filmed the thing in 2160p and then downsampled it for the Blu-Ray disc. This won't automatically give you a better picture than filming in 1080p. It might make a difference, but it's much less important than the quality of the camera and the technical and artistic competence of everyone involved. -- BenRG (talk) 18:54, 21 August 2014 (UTC) ## Android :Data connection get lost automatically My Mobile phone is Karbonn A50 Android version 2.3.6 . My problem is that while using internet continiously through Mobile network, suddenly wifi turn on automatically and itself get turned off. When I continue using internet then the internet sign get lost. The only option that remain is to restart to gain the signal. I first thought it was dur to malware and performed complete reset but even the problem persists. What may be the reason behind it? — Preceding unsigned comment added by Amrit.ghimire13 (talkcontribs) 17:23, 21 August 2014 (UTC) ## Windows 9 Do we have an article on Microsoft Windows 9? I can't seem to find anything. Thanks. Joseph A. Spadaro (talk) 17:39, 21 August 2014 (UTC) Since Microsoft apparently won't announce it until the end of next month, there's nothing yet to go into any article. We try to avoid speculation about future events. Rojomoke (talk) 17:57, 21 August 2014 (UTC) Thanks. But, it is quite common that we write articles in advance of events (for example, Super Bowl LII in 2018, the 2028 Summer Olympics in 2028, etc.). I had assumed this would be the same. Thanks. Joseph A. Spadaro (talk) 19:36, 21 August 2014 (UTC) There is solid, proven information that exists for those events: The Superbowl has a venue and the Olympics have preliminary meetings that are already established. Windows 9 has none of those things. The time will come, shortly, I imagine. Mingmingla (talk) 00:51, 22 August 2014 (UTC) # August 22 ## Arrays With Definite, But Unknown, Size I'm working on an image enhancement program (my own tinkering) in Ruby and have a particularly involved algorithm - it takes a few hours on a non-HD image. Generally, I don't mind waiting, but, in this case, it is becoming a real pain. So, I am looking, essentially, to run this specific process in a more performance focused language (C, C++, C#, Java, etc.). My stumbling block is the following: I need to use several arrays whose size will depend on the resolution of the input image, but I do not want to use dynamic arrays - for any given input, the size of the array is fixed, so is there any language that supports static sized arrays that are declared using a variable instead of a literal number? (For example, something like "v = image_x_size; new array = stuff[v]"). Thank you for any help - sorry for any lack of clarity, I don't do a lot of actual programming so am not exactly sure how to phrase stuff - or, if there are any other things anyone might suggest; I have no problem learning language features, I'm just not sure which ones to learn.Phoenixia1177 (talk) 05:36, 22 August 2014 (UTC) Let me add this to the question: if I declare a really large array, but only use a portion of it, does this have a major performance impact? For example, if I know every image is under 5000 x 5000, could I just use arrays of size 5000 without penalty?Phoenixia1177 (talk) 05:38, 22 August 2014 (UTC) I don't see why you wouldn't want to use dynamic arrays. Just set the initial size big enough for your input. Bubba73 You talkin' to me? 05:52, 22 August 2014 (UTC) # Science # August 18 ## Conclusions of an autopsy A recent case got me to thinking about what information can or cannot be concluded from an autopsy. So, two questions. (1) Can an autopsy determine if the decedent were moving (e.g., running) versus standing still when the decedent was shot? And (2) Can an autopsy determine the position of the decedent's body when he was shot (e.g., whether or not he was holding his hands up in a "surrender" position?)? If indeed the medical examiner can make conclusions about these two matters, how would he do so? Thanks. Joseph A. Spadaro (talk) 04:25, 18 August 2014 (UTC) The position of the body should show if he was running (unless he survived for some time after being shot and changed his position). Also, if he was running on a road or sidewalk, you'd expect abrasions where he slid on the cement. On grass his clothes should have grass stains. And the path of the bullet through the body would reveal the position of the part of the body it hit. If the body was vertical at the time, that would tend to indicate standing, while if it was angled, that would indicate running (accounting for the height and distance at which the bullet was fired). Detecting the hands up position would be a lot trickier. If the shooter was close enough that the victim was sprayed with gunpowder residue, then the location and density of the spray would indicate that the hands were up, but with a distance shot this method wouldn't work. Blood spatter from the victim could be used in a similar way, but there might not be much spatter, especially if the bullet is small, doesn't exit the body, and the victim was wearing thick clothes, like a winter coat. On the other hand, with a case like the fatal JFK head shot, there was all kinds of spatter to work with. StuRat (talk) 04:57, 18 August 2014 (UTC) Thanks. But, I still have some confusion. You said: The position of the body should show if he was running. Why is that? Once you are shot, don't you just sort of "plop" down, regardless of whether you were running or standing still? You also said: Also, if he was running on a road or sidewalk, you'd expect abrasions where he slid on the cement. When your body hits the ground, wouldn't you get abrasions either way, whether running or standing still? Thanks. Joseph A. Spadaro (talk) 05:31, 18 August 2014 (UTC) At the very least, if he was hit in the back instead of the front, that would indicate he was leaving the scene. ←Baseball Bugs What's up, Doc? carrots→ 06:52, 18 August 2014 (UTC) In the specific case of Shooting of Michael Brown, that doesn't seem to be a significant factor. Okay there are suggestions from witness statements that he was shot in the back, which may be problematic if there's no evidence of sufficient risk to anyone at the time to justify such a shooting. But although it's difficult to say since we only have third party reports of the officers account, the main dispute, as I think the OP knows appears to be whether he was kneeling on the groundfacing forward but not moving instead surrendering to the officer, or rushing towards the officer at the time of the fatal shots, after an earlier alleged attempt to grab the officers gun, before he started to run away. Nil Einne (talk) 08:02, 20 August 2014 (UTC) Momentum is a factor here. If the victim is moving quickly, they will keep moving quickly after being shot (unless shot with something large and fast enough to cancel out their forward momentum). I'd expect there to be a difference between abrasions resulting from a straight fall down or backwards, and abrasions resulting from a fall when running, which results in sliding across the ground for a small distance. MChesterMC (talk) 08:41, 18 August 2014 (UTC) Moment of inertia seems appropriate, as well. Though I'm what "laymen" call an idiot, sometimes. InedibleHulk (talk) 22:02, August 18, 2014 (UTC) A-ha. That all makes sense. Thanks! Joseph A. Spadaro (talk) 08:49, 18 August 2014 (UTC) As for the abrasions, you'd expect them to be longer and deeper if the victim was running when they dropped on cement or stones, or for the grass stains to be darker and longer if they dropped on grass. Of course, if the wounds weren't immediately fatal, they might have stopped running before they dropped. Regarding the angle of the bullets, the first should best show the initial position of the victim, but with rapid firing the victim's position might not change much between shots. StuRat (talk) 17:07, 19 August 2014 (UTC) • The problematic word here is "concluded" the medical examiner will describe a bunch of facts, that a bullet entered in one location and exited at another, that certain wounds were found, perhaps any signs of intoxication, cause of death (blood loss, brain trauma). It will be the forensic specialists who argue the case in court who will try to convince the jury of their theories of what happened. They will argue the patterns show he must have been standing, running away, shot while falling, etc. μηδείς (talk) 16:48, 18 August 2014 (UTC) A medical examiner can conclude lots of things, as Steven Hayne illustrated. —Tamfang (talk) 20:03, 18 August 2014 (UTC) Of course, he can conclude all sorts of things, such as cause and approximate time of death, type of weapon used, trajectory of a bullet though the body. He can have his own theory, if asked to testify as a witness. But he can't conclude guilt or criminal fact in the legal sense, which is what the OP seems to be getting at, given the recent shooting in MO. μηδείς (talk) 22:13, 18 August 2014 (UTC) Though, of course, he may be getting at The Huston Plan. Inconclusive, I declare. InedibleHulk (talk) 22:20, August 18, 2014 (UTC) Thanks, all. Joseph A. Spadaro (talk) 21:03, 19 August 2014 (UTC) ## Mayer bullets Mayer bullets compared to an AA battery There is an article on Russian Wikipedia about something called Mayer bullets or Mayer slugs. According to Google translate the article seems to say these are used in shotguns. How does that work exactly? Is a cartridge full of propellant loaded behind the slug? Are the Russians still using muzzle loaders? Our article on shotgun slugs seems to show the slug always crimped to a shell, but in the images in the Russian article just shows the slugs by themselves. SpinningSpark 10:48, 18 August 2014 (UTC) My guess is that they are a normal type of slug, normally fired from a complete shell. I think they are just pictured solo for illustrative convenience. If you do an image search for shotgun slug, you'll see lots of photos where the slugs are removed from the shell for comparison purposes. Here's an article all about modern slugs, and it mentions a guy named Mayer, but it's probably not the same Mayer [5] SemanticMantis (talk) 14:58, 18 August 2014 (UTC) Yup, not the same Mayer. That's Steve Mayer of Winchester, we're looking for A. K. Mayer (А. К. Майера) who invented a slug in 1963. SpinningSpark 16:22, 18 August 2014 (UTC) They certainly seem to be on sale as bullets only without a shell [6][7]. SpinningSpark 16:54, 18 August 2014 (UTC) I found a video where a guy is shooting them. I have no idea how they are commonly sold, but he shows the single slugs, then packs one into a shell, then fires it from a seemingly normal Break_action shotgun [8]. This video seems to be the same guy, and shows a little more about how the shell is assembled [9]. I found the videos by searching /Майера ружье/, with the second word meaning "shotgun" in Russian, according to google translate. SemanticMantis (talk) 21:58, 18 August 2014 (UTC) Thanks, that about answers it then. SpinningSpark 23:57, 18 August 2014 (UTC) ## Nuclear contrail thingies Yeah, I'm sure that's not the correct term, but since I have no idea what they are, I also have no idea what their name is. You can see them in the image at right; I've seen better images of them before but wasn't able to find any with a quick check of Commons. They are quite distinct white-ish lines of what look like water vapor, and they seem to have a strange habit of appearing in the area of nuclear weapon tests. I have a guess as to what they are, but it's probably wrong, and I'm sure someone here knows. Thanks in advance! Evan (talk|contribs) 16:05, 18 August 2014 (UTC) They are smoke trails from small rockets launched just prior to the nuclear detonation. The visual distortion of the trails provides information about the detonation. Trying to find the relevant articles... DMacks (talk) 16:11, 18 August 2014 (UTC) Mentioned with cite at Effects of nuclear explosions#Other phenomena. I know I've seen more detail of the history of this use (originally discovered accidentally!). DMacks (talk) 16:21, 18 August 2014 (UTC) Fantastic! Thanks for the speedy response. Evan (talk|contribs) 16:24, 18 August 2014 (UTC) How about an entire book on the history and role of such rockets? NASA Sounding Rockets, 1958-1968: A Historical Summary. This book focuses on civilian sounding rockets, including many that were fired at White Sands, but if I recall, it also has a section on the early Army rockets launched during the Trinity test in 1945. The photograph posted in the original question is a 1953 test at a different Department of Energy facility, the Nevada Test Site. Those sounding rockets were almost certainly small Army rockets and their smoke-trails would have been used as an indicator of the winds aloft (after the blast) at various distances. For some tests, the rockets would also be equipped with radiological, physical, and chemical detection and sample-collection equipment. You can find historical records of such tests from the Nevada Test Site's OpenLibrary web-page, hosted by the Department of Energy's Office of Scientific and Technical Information. In just a few moments of browsing, I found a technical report on the specific purpose of sounding rockets during Operation Hardtack, Aircraft and Rocket Fallout (1959). If you're interested in the exact test pictured above (Upshot-Knothole Grable, (1953)), I'm sure you can spend a few more hours browsing those resources. Nimur (talk) 17:16, 18 August 2014 (UTC) Sounding rocket. —E:71.20.250.51 (talk) 17:41, 18 August 2014 (UTC) Here is the accidental first use of visual effect I was remembering: File:Trinity explosion film strip.jpg. And according to ISBN 9783540304210 page 992, the smoke trails are actually not even from really rockets, just simple mortars (in this context they are only used for the smoke trails, not the object being lofted). DMacks (talk) 16:57, 19 August 2014 (UTC) ## Water jet cutter as a weapon About how effective would a water jet cutter be as a weapon?(ignoring the bulk of the surrounding hardware) Would the stream just dissipate into steam after a few feet? 108.170.113.22 (talk) 16:37, 18 August 2014 (UTC) Our article does say "The penetrating power of these tools has led to the exploration of their use as anti-tank weapons but, due to their short range and the advent of composite armour, research was discontinued.[citation needed]". Rojomoke (talk) 16:45, 18 August 2014 (UTC) Yeah I saw that, but ya know. Citation needed, plus I want to know what causes the range to be limited. 108.170.113.22 (talk) 16:57, 18 August 2014 (UTC) Air resistance and turbulent flow limit the effective range at which you can shoot a stream of high-velocity liquid. You read a two-sentence overview at the terminal velocity section of our article on water drops. Momentum and energy - which you would want to direct into the target - are instead lost to the air around the stream of water as it "sloshes." The faster you move the water, the more it sloshes, because air flowing past the "edges" of the water stream induces a viscous flow shear force. Nimur (talk) 17:02, 18 August 2014 (UTC) I remember reading that in the article when I first started at my current job (we have a waterjet cutting machine) and pointing it out to a colleague who laughed. When it comes to steel, particularly thicker/harder steel, it is very slow. To give some numbers, the M1A2 Abrahms tank apparently has armour 120mm thick (according to google, yeesh), the feed rate for that thickness is somewhere in the region of 2-3mm a minute. That means to cut through 1m of steel would take some 6-8 hours. In that time your tank could have driven 250-340 miles--Jac16888 Talk 17:34, 18 August 2014 (UTC) The rate at which the machine could cut a slot might not matter if you could aim it sufficiently well - a single penetrating hole one millimeter in diameter would be plenty if you can hit exactly the right spot in the engine bay and have the water jet drill a 1mm hole through some vital engine part or electronics. But I agree that keeping the water flow focussed over significant distances would be the downfall of such a weapon. I doubt that it's practical beyond a foot or two. SteveBaker (talk) 20:27, 18 August 2014 (UTC) 1mm could take 30 seconds, which a long time considering at the same time a tank-turret is probably turning around to face you--Jac16888 Talk 21:48, 18 August 2014 (UTC) That sentence, which evolved out of something posted by someone at Central Michigan University in 2007, was apparently inspired by the use of a water jet cutter in the video game Metal Gear Solid 2. See the original addition. I can't find anything using Google that would support that sentence, so I removed it. Red Act (talk) 20:32, 18 August 2014 (UTC) Would shooting another liquid that has a higher density and/or boiling point at high velocity make a difference? Liquid metal perhaps? 69.121.131.137 (talk) 22:31, 18 August 2014 (UTC) You're on the right way, since most portable anti-tank weapons use metal, which behaves like a liquid at the kind of pressure involved. Generating that kind of pressure (I've read it's in the TPa range[citation needed], which is more than 107 times atmospheric pressure) using non-destructive equipment (in the sense that it doesn't blow itself apart in the process) is difficult even with today's technology. Sidney Alford#Early Inventions lists some shaped charges using water, so the idea isn't flawed as much as it hits its limits if applied to modern armor. Also note that a [citation needed] tag does not necessarily indicate that the tagged statement is dubious; it indicates that a key fact is not backed by a source in the list of references. For dubious statements, we have the [dubious] tag. - ¡Ouch! (hurt me / more pain) 05:49, 19 August 2014 (UTC) It is a common application in manufacturing engineering. See Water jet cutter. It only works on very short distance but is a very cost efficient, precise, fast and reliable technology to cut flat materials like steel plates. But it wouldnt make much sense as a weapon. --Kharon (talk) 16:51, 19 August 2014 (UTC) Note that shaped charges don't work either if the range is too high or too low. If the distance between charge and target surface is off, the effect can be severely diminished or even completely fall flat. From Shaped charge: The location of the charge relative to its target is critical for optimum penetration for two reasons. If the charge is detonated too close there is not enough time for the jet to fully develop. But the jet disintegrates and disperses after a relatively short distance, usually well under 2 meters. At such standoffs, it breaks into particles which tend to tumble and drift off the axis of penetration ; OTOH, a water jet cutter wouldn't work well even at 1m, where the shaped charge only begins to exhibit severe degradation. - ¡Ouch! (hurt me / more pain) 08:33, 20 August 2014 (UTC) In the Yom Kippur War, very low tech predecessors of the water jet cutter were efficiently used as weapons by the Egyptian army on the Bar Lev Line. --Dweller (talk) 12:14, 21 August 2014 (UTC) ## Kidney function questions A complicated process. :) The other day I started wondering about kidney function. Firstly, does the filtering ability of the kidneys dynamically respond to waste concentrations in the blood? If a person happens to have high levels of urea, or salt, or something else in their blood does the body have the ability to increase the activity of the kidneys, or are they pretty much going to filter the blood at a fixed rate regardless? Secondly, for a fixed level of hydration, if one has more waste in the blood (e.g. urea / excess salt) does that lead the kidneys to excrete more water as well or is the water output about the same but the waste in the urine more concentrated? Dragons flight (talk) 23:10, 18 August 2014 (UTC) First of all, it's important to clarify that the kidney only removes excess organic molecules and/or wastes. The answer to your first question, as far as I can tell, is yes. Refer to Clearance (medicine). Not sure about the answer to your second question, sorry. ceranthor 00:25, 19 August 2014 (UTC) The removal of waste and water are largely independent (although obviously some water is needed to carry the waste out). If you drink a very large quantity of water, but don't eat much or do much, your urine will be clear, since it's mostly water. If you are dehydrated, but have eaten a lot and done a lot of exercise, your urine will be brightly colored, since it's much more concentrated with waste. Obviously that wouldn't be a safe test, but you can take some vitamin C, instead. That will turn your urine brighter yellow, which indicates it has a higher concentration of waste (vitamin C, in this case). I suspect that salt is a special case, though, where the concentration of salt in the urine can't be changed much relative to the concentration in the blood. This would explain why eating salty things makes you thirsty, because the salt must be diluted, as it can't easily be removed at high concentrations. StuRat (talk) 00:38, 19 August 2014 (UTC) I would suggest conceptualizing the kidney as an organ of absorption rather than merely excretion. For the example of Vitamin C, one should realize that all the vitamin C in the serum passes into the renal tubules, and then only a certain amount is reabsorbed. So the kidney isn't responding to a high level of vitamin C and excreting more, it's just excreting all the vitamin C regardless of its blood level, and then reabsorbing the same amount it always does. Salt, as StuRat says, must be considered separately, as it's not a simple matter of passive diffusion; there are a variety of means of regulating salt (active transport, hormones, countercurrent multiplication, etc.). You may be interested in the concept of obligatory water loss, which is the amount of water that must be excreted in order to remove waste products and thereby maintain health. - Nunh-huh 01:01, 19 August 2014 (UTC) I see we don't have an article on obligatory water loss, but you will find a brief mention in dehydration. - Nunh-huh 01:01, 19 August 2014 (UTC) Let's take a step back here. Kidney function starts with what seems to be a pretty straightforward filtration in Bowman's capsule, (lovely illustrations in our article!) where most contents of the serum (but not proteins) are allowed to escape into the system. Then here is more activity proximal convoluted tubule where more things can be specifically excreted into this ever-flowing stream. Then this, the loop of Henle and distal convoluted tubule remove things that you want to keep, like water and salt, and finally what is left is collected and dumped. All of this is massive generalization, since each and every cell is a tremendously complicated living thing capable of a vast range of behavior; you'd really have to look up for your molecule of interest what happens. But urea and salt are on the diagram I've added at the top of this section. Note of course that every process done to a solute - filtration, secretion, reabsorption - will tend to be influenced by the internal concentration of whatever it processes by Le Chatelier's principle, linearly if it follows a first order relationship, otherwise in some more complicated way. But it generally is more complicated; the kidneys have primary responsibility for keeping many of the overall concentrations of things in the blood, especially ions, at the right values. For example an ACE inhibitor for high blood pressure ultimately affects sodium reabsorption in the kidney (see angiotensin). Wnt (talk) 12:58, 21 August 2014 (UTC) # August 19 ## Lowest Possible Temperature We know there is a lowest possible temperature, but is there a theoretical highest? KägeTorä - () (Chin Wag) 01:18, 19 August 2014 (UTC) WHAAOE. Absolute hot. --Jayron32 01:20, 19 August 2014 (UTC) There's also negative temperature. Dmcq (talk) 16:09, 19 August 2014 (UTC) So, if a system at negative temperature is brought into the presence of a system at absolute hot, which way will heat flow? The article says " If a negative-temperature system and a positive-temperature system come in contact, heat will flow from the negative- to the positive-temperature system." - but I have no idea if that applies to absolute hot... SemanticMantis (talk) 16:52, 19 August 2014 (UTC) ## Atoms as fact When did the scientific consensus become that atoms are real? I read atomic theory, but it doesn't mention any point in time or event. Bubba73 You talkin' to me? 04:20, 19 August 2014 (UTC) See there about Dalton in the section 'First evidence-based theory' and his presentations of the atomic theory at the start of the nineteenth century. His first oral presentation in 1803 is one good date and his textbook in 1808 is another. Dmcq (talk) 08:03, 19 August 2014 (UTC) The term "atom" or "indivisible particle" was revived 1805 from ancient Greek philosophical speculation by John Dalton. In 1828 "atom" was evidently part of Christian truth with which Noah Webster was concerned in his dictionary. Understanding of the atom has progressed from the cubic model (1902), the plum-pudding model (1904), the Saturnian model (1904), and the Rutherford model (1911) to the Rutherford–Bohr model or just Bohr model for short (1913) whose image is most recognized today. The Bohr model is widely taught as real and gives an explanation of some spectral emissions. It may be said to have reached popular consensus though scientific consensus favours the quantum mechanical atomic model introduced by Wolfgang Pauli in 1925. 84.209.89.214 (talk) 10:41, 19 August 2014 (UTC) First of all, scientists don't think in terms of "facts" and "proof". The think in terms of "evidence". Dalton's atomic theory was well a well accepted conjecture by the middle 19th century, but the definitive empirical justification ("proof" if you want) is usually cited as Einstein's paper on Brownian motion in 1905 (his Annus Mirabilis. See Annus Mirabilis papers). The other parts of atomic theory, those dealing with the internal structure of atoms, built up over time, with the experiments and conjectures cited above by 82.209.89.214, who did a great job laying out the history of Atomic theory. There were also some false starts in Atomic theory, see Prout's hypothesis for a more famous one. --Jayron32 14:09, 19 August 2014 (UTC) That is kind of what I was getting at. The 19th century chemists had a model that worked beautifully, but I don't think any of them "detected" an atom. Bubba73 You talkin' to me? 02:56, 20 August 2014 (UTC) I'm sure I have read somewhere that atoms were widely accepted among scientists as a model by 1905 but there were still some who didn't. Einstein's Brownian motion paper which provided another way to calculate the size of atoms was an extra bit of useful evidence that atoms existed and weren't just an apparent building block of solids that was actually made up of other things of different sizes. (oops should have read Jayron's answer first) 18:53, 19 August 2014 (UTC) There is a subtle confusion here. Once the experimental results were in and the math had been crunched, it would have been valid to say "The world operates as if matter was made of atoms" - but you still wouldn't know that there actually ARE atoms. These days, we've actually imaged them so we have direct evidence - but that's a rather recent thing. SteveBaker (talk) 05:24, 20 August 2014 (UTC) ## Can you accelerate the decay of radioactive material? Or do you always have to bury it and wait 10,000 years? OsmanRF34 (talk) 15:10, 19 August 2014 (UTC) For practical purposes, decay rates for spontaneous radioactive decay are constant. Radioactive decay#Changing decay rates says "The radioactive decay modes of electron capture and internal conversion are known to be slightly sensitive to chemical and environmental effects that change the electronic structure of the atom, which in turn affects the presence of 1s and 2s electrons that participate in the decay process. A small number of mostly light nuclides are affected ... A number of experiments have found that decay rates of other modes of artificial and naturally occurring radioisotopes are, to a high degree of precision, unaffected by external conditions such as temperature, pressure, the chemical environment, and electric, magnetic, or gravitational fields". Gandalf61 (talk) 15:22, 19 August 2014 (UTC) The key words here are *spontaneous* radioactive decay. While temperature, pressure, electromagnetic fields, etc. don't substantially increase decay rate, neutron flux will. See Nuclear transmutation#Artificial transmutation of nuclear waste for details. -- 160.129.138.186 (talk) 16:21, 19 August 2014 (UTC) Well surprisingly you can just about do the opposite see Quantum Zeno effect. And of course sending particles at something will start splitting it up, a nuclear bomb is a good example. Dmcq (talk) 16:02, 19 August 2014 (UTC) You can sort of do that partly, by refining the material aka split it up into active and decayed matter with physical and/or chemical methodes of process engineering. This is actually done to an limited extend for some Time with radioactive waste because in most countries space in radioactive waste repositories is very expensive. --Kharon (talk) 16:35, 19 August 2014 (UTC) You should be able to change a radioactive isotope into something else by bombarding it with enough of the right type of radiation. However, it may turn into something even nastier. Also, you are likely to get many different products, so now you need to separate the stable from the radioactive. There's also the risk that you might get more heat than anticipated, due to unknown interactions between all the products and radiation, and have an explosion or meltdown. StuRat (talk) 16:56, 19 August 2014 (UTC) If you want to accelerate the decay, that means you want something "even nastier". Things that decay slowly are not very radioactive. But as Stu says, the problem is that you are likely to get many different products. I don't believe it's practical at present to convert all of a chunk of some substance into another by irradiating it. --50.100.184.117 (talk) 00:24, 20 August 2014 (UTC) It is possible using fast breeder reactors, but the anti-nuclear movement has stopped the development of large scale nuclear power making fast breeder reactors uneconomical at present. The Integral fast reactor was never completed, the article says: "Fast reactors can "burn" long lasting nuclear transuranic waste (TRU) waste components (actinides: reactor-grade plutonium and minor actinides), turning liabilities into assets. Another major waste component, fission products (FP), would stabilize at a lower level of radioactivity than the original natural uranium ore it was attained from in two to four centuries, rather than tens of thousands of years." Count Iblis (talk) 17:34, 19 August 2014 (UTC) Giant resonance does not need fast breeding reactors or other sources of neutrons. But probably prohibitive amounts of energy. 95.112.198.190 (talk) 19:12, 19 August 2014 (UTC) Another option is to separate out the radioactive isotopes from the non radioactive material. This my make a valuable resource, or at the least make a smaller waste output. Graeme Bartlett (talk) 23:10, 19 August 2014 (UTC) What if extremely strong magnetic fields are used to deform the core atomic orbitals? Will that not affect the stability of the nucleus toward certain types of decay? Plasmic Physics (talk) 00:16, 21 August 2014 (UTC) ## Decline of large aerial predators The amount of large aerial predators seem to be nonexistent, which is counter-intuitive to me. Considering there used to be creatures with wingspans the width of a basketball court, what led to their extinction? Considering there are still whales and elephants, it seems weird to me that bustards are the largest bird left around, with no large bird-of-preys. Was it tied to lowered oxygen levels? Climate change affecting updraft? Trees growing taller to hide prey? Just curious. --Wirbelwind(ヴィルヴェルヴィント) 19:26, 19 August 2014 (UTC) No large birds of prey? Tell that to the harpy eagle or the golden eagle. Here's a nice video about the harpy eating monkeys [10], and here's one about the golden hunting wolves [11]. As for the biggest flyers ever, what do you know of with a ~50 ft wingspan? (the width of a basketball court). Pterosaur_size tops out at ~35 feet, according to our article. The largest bird we have evidence of is currently Pelagornis_sandersi, which, with a wingspan of ~20 feet is admittedly ~2x the wingspan of our current leader, the wandering albatross. But enough with questioning your premise: You're right that were some larger flyers in the past, but there were also lizard type things the size of school buses, and they went away too, most likely due to the Chicxulub impact. So the pterosaurs et al. went extinct due to massive disruption of the food chain, as all photosynthesis on earth was severely compromised for a long time (more info at dinosaur extinction). After that, everything was much smaller, and there was a lot of value on the R side of R-K selection. Now, we might ask the question, "why have no very large flying predators evolved again?" I think the key here is that size is relative. We lost most of our megafauna in the Holocene extinction, and even though that was pretty recent, things have pretty much stayed smaller since then. I don't personally think O2 levels or updraft patterns are the culprit, but that's hard to find references to support. Even though the Square-cube_law has never changed, I think its importance might be strengthened in a world with much more pathogens, complex food webs, greater diversity of terrestrial vertebrates, etc. The main thing to think of is the ecological niche, and, for whatever reasons, the niche space is just not there anymore, even if it used to be. SemanticMantis (talk) 20:13, 19 August 2014 (UTC) I wasn't aware of golden eagles hunting wolves, but that does seem like a partially human-influenced behavior. Looking at the statistics in the article, the most commonly hunted canid is the fox, which still comprises of a tiny percentage. As for the 50' wingspan, blame National Geographic (or similar) for that figure. It was compared to a basketball court in a documentary. As for everything shrinking, I'm aware of that. I just meant it's counter-intuitive (maybe only) to me that aerial predators haven't thrived due to a lot of advantages flight should bring. --Wirbelwind(ヴィルヴェルヴィント) 22:11, 20 August 2014 (UTC) A giant asteroid slammed into the Gulf of Mexico some 65 million years ago, setting off a chain of catastrophic events that ultimately led to the extinction of all big living creatures. Then mammals got bigger. And eventually they paid the price. Several mammoths and other big mammals died off during the Pleistocene/Holocene extinction event, which started around 50,000 years ago. whales were more mobile and could emmigrate to whenever they wanted. Animals bigger than elephants didn't have so much luck. If there is little food, you are better off being small and having lots of descendants as fast as possible. OsmanRF34 (talk) 20:19, 19 August 2014 (UTC) Thank you. This is more or less the kind of answer I was looking for. --Wirbelwind(ヴィルヴェルヴィント) 22:13, 20 August 2014 (UTC) Per Semantic Mantis, there are several birds of prey which can be strikingly large; it's just that humans rarely get up close to them to see them. All animals (aside from whales) are generally smaller than they were in the Mesozoic era and flying critters are no exception. However, that doesn't mean that all birds are pigeon-sized. Female bald eagles have a length of 3.5 feet or so (standing on the ground they'd come up past your belly button) and have a wingspan of 7.5 feet or more. The golden eagle noted by Semantic Mantis above can get even larger. Those are land-based raptors. Seabirds can also get pretty large; various kinds of pelicans can get as large as a person; 5+ feet in length with an over 8 foot wingspan. Obviously, they weigh less than people, but they are still quite big in size (bird physiology maximizes their ability to fly, and so tends to favor lower mass-to-size ratios than land animals). The grand-daddy of carnivorous birds is the California condor, which is a bit shorter than the largest pelican, but can have up to a 10-foot wingspan. Again, since most people never see one of these birds up close, it can be hard to judge them from context. If you ever do get to see one up close, it takes you aback at how big they can be. --Jayron32 22:00, 19 August 2014 (UTC) When it comes to pterosaurs, this is an open question. There is even a question about the question itself. Based on the fossil record, it appears that the pterosaurs reached peak diversity in the early Cretaceous period and then sharply declines before being finished off by the K-Pg extinction. However, it's possible that at least some of this apparent decline may be due to gaps in the fossil record ([12]). It should be noted that as far as we know, there were never any large, predatory pterosaurs (the thing with pterodactyls carrying prey off to their nest is a Hollywood invention;they didn't even have grasping feet, or bird-like nests). Why a highly diverse group like pterosaurs never produced any predatory forms is an interesting question and I'm not sure if it's been addressed. There may have been small hawk-sized predatory pterosaurs (this has been suggested for Darwinopterus), but even the biggest ones like azhdarchids seem to have been stork analogues, picking off small prey like lizards and baby dinosaurs. I guess that's still predatory, but maybe not the way most people think. It's true that birds have not yet ever attained sizes comparable to pterosaurs and are on average very small (pterosaurs were on average very big as adults with no known tiny species, probably because they took years to grow up unlike birds, and niches for small sized animals were occupied by babies of larger species). It has been suggested that birds are limited in size by their takeoff style. They need two well-developed sets of limbs - forelimbs for flight, and hind limbs for launching themselves into the air. That's two well-developed sets of muscles in creatures that need to stay as light as possible. Pterosaurs were quadrupeds and most had piddly little hind limbs. By all accounts, they both launched AND flew with the forelimbs, allowing the biggest pterosaurs to get a few times bigger than comparable birds. I don't think there have ever been any really large aerial predators. The largest I can think of is Haasts eagle, which isn't as large as the largest flying birds today, though larger than the extant predatory ones. All birds that ever lived larger than this have either been vulture-type birds (scavengers) or seabirds, which eat fish and can get larger than normal by taking advantage of oceanic winds to aid flight. Dinoguy2 (talk) 23:23, 19 August 2014 (UTC) 'Large, flighted, actively-hunting bird' is probably one of the most energy intensive animal 'designs' possible. Imagine how much food a 150lb+ bird that chased down and subdued live prey would need to eat in order to remain alive, let alone thrive, given that flying birds have a much faster metabolism than mammals (from what I've seen, birds tend to eat a huge amount for their size) - and how much territory it would need to fulfil its hunting needs. Such a critter would certainly find it difficult to survive and almost certainly be amongst the first to die out, should the world ever take a turn for the worse. The condors are huge and carnivorous, to be sure - but they are also mostly scavengers and gliders. --Kurt Shaped Box (talk) 23:36, 19 August 2014 (UTC) This is not a scientific answer because there is lack of scientific evidence for it. But I believe that not only is the percentage of oxygen higher in the past but the air pressure is higher in the past as well. In fact I believe the air pressure is 10 times to 50 times higher in the past than the air pressure is today. Therefore with higher air pressure in the past, flying creatures can be bigger because it can generate bigger lifts. Of course, air pressures leaves no "fossil records" and thus I am not able to offer any proof that air pressure is higher in the past. 202.177.218.59 (talk) 00:56, 20 August 2014 (UTC) "This is not a scientific answer because there is lack of scientific evidence for it." So why post it? The OP asked a scientific question, so he presumably was not looking for weird beliefs based on fantasy as an answer. Might as well answer with "Well, in Middle-Earth, the air might have been like this..." People often feel the need to explain giant Mesozoic animals by invoking air density, air pressure, or differences in gravity, simply because they don't understand that the biology of these animals was different from any living today. We do not have any quadrupedal fliers with extensive pneumatic lungs today, because they were all killed by an asteroid. We don't have any land animals with extensive air sacs today either. If mammals had air sacs and R-selection breeding strategies, they could easily reach or exceed the size of dinosaurs, but they don't. No need to call on strange differences in air pressure or gravity with no evidence when we have plenty of evidence pointing to simple biological explanations. Dinoguy2 (talk) 13:28, 21 August 2014 (UTC) We do not currently have a Thick atmosphere theory article, and Atmosphere of Earth#Evolution of Earth's atmosphere does not address pressure. (Faint young Sun paradox does discuss the posibilities of CO2 partial pressures as high as 10 bar, but long, long before the cambrian radiation, presumably only up until the GOE.) Here are a couple of interesting papers by Octave Levenspiel published in 2000 in ACS's Chemical Innovation: Earth’s atmosphere before the age of dinosaurs (with Thomas J. Fitzgerald & Donald Pettit, on the ACS site) and Atmospheric Pressure at the Time of Dinosaurs (on Levenspiel own site). -- ToE 05:01, 20 August 2014 (UTC) According to Quaternary extinction event and given the many near extinct species, caused by overhunting and -fishing done by humans up till today, its almost certain there where some but Homo sapiens sapiens killed them all. Even worse. Your contradiction regarding whales and elephants is wrong. We (as species) would likely have killed all whales and elephants by now if some international Commissions had not put a world wide ban on commercial whaling and ivory trading. --Kharon (talk) 02:37, 20 August 2014 (UTC) It's also interesting to note that the only continent left with an in-tact megafauna is sub-Sahara Africa, which also happens to be the only megafauna that co-evolved with humans, and presumably evolved strategies to avoid human predation. It was only after large scale access to killing using cars and guns that they went into steep decline. Dinoguy2 (talk) 13:39, 21 August 2014 (UTC) # August 20 ## Wheel base anf friction Can we say that wheel base is proportional to friction acting on a vehicle,when brakes are applied.I think i solved a problem in h c verma(12 class physics) using this assumption.please correct me if i am wrong. Sameerdubey.sbp (talk) — Preceding undated comment added 03:38, 20 August 2014 (UTC) Wheelbase is normally understood to mean the distance between the front and rear axles of a vehicle. Your statement accordingly makes no sense at all. AndyTheGrump (talk) 03:41, 20 August 2014 (UTC) I appreciate your effort in commenting Grump.See google bookpg 371,there's a derivation that has wheel base in numerator and denominator as well.Then what do you say?whether frictional force would increase or decrease with wheel base. please read derivation and then comment.Bit engineeering involved. SD — Preceding unsigned comment added by Sameerdubey.sbp (talkcontribs) 07:12, 20 August 2014 (UTC) Link is broken. yes there is a bit of physics involved, that's a high school physics problem judging by the search terms, but your question is at best very misleading, but answering the most likely rendition , you are wrong. Greglocock (talk) 07:55, 20 August 2014 (UTC) Mr cock ,justify whatever you want to say.let it be high school physics. SD — Preceding unsigned comment added by Sameerdubey.sbp (talkcontribs) 09:58, 20 August 2014 (UTC) To the respondents who seemed to assume the OP was crazy wrong, without sufficient evidence :) I was able to get the link to work, but google books is notoriously hard to link to... try this one maybe [13]. Anyway, as far as I can tell, the OP's claim is sound, if we understand it not to be about friction per se but the retardation in speed as the book calls it. The book uses D'Alembert's_principle to calculate the retardation of applied brakes in a three scenarios, 1)rear brakes, 2) front brakes, 3) all four wheels. Basically, the wheelbase L comes into play because the car is going up an inclined plane, and the the brakes are only applied to the rear wheels in that example. This setup effectively creates a moment arm due to the fact that the center of gravity is above the plane containing the centers of the wheels. This should make intuitive sense: if the car is going uphill quickly, then brakes only using rear brakes, the car will start to lift at the rear, thus reducing the normal force on the rear wheels, thus diminishing the effect of braking. Using a very long wheelbase truck, e.g. a Ford F-650, this effective decrease in retardation will have lesser magnitude, compared to e.g. the same effect in a Mini. Likewise, L appears in the solution to the front brakes only.In the later example of all four wheels braking, no L term appears. This book contains a bunch of fairly complicated and analyses of force diagrams, including some bothersome algebra and calculus. So, while not terribly "hard" math, it's more than I can work through and explain in a few minutes, which is all I have to spare right now :) So, OP, you are not entirely wrong, and I'd give a gentle trouting to the above posters for assuming you were wrong without really looking for how you might be right! I still can't tell what your specific question is, nor can I check your answers. But the idea that the effect of braking, "retardation", can depend on wheelbase, is sound, provided that we are interested in the case of an inclined surface and brakes not applied to all wheels (or with different types of brakes on front and rear wheels, which used to be common). As the equations show, wheelbase can affect retardation in that scenario, but it is still incorrect to say the wheelbase is directly proportional to the retardation, because you cannot factor equation 8.24 into the form a=L*(a constant term), where a is the symbol for retardation. Hope that helps, SemanticMantis (talk) 17:43, 20 August 2014 (UTC) Trout all you like, " wheel base is proportional to friction acting on a vehicle,when brakes are applied" is wrong. If you double the wheelbase of a typical vehicle (say cgz=0.7m, wb=2.6m) on a typical slope (up to say 0.25) then the frictional braking force at any axle is NOT doubled. Do the physics, no calculus required. The OP asked if he was right or wrong, he is wrong.Greglocock (talk) 22:13, 20 August 2014 (UTC) Well, I did say a gentle trouting :) and I did specify that it is not correct to say that it's directly proportional. I'm assuming OP doesn't have English as a first language, and is also learning new physics. And based on the ref OP provides, it is true that wheelbase can affect braking effectiveness if not all four wheels have equal braking power. The equation in the book gives for rear-wheel breaking up an incline is $a_{retartadion}= \frac{(L-x)(\mu g \cos \alpha)}{(\mu h +L)} + g \sin \alpha$. True, that is not what we call directly proportional, but there is a near linear dependence there. For certain values of the parameters (e.g. large L>>1, x <<1, 0< sin \alpha <<1 ), it is very nearly proportional. I mainly brought up trouting because I assumed from your response that you didn't even look at the OP's link before responding. SemanticMantis (talk) 00:20, 21 August 2014 (UTC) Semantic is the man,thanks a lot!!,It means,i said the reverse.while riding a vehicle,without the brakes applied.I must say wheelbase is inversely proportional(Third Case) to the retarding force acting to bring vehicle to motion or keep it in motion.since braking force is proportional to (mu*constant/L),where L is the wheelbase(See the third case in Bookpg347).Now as L increases opposing force or braking force on vehicle decreases.Hence Low wheelbase vehicles are harder to bring into motion and less fuel efficient.Is it the thing Practically,i feel the reverse.What do u say? Mr.Cock be Human. — Preceding unsigned comment added by 121.242.75.225 (talk) 03:18, 21 August 2014 (UTC) I think you need to be careful about generalizing from the math shown in the book. While fairly detailed, this is still very much an idealized representation of car physics. Equation 8.26 is the conclusion of third case, where all four brakes are applied equally, and no L terms occur. There are L terms in the previous lines, but they eventually cancel out. I think L will only come into play for braking two wheels at a time, which isn't very common in the real world. I don't think this analysis will help you draw any conclusions about cars with small wheelbase being less fuel efficient. In the real world, smaller cars tend to be more fuel efficient in terms of miles per gallon, because they usually weigh much less. If you factor weight into your idea of efficiency, then perhaps some larger cars have a higher (miles)*(weight)/gallon. But for real world scenarios, there are far more details than included in your linked book. This is why things like mpg are tested empirically, not calculated from first principles of physics. Anyway, I hope I've helped clear up this example. If you have more questions I'd probably recommend starting a new thread, and spending a little more time composing your English. While I can understand you, it is a bit difficult to do so, and some people make the mistake of thinking poor English means the writer is not that smart ;) SemanticMantis (talk) 14:27, 21 August 2014 (UTC) Actually due to tire load sensitivity in the real world there is always an L term present even with 2 axles braking and on a flat road, that is, weight transfer always matters. Greglocock (talk) 00:27, 22 August 2014 (UTC) ## Velocity of Saturn's moons Any of the many, doesn't matter - I'm writing a fantasy where there's a vehicle tethered to one of Saturn's satellites, towing it around one of the rings. My preference is for one of the Inuit, Gallic, or Norse moons, because their names are so cool, but I gather they're further out than the orbit of the rings. Thanks for your indulgence Adambrowne666 (talk) 04:42, 20 August 2014 (UTC) Velocity relative to what? Saturn? If one end is tethered to the satellite, what's the other end tethered to? (It can't be Saturn, because it doesn't have a solid surface.) --Bowlhover (talk) 05:06, 20 August 2014 (UTC) Note that if you have a tether running from the spacecraft to the moon, remember that you only need the tow to get the vehicle up to the speed of the moon - then you can cut the tether and the spacecraft will continue to follow the moon around. Of course the moon will have some tiny amount of gravity - so after that initial acceleration, you'd pretty much have a slack tether. So calling this a "tow" is a little confusing. SteveBaker (talk) 05:20, 20 August 2014 (UTC) The statement that Saturn doesn't have a solid surface isn't entirely correct. Like Jupiter and the other gas giants, it does have a nickel-iron core, surrounded by a layer of ultra-dense hydrogen metal. The metallic hydrogen is probably a liquid, but the nickel-iron core is presumably definitely solid, and certainly has a surface. Saturn is mostly hydrogen all the way down, so the prevailing theory is that changes in pressure mean that the metallic core is surrounded by a giant hydrogen sea just beneath the gaseous layers we're familiar with. According to our article on Saturn, the transition from gaseous to liquid hydrogen occurs at such an altitude that 99.9% of Saturn's mass is within the pressure range for liquid hydrogen—so maybe we should be calling it a liquid giant. As an aside, some scientists now think that Jupiter and Saturn's magnetic fields are largely produced by this massive amount of metallic hydrogen, rather than by their fairly small nickel-iron cores. Given strong enough materials, you could easily utilize the principle behind Clarke's space elevator to either tether something directly to the solid core, or to a buoyant object floating in that sea. Evan (talk|contribs) 15:54, 20 August 2014 (UTC) This must be some meaning of the word "easily" of which I was previously unaware. SteveBaker (talk) 19:08, 20 August 2014 (UTC) I am assuming, of course, that someone wants to spend the money necessary. Space elevators are completely possible given current technology; a simple tether (read: spaceworthy bit of string) would be even easier. Evan (talk|contribs) 19:33, 20 August 2014 (UTC) No, space elevators are impossible with current technology, even on Earth. The only known material strong and light enough is carbon nanotudes, and it's not currently possible to make more than a few centimeters of it. See space elevator. --Bowlhover (talk) 05:19, 21 August 2014 (UTC) I've read the article, but I think we're talking past each other. Carbon nanotubes seem to be the technology practical space elevators will require; the problem is manufacturing them in large enough chunks for a construction process of that magnitude. I look at that as a manufacturing (and not insignificantly, a funding) problem. I might have too much faith in science, but I struggle to imagine the world's scientific community failing to work out the manufacturing difficulties, given access to Apollo-project-style funding. "Impossible" is a strong word; "hasn't been done yet" is more appropriate. As an aside, space tether is another fun article. Evan (talk|contribs) 18:53, 21 August 2014 (UTC) Which is totally irrelevant anyway, as I just noticed. Adam specifies that the satellite is tethered to a vehicle (though perhaps vice-versa would be more appropriate), and I'm thinking that means the vehicle is either in orbit around the satellite or trailing behind it (being towed) in the same orbit around Saturn. If the latter, then what you're looking for is the orbital velocity of whichever moon you'd like to use—meaning the moon's velocity relative to Saturn—since a perfectly tethered object would, of course, attain the same velocity relative to Saturn as the body towing it. If the former, then you need to find the moon's escape velocity—i.e., the minimum speed an object must achieve to escape the surface and enter an orbit around that moon— There are probably orbital velocities listed for most or all of Saturn's moons... somewhere. And keep in mind that the easiest orbital tether is going to be one with the "space end" in geosynchronous (lunosynchronous? selenosynchronous?) orbit, so that is probably the number you want. Evan (talk|contribs) 16:29, 20 August 2014 (UTC) The only reason I can see to "tow" something "around the rings" is if you want it to move at a speed different from that of the ring particles (without constantly expending reaction mass), so I'm guessing you mean to hang your vehicle from a body in higher orbit? So you want to divide the circumference of a ring orbit (2π× the radius of some circle in the ring) by the period of whichever moon you use as the anchor, and that gives you the speed. —Tamfang (talk) 01:17, 21 August 2014 (UTC) I'm not too sure about the antecedents, but this does seem like a clever use of a space elevator, or really, a space tether. Because the gravity of Saturn's moons is so small, very little tensile strength is needed for a short distance - of course, if you're laying 500,000 km of cable from Rhea (moon) to somewhere deep in the atmosphere of Saturn, then no standard-issue nanocarbon space elevator cable would be sufficient. But if you're just looking to hang off some shepherd moon and scoop up chunks of ice out of the rings for whatever purpose you have in mind (batting practice???), my guess is you can do it with plain steel. (Though I'm too lazy to work the math) The advantage of using a moon is that you don't need to worry about a counterweight; the moon is so heavy that its equilibrium will be little altered by the hanging cable. Wnt (talk) 22:23, 21 August 2014 (UTC) ## Can a shooting cause gradual brain death? Hello. In a script I'm writing, a character is mortally wounded by gunfire. After a protracted period, the character suffers brain death. Is this plausible? I've read some articles on the subject and I'm not entirely sure how a bullet wound would lead to slow brain death. 73.184.21.12 (talk) 05:36, 20 August 2014 (UTC) Your question is misleading. If a human is suffering from a gunshot wound. The human will suffer from a slow brain death while they are also suffering from a slow liver death and a slow death for every part of their body. The blood system in a human body is for all parts of the human organ. So technically yes, the character will suffer a slow brain death. 202.177.218.59 (talk) 05:59, 20 August 2014 (UTC) Thank you for the response. I've been doing mental gymnastics trying to figure out how a person's brain would die slowly from indirect bullet wounds a la drowning, while idiotically overlooking the fact that the whole body would slowly succumb from such an injury. 73.184.21.12 (talk) 06:28, 20 August 2014 (UTC) In general terms, this would be the basis for the notion of charging Hinkley with murder 34 years after the fact. ←Baseball Bugs What's up, Doc? carrots→ 08:59, 20 August 2014 (UTC) Presumably you mean not Olaf "Braindead" Hinkley the lead guitarist of Norwegian CyberPunk-Polka fusion band "Real Asset" that disbanded in 1979 but this Hinkley. If you propose a test case to try the contention that every "attempted" murder must in the natural order of things eventually succeed, the defence will likely point to the extenuating circumstance that so-called murder victims are all biochemically pre-programmed to die anyway. Observation of Brain death can lead to a false positive test on a patient that may recover with more time. Zack Dunlap in 2008 had a false positive of this type, likely due to temporary Cerebral edema. Such events feed the fear of being buried alive that has troubled humankind for centuries. Plato wrote in "The Republic" in 380 B.C., about an Armenian soldier who was revived two days after being pronounced dead. Fear turned to frenzy in the 19th century, when wrongful burial inventions were marketed with some success. The Safety coffin was a casket with a bell attached by a piece of string which might be pulled to alert people that the buried person was in fact alive (but it is not true that this is the origin of the phrase "saved by the bell"). However if the internee really is dead, his rest in peace or maybe pieces could be assured by a US patent in 1881 on deterring grave robbers by exploding shells that fit onto a coffin. 84.209.89.214 (talk) 12:00, 20 August 2014 (UTC) And I remember when the exploding whale video was the coolest thing. One slip-up with the arming mechanism and that would be a funeral to remember! Wnt (talk) 12:04, 20 August 2014 (UTC) • Although of course it's true, as others have pointed out, that a wound to any part of the body can eventually lead to general system failure which causes brain death, it's also quite possible for an injury directly to the brain to cause brain death after a protracted period -- days, weeks, months, or even years. The main causes of delayed brain death are (1) the initial injury causes swelling of the brain, which gradually crushes other parts, or (2) the initial injury causes an infection inside the brain. It can also happen that the initial injury causes a blood clot that eventually breaks loose, causing a stroke. Or you can get a subdural hematoma. Looie496 (talk) 13:59, 20 August 2014 (UTC) According to our article Mortal wound, "A mortal wound is a very severe and serious injury ...... which leads directly to the death of the victim. Death need not be instantaneous, but follows soon after." Based on this, a wound that results in a slow lingering death would not usually be called a "mortal wound". CBHA (talk) 14:13, 20 August 2014 (UTC) ## Question my nephew asked me to pass on Eight ingots of pure sodium walk into a bar. The juke-box immediately starts playing this music. Why? --Shirt58 (talk) 12:27, 20 August 2014 (UTC) The Batman Theme's lyrics are "nananananananana BATMAN". Na is the atomic symbol for sodium. --Jayron32 12:41, 20 August 2014 (UTC) And as they begin to leave the establishment, someone could play Na Na Hey Hey Goodbye. ←Baseball Bugs What's up, Doc? carrots→ 13:07, 20 August 2014 (UTC) Naa na na nana na naa, nana na naa, Hey Jude ... Gandalf61 (talk) 13:22, 20 August 2014 (UTC) Presumably these songs fall within the genre of Light Metal. {The poster formerly known as 87.81.230.195} 212.95.237.92 (talk) 13:24, 20 August 2014 (UTC) Wrong answer! That light pop act from the 1980's "BaNaNaRaMA" are by definition an admixture of light and heavy metals. Or something like along those lines.--Shirt58 (talk) 13:56, 20 August 2014 (UTC) Vic Bondi's band opened for them. DMacks (talk) 14:23, 20 August 2014 (UTC) ## Plastics oxidation Did the plastics had been oxidation by water?--Alex Sazonov (talk) 14:01, 20 August 2014 (UTC) There is no common plastic that reacts with water. But see the article on Biodegradable plastic. For example, aliphatic polyesters are biodegradable due to their potentially hydrolysable ester bonds. 84.209.89.214 (talk) 18:27, 20 August 2014 (UTC) Is it the paradox that, the water which is the simple chemical substance is reacted with complex (implex) chemical substances as plastics?--Alex Sazonov (talk) 16:37, 21 August 2014 (UTC) I know that, only simple chemical substances always are reacted with simple chemical substances and only complex (implex) chemical substances always are reacted with complex (implex) chemical substances, is it right?--Alex Sazonov (talk) 17:52, 21 August 2014 (UTC) I know that, a water always had the simple chemical valence.--Alex Sazonov (talk) 19:56, 21 August 2014 (UTC) ## Opera singer vs bulletproof glass This question was inspired by X-Men: Days of Future Past, in which one character is breaking another character out of a glass-and-plastic prison. I am aware that superhero movies are rarely reliable sources for how real-world physical laws behave, but I'm curious about the general principle behind the first character's method of pulling off the jailbreak: Since in the story his mutant power is the ability to move at very, very high speeds, what he essentially does is press both of his hands to the pane of bulletproof glass separating him from the imprisoned character and vibrate his hands at a high rate of speed. The glass, of course, shatters. It seems to me that the filmmakers intend for this method to work on the same physical principle by which opera singers are capable (under certain circumstances) of shattering wine glasses. The two main problems I see with this idea are, 1) Unlike wine glasses, bulletproof glass is not hollow and thus does not resonate as much as a wine glass, and 2) Bulletproof glass is... well, bulletproof, at least in theory. It ought to be much harder to break it than your average wine glass using only sound, and the amplitude required to do so would probably be great enough that it would be very hard to contain the damage to the glass alone. While I don't doubt that you could construct a sonic cannon of some kind that could break bulletproof glass, I wonder what difficulties there would be in doing so without destroying just about everything else in the surrounding area, including human (or mutant) eardrums. Evan (talk|contribs) 15:43, 20 August 2014 (UTC) Presumably the destructive power applied by contact is ultrasound. In established Ultrasonic welding of plastics, high frequency low amplitude vibration is used to create heat by way of friction between the materials to be joined. Increasing the sound power to the liquefied plastic could cause Cavitation as employed in ultrasonic cleaning baths, which can erode holes in a metal foil. Crazing (sudden formation of a network of cracks) can be triggered in some glassy polymers, which offers interesting Special effect possibilities in filming. Humans exposed to ultrasound will not necessarily hear the inaudible vibrations, although it is possible to generate audible sound frequencies by mixing of ultrasonic frequencies in body tissue, but they are vulnerable to cavitation damage that may cause nausea, headache, tinnitus, pain, dizziness, and fatigue. See the article Sonic weapon. 84.209.89.214 (talk) 18:10, 20 August 2014 (UTC) Bullet RESISTANT glass is a laminate made up of thick glass panes and/or polycarbonates/laminates. The very design makes it impossible to fully shatter via sound or direct vibrations. Justin15w (talk) 15:40, 21 August 2014 (UTC) Agreed. Only very hard items are subject to shattering due to vibration, because they can't move much. Sandwiching in softer materials allows them to squish around and absorb vibrations and change them to heat. So, melting is more likely than shattering. Note that a similar medieval technique was to combine wooden fortress defense walls with layers of sand, which would absorb impacts. (Quartz sand, ironically, is glass, so is quite hard, but the spaces between the grains allow it to move to absorb impacts or vibrations.) StuRat (talk) 16:19, 21 August 2014 (UTC) You should be able to break it in theory. Shattering is another story. I don't know if ultrasonoic is all that destructive, but Quicksilver should presumably find the resonant frequency of the plane of glass, which can be very destructive. --Wirbelwind(ヴィルヴェルヴィント) 23:42, 21 August 2014 (UTC) Did the movie actually indicate the glass was bulletproof? I don't recall that it did, though I certainly could have missed it. My impression was that it was simply a thick layer of ordinary glass (which of course could shatter). Though to be fair, I may have formed that impression simply because Quicksilver shattered the glass and I already knew that bulletproof glass would never break that way. Dragons flight (talk) 00:47, 22 August 2014 (UTC) If I'm reading correctly, true Bulletproof glass is a combination of different kinds of glass as well as polymers. It's vaguely like a transparent equivalent of plywood. ←Baseball Bugs What's up, Doc? carrots→ 04:05, 22 August 2014 (UTC) ## Feral estrildid-like finches-- ID needed I just saw these odd little birds at a local park; they seem to be some type of estrildid finch, possibly a domestic breed. I assume they are cage escapees because no estrildids are native to my area, though some have been reported (I have recently seen a Zebra Finch myself). Photos are at the bottom of my eBird checklist: http://ebird.org/ebird/view/checklist?subID=S19523282 75.4.19.68 (talk) 16:40, 20 August 2014 (UTC) Are all the photos of the same bird? Anyway, small chance it could be a society finch, they are basically the domesticated version of the zebra finch White-rumped_munia. However, their coloration patterns are highly variable (do some google image searches), so I don't think you could confirm it as a society finches without catching one... Society finch is also a parsimonious answer, as they are commonly kept as pets. While some people do keep e.g. Gouldian_finches or Red-cheeked_cordon-bleu, the Society and Zebra finches are far more common outside their native ranges. SemanticMantis (talk) 22:14, 20 August 2014 (UTC) Those are two different birds, but they looked identical. Society finches look plausible, except I don't see any on Google with orange beaks. I might also note that there have been some odd sightings of orange-cheeked waxbills and bronze mannikins around here, but neither of those seem likely. 75.4.19.68 (talk) 22:24, 20 August 2014 (UTC) Yeah, the orange/red color on the beak made me suspicious too. The only other guess I have is female or juvenile strawberry finch aka Red_avadavat, though again, they have a lot of variation in color, especially on the pet market where many birds are not purely wild type. Actually, come to think of it males probably wouldn't be in full color this time of year, assuming you are in North America. I'm fairly sure society finches can and will breed with other estrildids, especially if if a conspecific mate for the wild type is lacking (they are much easier to breed than wild types, and are often used as living incubators for other species). So, a hybrid (e.g. society and zebra) might be an option too. Looking through Estrildid_finch I only see a handful that I've ever heard of for sale on the pet market (my mom used to breed finches, so I heard a lot about that market...) Of course it might not even be an estrildid, but I agree with you that that's what these unknowns look like, based on size, body shape, and beak shape. That's about all I've got, good luck! SemanticMantis (talk) 00:03, 21 August 2014 (UTC) Juvenile avadavats do seem like the most plausible option I've investigated so far. I have also wondered if their two-tone beaks are in a transitional stage, from juvenile to adult or nonbreeding to breeding. 75.4.19.68 (talk) 00:13, 21 August 2014 (UTC) OP here: I have talked to a local birder who saw my eBird post, and it seems my birds are not estrildids at all. They are juvenile Pin-tailed Whydahs, which look like estrildids because they are both related to, and brood parasites of, birds in that group. So can I get this marked as resolved? 75.4.24.91 (talk) 18:47, 21 August 2014 (UTC) Interesting! I can't find many good photos of juveniles, but I'm willing to trust the judgement over a local birder over my own armchair guesses :) FYI, you can mark any of your own questions as resolved whenever you like, using the {{resolved}} tag, which I will do now below. Cheers, SemanticMantis (talk) 21:27, 21 August 2014 (UTC) Resolved # August 21 ## Hydrocolloid techology (plaster) Please check if the chemistry behind Compeed plaster is properly described in Techology part. I was using sources like patents, Compeed description at Expainthatstuff article]) as well as Amazon ingredients data. -- TigerInWoods — Preceding undated comment added 03:33, 21 August 2014 (UTC) ## Explosive gel/foam In some video games, like Batman Arkham Asylum, they have a gel or foam that comes out of an aerosol can that you can use to blow stuff up. Does something like this exist IRL? 69.121.131.137 (talk) 03:37, 21 August 2014 (UTC) You can buy aerosol cans of shaving foam and Polystyrene foam (Styrofoam). The latter solidifies and is useful for filling cavities in house walls and lifeboats, is ubiquitous in litter such as packing peanuts and disposable coffee cups, but is hardly explosive enough to impress the batty rogues of Gotham City. 84.209.89.214 (talk) 13:48, 21 August 2014 (UTC) Does the foam go out an explode on its own, or is it more like spray the foam, then ignite to start an explosion? For instance, If you were to take a can of the spray Polystyrene mentioned above, and mix it with gasoline, you'd get a version of napalm. Not really explosive, but I can see Batman spraying napalm on a bad guy then throwing a match to light it. Vaguely similar real-world weapons are the Greek_Fire and Flame_fougasse, but they are both more firey than explosive. SemanticMantis (talk) 14:34, 21 August 2014 (UTC) Well, if you could get the foam to have the right ratio of oxygen and fuel, and little else, you might be able to create a sort of thermobaric weapon, although this one would have it's own 100% oxygen inside the bubbles, and not rely on atmospheric oxygen. The bubble material would be the fuel. I suspect you'd get more of an explosion this way than if the foam was all fuel and needed oxygen from the air. That would only burn at the edges, not explode, since air is only 21% oxygen. StuRat (talk) 16:27, 21 August 2014 (UTC) While not foamy, C-4 is malleable. I always assumed Batman used something a little more advanced, but similar. --Wirbelwind(ヴィルヴェルヴィント) 23:28, 21 August 2014 (UTC) I wonder what would the effect would be of mixing RDX with a polyurethane spray foam? Plasmic Physics (talk) 01:15, 22 August 2014 (UTC) # August 22 # Mathematics # July 29 # August 9 # August 11 # August 16 ## Knuth's up-arrow notation How much money is being paid by the check in this xkcd comic? I found Knuth's up-arrow notation but didn't understand it. 00:22, 16 August 2014 (UTC) — Preceding unsigned comment added by 71.79.68.10 (talk) It is an extremely large number. It is way to big to write the digits. In fact, it is proabably way to big to even write the number of digits. Offhand, I'd guess that the number of digits in the number is way bigger than the number of atoms in the universe. Bubba73 You talkin' to me? 00:46, 16 August 2014 (UTC) Even the number of digits in the number of digits in the number is larger than the number of atoms in the visible universe, as is the number of digits in the number of digits in the number of digits in the number, and so in. In fact, the number of times I would have to prepend "number of digits in" before the number could be written down is larger than the number of atoms in the visible universe. As is the number of digits in it. -- BenRG (talk) 01:33, 16 August 2014 (UTC) It's even bigger than that: The number of digits in the number of times you would have to prepend "number of digits in" before the number is larger than the number of atoms in the visible universe. Sławomir Biały (talk) 12:01, 16 August 2014 (UTC) Can anyone figure out what the third term (i.e. S¤¤(1000)) on the right is meant to be? —Quondum 13:59, 16 August 2014 (UTC) I was only focused on the term with the arrows. I thought maybe the S thingie was something to do with states in statistical mechanics, although it would be quite amusing if this was actually some stupendously small number, rendering the amount on the check some trivial number of cents. This seems unlikely though. Sławomir Biały (talk) 14:10, 16 August 2014 (UTC) When the general context is xkcd humor, anything could be the case. But in the context of the specific xkcd what if page, it seems that a large number is intended. —Quondum 15:15, 16 August 2014 (UTC) It may be SBB, referring to the busy beaver function. -- BenRG (talk) 18:39, 16 August 2014 (UTC) Sounds right. In this case, not only is it a huge number, it's also probably non-computable. -- Meni Rosenfeld (talk) 22:19, 16 August 2014 (UTC) Not sure exactly what you mean by that. Every natural number, of course, is a computable number well, that is, its image under the natural map into the reals is, hi Bo. Maybe you have in mind some sort of feasible computation, something that can actually be done within the bounds of physical realizability? In that case, we have other problems, because (say) the decimal representation of the number isn't one that can be feasibly written down, never mind computed, which makes it sort of trivial to say it can't be feasibly computed. If you allow more compact representations, then what's wrong with one that just represents it in terms of the Busy Beaver function? That representation is certainly computable. So not saying you're wrong, just that it's not terribly clear what the claim means. --Trovatore (talk) 22:44, 16 August 2014 (UTC) Hmm... I'm not sure myself what I mean, but it's certainly not that it's not feasible in the physical universe (that could be said about the Knuth arrow number here, but I wouldn't call it non-computable. Given a classical computer and a huge, but finite, amount of RAM and CPU time, I can tell you the value of any digit you please of this number). Now that you say it, it does sound obvious that every natural number is computable, but since the BB function is not computable, it makes sense to me that some of its values (such as $S(1000)$) are non-computable in some way. Maybe not that the number itself is not computable, but that it's impossible to compute the equivalence of its BB representation and its more usual representations, such as binary expansion. Maybe something along the lines of "there exists an integer $n$ such that for every $m\in\{0,1\}$, there is no proof in ZFC that the nth binary digit of $S(1000)$ is m"? (where, when we make this statement formal, we don't substitute the actual number for S(1000), we write down the definition.) Does that make sense? Or maybe I'm just wrong and there is no sense in which particular values of the BB function are not computable. -- Meni Rosenfeld (talk) 07:53, 17 August 2014 (UTC) It makes sense, although I'm not sure it's true at 1000. It's certainly true for some $S_{BB}(k)$, purely on the grounds of noncomputability; otherwise, we could compute $S_{BB}$ by enumerating all ZFC proofs until we find the one that gives us the value of $S_{BB}$ on our desired input. In fact, we can construct a $k$ where it holds: let $M$ be the machine that searches for a ZFC proof of $0=1$, then outputs the Gödel number of that proof. Let $k$ be the number of states in $M$. Then a ZFC proof of $S_{BB}(k)$ would allow you to prove consistency of ZFC simply by checking that none of the first $S_{BB}(k)$ proofs prove $0=1$.--80.109.80.78 (talk) 08:43, 17 August 2014 (UTC) ──────────────────────────────────────────────────────────────────────────────────────────────────── I thought something like that might have been what you (Meni) had in mind. Yes, absolutely, it could be the case that you can't prove in ZFC what the value of BB(1000) is. I don't know whether that's actually the case or not, but it may well be. Definitely there is some N such that you can't prove in ZFC what the value of BB(N) is. That does not, however, make the value non-computable. It just means that ZFC is insufficiently strong to decide what it is. There is a real answer, Platonistically; a particular first-order theory just might not get you there. There is no such thing as a non-computable natural number, or a non-computable value of a function from the naturals to the naturals. Non-computability applies only when you have infinitely many values to produce. Any finitely many natural numbers are always computable. Here's the confusion, maybe. Computability is not about justifying an answer. It's only about whether there can exist a program that correctly finds the answer, whether the program is justified or not. The program might produce the answer completely by accident, as it were, and it would nevertheless witness computability. --Trovatore (talk) 09:26, 17 August 2014 (UTC) Going back to the psychology/intent of the xkcd strip: I find it interesting that it used a product of three big numbers, each of which seems to require a deeper level of understanding of its sheer size, perhaps so that the smaller numbers fill in where understanding of the larger number(s) is just missing. There is also an interesting irony in the strip: that the cheque (check) would be inherently valueless, something that is not alluded to in the strip but could not have escaped Randall. I am reminded of a challenge run by Scientific American decades ago: readers were to mail in a whole number, and the reader submitting the largest number would receive1,000,000 divided by the sum of all received numbers (or something to that effect). They even pointed out the optimal strategy. Apparently some of the numbers submitted were of the same ilk as on the xkcd cheque, so no money needed to be paid. —Quondum 15:24, 17 August 2014 (UTC)
That was the Luring lottery. Some people did submit the largest number they could manage to define on a postcard. Hofstadter wrote in his next column about how sad that made him because it showed how blindly selfish some of his readers were, in contrast to his superrational self, of course. I think the selfish ones were the people who tried to extract a substantial payout from SA (that it could ill afford) while doing nothing of value themselves. The people who submitted large numbers saved SA from a potentially difficult situation, and some of them were apparently pretty creative about it, unlike the people who followed Hofstadter's instructions. Anyway, getting back to the check, yes, it didn't make sense. -- BenRG (talk) 22:37, 17 August 2014 (UTC)
Interesting point. I have never agreed with Hofstatder about "superrationality", but this is an angle that I can't recall ever occurred to me.
(Would a mil actually have hurt SA that badly, even if they'd had to pay out the whole thing? I guess a million dollars was a lot of money back then.) --Trovatore (talk) 23:33, 17 August 2014 (UTC)

# August 18

## Determining relative advantages of traits

So I'm comparing the fitness of organisms. I can take an organism with a collection of traits (say, a, b, and c) and compare it to an organism with another collection of traits (x and y) and see which has greater fitness. I can never compare individual traits. If I've got a sample of a bunch of matchups (not necessarily every possible combination of a given number of traits), how do I go about finding which individual traits, which combinations, etc. best promote organism fitness? --2404:2000:2000:5:0:0:0:C2 (talk) 04:23, 18 August 2014 (UTC)

Okay here's a tentative idea I had: represent each matchup as an inequality (e.g. a+b+c-x-y>0) (note there are only finitely many traits), and I get a system of inequalities. The more samples, the narrower my solution space. But this works under the assumption that each trait contributes a fixed value to fitness, and there's no added value from particular combinations. But it might work reasonably well anyway I think? --2404:2000:2000:5:0:0:0:C2 (talk) 04:56, 18 August 2014 (UTC)
You need to figure out what fitness function you want to optimize, and how the traits contribute to it. For example, what's the better deal? A 2L bottle of soda for $5, or a 500mL bottle for$2? The 2L has a better per-unit cost ($2.5/L versus$4/L) but if you're only going to drink 400mL, with the rest going flat and being dumped out, the 500mL is a better deal, as total cost is better ($2 versus$5). Add in the fact that the 500mL bottle is refrigerated and the 2L isn't (how much is cold soda worth to you?), or perhaps that the 2L comes in your favorite flavor, but the 500mL doesn't, and you have a complex optimization problem that can't just be reduced to a simple "what's the price per liter?". There isn't any single answer as long as you're unclear on how the traits relate to each other, fitnesswise. - What you need to do if you really want to compare fitness is convert each independent trait to a single numerical value that's consistent within and between each other trait. That is, give each trait a certain number of "points", and for each organism sum the number of "fitness points" it has. So you may have 10 points for being cold, but 12 points for coming in your favorite flavor. You can get more complex if your want - trait a and trait b each get so many points individually, but when they occur together, they get a certain number of points for bonus (or penalty). The fitness function need not be a linear combination of the individual traits. - If you can't convert the values to a single consistent "point" scale, you may want to look into Pareto optimization. That is, you can't necessarily rank all the organisms in single file, but you can say "this set of organisms, when taken as a group, have a better fitness than any of these other organisms". Even then, though, you'll want to reduce your dimensionality as much as possible by combining those traits that can be combined into a reduced number of metrics, and if you want to rank organisms on the Pareto front, you'll need to determine a fitness function. -- 160.129.138.186 (talk) 18:39, 18 August 2014 (UTC)

It depends on what you want to do, and there isn't one general answer. I'll assume you are interested in concepts from real biology. One perspective is that traits are only adaptive traits if they lead to a persistent population, i.e. the species/strain doesn't go extinct. Then "fitness" only makes sense in terms of the processes that affect population biology, things like reproduction, predation, resource competition, and so on. This is basically the stuff in Fitness_(biology).
In theoretical ecology, we often use the the long term low density growth rate, as described here [14]. The basic idea is that populations that can reliably grow back from low density while competing with others will not go extinct. If all types can do this, we can infer species coexistence. This LTLDGR can be measured empirically if good data is available, or calculated from a model. Another perspective on fitness is to take the expected value of the number of "grandchildren". Again, this can be computed for a population if data good, but will otherwise need a model. Really, there are just a lot of ways that "fitness" can be quantified, and what is best/most useful depends on the details of your problem. As for your suggestion of just adding together numbers, that is not something that makes much sense. Not only does that disallow interactions between traits, but it also assumes that all traits are somehow on comparable scales... Anyway, if you'd like to know more about any of the stuff I wrote up just ping me, I'll be happy to give more detail/refs. SemanticMantis (talk) 22:50, 18 August 2014 (UTC)
As regards "what I want to do": after taking a sample, I'd like to be able to predict which of two collections of traits has greater fitness. --2404:2000:2000:5:0:0:0:C2 (talk) 23:55, 18 August 2014 (UTC)
The "good" and useful answers for you will be very different, depending on your application. E.g. a highschool project on mice is very different from a research paper on theoretical ecology, which is very different from a video game that uses evolutionary ideas. Unfortunately your response could be true for any of those scenarios, but I'll still try to explain.
If you want to "take a sample" and see which type has "greater fitness", you have to have either (a lot of) data from the real world or a model of some sort. There are a few definitions for measurements at Fitness_(biology)#Measures_of_fitness, and I mentioned the LTDGR above. There are a few others, but they all revolve around the dynamics of the population over time. So, you have to quantify how much each genotype or phenotype contributes to the next generation. The entire notion of "fitness" in biology is about survival and reproduction. No trait is "better" or "worse", except in that context. There is no biologically meaningful way of measuring fitness of traits in a vacuum. You need to account for, at minimum, survival and reproduction over time. This is somewhat a problem of terminology, as this has very little to do with some other uses of the word "fit". I understand this is the math desk, but this is an area of evolution/ecology that actually has a lot of mathematical tools and techniques. If this is just for some small project or video game or something, you can make up whatever you like, or follow some of the other suggestions. If you want your answer to make sense in terms of the modern understanding of fitness in biology, you have to use one of the established mathematical frameworks. I apologize if I sound harsh, but I want to make it clear that this is a well-studied area of research, and making something up ad hoc might not be very useful. SemanticMantis (talk) 15:47, 19 August 2014 (UTC)
If you assume all the traits are independent, then you can do the following:
1) Compare all the cases with trait "a" to all those which lack trait "a", even though each of the two groups will contain a mixture of every other trait.
2) Repeat for trait "b", "c", "x", "y", and any other traits.
3) For each trait, you will then have either a positive or negative differential, or no significant difference in fitness, based on whether that trait is present or absent.
4) You could then conclude that the combination of all the positive traits, and absence of all the negative traits, is the most fit organism.
However, again note that this assumed that all the traits were independent. You may very well find this not to be the case. For example, cats with white fur and blue eyes might be desirable, but such cats also tend to be deaf. So, if this turns out to be the case, things get more complex. StuRat (talk) 00:26, 19 August 2014 (UTC)

# August 19

## Thermal resistance from a wire through a disk

Please see attached diagrams in http://i62.tinypic.com/2rdg6yg.jpg

The flow of heat through a solid is governed by the solid's thermal resistivity, R, a property of the solid. For a simple bar shape, the flow of heat from one side to the opposite side as shown in Fig 1 is determined by the particular shape's thermal resistance, R, determined from R and the length, width, and height by the simple formula shown.

For a perfectly heat conducting wire or rod passing through a thermally resistive disk, and in perfect contact with the disk, the thermal resistance from wire to disk perimeter is also given by a standard formula: R = R Ln(Rd/Rw)/(2 Pi T) - See fig 2 in the attached file.

I need to find the thermal resistance from a wire to the disk perimeter edge where a pear-shaped hole is cut into the disk, so that the wire makes contact (assumed to be perfect contact) only over a limited angle, as show in Fig 3. The area of the hole can be assumed large compared to the cross section of the wire but small compared with the disk area. Assume heat only flows through solids, and not across any gap, and that there is negligible radiation.

How can I get or derive a formula, either approximate or exact? 124.178.49.97 (talk) 10:13, 19 August 2014 (UTC)

While the original problem has cylindrical symmetry which makes for a simple analytic solution (see for instance Thermal conduction#Cylindrical shells), with the cutout getting an analytic solution would be more challenging. For more complex geometries like this, it may be best to numerically approximate the solution to the heat equation. Energy2d is a free program that may be sufficient for your needs, but there are many full featured commercial programs, too. --Mark viking (talk) 21:37, 19 August 2014 (UTC)
Well yes, the solution for a plain disk is in almost any textbook on heat flow - I gave it in the drawing I attached. Yes, a numeric solution can be used. But a formula would be MUCH more convenient, and it need not be an exact solution. Within 20% or so would be quite good enough. 124.178.49.97 (talk) 01:30, 20 August 2014 (UTC)

## Components Exceed The Average Squared

The following problem has come up in something I'm working on and I can't seem to find a good way to solve it. For reals a1,...an so 0 <= ai <= 1, when is ak >= Average(ai) ** 2 for all k? A specific answer would be wonderful, though, even if the set could simply be characterized, I would be much obliged. Ideally, I need to find a continuous transform of the unit n-cube into the solution that moves around the points as little as possible (various other constraints as well, but I'm not worrying about that at the moment). If the above is simply solved, I'd be even more interested in the general problem: given ai and linear combinations f1,...fm of them, when is ai >= f1 * f2 *...fm for all i? Thank you for all help - this problem is outside of what I'm good at, so any help is quite greatly appreciated:-)Phoenixia1177 (talk) 19:00, 19 August 2014 (UTC)

If I understand you correctly, any constant sequence will do: $a_1,\dots,a_n = p$ gives average of $p$ and $p \ge p^2$. Am I missing something...? --CiaPan (talk) 20:15, 19 August 2014 (UTC)
Phoenixia1177 wants a classification of all such points, not just an example. Is it obvious that the set is even convex?--80.109.80.78 (talk) 20:45, 19 August 2014 (UTC)

## Simplification of bincoef series?

Keeping in mind that

$\sum_{j=m}^\infty \frac 1 {\binom j k}=\frac k{(k-1)\binom{m-1}{k-1}}$ and $\sum_{j=m}^{M-1}\frac 1 {k\binom j k}=\frac 1{(k-1)\binom{m-1}{k-1}}-\frac 1{(k-1)\binom{M-1}{k-1}}$,

is there a similar simplification for

$\sum_{k=1}^M \frac{1}{\binom{2k}{2}}=\frac{1}{\binom{2}{2}}+\frac{1}{\binom{4}{2}}+\frac{1}{\binom{6}{2}}+\frac{1}{\binom{8}{2}}+\frac{1}{\binom{10}{2}}+\dots+\frac{1}{\binom{2M}{2}}\,\!$?

I do know that $\sum_{k=1}^\infty \frac{1}{\binom{2k}{2}}=\ln(4)\,\!$.

~Kaimbridge~ (talk) 21:01, 19 August 2014 (UTC)
Given that the last series converges to an irrational it's unlikely there would be a closed form for the partial sums. Note that it's a variation on 1/1-1/2+1/3-...=ln 2. You could perhaps get an asymptotic formula for the partial sums using the Euler–Maclaurin formula. --RDBury (talk) 04:14, 20 August 2014 (UTC)
The formula is $~H_{_{M-\frac12}}-H_{_M}+\ln4,$ where the values of harmonic numbers of fractional argument are computed with the help of this formula. — 79.113.222.166 (talk) 09:51, 20 August 2014 (UTC)
While my version of Mathematica seems to find this summation easy (and verifies your answer, 79.113.222.166), I can't see how to prove it myself. Could anyone enlighten me? 129.234.186.11 (talk) 14:42, 20 August 2014 (UTC)
You should be able to prove it by induction using the properties $H_\alpha = H_{\alpha-1}+\frac{1}{\alpha}$ and $H_{\frac{1}{2}} = 2 -2\ln{2}$ found in this section. Egnau (talk) 16:28, 20 August 2014 (UTC)

# August 21

## Deriving the Taylor series of the secant function

Basically, how does one show that the explicit formula(s) of the Euler numbers (given in the article) define the coefficients of the Taylor series of the secant function (up to a change in sign)?

One guess I have is to take advantage of the integral definition of the inverse secant, $\arcsec(x) = \int_1^x \frac{dt}{t\sqrt{t^2-1}}$, expand the square root with a binomial series, antidifferentiate, and then apply the Lagrange inversion theorem, but I do not have experience applying that.

Once this series is found, the Cauchy product of it with the series for sine produces the tangent function's series.--Jasper Deng (talk) 01:40, 21 August 2014 (UTC)

# August 17

## Old English Adjectives as substantives

[Moved to WP:RD/L] Tevildo (talk) 14:39, 17 August 2014 (UTC)

## What is the difference between fascism and dictatorship

^Topic ScienceApe (talk) 14:43, 17 August 2014 (UTC)

i know fascism has to have an authoritarian state which can be a dictatorship or otherwise, but this seems to be a case of WP:WHAAOE (see articles fascism and dictatorship) ~Helicopter Llama~ 14:54, 17 August 2014 (UTC)
(ec) See Fascism and Dictatorship (and Authoritarianism might also be useful). Basically, in fascism, the emphasis is on the rule of the State and what's good for it (as opposed to what the people might want, or what might be good for them as individuals). The fascist state may be (and all real examples have been) personified in a dictator, but it's theoretically possible for a state to be fascist yet run by a body of people (Plato's Nocturnal Council comes to mind). [No article! See the Laws and the Epinomis, then.] A dictatorship, on the other hand, is just a state (effectively) run by one person, with no connotations of political ideology. Tevildo (talk) 14:59, 17 August 2014 (UTC)
Fascism is one type of dictatorship. ←Baseball Bugs What's up, Doc? carrots→ 15:04, 17 August 2014 (UTC)
The difference between different types of authoritarian dictatorships is the stated goals or philosophy of the dictatorships; that is the justification the use for their hold on power and their oppression of dissenting views. In practice, all authoritarian dictatorships are functionally equivalent for the people who disagree with them, or the people whose ethnicity or religion they feel are a threat to their power. Philosophies used to support dictatorships include fascism (the devotion to the nation-state), communism (promotion of worker's rights), national socialism (racial purity), cult of personality (pseudo-religious devotion to the dictator and his/her family, see Juche), etc. etc. It's quite important to remember that none of these ex-post-facto justifications makes one lick of difference to the average people living under these regimes. It's either "agree vehemently with the dictator and his stated philosophy" or "get imprisoned, tortured, or killed". It was probably best said by Russian philosopher Mikhail Bakunin, who said "When the people are being beaten with a stick, they are not much happier if it is called "the People's Stick."" Bakunin had a lot of crazy ideas, but that one probably comes a little too close to the truth... --Jayron32 19:28, 17 August 2014 (UTC)
The prominent examples that we have had have been dictatorships, but is that required of fascism? That is, if you have a "fascist-like" state where power ultimately rests in a committee, or a nebulous group of party elite, or even an "elected" representative council, would that still be "fascism"? I'm thinking of an analogy with (20th century) communism, where early examples could arguably have fell into the "dictator" bin (Stalin, Mao, the Kims in North Korea), but where, at least for the Soviet Union and China, they transitioned into a model that was still arguably "communist" but not really "dictatorship" per se. Could something similar have happened to "fascist" regimes, were they have to persisted, or would a transition to a looser control structure mean they no longer would be "fascist"? -- 160.129.138.186 (talk) 19:00, 18 August 2014 (UTC)
Well, they were certainly authoritarian regimes; oligarchy if you will; where the state apparatus still operates as oppressive and authoritarian, though without the singular leader. The Soviet Union in the late 70s - early 80s in the post-Brezhnev years were run by the Nomenklatura, for example. Dictatorship by bureaucracy is still dictatorial... --Jayron32 21:20, 18 August 2014 (UTC)

At least in Fascist theory, it is certainly possible for a fascist state to be run by an oligarchic body rather than a single autocrat. See Grand Council of Fascism. I don't really know how much authority they had in day-to-day decisions, but they were certainly relevant on 25 Luglio, 1943. --Trovatore (talk) 21:48, 18 August 2014 (UTC)

## Baker McKenzie article

Why is it that the Baker McKenzie article is still flagged for advertisement when it has been updated with appropriate citations? — Preceding unsigned comment added by 65.40.217.246 (talk) 16:09, 17 August 2014 (UTC)

This question would be better on the Baker & McKenzie talk page. However, looking at the article, the "Transactional focus" and "Awards and Rankings" sections need to be drastically cut down and re-written as prose rather than a list of bullet points, and the list of cities where the firm has offices and the "Practice Areas" section should be replaced by a couple of summary paragraphs in the lead. Tevildo (talk) 17:16, 17 August 2014 (UTC)

# August 18

## History of social equality

Which societies in the past 3000 years have offered the greatest level of equality.75.90.109.203 (talk) 00:47, 18 August 2014 (UTC)

See Gini coefficient for one method of quantifying equality. --Jayron32 01:29, 18 August 2014 (UTC)
See my comments at Wikipedia:Reference desk/Archives/Humanities/2014 July 8#Origin of Kings for anthropological typology of societies (corresponding Wikipedia article Sociopolitical typology doesn't discuss equality/inequality)... AnonMoos (talk) 04:22, 18 August 2014 (UTC)

## Is there a difference between apostate and unchurched?

Is there a (significant) difference between apostate and unchurched so that they deserve their own Wikipedia pages? An apostate is someone that leaves the church. An unchurched individual is, well, someone that is not affiliated with a church, especially someone who was raised Christian or have family members or ancestors who were Christians. Hence the familial-cultural relationship between unchurched individuals and the church. Is there a concrete or widely accepted distinction between "apostate" and "unchurched"? 65.24.105.132 (talk) 01:51, 18 August 2014 (UTC)

Yes, there is a significant difference. An apostate refers to one who undermines a particular church from within. An unchurched is does not necessarily undermine a church, and by definition, does not act from within. Plasmic Physics (talk) 02:02, 18 August 2014 (UTC)
Another way to look at it: The apostate is a former believer who has decided to reject their former beliefs. The unchurched is an unspecific term. In some contexts, it means people who were never believers. In another context, it means people who are believers still, but who are not attending worship services for various reasons. In yet another context, it can mean people who are and/or were believers, but have become apathetic about the practice of their faith, without outright rejecting it. The apostate is usually taken to mean someone who is more than apathetic or not attending worship services. The apostate is someone who actively rejects or speaks against their former faith. --Jayron32 02:11, 18 August 2014 (UTC)
Fine. The unchurched article shouldn't be nominated for deletion then, even though it's really short and undeveloped. 65.24.105.132 (talk) 03:30, 18 August 2014 (UTC)
I'd support deletion. That said, it would make for a fine Wiktionary article. Plasmic Physics (talk) 03:44, 18 August 2014 (UTC)
Wiktionary already has an entry and will not welcome an essay. Dbfirs 06:37, 18 August 2014 (UTC)
For instance, Sodom and Gomorrah were apostate cities, they were cities of the nation of Israel (Israel is synonymous with church). They were destroyed for becoming a stumbling block for the remainder of Israel. Ancient Memphis could be considered was "unchurched", as it was never part of the nation of Israel. Plasmic Physics (talk) 02:16, 18 August 2014 (UTC)
Neither were Sodom and Gomorrah ever part of a nation of Israel. The people of Israel did not exist back then, even their ancestor Israel had not yet been born when Sodom and Gomorrah were destroyed. - Lindert (talk) 08:15, 18 August 2014 (UTC)
Very well, however they were nonetheless considered to be a stumbling block to God-fearing men. Plasmic Physics (talk) 09:58, 18 August 2014 (UTC)

65.24.105.132 -- The word "unchurched" (someone without a current formal denominational affiliation or place to attend regular worship services) is linguistically parallel to "unbanked" (someone currently without a bank account). It has little to do with doctrinal heresy. The word "unchurched" is somewhat of a jargon term used within religious bodies to refer to one category of people targeted for outreach, but I'm not sure why the article should be deleted... AnonMoos (talk) 04:10, 18 August 2014 (UTC)

Another obvious difference is that "unchurched" would only be used by religions having churches (primarily Christian and derivatives) -- Q Chris (talk) 14:15, 18 August 2014 (UTC)

## Members of the British Royal family who dropped their German titles during WWI

Does anyone have a comprehensive list of British royals who dropped their German titles during WWI? Was it just the Mountbattens/Battenbergs, descendants of Prince Louis (who adopted the title of Marquess of Milford Haven, and Prince Henry or were there others? Sotakeit (Sotakeit) 10:13, 18 August 2014 (UTC)

As far as I know, it's everyone who went from Battenberg to Mountbatten, everyone who went from Teck to Cambridge, and obviously the royal house itself changing from Saxe-Coburg-Gotha to Windsor. Do you want a long list of personal names, or is that enough? AlexTiefling (talk) 10:52, 18 August 2014 (UTC)
No, that's great, cheers. Hadn't thought of the Tecks. Sotakeit (talk) 11:23, 18 August 2014 (UTC)
Don't forget the children of Princess Helena. Surtsicna (talk) 11:58, 18 August 2014 (UTC)

## Jack Shaftoe

Jack Shaftoe is one of the main characters in Neal Stephenson's series called The Baroque Cycle. I had always assumed that he was purely invented, and Stephenson has said as much in interviews -- so I was quite surprised yesterday, while reading Thackeray's 1852 novel The History of Henry Esmond, to come across the following passage: "Twenty ships were burned or taken in the Port of Redondilla, and a vast deal more plunder than was ever accounted for; but poor men before that expedition were rich afterwards, and so often was it found and remarked that the Vigo officers came home with pockets full of money, that the notorious Jack Shafto, who made such a figure at the coffeehouses and gaming-tables in London, and gave out that he had been a soldier at Vigo, owned, when he was about to be hanged, that Bagshot Heath had been HIS Vigo, and that he only spoke of La Redondilla to turn away people's eyes from the real place where the booty lay." This suggests that such a person actually existed at the right time, but I haven't been able to find any more information at all about him. Any thoughts? Looie496 (talk) 18:35, 18 August 2014 (UTC)

This search on Ancestry.com claims to have info on a Jack Shafto of England/Wales, 1837-1915 [15], but you have to sign up for a free account to get it. Also keep in mind that it seems to be a not uncommon surname, and a rather common first name. There are three Jack Shaftos on facebook alone, not to mention various phone directories and the Shaftoe spelling. I'm tempted to take Stephenson at his word, he'd probably be happy to share the history if he'd been inspired by some real rogue Shaftoe from history. SemanticMantis (talk) 22:17, 18 August 2014 (UTC)
Maybe I should have given a little more information. The Battle of Vigo Bay referred to in the sentence I quoted took place in 1702, and had features reminiscent of the escapade in which Jack and his companions stole the Spanish gold (although in Bonanza that took place in Cadiz in 1690). I'm convinced that there is some connection here; I'm just puzzled about exactly what. Looie496 (talk) 22:41, 18 August 2014 (UTC)
Yeah as soon as I submitted I realized that the novel was probably referring to events long before the publication date. AFAIK, Stephenson isn't that responsive to press or fan inquiries. Didn't he say something once to the effect of "Please stop writing me, it will just delay my next book"? SemanticMantis (talk) 15:56, 19 August 2014 (UTC)

## Is there any place that use some sort of reverse of two round system, voting system?

On the two round system, people pick the best and the ones with more votes (if he has more than 50% of votes wins), if not a new poll with just the 2 most voted ones is held and the one with most votes win.
Is there any country that use the reverse of that, where you pick a guy that you really doenst want, and all the guys excluding the one with the most amount of "not wanted" votes goes to a second similar poll and the one with least amount of "not wanted" votes wins? What voting system criteions would this system comply?201.78.190.123 (talk) 20:25, 18 August 2014 (UTC)

Disapproval voting might be of some interest, though it doesn't seem to list any "pure" cases like this. Andrew Gray (talk) 20:36, 18 August 2014 (UTC)
Thanks the disaproval page shows anti-plularity page, its a little simlar to my idea, but not exacly (it doenst have the second step of the poll) 201.78.190.123 (talk) 13:08, 20 August 2014 (UTC)

## What're the cheapest useful amounts of a physical thing in the continental US (or Hawaii)?

And what're the lowest prices on a label/sticker/tag here? (Real price, no spend $20 at Staples get a notebook for a cent, buy 2,000 lbs of coal for$20, and use it for cents per meal fire)

Resolved

# August 19

## Cartoons from 70 years ago

I am looking for two cartoons from 70 or more years ago.

• The first - possibly a Bugs Bunny cartoon - finishes with a parody of the Bob Hope movie The Princess and the Pirate. Viz., the cartoon ends with a sudden very bad turn of events for the "hero" (Bugs?), as he desparately and vainly tries to stop the final screen credits from rolling.
• The second is a parody of Abbott and Costello, featuring rwo mice in a department store.Bh12 (talk) 12:31, 19 August 2014 (UTC)
The first one I'm not sure about. The second one would be an appearance by "Babbit and Catstello", who appeared as cats in A Tale of Two Kitties (which was also Tweety's debut), as mice in A Tale of Two Mice and The Mouse-Merized Cat and as dogs in Hollywood Canine Canteen. ←Baseball Bugs What's up, Doc? carrots→ 13:03, 19 August 2014 (UTC)
First one may be Rabbit Punch. Matt Deres (talk) 13:42, 19 August 2014 (UTC)

I went and saw all the suggested cartoons, but none of them are what I seek. But I did have a good time. Thanks!!Bh12 (talk) 02:04, 20 August 2014 (UTC)

I recommend that you walk through the plots given for the various cartoons in the classic Warner list (many of which have articles here) and see if anything looks familiar. ←Baseball Bugs What's up, Doc? carrots→ 08:53, 20 August 2014 (UTC)

## I'm looking for an episode of ER

Hi!

I'm trying to identify an episode of ER in which Dr. Carter supposedly gave his own blood to a patient. I could be wrong though, it could be something else or maybe it wasn't Dr. Carter because I've searched plenty for

carter+gave+blood+episode

and all kinds of variations of it and didn't find it. It's not Carter's Choice.

Starfsmanna (talk) 18:12, 19 August 2014 (UTC)

Are you sure it isn't Carter's Choice? I've read several synopses, and that sounds like the only match I can find. --Jayron32 19:30, 19 August 2014 (UTC)

In Carter's Choice he gave the patient's lost blood back to the patient. What I'm looking for is when he gave his own blood to a patient. — Preceding unsigned comment added by Starfsmanna (talkcontribs) 19:34, 19 August 2014 (UTC)

## Can someone help identify this song?

Can someone help identify the song used in this YouTube video https://www.youtube.com/watch?v=bO_Ba3A7iEU from the beginning of the video to about 4 minutes 20 seconds into the video. I tried the obvious (searching for the bits of lyrics I could make out "save me", "come and rescue me", etc. but no luck). Any help appreciated. Please ping me (). Thanks. Contact Basemetal here 18:24, 19 August 2014 (UTC)

It's "The Wolf" by Felxprod, with vocals by Thallie Ann Seenyen. We don't have articles on any of those, but you can find the song on Spotify, YouTube, and most music services. --Jayron32 20:28, 19 August 2014 (UTC)
Thank you. How did you manage to find out so quickly? Contact Basemetal here 10:05, 20 August 2014 (UTC)
I have a little utility on my smart phone that lets you play a song, and it identifies the song for you. It's like Shazam (service), but came free with the phone. I think it's tied to Google Now somehow. --Jayron32 12:45, 20 August 2014 (UTC)

# August 20

## Music myth

I would like to know if anyone can explain the origin of the myth that F major is the hardest key to sing in. Does anyone know where this myth began?? Georgia guy (talk) 00:29, 20 August 2014 (UTC)

This ain't really gonna answer your question but take a look at this http://www.choralnet.org/view/220889. You may be right it is a myth but the people who posted in that thread, who are choral directors and so on, seem to believe that it is not. In any case you could try to contact one of them and ask them. Contact Basemetal here 19:48, 20 August 2014 (UTC)
Speaking as one who knows next to nothing about music theory... C major would be the classic "simple" key, right? (No sharps or flats on the staff.) Being a major key, it would have the usual "do-re-mi-fa-so-la-ti-do" structure. And if it's F major, then "do-re-mi..." starts on F instead of C, right? So why would it be so hard to sing do-re-mi in F major as opposed to C major? ←Baseball Bugs What's up, Doc? carrots→ 20:36, 20 August 2014 (UTC)
Well if you're right, then a lot of songs would be in that simple key. But F major would mean that vocalists have to pitch their voice five semitones up (or seven semitones down). People used to C major and songs around there might find F major significantly more difficult. But that really doesn't explain why F# Major is given as the toughest to sing... ~Helicopter Llama~ 21:08, 20 August 2014 (UTC)
Being too high-pitched occurred to me, but that would be more true for G than for F, I should think. And is it F major, or F-sharp major? ←Baseball Bugs What's up, Doc? carrots→ 21:16, 20 August 2014 (UTC)
(for what it's worth, no good reference) It's F major, and it has to do with how the root harmony (F major) is voiced among the soprano, altos, tenors, basses etc in a mixed choir. The fact that this is about choirs is relevant, because it's about the quality of sung intervals and chords in harmony. Even if the alleged problems applied, say, to only 30% of all singers, you will hear the difference in a large group, while you might hear it less in solo or small ensemble performances. (even if the 30% choose not to sing, you'd still hear the difference).
For example, most amateur basses in choirs can sing a smooth voluminous low G, but some will struggle with the F, the chord's root note {tonic), most often given to the basses for the composition's final chord, for example. The struggling might result in a different timbre, or even in a tendency to intonate it sharp. Similarly, it is said that F major's chord notes often lie in the area where the vocal register changes for a number of female choir members (see passaggio) which (again for some of the non-professionals) might result in flat intonation. All together this can lead to a thin-sounding, or, worse, to a clashing chord, which is particularly ugly when it's what is supposed be the music's tonal center, and also the sound that will linger in your ears after the music stops.
That's the theory I've heard, I don't have any good reference beyond forums, and I've heard choir leaders say it's rubbish. ---Sluzzelin talk 21:45, 20 August 2014 (UTC)
It's not and there is no key that can be said to be the "hardest" to sing in. The range of the melody is more important. Many untrained singers cannot easily sing a melody whose range exceeds an octave. For example, The Star-Spangled Banner is often thought of as being hard to sing because of its larger-than-average range of an octave and a fifth, while Mary Had A Little Lamb may be considered "easier" because of its limited range of only a fifth. In the original Broadway production of The Sound of Music, the song Do-Re-Mi has a melody that starts and ends on the tonic note of C, with a range of an octave. This may be comfortable for many singers, but the melody of Amazing Grace, if sung in the same key of C-major, actually lies lower in pitch because the range goes from G to G, rather than C to C. --Thomprod (talk) 01:29, 21 August 2014 (UTC)
The main issue seems to be one of range. So it's reasonable to suppose that John Gary could have handled these difficult keys rather better than, say, Ringo Starr or Herb Alpert. ←Baseball Bugs What's up, Doc? carrots→ 04:08, 22 August 2014 (UTC)

## Late 90's isometric shooter game for the PC.

Hi all,

I am trying to recollect the name of a PC game I played many years go, but sadly has forgotten the name of. The game must be from late 90s or early 2000s, since that is when I was playing it, and graphics of the game surely was of that era. It was an isometric shooter, with the main character being a sort of robotic vehicle that zooms around and shoots where you click. The vehicle/ character would be the same size a single unit in an RTS, say Command and Conquer:Red Alert. The setting was a futuristic city outdoors set out with really flat terrain, with streets and small buildings. One of the weapons that was available to be used was a gatling gun. The only thing I faintly remember is that the game or its tag line somewhere had the word "virus" in it. Much googling has failed to bring up any further clues. Perhaps it was an obscure port of some console game. Any hint/ info will be much appreciated.

Thanks Gulielmus estavius (talk) 15:05, 20 August 2014 (UTC)

You might take a look at our list of third-person shooters (which is sortable by release date and platform, among other criteria) and see if anything jumps out at you. The only such game on our list with the word "virus" in its title is this one, which was released in your stated timeframe; though the gameplay description doesn't seem to match at all. Good hunting. 15:52, 20 August 2014 (UTC)
Streets, small buildings and a gatling gun ? That sounds like one of the Syndicate games
Possibly Syndicate wars: the in-game story was that a computer virus - "Harbinger" - had infected various technology, including the mind-control implants used by each faction.
90.244.143.220 (talk) 16:55, 20 August 2014 (UTC)
The game I was thinking of is neither Syndicate wars nor the virus game mentioned above, but going through the list of 3rd person shooters, I find something resembling to what I had played: Future Cop: LAPD, but only I find the game I remember having played was having a small hovertank type of vessel or craft as the players unit, instead of a walking robot, and also the unit movement in the isometric view much more smoother and better done. Also it had a lot of barrels and crates to be shot up for powerups. And the city setting was a lot more industrial, with lots of tubing and boiler type of structures, and generally better graphics than Future Cop. Gulielmus estavius (talk) 17:39, 20 August 2014 (UTC)

# August 21

## Star Wars

I'm looking for the name of a Star Wars game. At that time, I had never watched a Star Wars movie, just played the game because my friend was a great fan. Currently, I have just finished watching the original triology, but I don't mind spoilers from newer films. I want to point this out because I don't know the franchise very well yet, so my description of the game could be poor. I remember playing it on Xbox at a friend's house back in 2005 I think. Some available characters to play were: different types of stormtroopers armed with bazookas, grenades or as sharpshooters and a spider-like robot I often chose because it could create force fields. Somehow my friend managed to switch to Yoda in the middle of the game, he just didn't want to tell me how. I can't recall the exact aim of this multiplayer mode, I just shot the enemies. --2.245.66.137 (talk) 19:33, 21 August 2014 (UTC)

Star Wars games around that time would include Star Wars: Battlefront II and Lego Star Wars. Sounds like the former to me, but switching to Yoda suggests the latter, although I'm sure if they were Lego characters you'd have noticed, so it's probably not that. --McDoobAU93 19:39, 21 August 2014 (UTC)
Yes, the former one looks like it. Thanks. --2.245.66.137 (talk) 20:17, 21 August 2014 (UTC)

# August 17

## Economic Multiple Choice Questions

1. Which of the following statements about the financial and real sectors is true?

A) For every financial asset there is a real asset.
B) For every real asset there is a financial asset.
C) For every financial transaction there is a real transaction.
D) For every real transaction there is a financial transaction.


2. Without a financial sector:

A) borrowing and lending would not occur.
B) borrowing and lending would be much more difficult.
C) saving and investment would increase.
D) economic activity would continue as before.


3. If the financial sector causes more to flow into spending than is saved, most likely:

A) the supply of real assets will exceed the demand for real assets.
B) there will be too many real assets produced.
C) the economy will experience inflation.
D) the economy will experience recession.


4. Flows that do not enter the spending stream enter the financial sector in the form of:

A) saving.
B) investment.
C) real assets.
D) expenditures.


5. The funds acquired from the sale of a financial asset:

A) may re-enter the spending stream as a financial liability.
B) may re-enter the spending stream as consumption and borrowing.
C) may re-enter the spending stream as a financial asset.
D) cannot re-enter the spending stream.
`

— Preceding unsigned comment added by Walidalrawi (talkcontribs) 17:04, 17 August 2014 (UTC)

Welcome to the Wikipedia Reference Desk. Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our aim here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know. StuRat (talk) 17:15, 17 August 2014 (UTC)
A few links: financial asset, real asset, real transaction, financial transaction, economic activity, spending stream Rmhermen (talk) 17:28, 17 August 2014 (UTC)
You do know that fully half of those "links" aren't links...right? You might try actually following the links you recommend before posting them! SteveBaker (talk) 02:46, 18 August 2014 (UTC)
Sometimes the reference deskers will try to improve the encyclopedia by turning those red links to blue. We even have a template to point out when we've done it. One can hope. 75.41.109.190 (talk) 19:48, 18 August 2014 (UTC)
It looks like Economics is the only reasonable redirect for the remaining ones. Should we create them? Tevildo (talk) 20:04, 18 August 2014 (UTC)
Normally, I'd agree that using red links where you think an article should exist (but doesn't) is a good thing - but when someone asks for help and the answer is "Read these documents...which, by the way, don't exist" - then it's not especially helpful to the OP! Worse still, if you're recommending that someone read one of our articles, you really should at least skim it yourself to be sure it actually does answer the question and isn't the title of the deeply moving, third track from the acclaimed self-titled album of a Norwegian CyberPunk-Polka fusion band "Real Asset" that disbanded in 1979. Clearly if you just type a bunch of likely titles in square brackets, and half of them don't exist, it strongly implies that this minimal level of due diligence was not undertaken. SteveBaker (talk) 20:18, 18 August 2014 (UTC)
I didn't choose the links - I simply linked some words in the OP's question and then deleted the surrounding words. If Wikipedia fails to have articles on basic economics topic, it seems to show a problem the Reference desk used to love to tackle. Rmhermen (talk) 21:24, 18 August 2014 (UTC)
No, SteveBaker is right – the problem is yours, for failing to check whether those are articles. --Viennese Waltz 07:50, 19 August 2014 (UTC)
Agreed. Walidalrawi (the OP) might have already typed in these words and found Wikipedia unhelpful. The point about missing articles would have been better made in a comment separate from a reply purporting to be helpful. Dbfirs 20:52, 19 August 2014 (UTC)

# August 18

## Putting someone to sleep with a healing Superpower

My character in a roleplay has the power to heal people of their wounds. By extension, he has the power to do the opposite; accelerate cancer cells, prevent blood from clotting, and pinch off a blood vessel until part of the brain dies. However, he's very kindhearted and doesn't want to do any of that lethal stuff. I'm just wondering what some believable ways there are for this character to use his power just to put people to sleep, or at worse knock them out. Nothing that causes longterm harm (or ideally, short term harm). 98.27.241.101 (talk) 02:54, 18 August 2014 (UTC)

Something like the Vulcan nerve pinch? According to our article (but unsourced):  "... the ability to project telepathic energy from their fingertips ... which if applied to a nerve cluster correctly could render a human unconscious."  —71.20.250.51 (talk) 06:09, 18 August 2014 (UTC)
From that, it wouldn't be much of a stretch that he can stop panic and calm other characters down, and maybe extend that to induce sleepiness. However, that would take a lot of time and couldn't work as fast as Spock's nerve pinch, and probably requires that the character remains unspotted through the whole trick. - ¡Ouch! (hurt me / more pain) 07:00, 18 August 2014 (UTC)
A little hypoxia is relatively (to poison or clubs) harmless. When it's fatal, it's relatively (to arrows and fire magic) painless. If you're a really white mage, you may want to transfer some oxygen (and Speed, Intelligence, Dexterity, whichever) from an enemy to an ally. Waste not, want not. Temporarily, of course. InedibleHulk (talk) 21:46, August 18, 2014 (UTC)
Judging by your character's abilities (being able to control cell activity it appears), I don't think it would be a stretch to believe this character can control cell activity in general. In that case, I would think your character could induce relevant hormonal release (melatonin and the like) and induce sleep-related neural patterns by manipulating neurons. That or the character could act like many hypnotic drugs and target the person's GABA receptors. Inducing brief hypoxia as mentioned above would probably work as well. Plenty of ways, assuming your character has this level of control over bodily functions. Brambleclawx 14:13, 19 August 2014 (UTC)
According to Strangling, "Incomplete occlusion of the carotid arteries is expected and, in cases of homicide, the victim may struggle for a period of time, with unconsciousness typically occurring in 10 to 15 seconds." So, just a brief pinching of the carotid arteries should be fine to justify this. uhhlive (talk) 21:15, 19 August 2014 (UTC)
See also Choke hold#Use in law enforcement. It is quite reliable if used properly. Its use, even by trained personnel, is restricted now; even a low risk of permanent damage can be quite severe, even more so with multi-million dollar lawsuits. - ¡Ouch! (hurt me / more pain) 08:38, 20 August 2014 (UTC)

## Ship maneuvers during a beach landing

I just finished watching Flags of Our Fathers and took this screenshot during the film. For those who haven't seen the movie, it's about the flag raising at Iwo Jima. What I'm wondering is what those boats are doing going in circular patterns. Can anyone explain that to me? Thanks, Dismas|(talk) 06:33, 18 August 2014 (UTC)

It is the same technique when launching a formation from an aircraft carrier. Each craft can only be launched one-at-a-time, yet they need to be in formation for the mission. This method prevents them from bunching up; also allows everyone to begin assault at the same speed; otherwise, the folks at the back would have to wait for the ones in front to start moving before they could begin. This way, they can all move at the same time with the same speed. Also, the "circles" become larger as individual landing craft are added; this is simpler than trying to arrange rows & columns. One doesn't need to figure out which row and/or column to go to; one simply joins a circle.  —Sorry that I don't have time to find sources. ~:71.20.250.51 (talk) 07:06, 18 August 2014 (UTC)
An unanchored, non-powered boat, in a sea-swell, will tend to turn side-onto the waves. It will then start to rock with the waves, and can capsize. For this reason, in mass-start sail-boat races, the crew will have their boats turning in circles just before (the very long) start line. CS Miller (talk) 09:07, 18 August 2014 (UTC)
I had a look for a reference to back up these explanations and found lots of accounts of landing craft circling, but only one which attempts to explain it, thus: "In the middle foreground are some LCVP's moving in a circle. This maneuver is performed until all the craft are assembled and are given the signal to move up to the line for the final dash in." [17] CS Miller's point above about the need to keep headway in a swell explains why they don't just wait "dead in the water". Alansplodge (talk) 12:24, 18 August 2014 (UTC)

Thank you for the responses, everyone! My own theory for why they would want to keep moving was so that the guns on the shore would have a harder time hitting the boats. Thanks again, Dismas|(talk) 00:21, 19 August 2014 (UTC)

## Vector analysis of course(s) taken by a nation

I have seen vectors (positive and negative in direction <---|--> = <-|} used to describe and explain single-issue choices made by the people of a community such as a nation. It should, then, be possible to plot a large number of single-issue vectors and attempt to account for the general course that the community/nation is taking. For one thing, researchers would have to identify the relevant motivations/forces that determine complex decisions And there would be technical difficulties with the calculations if vector pairs were cross-linked with other vector pairs.

This is the way I was taught to think about political decisions, but I want to find an academic source or sources that I can link to.

Thanks. P0M (talk) 19:49, 18 August 2014 (UTC)

Interesting. What you describe is a game mechanic in the Europa Universalis series by Paradox Interactive, along with many of its other games. You use "sliders" to alter your nations political landscape (similar to the vectors you describe) and your get certain benefits or penalties based on your political decisions. Your strategy depends on how you choose to set your "sliders". --Jayron32 21:29, 18 August 2014 (UTC)
There is an "ant-learning" function implied in the way a 1950s politician explained it to me, or you could say it is like the experiments where many people try to guess the number of beans in a large glass container. Individually, nobody may get particularly close, but the average of all guesses is a good estimate of the true number. So at one time crime may be way out of control and so many people are recruited to the "lock 'em in jail and throw the key away" school. Prison sentences become more and more extreme and gradually more and more people get recruited to the "get them to repent, reform, and then release" side of the balance. Things can't go too far in any direction because individual humans are pretty accurate observers of their own condition, so if a large number get sick of some social condition their attitude will show up in the change of the appropriate vector.P0M (talk) 04:22, 19 August 2014 (UTC)
How does that theory apply in a place like North Korea? ←Baseball Bugs What's up, Doc? carrots→ 07:08, 19 August 2014 (UTC)
Scott E. Page introduced a "Wisdom of the crowd" diversity prediction theorem: "The squared error of the collective prediction equals the average squared error minus the predictive diversity". North Korea's Ten Principles for the Establishment of a Monolithic Ideological System replaces diversity by the principle of unconditional obedience in carrying out the Great Leader comrade Kim Il-sung's instructions. Thereby the thesis of The Wisdom of Crowds, namely that independently deciding individuals will make better decisions collectively than a single expert, is overturned in NK's Juche absolutism that calls on the working class not to think for themselves, but instead to think through the "Great Leader". 84.209.89.214 (talk) 14:04, 19 August 2014 (UTC)
Good point, Basebaall Bugs! It gets at the more basic problem I have been working on, how to try to manage situations like Iraq in which there may be no leadership candidates when a Saddam Hussein gets taken out because the system has been constrained for so long. Imagine what it would be like if the core government of N. Korea disappeared overnight. There would be utter chaos, refugees would stream into China, creating huge problems for them, and any leaders emerging in N. Korea would have had only the role models of the Kim dynasty to base their own attempts to govern on. I would wish for a Korean Nelson Mandela to appear, but the chances would be pretty slim.
According to a vector model only an opposing force can counteract an emerging force that somebody who wants control has decided to repress. It is one of the primary ideas of Daoism that in such situations, what doesn't come out straight will come out sidewise. In other words, if you screw a cap on the end of a garden hose to stop outflow and then you keep increasing the pump pressure on the other end, the weakest point in the hose will break and water will start coming out. When the U.S. instituted Prohibition, many people still wanted to drink. So bootlegging, bathtub gin production, basement wine production, etc. etc. proliferated, and in addition those "streams" influenced other vectors pertaining to things like organized crime, smuggling, etc.
Metal springs expand when heated. To stop a spring from expanding you could put it in a heavy C-clamp. If spring pressure mounts up to the point that the constraint device fails, then the potential energy stored up in the spring will be released explosively as kinetic energy, and you wouldn't want to be along the trajectory of the broken clamp parts.
In North Korea, every natural impulse must be being opposed by applications of brute force. It would be a fascinating study to work out how a ruler can recruit coercive force from his subordinates and use that force to control those subordinates and, through them, to control successive lower levels in the hierarchy all the way down to babies in the womb. The latest "dear leader" gave one demonstration of maintaining the power of the ruler when he had his own uncle (?) dragged off to be executed. P0M (talk) 16:37, 19 August 2014 (UTC)
Uncle by marriage, iirc. —Tamfang (talk) 04:51, 20 August 2014 (UTC)
The question reminds me of various attempts to reduce the universe of political opinions to a small number of dimensions by measuring the correlations between (e.g.) votes in a legislature or answers to a questionnaire. —Tamfang (talk) 04:51, 20 August 2014 (UTC)
It's probably a little like predicting weather by characterizing equal-sized volumes of the atmosphere, the more closely you dice up the atmosphere, the more difficult the math becomes. The more "dimensions" there are, the more complex the math. On top of everything else, like the weather, there is a sort of cross-linking of dimensions, i.e., changing something going on in one dimension can "drag" something going on in another dimension. Questionnaires that show the tolerance for violence of members of a population may change from time to time, and questionnaires that show the prevalence of childhood abuse may also change from time to time. Then you find out that if something happens to increase tolerance for violence (a long war for instance) the other questionnaires show a growing tendency toward child abuse. Or if something happens to increase child abuse (some kind of propaganda attack involving psychobabble perhaps), the tolerance for violence measures may go up. The tricky part of the math (if the analogy to weather prediction holds, for instance) is that a tiny change in one measure in one direction can result in a major change in another measure a little while down the road.
I'm out of my depth when it comes to discussing this stuff on a firm mathematical basis, and it may seem irrelevant to others if no professionals in the field happen to use this kind of approach. So I'd like to know if there is a formal treatment of this stuff somewhere.P0M (talk) 05:25, 20 August 2014 (UTC)

## When do you need to sign when using credit card?

In North America, when using my Visa credit card, sometimes the cashier asks me to sign the receipt and sometimes I am not asked to sign. Why is there this inconsistency? Acceptable (talk) 21:50, 18 August 2014 (UTC)

I know it's not what the question is asking, but since the beginning of this month in Australia we have not been allowed to sign. HiLo48 (talk) 22:00, 18 August 2014 (UTC)
Not allowed to sign? Why? ←Baseball Bugs What's up, Doc? carrots→ 22:53, 18 August 2014 (UTC)
Switching over to PIN verification only. See Sign-off looms for credit card signatures (The Sydney Morning Herald). -- ToE 00:39, 19 August 2014 (UTC)
My experience is that, at most points of sale, there is a threshold amount; if the transaction is above that, you will be asked to sign; if below, you will not. Usually it's 25 or 50 dollars. But it depends on the retailer; some will always ask you to sign (especially in an eating or drinking establishment, when there's a line for tips). On the other hand, for gasoline, there's generally not even an option to sign. --Trovatore (talk) 22:08, 18 August 2014 (UTC)
Gas pumps often ask for some vital info, typically your zip code which I assume is embedded on the card's mag strip. ←Baseball Bugs What's up, Doc? carrots→ 22:53, 18 August 2014 (UTC)
Yes, because after all, people who want to buy gas but don't live in the US and therefore don't have a ZIP code are of no importance whatever. Sigh. --50.100.184.117 (talk)
You can always go inside the store to charge the purchase, or - gasp - pay in cash. ←Baseball Bugs What's up, Doc? carrots→ 07:01, 19 August 2014 (UTC)
Yes, and line up to do it. Twice, if I want to fill the tank, because these days the stations all require prepayment and if I'm filling it up I need change. And if I use a credit card inside, they still want a prepayment: say I prepay $50 and the fillup costs$38 so I get $12 back, then several percent of the$12 goes to the bank as they don't offer the same currency exchange rate for reverse transactions. None of this a big deal, of course, but it is an annoyance to be treated as a second-class customer. --50.100.184.117 (talk) — Preceding undated comment added 07:53, 19 August 2014 (UTC)
I'm having trouble finding anything due to recent changes to some state laws about minimum purchases with credit cards. Here in Canada at least, signing is being phased out; I don't believe I've signed anything in more than a year and I buy everything on M/C. For cheaper transactions, no verification is needed at all, though I don't know if that minimum is set by the retailer or the card company. Above that threshold, we need to insert the chip on the side of our card and enter a PIN. That's perhaps what HiLo was referring to regarding not being able to sign; it's sure not an option for me. Matt Deres (talk) 23:46, 18 August 2014 (UTC)
Yes, that's the way it is now in Australia. Just the card for many small transactions, card plus pin for larger ones. No option to sign at all for any transactions. I have wondered what will happen next time I visit the US and am expected to tip everywhere. HiLo48 (talk) 00:52, 19 August 2014 (UTC)
There were apparently issues for a lot of Americans at the recent soccer World Cup who had cards without a chip and a PIN. Hack (talk) 02:55, 19 August 2014 (UTC)
The relevant articles about this are at Chip and PIN, Smart card, and the links therein, but we're drifting further from the OP's question. Matt Deres (talk) 03:13, 19 August 2014 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── I live in the U.S. A few years ago I went into a fast-food shop and bought my lunch, expecting to have to input the PIN for my debit card. However, I just got a receipt. There is a limit, probably set by each merchant, below which they don't want to be bothered with the details. If a stolen credit card is used, the true owner of the card won't be charged, so either the bank or the merchant has to take the risk. Above the limit, the merchants that use this method will require a signature or a PIN. As far as I know, nobody announced this change. Procedures were simply changed. For a long time the card-reader devices on gasoline pumps did not require any signature or equivalent. A few years ago some started asking for the postal code for my billing address, and others started requiring the PIN for my debit card. P0M (talk) 04:04, 19 August 2014 (UTC)

I live in Austria. My credit card is signature-only, no PIN. I always have to sign. --Viennese Waltz 07:48, 19 August 2014 (UTC)
Banks charge different amounts for credit card transactions based on differing factors. They assume that transactions without signatures are more likely to be fraudulent, so prefer higher amounts (say, over $15) to be accompanied by a signature. For example, X Bank may charge companies 1% for all transactions accompanied by signatures because they are low risk; they may charge 3% for all transactions without signatures below$15 because they are higher risk, but not such a financial burden if fraudulent; they may charge 5% for all transactions without signatures over $15 because they are higher risk and more of a financial burden if fraudulent. Companies such as Subway, KFC etc take on this higher cost for unsigned transactions because their business model means they need to deal with customers quickly. So, whilst they may by a little more to the Bank, they don't have to take the time to ask for signatures and can get through more customers' orders. Here in the UK, all cards are chip and pin, so we never have to sign for a transaction.Sotakeit (talk) 12:57, 19 August 2014 (UTC) On pumping gas/petrol in foreign countries: I always use cash because I get a better exchange rate on ATM transactions than on credit-card transactions. I suggest that approach for people visiting the United States. Yes, you will generally have to queue/stand in line twice, but usually the wait isn't so long in those places. (There are still remote rural parts of the United States where they trust you to pay after pumping.) Marco polo (talk) 18:36, 19 August 2014 (UTC) I'll still have no idea how much to tip and, because shelf prices aren't tax inclusive as they are elsewhere, how much I will have to pay. I love visiting the USA, but financial transactions there annoy the crap out of me. HiLo48 (talk) 21:18, 19 August 2014 (UTC) Your problem, HiLo is that you don't realize you are visiting 50 sovereign states, not one. Next time you vistit go to a stste without sales tax or don't complain--it's not like you've been kidnapped. Tipping 15% excluding any tax is standard. Round up if the service is good, rodund down if it's poor. μηδείς (talk) 21:35, 19 August 2014 (UTC) Your problem, Medeis, is that you don't realise that my country also comprises six sovereign states (and two territories) but we've had the sense to legislate that shelf prices reflect cash register prices. It's not all that difficult to achieve. And tipping is still a mystery. Do I tip at petrol stations? Train stations? Bus drivers? Don't answer. My questions just highlight the mysteries. HiLo48 (talk) 22:15, 19 August 2014 (UTC) Yes, and the reason for those difference is that they exist. It isn't necessary to consider one's own personal situation as normative. Australia and the U.S. (just to pick two countries at random) have different traditions regarding pricing and payments, and neither is better merely because one has grown up in one system or the other. They are different, and they can just be different, without having to defend the one, or denigrate the other. --Jayron32 22:18, 19 August 2014 (UTC) I think I can defend a system of shelf pricing against one that makes no comparative sense, and would be very easy to change if people and legislators actually cared. I understand the difference in tipping being a cultural thing, but I retain my right to admit massive confusion, and a constant feeling of guilt that I will get it wrong, and either rip someone off, or tip inappropriately and offend. And, getting back to the topic of credit cards, tipping with cards, especially now we can't sign with our cards in Australia, will only be more messy. HiLo48 (talk) 22:42, 19 August 2014 (UTC) At the risk of getting even farther off topic, how would not signing make it more messy? If you're entering a PIN, can't you also enter a tip percentage or amount? Dismas|(talk) 00:18, 20 August 2014 (UTC) If I buy a small item such as a coffee, I just wave my card at the machine and off I go. No PIN required. No mechanism for tipping. HiLo48 (talk) 01:21, 20 August 2014 (UTC) Ah! For small purchases. Got it. I was thinking about meals where you'd have a larger bill. Dismas|(talk) 01:30, 20 August 2014 (UTC) There's no fixed rule, but I've experienced "no pin" for amounts up to$100. HiLo48 (talk) 03:12, 20 August 2014 (UTC)
If you're talking about Contactless payment, according to our article actually AU$100 is the maximum allowed by the credit card companies in Australia so there is a fixed rule. (It varies from country to country, here in NZ it's NZ$80.) It's possible some companies may choose to impose additional limits (I think this is possible but I'm not sure). Note that there are often also additional security measures such as requiring a PIN after a set number of contactless payments (to reduce fraud in the case of a loss or stolen card). Nil Einne (talk) 14:37, 20 August 2014 (UTC)
Regarding tipping on card, in the UK, it's only really chip and pin machines at restaurants that give you the option to leave a tip. Anywhere else (hotels, taxis, stores, fast food establishments etc) the machine doesn't allow you to, so if for any reason you want to tip you'd have to do it in cash after the card payment. Sotakeit (talk) 08:30, 20 August 2014 (UTC)
Having recently gotten interested in this and also gotten in to a minor edit war at EMV, I can say that it's actually more complicated than pin or signature. You can actually have offline PIN verification or online PIN verification rather than simply PIN. While this may be largely transparent to the end user it can mean differences in acceptance.
For example, online PIN is the number here in NZ (as I think Australia) and has been since long before chipped cards arrived here. In the case of my specific credit card, I don't believe it even supports offline PIN verification by default or at least in some case. I say this because it's possible to set up the PIN without visiting the bank at all, solely by doing it over the internet on my online account (2FA is required).
It's possible that the offline PIN is set by online POS terminals, but for security reasons, I find this unlikely. So more likely, my current card has no offline PIN set up. I may be able to set it up in the bank (I had trouble finding any info on this though). Unsurprisingly, I have heard of people who've visited countries where the PIN is used who've found they needed to sign, I presume these may be terminals where offline PIN is used, or alternatively the online PIN couldn't be verified.
As hinted in our EMV article, even that is an over simplification as there can be cases where you need both the PIN and signature. IIRC I had that experience in Malaysia at times. From the discussion above, it sounds like some are using the Address Verification System instead of PIN in the US.
Basically as I understand our EMV article, the credit card itself has a list of cardholder verification methods that are allowed by the card in order of preference. The terminals similarly have a list of cardholder verification methods that they allow (possibly without preference but I'm not sure). The terminal queries the card and chooses what CWM method is suitable based on the respective lists and any additional flags (e.g. transaction amount and I wonder if some have additional flags for what they consider high risk transactions).
Nil Einne (talk) 14:37, 20 August 2014 (UTC)

# August 19

## "October 30" article

Hi,

In the "October 30" article, "birth" category, you forgot to mention that Yana Sokolova (very famous russian actress) was born on the 30th of October 1986. How to add it in the article?

Thank you Anton — Preceding unsigned comment added by 92.132.234.53 (talk) 07:13, 19 August 2014 (UTC)

There are two issues here. Ms Sokolova doesn't have an article - in order for her to have one, we'll need evidence from reliable sources that she's notable. WP:ENT is the relevant guideline. Secondly, as she's (presumably) still alive, any facts about her have to pass WP:BLP, so we'll also need a reliable source specifically for her birth date. I've done a quick Google search and there doesn't appear to be anything immediately available which will enable this to happen. Tevildo (talk) 07:30, 19 August 2014 (UTC)
Googled the name. By very famous, do you mean the youtube starlet or the personal coach or who? врать нехорошо. Asmrulz (talk) 04:16, 20 August 2014 (UTC)

## What is the common connotation of "The Internet"? Just the WWW/HTTP one?

The http;// style "web browser" accessed internet started to go mainstream in about 1994 in America. Before that, however, many home enthusiasts, such as myself, used local Telnets, Freenets, Compuserv in the early 90's, and BBS's in the 1980's. Are those considered "The Internet", or does the Internet only mean the WWW/HTTP style internet? Thanks. — Preceding unsigned comment added by Zombiesturm (talkcontribs) 13:21, 19 August 2014 (UTC) Sorry forgot to sign Zombiesturm (talk) 13:21, 19 August 2014 (UTC)

Those are all part of the internet, yes. The web is also a part of it. --Viennese Waltz 13:22, 19 August 2014 (UTC)
^This is wrong; most of the above didn't use IP. See Internet and Internet Protocol. -- BenRG (talk) 19:35, 20 August 2014 (UTC)
Yeah but nobody called it "The Internet" until the WWW/http style browsers came out. We called it "BBS'ing". Zombiesturm (talk) 13:27, 19 August 2014 (UTC)
Well I was on the internet in 1994 when the web was just starting. I wasn't on BBSs but I was on things like telnet and gopher. We certainly called those the internet. --Viennese Waltz 13:51, 19 August 2014 (UTC)
See History of the Internet and History of the World Wide Web. While the origins of the Internet can be traced as early as development in the 60s of packet network systems such as the ARPANET, the first network to implement TCP/IP, creation of the first web page by Berners-Lee on servers at CERN can be dated to January 1991. 84.209.89.214 (talk) 14:25, 19 August 2014 (UTC)
Zombiesturm, that's not true at all.
The Internet and BBSs are not the same thing. Sometimes they're not even connected.
That's like saying "We called it AOLing". No. AOL existed separately, and eventually they offered internet access through their service. APL (talk) 21:21, 19 August 2014 (UTC)
The "internet" (inter network) and the "World Wide Web" (WWW) are two seperate things. You can read the articles or if you have 10 minutes this video on youtube clarifies it [18]. -- Sincerely, Taketa (talk) 15:59, 19 August 2014 (UTC)
That's technically true, but we must pay some attention to WP:COMMONNAME. I was there in the BBS, Telnet and Gopher days too, but now even my spellchecker regards the lower case form of "internet" as being wrong. HiLo48 (talk) 16:43, 19 August 2014 (UTC)
As a point of clarification, our article says TCP/IP is the sine qua non of the 'internet'. So, if you were using Xmodem or Zmodem, you weren't using the internet, just using a network that connects users in a star topology. Now, our article on Bulletin board system says that some used telnet and packet switching, but that wasn't really common in the heyday of BBSs. What was common was Fidomail FidoNet and other such services, which effectively asynchronously linked lots of BBSs together. To me, it seem that using Fidomail in the 1990s was basically using "the internet," in the sense of an interconnected computer network, regardless of whether it used TCP/IP. SemanticMantis (talk) 17:08, 19 August 2014 (UTC)
While I did my first searches on FTP-site spider Archie, I do think the general connotation of "Internet" is the things you do using a browser. Example poll question: "do you use Internet for WhatsApp?" My guess is that a majority people would respond with answers like "no, I can only use it on my phone" (while knowing you need to buy "data" from your phone company). Joepnl (talk) 20:31, 19 August 2014 (UTC)
CompuServe, dial-up BBSes, and Free-net were definitely not the Internet unless you're talking about later in their history when some of them were (also) connected to the Internet. If you meant Telenet rather than telnet, that was not the Internet either. Neither were FidoNet or the UUCP network. I don't recall anyone ever (incorrectly) calling them the Internet, either. The Internet was the new(ly popular) thing that displaced them. -- BenRG (talk) 19:35, 20 August 2014 (UTC)

## 2014 FIDE election with Garry Kasparov

Anyone know where to find which countries voted for Kasparov and which voted for Ilyumzhinov, compared to how the federations voted in 2010? Thanks. Zombiesturm (talk) 17:10, 19 August 2014 (UTC)

FIDE is the Fédération internationale des échecs or World Chess Federation. The published results of FIDE 2014 election report the re-election of Kirsan Ilyumzhinov as President and elections of other officials, but do not reveal how countries voted. Ilyumzhinov defeated Garry Kasparov, winning 110-61. 84.209.89.214 (talk) 23:50, 19 August 2014 (UTC)
Apparently it was a secret ballot (last sentence). Dalliance (talk) 12:56, 20 August 2014 (UTC)
Is anyone surprised? Bzweebl (talkcontribs) 01:18, 21 August 2014 (UTC)
You have a problem with secret ballots? -- Jack of Oz [pleasantries] 20:59, 21 August 2014 (UTC)
No, just pointing out that no one can really be surprised that the federations that voted for Ilyumzhinov are a secret. Bzweebl (talkcontribs) 23:45, 21 August 2014 (UTC)
Do whinging rhetorical questions show insincerity that should be kept in check (except this one) ? 84.209.89.214 (talk) 02:54, 22 August 2014 (UTC)

## Why don't we use luminous paint in houses to save energy during the day to be used at night?

I read that this is done in the Netherlands on certain roads, so I'm curious why it isn't done in houses. It seems like an obvious idea.--Leon (talk) 20:01, 19 August 2014 (UTC)

i would think that it has to do with the lack of control over the emission of light. you can simply flick off a light bulb, but the glow which a painted wall would give off would last for hours fading slowly over time. roads are more practical because cars have their headlamps and the lines can be seen from the repeated exposures. houses, not so much, since it's too dark for practical use but too bright for if you want to sleep or whateverer idk this is mainly speculation lol ~Helicopter Llama~ 20:11, 19 August 2014 (UTC)
Radioluminescent types of luminous paint are based on a beta emitting radioactive isotope (radionuclide) combined with a radioluminescent substance. Their radioactivity is a health hazard, demonstrated in the case of the Radium Girls who painted watch dials around 1917, and they decay after a number of years, depending on the chosen isotope and phosphor. Chinese suppliers offer purportedly non-toxic luminescent water-based paint for road marking. Information found about their formulation is "made by firing a mixture of alumina and rare earth" and "rare earth-activated silicate aluminate", categorized as an Alkene. See the article Luminous paint. 84.209.89.214 (talk) 23:32, 19 August 2014 (UTC)

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The kinds of "glow in the dark" products I am familiar with put out only a faint glow. I have made a sort of experiment because I have a room with a light switch well inside the entrance. To help find it I placed a couple of luminescent appliance boxes from my dentist next to the switch. If the lights have been on for a while the luminescent boxes will grow brightly when the electric lights are turned off. However, the material quickly sheds its energy becoming dimmer and dimmer.
If I were going to use sunlight to provide for night time lighting of a road sign or something of that sort then I would use a photovoltaic screen to charge a battery during the daylight hours and have the electric light switched on and off by a photoreceptor switch. This scheme is used fairly frequently in the U.S., but the panels I've seen on power poles or telephone poles by the sides of highways do not connect to electric lights. I think they are used to provide current for low-amperage radio transmitters or other devices that use relatively little energy. (Probably 4 D-cells would be enough to power the same units for a day or two. Much larger solar panels would be needed to provide enough juice to light up a couple of floodlights. Signs that create a message by selectively turning on or off the extensive grid of little LEDs would be the most energy-efficient signs that we could produce today. P0M (talk) 00:58, 20 August 2014 (UTC)
A light switch containing an NE2 neon is still a better choice for your room. An LCD matrix display takes less energy than an LED matrix. 84.209.89.214 (talk) 16:02, 21 August 2014 (UTC)

# August 21

## Repair oscilloscope

The TRACE SEP control on my oscilloscope is dead. Can someone point it out on the circuit diagram? The oscilloscope is 100MHz dual-beam with delayed trigger and otherwise works fine. Here you can download the circuit (click "Descargar Meguro MO-1255.rar"). It comes as a .rar file which contains .pdf files. Here are pictures of the oscilloscope. 84.209.89.214 (talk) 23:29, 21 August 2014 (UTC)