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May 25

Are super-tankers fully automated ?

Hi Everyone.
In Superman III and Hackers (and many other fictions, I guess), it is said that modern oil tankers can not be controlled manualy and are totaly driven by computers. I wonder if this is accurate. I know that in the 1970s there have been numerous tankers hijacking stories and I guess automation is a way to avoid that ? If there is a super-tanker captain here, I'd be glad to here what he says about that ;-) Jean-no (talk) 13:43, 25 May 2013 (UTC)

If by fully automated you mean so automated that computers set the course in a way that humans can't override, certainly not. That would be insane. See Exxon Valdez oil spill, among other things. Looie496 (talk) 14:40, 25 May 2013 (UTC)

According to the article on that spill, the main causes were human fatigue and failure to maintain equipment. It seems like full automation may have mitigated or even prevented it. 202.155.85.18 (talk) 02:18, 27 May 2013 (UTC)

In the movies I mention, the ship's course is decided by distant and centralized computers. It seems quite dangerous to me, so I guess the writers didn't understand well something... Jean-no (talk) 15:01, 25 May 2013 (UTC)

I suppose by automated they could mean computerized, such that the controls could be hijacked. So not like the captain and crew does nothing, but more like Fly-by-wire for boats. Mingmingla (talk) 15:22, 25 May 2013 (UTC)

There are (at least) two separate questions there. The first is whether or not such functions are computerized/automated, the second is whether or not the computer is required to carry out those functions: adjusting ballast, controlling the engine and rudder settings. (The third implicit question, I suppose, is whether or not those functions are, or can be, remotely controlled. My common-sense response is "Why the hell would you put that on the internet?", though dumber things have happened. Absent any evidence to the contrary, I would be very reluctant to presume that the capability exists; there probably isn't an idiot oil-industry exec who has said "Please, can I adjust ballast on a supertanker from my iPhone?") TenOfAllTrades(talk) 16:40, 25 May 2013 (UTC)

My unschooled thought is that more security would be needed than you'd think. At some point the computer now on board the tanker could have been connected to the Internet, and somebody might have had a pop-up "Would you like to update your map of the reef to include the most recent soundings?" and not realized that someone was spoofing the update site and uploading a map that shows clear water sailing straight through Diamond Head. The ship probably has an autopilot, which could remain engaged if the crew had ... an accident. Indeed, the 'accident' might well have been loaded on board together with the new navigation computer. I suspect the movies were more dramatic than this, though! Wnt (talk) 17:47, 25 May 2013 (UTC)

Movie plot threats aside, do you actually know anything about how navigational or control systems on board a supertanker work? TenOfAllTrades(talk) 22:39, 25 May 2013 (UTC)

I didn't know the expression "Movie plot threat", I love it. Jean-no (talk) 22:53, 25 May 2013 (UTC)

The real movie plot threat is the Terminator 2: Judgement Day! The singularity is near!Shadowjams (talk) 00:53, 26 May 2013 (UTC)

To be clear - no. I just wanted to keep people's minds open about the idea in theory, as SteveBaker has done at more length below. Wnt (talk) 18:44, 26 May 2013 (UTC)

Several approaches exist to infecting and controlling computers that are not, nor have ever been connected to any networks whatever. You can even devise attacks for computers that are physically incapable of being connected to any outside communications whatever!

This seems unlikely - but it's actually happened. The most famous is the Stuxnet system which was an effort (allegedly by the US and/or Israel) to disrupt uranium enrichment plants in Iran that were controlled only by very simple microcontroller chips with no network capability whatever.

It worked by first infecting computers that WERE connected to the Internet, then having those machines place malware on things like thumb-drives, cellphones and MP3 players that were plugged into those machines - then when someone who designed automation software for Iran charged their infected phone or MP3 player by plugging it into their (network-isolated) software design workstation, the infection was spread into the software that was used to program the dedicated microcontrollers - which in turn caused covert software to be placed into their firmware that caused them to fail under some future circumstances and to hide that failure from instrumentation designed to see faults exactly like that!

That approach requires massive amounts of patience and investment in time and money to get all of those steps to work correctly - but the outcome in that case is well known to have been moderately successful.

It seems entirely reasonable to me that a similar trick - planned years in advance by some kind of James Bond super-villian - could allow one to give a super-tanker some predefined commands that would be hard for the crew to diagnose or rectify without knowing what was happening and why.

That said, the emphasis would be on "predefined". It would likely be impossible for any degree of control over the tanker to be had remotely during such an event. But a sufficiently cunning bad guy could certainly have the thing subtly veer off course and crash into something important unless the captain enters some special code-word into the computer via whatever controls he has. A system like Stuxnet is capable of doing just that. Now, obviously if it took control of the tanker hours before this impact, the crew could disconnect the computers and shut down the engines by cutting power lines with an axe or something - but if it jammed the bow thrusters into full power right in the middle of threading a course through some narrow gap between two rocky outcrops in the middle of the night - and the radar and other navigation computers were rigged to make it look like the correct course were being followed - it could probably cause the needed mayhem before the crew could figure out what was happening.

The plot of that Bond movie where the British warship is sent off-course into Chinese waters by doing something nasty to its GPS is exactly the kind of thing that a Stuxnet type of system could use to have a supertanker run aground and cause an ecological and political nightmare someplace.

Basically, it *is* technologically plausible...but unlikely.

SteveBaker (talk) 02:56, 26 May 2013 (UTC)

Again I ask, does anyone know anything specific about the degree of automation or computerization of the controls of a supertanker or large freighter? Is there actually a USB port on the bridge where a crewmember can plug in his mp3 player and run arbitrary, malicious Windows code on the navigational and control systems simultaneously? I can't speak to the plausibility of Steve's scenario, because – correct me if I am mistaken – no one here has actually done any research into the questions asked, nor admitted to so much as working aboard a ship, let alone ever reflashing a supertanker's firmware. TenOfAllTrades(talk) 19:14, 26 May 2013 (UTC)

The lesson we should take away from Stuxnet is that even if the supertanker's computers had no internet or USB ports, they could still have malicious code placed there when the ship was first built if the computer on which the supertanker's software was written was connected to the internet or had an infected device plugged into one of the USB ports. However, the skills and resources needed to make that happen are huge - and the need to plan all of this years in advance - make it quite unlikely that this kind of exploit has ever actually been used against supertankers. But it's definitely possible. SteveBaker (talk) 12:52, 28 May 2013 (UTC)

Well, it's something of a hypothetical question -- pirate attacks do occur, but they actually do encounter a crew. (in one case, 25) Of course, the way pirate attacks usually go, the crew ends up being a liability as hostages, not really a guarantee nothing bad is going to happen. Wnt (talk) 21:13, 26 May 2013 (UTC)

For an interesting parallel, see [1]. That's about airplanes, but the point is, apparently in the corporate world nobody really cares what could happen, as long as they can get through tomorrow. Wnt (talk) 03:56, 27 May 2013 (UTC)

I just love it when folk include links to articles as though the articles support the nonsense they claim. In this case there is a slight twist: The news item cited by Wnt does state that someone claimed you can misdirect an aircraft with a phone. But there is a link at the bottom of it to another news item issued a couple of days later. It quotes an official American FAA press release and the relevant systems manufacturer - both state that its a load of codswallop - you simply cannot take over a plane with an andriod phone - and some technical detail why is given. Wickwack 120.145.154.162 (talk) 10:59, 27 May 2013 (UTC)

Thanks for pointing out that response, but it isn't as firm a denunciation as you think. "Neither the FMS nor the autopilot flies the plane. The crew flies the plane through these components. We tell it what to do, when to do it, and how to do it. Whatever data finds its way into the FMS, and regardless of where it's coming from, it still needs to make sense to the crew. If it doesn't, we're not going to allow the plane, or ourselves, to follow it." No, the plane won't do loop-the-loop if you drop your accelerometer-enabled Android phone in the toilet. But how about if the weather is foggy and the crew thinks they're landing on a runway that is just barely long enough for the plane but actually it's another runway at that airport that isn't long enough, because they're not quite where the instruments say they are? Wnt (talk) 13:48, 27 May 2013 (UTC) (I suppose I shouldn't leave without a mention of Die Hard 2...)

Yes, it is a firm denuciation. The perpetrator said there is NO security on these systems. But the FAA and the manufactuer says there is. I'll believe the FAA before I rely on some nutter who gets the ear of a journo. I can think of multiple reasons for not believing this rubbish anyway. Here's the first one: How is the andriod phone hardware to communicate with the airplane systems? They do not share frequencies. That does not preclude some villian with a purchased or custom-made system that IS on the right frequency of course, but that requires a lot more resources, and technically sophisticated ones at that. Wickwack 120.145.148.85 (talk) 15:02, 27 May 2013 (UTC)

I don't know how myself (but half the time "apps" discussed in this manner end up involving some kind of hardware accessory, e.g. for terahertz imaging). However, I leave it to readers of the article [2] to decide themselves what it says. I think it is pretty clearly saying that access to the FMS does not allow direct control of the autopilot or plane, not that it can't be hacked into or mislead pilots. Wnt (talk) 17:07, 28 May 2013 (UTC)

Well, as I said before, but apparently you missed it, it says very clearly in the 7th paragraph that aircraft systems have high levels of security. It was the perp's claim that there was no security. So even with the right transmission hardware, his claims are simply not true. Wickwack 124.178.175.45 (talk) 00:08, 29 May 2013 (UTC)

I've just spoken to a youth who is studying to be a Merchant Navy officer, and has been to sea a couple of times in bulk carriers. He says that the navigation system is along similar lines to an aircraft autopilot and that in some ships, the control functions are computerised, in the manner of fly-by-wire in aircraft. He doesn't think it would be possible to hack into a ship's systems. Alansplodge (talk) 14:10, 28 May 2013 (UTC)

• Followup: http://www.foxnews.com/tech/2013/07/26/exclusive-gps-flaw-could-let-terrorists-hijack-ships-planes/. Wnt (talk) 19:49, 28 July 2013 (UTC)

Solubility of Iron(II) oxalate

Iron(II) oxalate says it is slightly soluble, but Oxalate#Physiological effects says highly insoluble. Which is correct? — Preceding unsigned comment added by 93.132.188.84 (talk) 15:47, 25 May 2013 (UTC)

It's plausible that both are correct, insofar as they are subjective, context-specific descriptions. Iron oxalate obviously has a specific solubility constant in water; but it's not available in NIST's online database. The next step would be to check a handbook of chemistry and physics constants (e.g., the CRC Handbook of Chemistry and Physics); maybe one of our chemistry-minded regulars has a copy of such a resource handy. Nimur (talk) 16:23, 25 May 2013 (UTC)

Here it is at PubChem: FERROUS OXALATE, again only with subjective description of the solubility. Nimur (talk) 16:33, 25 May 2013 (UTC)

It's a bit of a shock if both should be correct in the respective (and highly unspecified) contexts. 93.132.188.84 (talk) 16:52, 25 May 2013 (UTC)

What's the difference between slightly sober and highly drunk? Seriously, words like "slightly" and "very" are quite imprecise, and there's nothing that makes "slightly soluble" and "highly insoluble" incompatible. If your really want to know, you need the K_sp value for Iron (II) oxalate. This says the K_sp value is 2 x 10^-7. Since this is a 1:1 ionic compound, that means that the molar solubility is SQRT (K_sp), which would be 2 x 10^-7/2 = 6 x 10^-4 mol/L. --Jayron32 18:39, 25 May 2013 (UTC)

So wouldn't it be better to avoid those imprecise (weasel-) words in those articles? At least in those fact-boxes for chemical substances? 93.132.188.84 (talk) 18:52, 25 May 2013 (UTC)

I'm neither here nor there on that. Many sources use terms like "slightly soluble". But if you wanted to add a bit to directly list the Ksp, and link to the reference I gave, additional information is always good. --Jayron32 19:04, 25 May 2013 (UTC)

Last few times I tried to edit anything on wikipedia failed due to one restriction or the other. I'd rather leave that to the "insiders". 93.132.188.84 (talk) 19:19, 25 May 2013 (UTC)

This reminds me of the question I asked earlier. The answer seems to be that as adjectives, 'very', 'highly', 'slightly', and the words 'soluble' and 'insoluble' are highly subjective terms. Other subjective words that also pop up frequently in science, include 'inorganic' and 'warm/hot' and 'metalloid'. Plasmic Physics (talk) 09:00, 27 May 2013 (UTC)

Universal constants are very important to effective scientific communication, but it seems that these words have escaped attention. Even arbitrarily bounded definitions would prevent such confusion. For now, they remain the bain of science, subject to the various schools of thought, and the rogue individual. Plasmic Physics (talk) 09:06, 27 May 2013 (UTC)

No, the words are fine. What you really need to know about something at first glance is what its solubility is based on three basic levels:

• If I take a spoonful of it and stir it into a big cup of water, will it essentially all dissolve
• Will it not dissolve completely, or even much at all, but will it still produce measurable or chemically significant amounts of ions in solution
• Will it do absolutely nothing, and produce no measurable or chemically significant change to the water

The first condition is always "soluble". The last condition is always "insoluble". Depending on why you are asking the question, the second condition could be "insoluble" or "slightly soluble". Context matters, but it doesn't mean that the words are completely useless. --Jayron32 18:49, 28 May 2013 (UTC)

Organ theft

Has there ever been a confirmed case where someone has been convicted of kidnapping people and stealing, then selling their organs on the black market? I've had a look around the web, and I see that people have occasionally been *accused* of it, but then the true story turns out to be something less sensational when it goes to trial.

I'm not talking about the urban legends of serial killers being paid by the Russian mafia/Triads/etc. to abduct hobos and teenage runaways from the streets of Western cities and 'harvest' their organs for sale to rich people in the far east either. I've heard that stuff before and I'm pretty sure that it is 100% 'hooey'. Or travellers who get their drinks spiked and wake up in motel room bathtubs having had their kidneys stolen. --87.112.25.55 (talk) 22:30, 25 May 2013 (UTC)

Organ theft in Kosovo. TenOfAllTrades(talk) 22:32, 25 May 2013 (UTC)

You may be interested in looking at the work of Nancy Scheper-Hughes. --Atethnekos (Discussion, Contributions) 06:50, 28 May 2013 (UTC)

May 26

Antipsychotic studies

in the text of this study http://www.sciencedirect.com/science/article/pii/S0006322310011716 it states "Fourth, our experimental design does not address whether the APD-induced morphological changes are reversible, a question of significant theoretical and practical relevance. Drug withdrawal studies to address this possibility are currently underway." That was in 2011. have these drug withdrawal studies been completed and published since then? — Preceding unsigned comment added by 63.247.60.254 (talk) 19:23, 26 May 2013 (UTC)

I just typed the last author's name into PubMed and got back a likely looking result: [3] (By convention, the last name on biological science papers is usually the person running the lab). If you want to dive deeper than that, you really can use the little envelope link next to Shitij Kapur's name and ask him directly, though it may be useful to make a few more PubMed searches first to get some background. Wnt (talk) 21:24, 26 May 2013 (UTC)

Sky cloudier near ocean

Does the sky near the ocean have more clouds than more inland, on the average? Bubba73 ^{You talkin' to me?} 21:52, 26 May 2013 (UTC)

I assume one realizes there are hundreds of thousands of miles of coastline? Condensation will occur when warm humid air blows into cool areas, such as that above land in the Fall when the water is still retaining the Summer's heat in relation to the land. But the question as stated is too vague for a yes/no response. μηδείς (talk) 22:48, 26 May 2013 (UTC)

This site has 25 years of global averaged cloud cover. Between that and the image at our cloud cover article (an average of October 2009), I observe that, broadly, cloud cover over the ocean tends to be at least as heavy as cloud cover shortly inland from that location. This does not hold everywhere, but is at least a rough trend. Note particularly how much of the coastline in the Oct 2009 image on Wikipedia is dark and sharply defined, indicating relatively low cloud cover. On the other hand, the majority of the North American and European coasts are hard to distinguish -- there's not much of that trend in those locations. In the area of Kenya, it even appears to be the opposite -- the coastline is apparent, but the sea is darker. — Lomn 22:52, 26 May 2013 (UTC)

Resolved

Thank you. It is not quite like I imagined it might be. Bubba73 ^{You talkin' to me?} 02:06, 27 May 2013 (UTC)

May 27

Salt and sea salt

There's a lot of advertising and hype about sea salt which, for reasons that remain mysterious to me, is better for you than other salt. I expected that this was a recent craze, but I was watching a not-so-recent film La Regle de Jeu where one of the characters is on a "diet" that she can't have salt but can have sea salt. The chef dismisses it as nonsense, subtitled as "She can eat like everybody else. Diets I can accept, but not obsessions." How far back does this go as a health craze? 71.231.186.92 (talk) 00:20, 27 May 2013 (UTC)

Sea salt contains a little bit of alternative ions to sodium, but it generally doesn't contain enough to really reduce the dose enough to help tremendously with sodium reduction (by comparison to pure or half-potassium formulations on the market). Editorial: I wish I could find good balanced salts for human consumption at supermarkets with better levels of potassium/magnesium/calcium/etc. In terms of nutrition, sea salt is a poor substitute for the more balanced land salt that our ancestors were accustomed to, and which is still favored in some traditional cultures. The notion everybody learns that "table salt" is "sodium chloride" is one of the more dangerous myths in modern culture. Wnt (talk) 01:06, 27 May 2013 (UTC)

Wnt, as you are aware, you can buy the readily available "Lite Salt", which is 50:50 sodium salt and potassium salt, marketed to people who want to reduce sodium intake. However, people usually increase the amount they use as it lacks taste. So you end up with just about as much sodium, and a lot more potassium, which can cause medical issues of its' own. You should be getting calcium from milk. Wickwack 120.145.190.145 (talk) 02:24, 27 May 2013 (UTC)

That's surprising to hear, because in my personal experience it isn't true; if I'm hungry for potassium then I have a hunger for salt but it doesn't fill the need, so I use more and more. Definitely I prefer the flavor of the salt with some potassium in it to the slightly sour taste of pure sodium salt, especially when I'm hungry for it. But I think "Lite Salt" can be formulated with at least a little and maybe a lot of magnesium and calcium with what I think could be an actual improvement in flavor for at least some applications. (I've seen some foods like chick peas actually packed in calcium salt solution) Wnt (talk) 04:02, 27 May 2013 (UTC)

Sea salt is not iodized. Some people think they're getting too much iodine, and those people are usually the types that carry on about eating "natural", so sea salt appeals to them. 202.155.85.18 (talk) 01:50, 27 May 2013 (UTC)

As far as a craze is concerned, it may depend on which country you live in. In Australia, by law, salt packaged for consumers is iodized (salts of iodine added) as it was found that thyriod problems due to iodine deficiency occurred in susceptable people. Australian salt has for decades been sold in very plain packaging, and it has always been sea salt, produced by evaporating sea water in large pans, by Dampier Salt and other companies. It was never labelled as "sea salt" - just "salt" or "table salt". However, in the last few years, shops have been stocking imported sea salt and it (mostly) is not iodised - it gets around the law as it is not packaged in Australia. It is also sold in modern attractive packaging and labelled as "sea salt". The craze is thus driven by three coincident things: a) it avoids the problem of many people who are distrustfull of "population medication" (same as the dubious objection to folate in bread, flouride in water, etc); b) more attractive modern packaging; and c) a hazy notion that as it is different and new, it must be better. For decades, thyroid disease has been very rare, but now to a minor extent it has come back. There is no scientific benefit in the imported sea salt - in fact you are better off with the local iodized salt. However I notice that recently the main Australian retail company has risen to the occaison by marketing "iodized sea salt" (actually exactly what they have always sold) in nice packaging, at a premium price. Wickwack 120.145.190.145 (talk) 02:10, 27 May 2013 (UTC)

Do you have a ref for the Australian law banning the packaging of non-iodized salt? I'm having trouble finding any other source that says that. 202.155.85.18 (talk) 03:14, 27 May 2013 (UTC)

There's no law banning the packaging of non-iodized salt - rather there is a mandatory food standard requiring that salt packaged for retail/domestic use be iodised, and bread for sale be made with iodized salt. Ref Mandatory Iodine Fortification, Food Standards Australia. Wickwack 124.178.154.108 (talk) 04:04, 27 May 2013 (UTC)

Does anybody actually have an answer for the OP: when this fad started? Clarityfiend (talk) 09:32, 27 May 2013 (UTC)

this link suggests that it has been within the last 15 years or so. Since the UK and France tend to be where these things started (Maldon, Fleur de Sel), I would be willing to take that at face value. -- [ UseTheCommandLine ~/talk ] # _ 10:27, 27 May 2013 (UTC)

And as I said in my first post, in Australia at least, within the last few years. Of course the OP is probably not in Australia, but I expect other Western countries to be similar - they usually are. Wickwack 120.145.154.162 (talk) 11:05, 27 May 2013 (UTC)

The OP noted a character on a sea-salt-only diet in a 1939 film. (Yes, I know it was a work of fiction.) Though I haven't seen the film, I get the impression from the OP and from our article that the point of mentioning the sea-salt diet was to mock the French upper classes' willingness to adopt the latest silly trends, much as we make fun of celebrity fad diets today. So the first question I would ask is whether or not the sea-salt-only restriction mentioned in the film was poking fun at a 'real' trend of the era, or just some sort of generic parody of celebrity fascination with fads.

In other words, though the Guardian might trace the current obsession with sea salt to the last 15 years, it's certainly plausible that it has had its ups and downs, or has had at least a small following, going at least back to 1939. Worth noting is that Switzerland introduced the first national iodised salt program in 1922 [4], and iodised salt first became widely available in the United States in 1924; many other countries followed suit over the next decade or so. Based on my experience with quack medicine, I would be frankly shocked if there weren't some sort of paranoid, reactionary pushback from that era's lunatic fringe in response—leading in turn to health gurus of the era preying on the fashionable and gullible. (See also the anti-vaccination and anti-fluoridation movements.) TenOfAllTrades(talk) 13:54, 27 May 2013 (UTC)

ELectrostatic Energy

What do you know by electrostatic energy of discrete and continous distribution of charges? — Preceding unsigned comment added by Titunsam (talk • contribs) 12:42, 27 May 2013 (UTC)

Oh, heaps and heaps. What do you want to know? — Preceding unsigned comment added by 60.231.241.154 (talk) 13:01, 27 May 2013 (UTC)

This is an encyclopedia. Please see our articles on Electrostatics, Static electricity, and Electric charge, and come back here if you have a more specific question.--Shantavira|^{feed me} 13:18, 27 May 2013 (UTC)

For the equations involved, see the article Electrostatic potential energy, and the article section Electrostatics#Electrostatic energy. Red Act (talk) 17:20, 27 May 2013 (UTC)

Purpose of small building connected to upper floor of generating station

Resolved

The now-defunct Richard L. Hearn Generating Station has a small shed-like building on "stilts" connected to one of the main building's upper floors by a short gangway (the building is visible in this photo, slightly down and to the left of the smokestack). I've seen similar buildings in photos of other old industrial buildings as well.

What is the purpose of these buildings? My guess is that they contain hoists for lifting equipment or material from rail cars or vehicles to the upper floors of the building to which they're attached, but this is only speculation. Confirmation of this guess or information about the true function of these buildings would be appreciated! 142.20.133.199 (talk) 13:24, 27 May 2013 (UTC)

A building I used to work at years ago had a similar attachment, used, as you guessed, as a hoist to lift things off of train cars. Dominus Vobisdu (talk) 14:08, 27 May 2013 (UTC)

This structure looks like it has angle braces which would prevent putting a rail car under it, and the extension to the building does not look to be very substantial, so I wonder how heavy items could be lifted. Edison (talk) 14:29, 27 May 2013 (UTC)

This particular power station was originally built to run on coal, and later converted to gas. The shed-like structure on silts may have been the head compartment of a coal conveyor (which would typically look like a long elongated shed ramping up from ground level at a low angle). The actual conveyor structure has, I am assuming, been removed and the head compartment left in situ. Maybe after the station was converted to gas firing, they needed the ground area for something else but had no particular need to spend money removing the header compartment. Wickwack 120.145.148.85 (talk) 14:48, 27 May 2013 (UTC)

Wickwack, I found a photo of the southwest corner of the main building from the 1960s that (unfortunately) doesn't show the shed-like building (which is attached to the east wall of the main building) but does depict a coal conveyor going directly into the building. It's possible that another conveyor went into the shed on stilts, but that seems somewhat unlikely given the existence of the one shown in the photograph.

Edison, I think the shed's supporting braces might be large enough that a rail car (or truck) could fit between them; admittedly, however, the shed and gangway do look rather delicate. Dominus, was the hoist building where you once worked supported by angle braces and of a similarly (perhaps deceptively) flimsy appearance as this one? 142.20.133.199 (talk) 15:26, 27 May 2013 (UTC)

It turns out that the shed was connected to a coal chute (very close to Wickwack's hypothesis). This photo from 2004 shows the chute; evidently it was removed before the photo of the building on Wikipedia was taken. There's another photo by the same person that shows the chute in more detail; perhaps it was torn down to prevent people from using it to get to the roof of the plant. Thanks for your assistance, everyone! 142.20.133.199 (talk) 16:49, 27 May 2013 (UTC)

Yep, that's a coal conveyor (a means to take coal from ground level up to the header), not a chute (a chute would guide material travelling downwards). Wickwack 121.215.149.216 (talk) 01:12, 28 May 2013 (UTC)

I need to know the names of 4 things

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

---

I need to know the names of these 4 things:

What is the name of the paper-packed plastic tool sold in pharmacies used to hook out the thing punctured into the gums by a dentist? There's the jewelry, gold or silver version of the tool for the same purpose.

What is the name of the flying machine which looks like a jet-ski machine? It has 2 controls, one to move forward and the other to rise up the air.

What is the name of the device used to draw or suck the soul out of a living body? It has a switch with 3 switch positions, the first being the off position and there are the switch position to draw the soul out and the switch position to suck the soul into the device.

What is the name of the white-coloured machine which is capable of teleportation? — Preceding unsigned comment added by Pnf1 (talk • contribs) 14:32, 27 May 2013 (UTC)

Please give us some background here: Are you asking about machines in movies, books, comics? Or conspiracy theories? Anyway, your 3rd question has been asked here [5], maybe you get some tips there.

Your first question is asked here [6]. Aaadddaaammm (talk) 14:48, 27 May 2013 (UTC)

Looks like we're getting another round of those god-damn online quizzes. Looie496 (talk) 19:06, 27 May 2013 (UTC)

I suggest someone close this thread as very obvious soul-sucking trolling. I also suggest we change the quidelines to say, "Do not ask unrelated questions in the same posting". μηδείς (talk) 20:57, 27 May 2013 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

How is water pumped to the treetop?

I have been told that capillarity did the job of transporting water through the tree from the root to the top, but that cannot be true because work has to be done all the time. There must be some kind of biochemical pump working in trees and other plants. Do we have an article about the phenomenon? Bo Jacoby (talk) 14:58, 27 May 2013 (UTC).

Evapotranspiration. The process relies on active and passive techniques to cause a pressure-gradient from the root to the leaf, and water flows upward against gravity, e.g. in the xylem. You are correct that it is a tremendous amount of work. Trees, and plants in general, are incredibly thermodynamically efficient; they extract solar energy through photosynthesis and use it to perform chemical and mechanical work. Nimur (talk) 15:04, 27 May 2013 (UTC)

Yes, I believe the majority of the work is passive, and controlled by vapor pressure deficit, among other factors. SemanticMantis (talk) 16:36, 27 May 2013 (UTC)

Get a piece of toilet paper end touch some water with one end to see the water rise to the the other end by capillarity alone. No need for active transport. As water evaporates from the top, more water will rise from the bottom to replace it. Dauto (talk) 18:01, 27 May 2013 (UTC)

The problem here is that you are just performing a thought experiment, but not a real one. If you performed a real one, and tried to pump water up to 100 m, which is what some trees do, you'll see that your physical reasoning is wrong. OsmanRF34 (talk) 22:50, 27 May 2013 (UTC)

In the reference to "Evapotranspiration" I do not quite see the answer. Neither does capillarity alone convince me. A vacuum will support only a column of about 10 meters. When evaporation causes a partial vacuum it might cause the water to rise, but not indefinitely. Some trees are 100 meters or more high. I am still curious about the "mechanism" behind it. --VanBuren (talk) 18:37, 27 May 2013 (UTC)

You have presented one example where purely passive action is insufficient to raise the water. That's why the plant, as a living organism, expends energy to control its osmotic pressure. In combination, the plant's active transport and the physical processes of passive transport work to move the water throughout the organism.

If you click on the link I provided, xylem (upward water transport), you'll see a lot more information.

Several years ago, I became very interested in active transport in plant life - specifically, at what point in Earth's history the first plant roots evolved; because, prior to the first root, the Earth soil would have been awfully inhospitable to life as we know it today. So I created the first Wikipedia article on plant evolution and researched as much as I could, hoping that a botanist would fill in some details. In fact, Evolutionary history of plants and several new articles were created, with more information than I ever expected to find on plant water- and nutrient- transport. For obvious reasons, tissue specifically adapted for water transport was among the first special-purpose multicellular items to evolve among any life form.

Nimur (talk) 18:57, 27 May 2013 (UTC)

And if that's not enough, Big Basin State Park has a whole textbook worth of Redwood Ecology and Natural History, including material suitable for students of all levels. There's a whole "science activity" where you calculate and balance water transport in a redwood forest. In places like Santa Cruz, fog drip is important: the forests are so huge that their water cycle is effectively at a dynamic equilibrium with the atmosphere. Sometimes, fog emanates from the trees as transpired water; and sometimes fog condenses from the atmosphere and enters the trees directly through the needles. Nimur (talk) 19:20, 27 May 2013 (UTC)

If people here are interested in the theoretical limits of this, they can consider the following thermodynamics problem. Suppose you have a glass of water at room temperature T and the relative humidity in the room is r. How much work can you extract from the water per unit mass of the water? To what altitude could you lift the water using that work? Count Iblis (talk) 21:47, 27 May 2013 (UTC)

Obviously, you allow life to evolve in the glass of water; preferably in the form of an algae that can convert atmospheric gases into stored hydrocarbons; then permit some of the lifeforms to decay into fossil fuel; and use the rest of the water to evolve intelligent life, who can use the fossil fuel to develop a manned space program and launch a small portion of the remaining water into Earth orbit and beyond. This is, of course, assuming that your thought-experiment has no time-limit and that you allow solar energy as an input to the otherwise-closed system. Nimur (talk) 22:10, 27 May 2013 (UTC)

We don't allow any external energy sources unless they are used in a fully neutral way (e.g. if you add work to the system you have to subtract that amount of work to compute how much net work you have gained from the water). The beauty of thermodynamics is, of course, that you can compute the answer without having to think about the details of how you would actually extract the work. Count Iblis (talk) 22:40, 27 May 2013 (UTC)

But, plants do extract energy from the sun. I don't think it's a good idea to model an individual organism (or an ecosystem of many organisms) as an Isolated system. There is a net input of energy that is available for non-conservative work. Nimur (talk) 22:58, 27 May 2013 (UTC)

Yes, but then the problem is that with solar energy there is no restriction to how high you can pump the water. Thing is that trees operate under the same constraints as one would have if the system were perfectly isolated. Count Iblis (talk) 23:41, 27 May 2013 (UTC)

I politely disagree; trees can use photosynthesis to set off a chain of biochemical reactions that expend energy to pump water. This is accomplished by using active transport at the cellular level to induce an osmotic pressure. So, a living tree with working cells can pump water higher than a dead tree with the same capillary vascular structure, as a result of energy input to the system. Nimur (talk) 23:55, 27 May 2013 (UTC)

I see, so solar energy does play an import role in how trees pump water and that is what the OP's question was about. Still, trees are not able to pump water higher than the thermodynamic limit for an isolated system (which is quite obvious if you compute it), so I'm still wondering if the energy derived form solar power is merely assisting in the thermodynamic processes for which the bulk of the work is derived from evaporation, rather than that energy itself being a large part of the work, because in the latter case you could easily evade the limits form the thermodynamics of the isolated system and there would then be no upper limit to the maximum height of trees. In the latter case, you would expect the height of trees to be limited at least approximately by the thermodynamic limit, which is indeed the case. Count Iblis (talk) 12:02, 28 May 2013 (UTC)

• I think all this boils down to that no one really knows the complete answer. See: Plant Physiology Online: How Water Climbs to the Top of a 112 Meter-Tall Tree. Some of this site's other essays are also interesting.Aspro (talk) 13:09, 28 May 2013 (UTC)

Funny i watched a youtube video about this very topic just a few days ago. Veritasium is a pretty decent "science" channel on youtube. Previously they did an experiment of how high you could "suck" water up a straw. They found that even a vacuum pump couldn't get water higher then 10m becuase after that point, the pressure has to be so low that the water literally boils. So, how does a tree do it? Search for "the most amazing thing about trees" on youtube, (i can't access youtube at work so can't paste the link). Vespine (talk) 03:34, 29 May 2013 (UTC)

My cat and formic acid, etc.

I have a lovely wonderful cat. I also have something of an ant infestation. My cat loves it. She stalks, kills AND EATS the ants. I don't know if that's common but she is having a ball. I have two issues. One is that I know ants have formic acid in them. Should I be worried about my cat's ingestion of quite a lot of ants? What I am more worried about is that I want to have an exterminator come in but if they poison the ants and then my cats eats the ants, she will get the poison. That has kept me from making an appointment. Any thoughts?--71.190.242.180 (talk) 15:43, 27 May 2013 (UTC)

From a quick google I see that there are a few mentions of cats going mad for formic acid, but I haven't been able to find any authoritative references. One of the things you could do is tip a kettle of boiling water over the ant nest which should kill most of the little blighters, if you are worried about noxious substances and your cat. --TammyMoet (talk) 19:22, 27 May 2013 (UTC)

I'd suggest you just express your concern to the relevant professional exterminator. There are supposedly "organic" solutions like oleic acid. A professional who can't comment might not be the one to go with. μηδείς (talk) 20:59, 27 May 2013 (UTC)

I wonder if you mean Boric acid which in the US is considered safe for children and pets as long as you keep them away whilst its being applied. [7] Once the little critters stop moving the pussy will no longer be interested in them. Aspro (talk) 12:58, 28 May 2013 (UTC)

Boric acid harms fertility and unborn children, and is a restricted product for the general public in the EU, so I question this casual attitude. 86.163.0.30 (talk) 19:27, 28 May 2013 (UTC)

Does this question violate the no medical advice policy? Count Iblis (talk) 23:17, 27 May 2013 (UTC)

Not if we give the proper advice, which is to see a professional. Or, in this case, two professionals: the vet, and the exterminator. Cats love to attack, kill and eat bugs, so there's certainly cause for concern. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:42, 27 May 2013 (UTC)

There's much better things to do with ants than try to kill them you know. 78.245.228.100 (talk) 06:39, 28 May 2013 (UTC)

One thing worth bearing in mind is that most common ant insecticides contain permethrin - which is pretty toxic for cats. You would definitely need to raise the issue with any exterminator you hire. Yunshui 雲‍水 10:40, 28 May 2013 (UTC)

Formic acid is a weak acid, much like acetic acid, the acid in vinegar. And there is much less acid in ants than there is in vinegar. So I wouldn't worry for your cat in terms of the acidity. — Preceding unsigned comment added by 148.177.1.217 (talk) 14:40, 28 May 2013 (UTC)

No blossoming

I've noticed that in a matter of weeks, the trees where I live (Colorado) have gone from being bare to being completely green. It looks like the blossoming phase has been completely skipped. We had a few snowstorms at the end of April and the beginning of May, completely freezing all the trees as they were starting to sprout on the branches. Is it possible that the blossoming phase rapidly sped up due to the cold and snow?71.229.194.243 (talk) 23:58, 27 May 2013 (UTC)

It's possible that the blossoms were frozen at a critical point so that they didn't form properly. --TammyMoet (talk) 09:47, 28 May 2013 (UTC)

It sounds like some trees had their bloom cycles aborted by a cold snap. That can have the effect of leaves emerging sooner, since they are not being "blocked" by the flowers. Other trees may have had a different reaction to the cold, e.g. very late emergers. Generally, this is the topic of phenology, and if you want to know more about what happened in CO this season, you can check out the US National Phenology Network, here [8]. SemanticMantis (talk) 12:01, 28 May 2013 (UTC)

May 28

What's New by Bob Park

Does anyone know what has happened to What's New by Bob Park? It used to come out weekly, but the last issue was nearly 3 months ago. Bubba73 ^{You talkin' to me?} 02:57, 28 May 2013 (UTC)

You could always email him and ask. Btw, this year's issues have been nothing like weekly. Only 4 in the first 5 months. -- Jack of Oz ^[Talk] 08:29, 28 May 2013 (UTC)

I didn't want to bother him - he may be very sick or something. Bubba73 ^{You talkin' to me?} 14:11, 28 May 2013 (UTC)

Self-contamination possible? Trying to understand bathroom germ contamination and how it works

I obviously know that washing your hands thoroughly after going to the bathroom is extremely important in order to avoid gathering bacteria or other diseases from the bathroom itself and also to avoid spreading them onto whatever you touch. But can you self-contaminate? For example, if I were to live for a month entirely on my own, with no contact with any other humans, is it still important to thouroughly wash my hands each time I go to the bathroom? Basically what I am thinking is that the disease that may be on my hands from my bathroom, can only come from my own human waste, which was already inside my body, so if it existed in there, I was already contaminated by it, wasn't I, and it was benign to me since I wasn't sick, wasn't it? (I am not planning to spend a month away from humanity, and even if I did, I would still wash thoroughly out of habit, whatever your answers will be. So do not worry about my hygiene, this is just a thought experiment to help me understand how bathroom germs cause contamination). --Lgriot (talk) 14:18, 28 May 2013 (UTC)

You can self-contaminate, because your gut flora should not be allowed to live in your eyes, ears or throat. Your bacteria is kind of self-contained in different parts of the body. Washing hands avoid them spreading to other parts of the body. OsmanRF34 (talk) 14:29, 28 May 2013 (UTC)

Ok, I didn't know bacteria was successfully contained by the body within specific parts of itself, I thought that once it was inside, it could flow with the bloodstream and reach other parts. It makes sense now. thanks. --Lgriot (talk) 14:58, 28 May 2013 (UTC)

Humans only started washing hands to get rid of germs in what decade? The 1870's or thereafter? before that, and after that in much of the world, I expect that people only washed their hands if they could see or smell something on them that they did not want to include in their meal. Germ removal from hands post-toilet and pre-meal is a cultural custom and public health practice of 140 years duration or so for most in the world, though some cultures practiced ritual washing for religious reasons for thousands of years before that. It seems like a great idea, but many of my ancestors lived to ages of 80 or over before anyone ever suggested handwashing for germ removal. Handwashing improves health, but it does not prevent pathogens from being ingested in a world where we eat lots of fresh lettuce and fruit, since normal washing with water of produce is not that effective in removing pathogens which got on it from contaminated irrigation water or contaminated rinsewater at the packaging factory. Isn't it likely that one's own fecal bacteria are less of a health hazard than that of someone else, as in contaminated drinking water or contaminated produce? Edison (talk) 15:42, 28 May 2013 (UTC)

Certain cultures (Hindus, Sikhs) have long held the tradition of using one hand to feed yourself with and the other one to clean yourself with. --TammyMoet (talk) 19:11, 28 May 2013 (UTC)

Our lettuce and fruit has a myriad of bacteria on them, however, they shouldn't have any meaningful (i.e. that can make you sick) amount of e. coli. OsmanRF34 (talk) 18:45, 28 May 2013 (UTC)

One famous example of bacteria that are benign/helpful in the intestines, but cause disease in the mouth/stomach is E. coli. As far as I know, this suggests the answer to you last question is "no, not necessarily." SemanticMantis (talk) 15:45, 28 May 2013 (UTC)

So far as I know E. coli pathogenicity depends on the strain (and as I recall "strains" vary a lot, a substantial proportion of the total distance to Salmonella) not on self-contamination. However, pork tapeworm is a case that actually can become far nastier after a trip through the intestine. Wnt (talk) 17:02, 28 May 2013 (UTC)

My point was, if you have a potentially dangerous strain of E. coli in your gut (not causing any problems there), then self-contamination would definitely be a risk, and perhaps moreso than contamination from a different person who had no dangerous strains. SemanticMantis (talk) 19:05, 28 May 2013 (UTC)

Well, enteropathogenic Escherichia coli is, well, enteropathogenic, i.e. causing its damage in the gut itself. But it is true that the uropathogenic strains involve self-infection, which can be shown to occur in an ascending manner from the urethra going upwards. [9] Wnt (talk) 22:36, 28 May 2013 (UTC)

Ah, yes, thanks for the clarification! SemanticMantis (talk) 22:41, 28 May 2013 (UTC)

I'm trying to work my way through the nice, euphemistic, American(?) use of "bathroom" here to work our what User:Lgriot is really asking about. Is it urinating? Or defecating? Or both? I have seen it argued that for a healthy man who has recently bathed (i.e. within the last few hours), and wearing clean underwear, washing hands after urinating is fairly pointless. Unless he is a lousy shot or very clumsy when aiming for the toilet bowl, his hands won't be impacted in any negative way at all from handling his clean penis. In fact, before the act, his hands are likely to be dirtier than his penis, so the logical thing to do is to wash his hands before urinating in order to keep his penis clean. But defecating. That's different. It obviously depends on how much your hands get involved in cleaning up after the act. And if one uses a bidet, the hands may still never go near one's faeces. So, Answer = It all depends. HiLo48 (talk) 04:34, 29 May 2013 (UTC)

Yes, Americans are quite secretive about the definition and use of the term "bathroom". Agree with much of your comment, except for the implication that getting urine on one's hands would contaminate them (as our article's lede indicates, it's typically sterile). -- Scray (talk) 04:41, 29 May 2013 (UTC)

Yes, that's true. So, if we're talking about a healthy, clean man simply urinating, washing hands afterwards could be seen as pointless. Now, being a fella, I not going to dare to attempt to comment on what the ladies should do. HiLo48 (talk) 04:47, 29 May 2013 (UTC)

Well, to answer explicitly, "going to the bathroom" in U.S. means urinating or defecating, but excludes things like nose-picking even though they may be done in the bathroom for privacy the same way (one hopes with hand-washing afterward) I can't tell you with absolute certainty, but I would suggest hand-washing after urination has something to do with [10]. There are times, like when omitting underwear with shorts in hot days of summer, when a last drop in the pants is just not presentable, and among the various options is to touch a hand to collect the last drop - however, honestly, the real reason is that many service employees can be fired for not hand-washing so they simply do it. (I also wonder if some of this goes back to days when people claimed that toilet seats could spread gonorrhea, etc.) Wnt (talk) 06:02, 29 May 2013 (UTC)

I am not American, Scray, but yeah, I was assuming that both activities could lead to bacteria on your hands, somehow. Notice I said "could", not "would", and I guess it depends on well you handle the action. :-) --Lgriot (talk) 08:04, 29 May 2013 (UTC)

Life expectancy corrected for sleeping time

Humans in Western countries can expect to live till about age 80, but if you correct for the time spent sleeping, this only amounts to something like 50 years spent awake. Some animals like elephants also live quite long but they sleep a lot less than humans. So, I was wondering what mammal has the longest life expectancy if one corrects for the time spent sleeping (cold blooded animals with a slow metabolism can live for every long, let's not consider such cases). Count Iblis (talk) 17:12, 28 May 2013 (UTC)

Why discount sleeping and not, for example, standing stock still, or defacating? Is one activity more relevant than the others for life expectancy? If so, why? -- Scray (talk) 20:44, 28 May 2013 (UTC)

Back to Biology class :(
The following discussion has been closed. Please do not modify it.
It could be more meaningful to have a list of long-lived creatures, including a column on average daily hours spent sleeping. Housecats seem to sleep a lot, yet they don't live very long. The creatures that live the longest are probably tortoises. That would be a good benchmark, if their daily average sleep time is known. ←Baseball Bugs What's up, Doc? carrots→ 21:01, 28 May 2013 (UTC) Regarding tortoises, Count Iblis specifically asked about mammals and not reptiles though. --Modocc (talk) 22:00, 28 May 2013 (UTC)

There seems to be an implication that sleeping is wasted time. But it's vital to mental health and memory and is quite pleasant if properly done. Googling sleep and life expectancy gives you lots of various sources and comments. I do remember reading something along the lines of "is time spent sleeping wasted time" in a science blog recently, but it doesn't seem to have been notable enough to find easily. I remember quite vividly an Italian Renaissance writer who in a sourcebook we used in my 400 level Renaissance and Reformation course advised his sons to sleep as little as possible, as time spent asleep was stolen from the total of one's life. It may have been in The Civilization of the Italian Renaissance: A Sourcebook, but I haven't been able to find the quote. μηδείς (talk) 21:38, 28 May 2013 (UTC)

Sleeping helps you during your waking time, but if you're already counting waking time, adding sleeping time is double counting. You are not capable of conscious experience for (most of) your sleeping time, so counting it seems to make about as much sense as counting the time after you die. It's not wasted time, but counting it along with the time spent awake would be like counting the money you spent on your house along with your house itself when calculating your net worth, on the basis that the house wasn't a waste of money. Why do you say it is pleasant? How can something you're not conscious during be pleasant? — Preceding unsigned comment added by DanielLC (talk • contribs) 00:58, 29 May 2013 (UTC)

Whales can live over 200 years (see maximum life span) and I saw a documentary not long ago that they do sleep. But they probably still have a longer sleep corrected longevity than other mammals. But they would probably be awake for many years longer than other mammals. -Modocc (talk) 21:59, 28 May 2013 (UTC)

Are you saying there actually is a scientific concept of sleep-corrected longevity, Modocc? μηδείς (talk) 23:46, 28 May 2013 (UTC)

Its conceptually similar to the concepts of the longevity or service life of engines or light-bulbs, in this case, the longevity of accumulative wakefulness, in other words sleep-corrected longevity. Its obviously a derivative of longevity, and sufficiently well-defined that it can be empirically measured. -Modocc (talk) 01:56, 29 May 2013 (UTC)

As I suggested in my initial response above, I remain doubtful that sleep-corrected longevity is a concept supported by scientific consensus. Your comments underscore the impression that this is synthesis of concepts from appliances that have an "on"/"off" state that does not clearly apply to animals. -- Scray (talk) 02:16, 29 May 2013 (UTC)

Thanks for answering Modocc, but I do suspect that you are applying a concept from engineering that simply does not apply to biology. Being asleep is in no way being "off". It is simply a different mode of being actively alive that applies to sentient organisms of a certain complexity. μηδείς (talk) 03:39, 29 May 2013 (UTC)

I didn't mean to suggest that being asleep was being off or not living though (see my explanation below for why I brought up machines). Its perfectly clear though that the OP was asking about the length of the time that we and animals spend awake however and that is a valid biological question with valid answers. I've revised my answer to avoid further objections though. Modocc (talk) 04:03, 29 May 2013 (UTC)

Googling the phrase "sleep corrected longevity" (ie put it quotes) returns precisely nothing. As does googling "sleep corrected life", and "sleep adjusted life". Googling without quotes returns lots of sites, but they aren't talking about Modocc's or Count Iblis's concept. They talk about things such as inadequate sleep can raise blood pressure and increase early death due to heart attacks, decreased attention and increased reaction time leading to more car accidents, and the like. So it rather does look like this a concept invented by Modocc. Even if valid, it would be very hard to measure as the amount of sleep you require depends on many factors. For instance, if your days are spend doing heavy physical labour, you will need more sleep, and you will sleep better. If your days are spent in learning new things requiring significant intellectual effort, you will need more sleep. Most people whose jobs involve heavy physical labour don't actually live that long. Those that are continually involved in intellectual stress, such as university professors involved in leading edge research tend to live longer than average. Another factor: My mother bred cocker spaniel dogs. I have owned an Australian Cattle dog. They sleep all day if you let them. Both are the same size. Cocker spaniels have a reasonable amount of energy, but spend a lot of time sleeping. Cattle dogs are a lot more active and sleep a lot less - about the same as humans. Both breeds, when used as domestic pets, live about the same - 14 to 16 years. Clearly other factors overide the duration of sleep when it comes to lifespan. Sloths spend about 18 hours a day asleep, and even when they are awake are very inactive. They live a maximum of 50 years in captivity if well looked after, compared with 50 to 90 years for similar sized and vastly more active apes. Wickwack 124.178.175.45 (talk) 02:40, 29 May 2013 (UTC)

Forgive me, but I only read part of the largely irrelevant wall-of-text... The machines that I mentioned are simply an analogy and a demonstration that the semantics of the term longevity is broad and I am sorry guys if my initial explanation was not entirely clear on that particular point. Sleep labs actually do measure accumulative sleep debt and wakefulness and the OP simply asked about knowing the longest of other mammals' accumulative wakefulness (the longest total accumulative time a mammal is awake and not asleep, an empirical quantity), thus I obliged in order to incrementally increase the state of our collective knowledge (although the actual time a whale is aware does depend greatly on where it exists during its tail-wagging short life). That said, I revised my answer. -Modocc (talk) 03:06, 29 May 2013 (UTC)

"List of long-living organisms" may be of interest.—Wavelength (talk) 22:02, 28 May 2013 (UTC)

Best Hook Orientation

I recently got into a very intense debate over which is the best hook orientation to use when hanging a part. Here are the two different methods. I would like to know which one is the best way, but more importantly how to tell which one is the best way? (NOTE: We are only disagreeing about the lower hook in the pictures)

Method A (Wrong Method) http://i40.tinypic.com/2qu6azd.jpg

Method B (Correct Method) http://i42.tinypic.com/2u4pun7.jpg

192.43.65.245 (talk) 21:53, 28 May 2013 (UTC)

The "wrong" is not ideal on either hook, the "correct" has better force distribution on both hooks. As for how you can tell: you can spend a lot of time learning about statics and structural loads. Alternatively, you can probably see intuitively that the "wrong" picture has more force acting to "unhook" the hooks, that is, to straighten them out. Another rubric: a hook like that should not have any appreciable angle to its chain while loaded. Compare all the angles between hooks and chains, and you will see that the "correct" picture has angles closer to 180. You want the force directed mainly to the chain, and only slightly into the hook. I should also note that this reasoning assumes that it requires less force to bend the hook than it would to break the chain. If you buy this sort of thing at a hardware store, it should list the safe working load, and sometime will have a picture showing how the hook is loaded to get that number. SemanticMantis (talk) 22:09, 28 May 2013 (UTC)

For the purposes of this question, please ignore the angle between the hook and the chain. They should be straight, but the model does not show this. The discussion we are having is over the direction the hook is facing. 204.54.36.245 (talk) 22:17, 28 May 2013 (UTC)

For that kind of setup (small holes in plates), the way the hook faces absolutely affects the angle with the chain. Even disregarding that aspect, I think the "correct" picture is better, but I'm also interested to hear what others have to say. SemanticMantis (talk) 22:37, 28 May 2013 (UTC)

Well, my comment is that if you look at the chains (not those in the diagram but real lifting tackle), you will see that they are designed to have the hooks facing out from the center of gravity. This helps to avoid the load being taken on the bill of the hook. The load ought to be taken on the saddle – which is the strongest part of the hook. Finally, if the hooks face the load, then, if and when, the load touches down and the chains go slack – the ruddy hooks can fall out! Same goes for attaching them properly in the first place when the chains are still slack.--Aspro (talk) 23:24, 28 May 2013 (UTC)

Absolutely! If you are operating the crane by yourself or with a dogger, neither of you should have to hold the hooks in place while the load is taken up, it's a sure-fire way to get a finger pinched or worse. 122.108.189.192 (talk) 05:01, 29 May 2013 (UTC)

May 29

A superacid under extreme conditions

In theory, is it possible to create the superacid cyclotrihydrogen(1+) tetrahydridoborate by pressurising a mixture of dihydrogen and borane in stoichiometrically amounts? If so, how much pressure could be adequate? (MPa/GPa?) Plasmic Physics (talk) 00:35, 29 May 2013 (UTC)

Berylium inhalation when needle-scaling.

I am trying to find references to recent reports that the cause of a number of cases of lung cancer has been traced back to operators of needle-scalers inhaling beryllium dust from the break-down of the beryllium-hardened needles. Can someone give me some advice on how to find that information please? Thanks in advance. 122.108.189.192 (talk) 04:56, 29 May 2013 (UTC)

Try a search like http://www.ncbi.nlm.nih.gov/pubmed/?term=beryllium%20cancer to get general information on beryllium and cancer. I don't know if you can find a source that directly evaluates needle scaling (honestly I have no idea what that is, so I may have missed the papers) - you'll probably need to divide the problem into a question of how much exposure the workers get and how much that exposure contributes to cancer. From the references it looks like even the idea that it causes cancer is still not well settled. You might want to follow up with more specific questions here. Wnt (talk) 06:10, 29 May 2013 (UTC)

Perfect answer. Thanks a lot Wnt. 122.108.189.192 (talk) 06:32, 29 May 2013 (UTC)

How can I measure the weight of a plant without unrooting it, or cutting it into pieces?

Any ideas?--朝鲜的轮子 (talk) 05:40, 29 May 2013 (UTC)

solar wind

any research report or reference is needed about mathematics formula of solar wind direction and movement path curve : 1) inside planetary disk 2)at outer part --78.38.28.3 A. mohammadzade (talk) 06:15, 29 May 2013 (UTC)

Are you asking us to do your homework again, Mr Mohammadzade? Tell us what you have done to resolve this yourself, then we may assist if you are stuck. Have you looked at our Solar Winds article? Chased up the references listed and seen where they lead? Tried googling "solar wind model" and such like? The Good Lord helps those who help themselves. Wickwack 124.182.169.60 (talk) 07:21, 29 May 2013 (UTC) excuse me not home work.

   The kappa of  solar wind  path  curvature is :

κ=|dT/ds|

R(t)=(ri(t), rj(t), rk(t))

the velocity is tangent to curve :

V(t)=(rʹi(t), rʹj(t), rʹk(t))

Then T will be:

T=V(t)/|V(t)|

The normal vector is :

N=Tʹ/|T|

B=TxN

Taw formula :

Ʈ=-(dB/ds).N

And we will use velocity vector for finding ds  :

dT/ds=(dT/dt). 1/(ds/dt)=Tʹ.(1/|V(t)|)

and dB/ds=dB/dt .dt/ds=dB/dt .(1/|V(t)|)

A. mohammadzade--78.38.28.3 (talk) 08:03, 29 May 2013 (UTC)

for finding movement path curve ,for example inside supposed plate we need its equation,

Ax2+Bxy +Cy2+Dx+Ey+F=0

Θ=1/2arc tan (C/B-A)

rotated coordinates is 

│■(x@y) │=│■(cos Θ&-sin Θ@sin Θ& cos Θ)││■(xʹ@yʹ)│

A. mohammadzade--78.38.28.3 (talk) 08:06, 29 May 2013 (UTC)

Physical attractiveness of men

I need to know what features women look in an ideal physically attractive man:

1. Eye size: 24 mm or more or less?
2. eyebrow size?
3. chest size?
4. skin color and skin texture? --Yoglti (talk) 08:14, 29 May 2013 (UTC)