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January 29

Challenger Deep vs. mantle and magma

If you traveled through the Earth's crust horizontally (keeping with the curvature of the Earth) from the bottom of Challenger Deep, would you remain within the oceanic crust, or would you eventually hit magma (outside of a mid-ocean ridge or other volcanic event) or even the mantle layer? — Preceding unsigned comment added by 67.42.179.140 (talk) 09:47, 29 January 2016 (UTC)[reply]

Take a look at this cross section, you will see that you don't have to go very far away from the trench at 10.9 km depth to get below the oceanic crust and into the mantle. Further to the west and you would be into the asthenosphere in the back-arc basin, which is not 'magma' just hot enough mantle that it flows. At the spreading centre in the back arc-basin there will be a series of magma chambers that you would almost certainly run into. Mikenorton (talk) 10:18, 29 January 2016 (UTC)[reply]

Thank you sincerely! 67.42.179.140 (talk) 23:38, 29 January 2016 (UTC)[reply]

Dateline as applied to historical dates

I have frequently wondered about historical dates and if they were in USA time and date or, if occurring West of the International Date Line. Example: We are told a time (presumably local) and a date for the bombing of Hiroshima, Japan: August 6, 1945. But being far West of the date-line it was a day later in Japan. So if the bombing occurred on August 6 US date, then Hiroshima was bombed the morning of August 7, 1945. So many events in the pacific do not correct for this obvious modifier of date an time. Why not and did Hiroshima get leveled on Aug 7, in actuality? - When it was still August 6 hereSteveSmS 10:30, 29 January 2016 (UTC) — Preceding unsigned comment added by Smshepard51 (talk • contribs)

It depends on the circumstances, but for most events which are tied to a single country, local time is used (international events sometimes use UTC). The Hiroshima bombing happened on August 6th 8:15 AM Japan time, which would have been August 5th for most of the United States (except Hawaii) - the official transcript of Truman's announcement of the bombing says "On August 6, while returning from the Potsdam Conference aboard the U.S.S. Augusta, the President was handed a message from Secretary Stimson informing him that the bomb had been dropped at 7:15 p.m. on August 5.", which would be Eastern Time. Smurrayinchester 13:01, 29 January 2016 (UTC)[reply]

(A weirder example of this practice: Western media talks about Russia's October Revolution, even though according to Western calendars, it happened in November - at that time, Russia's Julian calendar was about two weeks behind the more widely used Gregorian calendar). Smurrayinchester 13:06, 29 January 2016 (UTC)[reply]

Also in World War I, the Armistice took effect at 11 am French and British time, but in Canada it's commemorated in Remembrance Day ceremonies at 11 am local time. It wasn't even 11 am in Germany: the Western Front was effectively a time zone boundary, and it was noon on the other side. Since I learned this, I've liked to imagine German soldiers taking prisoners and telling them to "drop your weapons and set your watches ahead 1 hour!" --76.69.45.64 (talk) 15:16, 29 January 2016 (UTC)[reply]

And, of course, the French Revolutionary calendar, which decimalized the months, was used to mark key events during the Revolution. Pro-monarchy revisionist historians have back-filled our textbooks with historically-equivalent Gregorian calendar dates, so we know (for example) when Robespierre was guillotined. As any staunch Republican can tell you, 18 Brumaire was the day that freedom ended, or began, or something. It's very difficult for me to keep dates and Republican-ideologies straight.

Equally problematic are those historical events that took place in space: for example, during the Apollo 11 mission, humans first set foot upon the moon either July 20 or July 21, depending on your time zone. The mission used Houston time for many flight purposes, so we often commemorate July 20. On the moon, both July 20 and July 21 occur on the same lunar day - in fact, half of the month of July is the same lunar day - but regrettably, few humans use the lunar day as the defining astronomical event for their calendar. Some great distant time in the future, when errors of a few thousand hours accumulate, I suspect the unix epoch will be defined to begin at the exact instant humans first walked on the moon, with error of just a few thousand hours or so.

Nimur (talk) 16:32, 29 January 2016 (UTC)[reply]

And, of course, the French had the Thermidorian Reaction, which like the October Revolution, only makes sense on the local calendar. The rest of us would have called it the July Revolution or July Reaction, but historiographically speaking, there's another coup d'etat in July, and we call that the July Revolution. --Jayron 32 17:13, 29 January 2016 (UTC)[reply]

Not to be confused with the Thermite reaction. --ColinFine (talk) 22:31, 31 January 2016 (UTC) [reply]

Not to be confused with the termite reaction. StuRat (talk) 08:19, 1 February 2016 (UTC) [reply]

Gas giants and fast winds

When I watch astronomy documentaries that feature gas giants, I always hear about the extreme wind speeds and how devastating it would be on Earth. To me, this does not seem to be a fair comparison - wind speed is a relative quantity. Doesn't the danger just depend on how rapidly you navigate between different air currents? Could you comfortably fly at minimum true airspeed in a non-turbulent, 800km per hour air current on Jupiter? Plasmic Physics (talk) 10:30, 29 January 2016 (UTC)[reply]

Well yes, the devastation is only happening on Earth because we have 1. a ground that is not moving in sync with the winds and 2. things that are fixed to the ground. if you don't have that, there is nothing to "devastate".--74.101.111.23 (talk) 14:46, 29 January 2016 (UTC)[reply]

Right, and if Jupiter had a surface like Earth, that would slow the winds down dramatically. Similarly, on Earth, you tend to get much higher winds aloft, where there is no friction with the ground. Assuming your spaceship moved with the wind, the only devastation caused by it would be when you hit an eddy between two different bands (or spots), with winds moving in opposite directions. Then you would be in for some major turbulence. I wonder if we could make a ship that could survive that. StuRat (talk) 18:08, 29 January 2016 (UTC)[reply]

Jupiter's atmosphere is not "air" as we know it. If the pressure did not kill you immediately, you would suffocate trying to breathe the 89% hydrogen plus 10% helium mixture and there is no way that the reported crystals of frozen ammonia hitting at 800 km/h could be good for your flying machine. It is fair comparison to report that only the severest cyclone gusts recorded on Earth ever exceed 300-400 km/h, making comfortable flying impossible. AllBestFaith (talk) 16:34, 29 January 2016 (UTC)[reply]

I doubt anyone would consider an open cockpit design! Something like a bathyscape with robust cooling mechanisms might be feasible, which would have to enter the Jovian atmosphere in such a way as to match the atmospheric motions initially encountered as closely as possible. An existing terrestrial (if you know what I mean) submarine design, however, has been shown by Randall Monroe in his What if? blog to be inappropriate, as it would merely sink, melt and then be crushed. {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 19:10, 29 January 2016 (UTC)[reply]

The OP did make it clear that the craft is travelling in a non-turbulent flow along with the atmosphere around it. In that case being "struck" by crystals of ammonia and so forth is irrelevant, since they will be moving along with the craft in the same speed and direction. μηδείς (talk) 04:13, 30 January 2016 (UTC)[reply]

Then what about the Great Red Spot - would it be equally mild conditions, bar a continually changing direction? That would be an interesting situation, to be enveloped by the greatest extraterrestrial anticyclonic storm in the solar system, and not even realize it. Similar to ascending the very gentle of slopes Mons Olympus. Plasmic Physics (talk) 11:46, 30 January 2016 (UTC)[reply]

The Great Red Spot takes about 6 Earth days to rotate, so the "continually changing direction" would be too slow to notice. So, as long as you could find an area with laminar flow, and stay there, probably requiring station keeping, then it should be peaceful, indeed. StuRat (talk) 08:16, 1 February 2016 (UTC)[reply]

I've had my suspicions, but having had all of this confirmed is mind-blowing really. I'm starting to think of gas giants as having airscapes that must be navigated in the same way as rocky planets have landscapes. Very curious! Plasmic Physics (talk) 12:17, 1 February 2016 (UTC)[reply]

Jupiters wind speed is not uniform. There are shearing boundaries. The sun also has latitude dependent rotation rates. A solar "day" at the equator is shorter than mid latitude and this shearing is what gives rise to Joy's Law (astronomy) of sunspot angle. --DHeyward (talk) 17:57, 30 January 2016 (UTC)[reply]

That redlink is giving me no joy. StuRat (talk) 08:09, 1 February 2016 (UTC) [reply]

Stupid Wikipedia capitals and bad disambig --DHeyward (talk) 01:06, 2 February 2016 (UTC) [reply]

How do I generate radio waves?

The wording looks ambiguous. I do not mean to say how do I use my body to generate radio waves. I mean to say how do I make an apparatus that generates radio waves? 140.254.70.165 (talk) 12:48, 29 January 2016 (UTC)[reply]

Your body is always radiating radio waves, as a result of black body radiation. Radio transmitter is the human made apparatus. Graeme Bartlett (talk) 13:04, 29 January 2016 (UTC)[reply]

A search on phrases such as build your own radio transmitter will yield instructions for projects ranging from Build a very simple AM radio transmitter (which includes some discussion of theory) to much more complicated ones. -- ToE 14:20, 29 January 2016 (UTC)[reply]

It's entirely easy to generate radio waves - almost everything involving electricity does so as a by-product of whatever they are supposed to do. The trick is to produce the rather exacting kinds of radio waves that are useful for some particular purpose - such as transmitting music to people's car stereos or TV signals to their homes - using them to measure the distance and position of an airplane in flight - or the speed of a car suspected of driving too fast - transmitting them from a bunch of satellites to help people know which streets they are driving along...you name it!

So to provide you with a useful answer, it would help if you could narrow down the purpose of doing this.

SteveBaker (talk) 15:41, 29 January 2016 (UTC)[reply]

To get deeper into the technology we have Radio transmitter design and the Wikibooks Electronics chapter on Transmitter design. The essential physics is that of launching an electromagnetic wave that comprises oscillating electric and magnetic fields. Heinrich Hertz first conclusively proved that these two fields can sustain each other in the form of a radio wave that can travel through a vacuum. Mathematically speaking, a propagating radio wave is a solution to James Clerk Maxwell's set of partial differential equations, his monumental achievement being this Classical field theory that unifies the phenomena of light, radiant heat and radio waves. The article Dipole antenna is invaluable to understanding how to launch a radio wave properly. Less properly, we are surrounded by apparatus that generates radio waves unintentionally: anything that makes an electric spark including arc welders, car ignition circuits and commutated electric motors emits untuned radio interference called "EMI" or "RFI". Virtually every modern radio receiver is also a weak radio transmitter due its local oscillator radiation. Today you may read about but not operate a Spark-gap transmitter. AllBestFaith (talk) 16:03, 29 January 2016 (UTC)[reply]

In addition to modern electronic transmitters,.other means have been used to create radio waves. These may not correspond to present communications regulations. Radio waves have been generated and used for commercial purposes in the distant past with electromechanical induction coil (spark) transmitters (Marconi and others), with high speed alternators (E.F.W Alexanderson) and with electric arcs (Poulson). An electromechanical doorbell buzzer generates radio waves. Many electrical devices such as light switches, aquarium heaters, and electric blankets generate unintended radio waves when they turn on and off, and the radio waves are capable of causing objectionable radio interference several houses away. Edison (talk) 18:48, 29 January 2016 (UTC)[reply]

Whatch it! You need a licence to operate a transmitter, and the transmitter must comply with govt mandated technical standards. Goverments operate monitoring stations that may pick you up. In some contries there may be haevy fines or jail. 58.167.247.93 (talk) 23:39, 29 January 2016 (UTC)[reply]

In the U.S., at least, you don't need a license to operate a very low-power, home-built transmitter. Most likely the transmitter described in ToE's link would qualify. Detailed regulations are here. You can also operate certain low-powered commercially available devices such as a walkie-talkie on Family Radio Service frequencies without having a license. Shock Brigade Harvester Boris (talk) 01:46, 30 January 2016 (UTC)[reply]

Some of the advice above is given in good faith by textbook readers who have never built a transmitter and wouldn't know how. I suggest that the OP contact a radio amateur or join his local amateur radio society, which may be the ARRL, and which exist in almost every country. There are important considerations of the law, your entitlement to transmit, and safety involved. Akld guy (talk) 23:52, 29 January 2016 (UTC)[reply]

Briefly short circuit a nine-volt battery with a length of wire. You've just made a radio transmitter. You can pick up the sound of the radio frequency waves generated by the sparks on any AM radio tuned to any station you'd like. --Jayron 32 04:05, 30 January 2016 (UTC)[reply]

Or purchase an automobile made, say, before 1970. This is when coil, points and condenser ignition systems were used, and these generated quite a bit of radio noise (which had to be filtered out of radio receivers made for automobiles, not always with success). The US Air Force was able to find and bomb or strafe convoys of North Vietnamese Army supply trucks on the Ho Chi Minh Trail by using special radio receivers tuned to the frequency of the radio noise made by coil ignition systems in Russian-designed transport trucks. loupgarous (talk) 19:50, 1 February 2016 (UTC)[reply]

Family authoritarianism

A person who exhibits a tendency towards obedience in the realm of politics is called an authoritarian. What is the equivalent term for someone who exhibits such a predisposition towards members of their family within the context of psychology? I prefer a medical or psychiatric term. The closest I could come up with is eleutherophobe. 92.10.224.67 (talk) 12:57, 29 January 2016 (UTC)[reply]

In studies of social animals one finds the alpha male. A disparaging term for humans is the pseudo-psychological Control freak. AllBestFaith (talk) 16:15, 29 January 2016 (UTC)[reply]

Note: the term "alpha male" is deprecated in many, if not most scientific contexts. Our article needs serious improvement and updating. Last time the term came up, I explained some of my reasoning and gave several references, anyone interested can check it out here [1]. SemanticMantis (talk) 16:36, 29 January 2016 (UTC)[reply]

The word "disciplinarian" is often used (although a lot of psychologists do in fact use "authoritarian", according to our page Parenting styles). Psychologists often talk about the "strict father model" of upbringing. Smurrayinchester 16:26, 29 January 2016 (UTC)[reply]

The problem is that you can't go to the doctor and seek a diagnosis/ask about symptoms for being disciplinarian. Hence I tried to stress the medical scope of this predisposition for individuals who are particularly acute. Its also possible that such a word is non-existent. Dunno really. 92.10.224.67 (talk) 17:10, 29 January 2016 (UTC)[reply]

Narcissistic_personality_disorder may be relevant. Of course this is not a term that means someone who expects obedience out of family members, but some people with this disorder do indeed expect obedience from family members. SemanticMantis (talk) 20:54, 29 January 2016 (UTC)[reply]

Depending on the expectations and age of the OP, perhaps the term parenting is enough to qualify for the proper terminology. --Jayron 32 04:04, 30 January 2016 (UTC)[reply]

January 30

Sewing machine oil

What is it made from and what properties does it have for suitability in sewing machines?--213.205.192.13 (talk) 00:48, 30 January 2016 (UTC)[reply]

One special consideration is that it shouldn't stain, in case it gets on the fabric. A highly volatile oil that will dissipate on it's own would also be better than one which would require detergent to remove, as some fabrics, like felt, might be too fragile for that. Also, it shouldn't stink, so petroleum-based oils might not be the best choice. All of this would mean it would need to be applied frequently, though. StuRat (talk) 00:59, 30 January 2016 (UTC)[reply]

See here. --Jayron 32 04:00, 30 January 2016 (UTC)[reply]

The odds against us being here

Some lifeform billions of years ago had eggs. Most of the eggs died. We are the decendant of the egg that survived, right?

So, is there any way to guess at the odds against that lifeform's DNA surviving to this day? Or the other way around, is there any way to take a ballpark guess at the odds against a person making it this far? Anna Frodesiak (talk) 01:27, 30 January 2016 (UTC)[reply]

Did you ask pretty much the same question sometime in the last year? If so, wherever it's archived might contain some answers. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:32, 30 January 2016 (UTC)[reply]

Hi Baseball Bugs. Did I? I don't remember asking. I do have a terrible memory. I am very sorry if I did. Anna Frodesiak (talk) 03:06, 30 January 2016 (UTC)[reply]

My memory is no better. :) I recall a question like it, but I don't recall the author. ←Baseball Bugs ^{What's up, Doc?} carrots→ 09:07, 30 January 2016 (UTC)[reply]

The earliest lifeforms didn't lay eggs. As for the odds of a fragment of DNA surviving lots of generations unchanged, that depends on the importance of that fragment. If it was absolutely critical to survival, then only organisms with it would survive, and would therefore pass it down. On the other hand, if the DNA fragment is of no value whatsoever, then it probably won't last long, with random mutations deleting or altering it (see genetic drift versus natural selection). StuRat (talk) 01:35, 30 January 2016 (UTC)[reply]

Hi StuRat. I don't really mean DNA, but more ancestry, as in parents' parents' parents' all the way back. Anna Frodesiak (talk) 03:56, 30 January 2016 (UTC)[reply]

DNA is the primary mechanism of inheritance of traits. However, let me try to address this "odds" question differently. Let's say you roll a fair ten-sided die 12 times, to get the numbers 3,8,1,6,3,9,0,1,4,7,2,9. The odds of you then rolling the same sequence again would be one in a trillion. However, that doesn't mean you look at the numbers you already rolled and say "Wow, there was only a one in a trillion shot of rolling that sequence and yet I did, what amazing luck !", as you could have said that about whatever sequence you happened to roll. The same is true of the random events that created you. If the dice were rolled a bit differently, and somebody else was born instead of you, they could have also looked back and said it took an amazing number of "lucky rolls" to get them. StuRat (talk) 08:33, 30 January 2016 (UTC)[reply]

The odds of a fact being the case are exactly 1, and we cannot replay the movie. That being said, replaying the movie from the beginning is the theme of Stephen J. Gould's Wonderful Life. He interestingly pointed out the fact that if the dog had not been caught, one single Labrador retriever would likely have driven the Kiwi extinct. μηδείς (talk) 04:09, 30 January 2016 (UTC)[reply]

Thank you, μηδείς. I will try to get that book. I am sorry I keep asking questions that are so hard to answer. I think the problem is that I don't quite know how to ask them properly. Best, Anna Frodesiak (talk) 04:22, 30 January 2016 (UTC)[reply]

What!?!? Never. As the official bête noire of the RD, I can certify that you have never asked an offending question. (I do still find it hard to believe you are not related to the Frodesiaks of Passyunk Avenue. But that's a side issue.) μηδείς (talk) 04:57, 30 January 2016 (UTC)[reply]

Not being able to "replay the movie" is, of course, a variant of the anthropic principle in the sense that the universe which produced the current state it is in is the only possible universe which could exist to produce the current state it is in. Historically, this was also part of the conjectures of Gottfried Leibniz and "Pangloss" in Candide, see Best of all possible worlds; the notion that we must live in the only way history could have turned out, and it couldn't have possibly been better or different. --Jayron 32 05:03, 30 January 2016 (UTC)[reply]

I don't quite agree with your interpretation, Jayron32, but I do agree that anyone interested in the topic should be familiar with the items to which you have linked. The bottom line is that any such "replaying" would be imaginary. Physically, there is no way to do it, Doctor Who and The City on the Edge of Forever unwithstanding. μηδείς (talk) 06:09, 30 January 2016 (UTC)[reply]

If one wants to take it to a physics, rather than a metaphysics, issue, concepts such as the arrow of time, causality, entropy, the Second law of thermodynamics, and Minkowski space all require the fundamental concept of "we can't ever change the past so the present is the only possible present we could ever have." Of course, there are some interpretations of quantum mechanics which break principles of causality, and all principles of modern physics fly in the face of the clockwork universe such that all behavior at the fundamental particle level is stochastic and thus entirely unpredictable. So, if you want the physics answer, depending on your perspective, the odds are either "exactly 1 in 1" (that is purely deterministic) or "exactly 1 in infinity" (or never repeatable and thus purely unique). Interestingly, the answer is likely only one or the other (always or never) rather than any odds in between those two. Or in simpler terms, to paraphrase Murray Gell-Mann (among others, probably) "That which is not forbidden is mandatory". --Jayron 32 06:39, 30 January 2016 (UTC)[reply]

Thank you so much, μηδείς. I do not mean to be a nuissance here. I promise to get better at phrasing the question. Perhaps this is better:

If a mother had two kids and only one survived, then couldn't the kid say "I had a 50% chance of being the one who did not make it"?

And I'm not asking just for fun. I really want to know. At dinner last night, people were saying it is important to have kids to keep the genetic line going. Someone said that a person's mom and her mom etc. beat the odds time and time again, especially when that mom was a squirrel way back when (bigger litters). Our parents are always the ones who made it. Anna Frodesiak (talk) 06:29, 30 January 2016 (UTC)[reply]

Or, the kid could say "I had a 100% chance of survival, because I didn't get hit by the car that killed my sibling" (or disease, or whatever). Stats are merely personal perspective under the illusion of mathematical indeterminacy. See Lies, damned lies, and statistics. --Jayron 32 06:41, 30 January 2016 (UTC)[reply]

It would be 50% chance only if it was a prerequisite that one brother would die before reproducing. Just because one died out of 2 doesn't make it 50% chance. This is more of a maths question than a science question. Think of a pack of cards and draw one. You have a 100% chance of picking a card, 25% chance it is a diamond and a 2% chance it's an ace of diamonds. So from point of view of the end result it's 2% but all cards where 2%, so it not that surprising a card was drawn. So each individual being alive now has an almost vanishing probability of being here (think how many sperm does man produce in his lifetime). If you add all the probabilities up they are 1, so your answer depends on your view point. So at the start of life, you being you is extremely unlikely, but it's extremely likely something will be there (planet wide extinction excepted). As for the other way around this maybe workout able. How likely was it that Y-chromosomal Adam would be Y-chromosomal Adam, and not one of the other humans alive at the time, I don't know but maybe answerable. Dja1979 (talk) 06:56, 30 January 2016 (UTC)[reply]

You have a 50% chance of picking one of either of two cards before you pick them. You have a 100% chance of having already picked the card you already picked because it is in your hand right now and the other isn't. Stats are only useful in deciding the likelihood of future events. Events which have happened cannot be undone, and thus have already occurred to a known certainty. Schrodinger's cat is genuinely alive or genuinely dead even if you don't look, regardless of whatever the chance was that the particle would have decayed before it did. --Jayron 32 07:06, 30 January 2016 (UTC)[reply]

Or as Richard Feynman put it: "You know, the most amazing thing happened to me tonight. I was coming here, on the way to the lecture, and I came in through the parking lot. And you won't believe what happened. I saw a car with the license plate ARW 357. Can you imagine? Of all the millions of license plates in the state, what was the chance that I would see that particular one tonight? Amazing!" --71.119.131.184 (talk) 08:32, 30 January 2016 (UTC)[reply]

One thing to consider is the smaller scale of events. I've heard that about 1 out of every 4 pregnancies results in a miscarriage. I don't if that's true, but let's suppose it is. That means at the momenr you were conceived, you had about a 75% chance of not being miscarried. Any sort of mishap would have its own probabilities, but let's say you go your nine months and are successfully born. So far so good. Now consider other statistical probabilities. There's a 100 percent probability that you're going to die eventually, but there will be stats on what you're more or less likely to die from and at what age. ←Baseball Bugs ^{What's up, Doc?} carrots→ 09:24, 30 January 2016 (UTC)[reply]

It will depend on whether a miscarriage is defined as applying to all fertilised eggs or only those that have implanted in the womb, but this quote from a current BBC news article is relevant:

"Out of every 100 fertilised eggs, fewer than 50 reach the early blastocyst stage, 25 implant into the womb and only 13 develop beyond three months.

Thus a fertilised egg has only a 17% chance (not 75%) of resulting in a live birth, but of the non-surviving 83% only 52% (13 in 25) of those implanted or 13% overall would be classically termed a miscarriage. {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 16:27, 1 February 2016 (UTC)[reply]

Hmmmm...

All of the arguments about the probability of me being here being 1.0 are rather facetious. If I win the lottery - that doesn't change how improbable that event was at the time when the random number was generated. So we can ask: "at the time the first egg was produced what was the probability of that egg producing a being that would fall within the parameters of a recognizable human being on or before the year 2016?" - that's a perfectly valid question that statistics should be able to answer if the data were available about the various probabilities along the way.

So, that dealt with - can we say anything meaningful at all about the odds?

My feeling is that we don't have remotely enough information. The path taken by evolution is simultaneously driven by pure chance (due to quantum randomness and chaos theory randomness) - and also shaped by the nature of the environment. That's why we have such different organisms occupying the exact same ecological niche in different parts of the world. Since the overall inputs to the problem (the chemical and geological makeup of our planet - inputs from the sun, the moon, comets and meteors) could be considered largely constant - the random nature of the weather and genetic mutation and sexual reproduction is likely to be the main source of subsequent randomness. But the amount of that randomness is really hard to estimate.

The odds have to come out to be a truly astronomically low chance though. The probability of a being exactly like us being here is insanely small. When the crew of the USS Enterprise arrive at a planet with beings just exactly like us, and behaving just like 1920's Chicago - and it's put down to "Parallel Evolution"...um...No. Just no! It comes about because the show had a low budget and the sets and costumes were available for cheap!

But the odds of there being some kind of intelligent being are likely to be much higher - it's interesting to wonder whether life inevitably turns up intelligence eventually - or whether it's also astronomically unlikely. In that case, we can point to the fact that creatures like the octopus are pretty smart - and they developed that intelligence entirely independently of mammals - so it seems that being intelligent is something that does emerge fairly easily from the randomness. But whether it was inevitable that we'd have (for example) ten fingers seems much, much less likely.

So whether that first egg would ultimately result in exactly a human being seems insanely unlikely. But whether it would produce some kind of intelligent race of creatures seems very much higher...perhaps even close to a certainty if life continues to thrive for long enough and the environment is sufficiently complex to cause intelligence to be a useful adaptation.

SteveBaker (talk) 16:28, 30 January 2016 (UTC)[reply]

More formally stated, the conditional probability that an event occurs, given that we have already observed the event, is a mathematically distinct concept from the probability of the event before it was observed. Nearly all scientists would agree that the conditional probability that an event occurs, given that we have already observed the event is ~~almost certainly~~ exactly one. This is almost a convoluted definition of causality.

Only a few very esoteric postmodern philosophers would disagree with the statement that an event we have observed actually did occur. For an example of such mind-bending logic, consider reading the writings of Jorge Borges, whose fiction put forward the catastrophically wonderful idea that factual object-reality only exists consequent to the creation of an encyclopedia defining those facts, and the brains that think they are reading that encyclopedia who all agree to hron object reality back into existence, at the expense of causality, not to mention the hroning of meaningful language. Maybe extra-terrestrials, too? Nobody is certain. But Borges' work is not really science - it is fictions, I hope. Nimur (talk) 16:56, 30 January 2016 (UTC)[reply]

We don't have enough data to work from to make even a ballpark guess, Anna. It seems likely that some primordial DNA is contained in what we call Junk DNA, the sequences of DNA which aren't expressed (that we're aware, anyway) as proteins in the human body and aren't responsible for how our bodies work and look. But we don't have a way of identifying any particular unexpressed DNA sequence with that first organism you posit. And for all we know, there are things in our "working" DNA that can be traced back to the first organism. We just don't have a clue what. loupgarous (talk) 01:29, 31 January 2016 (UTC)[reply]

Very interesting indeed. I'm trying to get my head around the idea that "...Stats are only useful in deciding the likelihood of future events...". I've read everything above and think I get it. Thank you all. Sorry for the can-of worms question. Anna Frodesiak (talk) 01:39, 31 January 2016 (UTC)[reply]

I wouldn't sweat the "stats are only good for future events" thing - a trivial re-wording of your question would have fixed that - and our respondents should have realised that was your intention because anyone who understands that the probability of an event that's already happened is 1.0 would never have asked exactly what you did. So, it was reasonable to assume that you meant to ask what the future probability would have been at the time that first egg was laid. But sadly, there just isn't any way to estimate that probability - and the precise details of what is meant by "egg" and "human" would have drastic repercussions for whatever answer we could possibly give - and that would result in much more confusion! SteveBaker (talk) 16:32, 31 January 2016 (UTC)[reply]

I'd like to comment on something more fundamental, Anna Frodesiak. The question "What was the probability I would be me" can be looked at in two ways. Probability deals with potentialities in undetermined circumstances. Hence, if you asked, "Given a population of people with these genomes, what is the probability that an individual with a certain genome might randomly be born by the mating of two parents from that population?" it can be answered. It is a mere question of possible assortments.

But, if you get to the point of an actual existing being asking, "What is the chance that I am me?" or, even better, "Why was I born a middle-class child of Jews and Catholics in NY, instead of being the future British monarch?" then you are reduced to the banal, "What is the chance that any given person is the future King of England" (At this point, about 6/15 billion.) Or the tautological, "Why (what is the chance that) was I born me?"

The question, "Why am I me,?" is the equivalent to, "Why am I my body?" That question, "Why am I my body?" depends on the implicit assumption of Cartesian Dualism, the notion that we are "Ghosts in a Shell" and that our souls could have been born in different bodies. I don't know your belief system, but if you are not a believer in the supernatural, "Why is my soul in my body?" is an incoherent question that is raised only because our Western culture is thoroughly dualist in all its major assumptions. (Even materialists tacitly accept this in the notion that the self is an illusion, because they accept that there is a dichotomy between the physical and the spiritual.)

I was actually asked by someone, "How come I was born a white American, not a little girl in China?" I told her that she actually was a little girl in China, but that her soul had gotten switched. She said, "That makes no sense!" to which I responded, "No, it doesn't, does it?"

μηδείς (talk) 20:16, 1 February 2016 (UTC)[reply]

These kinds of questions are taken seriously by philosophers of Bayesian probability. For example, the doomsday argument argues that the chances of being born roughly in the middle of all humans ever born is most probable, and so one can extrapolate from the number of humans ever born the number of humans ever to be born. (I do not count myself a believer in this particular argument, however.) The anthropic principle is also relevant. Sławomir
Biały 23:51, 1 February 2016 (UTC)[reply]

Bayesian analysis seems to me to partake of voodoo, sometimes. The most successful applications of it I'm aware of was when the US Navy's maverick oceanographer John P. Craven had fellow specialists look at all the data surrounding the loss of a submerged object in deep water, and make bets (bottles of liquor were most often at stake) on where the object was. Craven's odd application of Bayesian analysis worked well enough to find a hydrogen bomb lost in deep water after the Palomares incident in 1966, then the USS Scorpion despite conventional analysis of the available evidence pointing away from the spot he and his specialists predicted - which is where the doomed ship was eventually found. loupgarous (talk) 01:58, 2 February 2016 (UTC)[reply]

Is electricity made up of electromagnetic or mechanical waves?

I know the difference between electromagnetic and mechanical waves (see [2], [3]); so since sound is a mechanical wave, and AC power can be heard, that would seem to indicate that electricity is a mechanical wave as well. But I thought that it was electromagnetic. Which is it? Eman235/talk 01:58, 30 January 2016 (UTC)[reply]

It's not a mechanical wave, and the sound isn't directly from the waves. Read your link to see the explanation (for an analogy, light could also create sound, if it warms something up that then expands or contracts) . Also note the dual wave/particle model of electricity (as well as light, etc.). The electron is the particle representation of a quanta of electricity. StuRat (talk) 02:04, 30 January 2016 (UTC)[reply]

Oh, I see. Electricity, under some circumstances, can cause a mechanical wave, but it isn't one itself. I'm assuming that AC is electromagnetic waves; but what is DC? Eman235/talk 02:34, 30 January 2016 (UTC)[reply]

See Direct current--213.205.192.13 (talk) 03:52, 30 January 2016 (UTC)[reply]

(edit conflict) AC is not electromagnetic waves, AC can cause electromagnetic waves in the radio frequency. Read Larmor formula for some background for the mathematics. "When any charged particle (such as an electron, a proton, or an ion) accelerates, it radiates away energy in the form of electromagnetic waves." Alternating current consists of electrons vibrating back and forth in place; to change direction the constantly accelerate and decelerate, thus generating a regular radio frequency wave; this is the source of what is called mains hum, which is what happens when this radio frequency wave is picked up by audio equipment. DC doesn't cause waves, but it does generate an electromagnetic field, see Ampère's circuital law, or Faraday's law of induction which is just the inverse of that. --Jayron 32 03:55, 30 January 2016 (UTC)[reply]

Hmmm Jayron, I would have said that dc in a stationary conductor can only create a magnetic field (not an electromagnetic field. But maybe you are now going to provre me wrong! :)--213.205.192.13 (talk) 04:06, 30 January 2016 (UTC)[reply]

All electric fields are magnetic fields, and visa-versa. You can, of course, describe such a field using only the magnetic force, or using only the electric force, but in reality, the two forces coexist at right angles to each other. Electromagnetic_field#Dynamics discusses the historical separation of the two "fields" into distinct force fields, and the work of James Clerk Maxwell in marrying the two into a single concept, see also Maxwell's equations which describe the interrelationship between electric fields and magnetic fields into a single "electromagnetic field". The modern field of quantum electrodynamics preserves this marrying of the two forces, and applies principles of quantum theory to it. --Jayron 32 04:55, 30 January 2016 (UTC)[reply]

It's easy to get confused between two types of wave here. Electricity is a wave because electrons have this duality between being particles and being waves. So even DC electricity is a wave. Then, we may choose to vary the amount of electricity we pass down a wire - or even reverse it's flow over time - that's AC. So the waves we make when we use AC power (which oscillate at 50 or 60 times per second depending on where you live) are really just variations in the flow rate of the electricity. If you look on a smaller timescale - like if you looked at the electricity for just a millisecond - then AC and DC wouldn't look all that different.

Perhaps an analogy might help. We see waves on the ocean going by maybe once every few seconds - but we also see tides - which cause the ocean to go up and down over the course of about half a day. So imagine the electromagnetic wave to be like the ocean waves and the AC current variation being like the tide.

Another closer analogy would be AM radio - where there is the frequency of the radio broadcast (maybe around 1MHz - a million vibrations per second) - and then the frequency of the sound imposed on top of that at a few thousand vibrations per second...in that case, the electromagnetic wave is yet a third wave.

And as others have said - you can't directly hear the electricity - but they may cause some physical effect that converts them into mechanical vibrations that you can hear. You won't hear the electromagnetic wave itself - but rather the AC variation in that wave which (at 50 to 60 vibrations per second) is a soft hum at the lower end of our hearing range when converted to sound waves in the air.

SteveBaker (talk) 16:04, 30 January 2016 (UTC)[reply]

The Larmor formula has no application to DC in a stationary conductor because no electrons are being accelerated and, as 213.205.192.13 correctly says, only a stationary Magnetic field is produced. Electromagnetic radiation is launched wherever there is simultaneous production of an oscillating E and H field oriented so as to give a finite value to S = E X H where S is the Poynting vector. AC power frequency is usually 50 or 60 Hz and its distribution unintentionally causes some electromagnetic radiation, mostly at harmonic frequencies since the length of wiring to create an efficient Dipole antenna at such low fundamental frequency would be as long as 1250 to 1500 km. Mains hum treats the sound associated with mains AC and should have made clear to the OP that one does not "hear the electricity", one may only hear mechanical sound waves produced via an intermediate process such as coupling into an audio system (stray capacitance, poor grounding and/or poor supply regulation contribute) or Magnetostriction in a transformer core. Electromagnetic waves travel in a vacuum whereas mechanical waves do not. The Electron has mass and charge but is not itself a wave. A "wave nature" is ascribed to the electron by De Broglie and Schrödinger meaning that a wave equation predicts the probability of finding its actual position, but I cannot support the claim that "DC electricity is a wave". Wave function treats this subject in quantum mechanics but the OP is clearly asking about classical mechanical waves i.e. Sound. AllBestFaith (talk) 16:47, 30 January 2016 (UTC)[reply]

We need to carefully review a few terms:

electrons, the small points that carry electric charge
electric current, any movement of electrons (or any other charged item)
the electric field, a physical effect that exerts force on any charged particle
the magnetic field, a physical effect that exerts force on any moving charged particle
electromagnetic waves, a special behavior that electric- and magnetic- fields may exhibit to propagate energy as a wave

Electricity is a little bit difficult to describe, because it involves all of these concepts at the same time. Every time an electron moves, it affects an electromagnetic field. Every time an electromagnetic field exists, it affects electron motion. We have lots of names for these effects, including the Lorentz force equation, and the very important Maxwell's equations. To understand these concepts, you must know that electrons affect electromagnetic fields, and electromagnetic fields affect electrons.

This circular logic is formally described using the mathematics of a differential equation. It so happens that the equation relating electric fields, magnetic fields, and moving point-charges can be represented as a wave equation. In other words, we can have a stable wave that describes a movement of electrons, and a change in electric- and magnetic- fields. However, not every case involves a propagating wave. For example, a steady DC current moving down a long, straight wire, can be adequately described (and we can solve all the field equations) without bringing up a propagating wave. So, electric current always involves an electric- and magnetic- field, but only yields an electromagnetic wave in some conditions.

When you use electricity in every day life, the energy can be carried by both the electromagnetic wave and by the movement of electrons. The exact details depend on how you're using that energy: for example, in a low-voltage DC lightbulb, the majority of energy that heats your filament is conveyed by the movement of electrons. Electrons lose kinetic energy by bouncing around in a resistive element, heating the wire until it is hot enough to glow. We can write a simple equation - Ohm's law - to describe the energy transfer, and we don't need to consider any wave behavior at all, for this case.

In the antenna of a handheld radio transmitter, electrons move back and forth, swaying across a very short distance. Energy is carried along the wire, and out into the air, by an electric field and a magnetic field. For a well-designed radio, we can nearly ignore the kinetic energy carried by the electrons in that antenna - the resistive losses are nearly zero.

In the microprocessor inside a computer, each transistor turns "on" and "off" to signify a digital, logical bit. To turn one single transistor "on", a voltage is applied at the "gate" of a field-effect transistor. This voltage applies an electric field over the device's "channel"; and electrons can flow across the channel. Energy is carried by the electrons, which we call the "switching current"; and energy is also carried by the changes in the electric field, which we call the "digital signal." If we switch the bits between zero and one, some energy is also lost in the form of an electromagnetic wave, which we call "electromagnetic interference," because that energy lost as a wave is unwanted.

If we zoom in and solve the equations rigorously, we find that there is always some component of energy in the electron-movement and some component of energy in the electromagnetic field. In the simple cases, we can use straightforward approximations and simpler equations so our work isn't so hard. Half of the work when you study electrical engineering is learning when you may safely use simplified approximations, and when you must solve the full-form, difficult equations.

Nimur (talk) 17:32, 30 January 2016 (UTC)[reply]

I'm not satisfied by the answers so far. I'm thinking that if you have ten amps of current in a wire, that's 10 coulomb per second, or 6.242×10¹⁹ electrons per second. Electron mass is 9.10938215(45)×10^-28 g, so that's 5.686 x10^-8 g, or 56.86 nanograms of electrons per second pass through a given point in the wire. Now that doesn't seem like very much, though I'll admit, I'm not sure how to convert the fact of it being batted back and forth each 1/60 second into a number I can compare to something. But to give an example, a 20-microliter drop of water will make a sound when it hits a surface, and that weighs 20 milligrams. If you atomize water to the point where it is mere nanoliters, it will be more like a mist striking a surface and I don't think you'd hear it. So though electrons are definitely physically moving, they do so with extraordinary lightness and ease compared to the things we know, and they are extraordinarily potent in carrying charge. Wnt (talk) 23:45, 30 January 2016 (UTC)[reply]

Most of the time, "mains hum" is referring to radio noise that can couple into an amplifier or a speaker. Speakers are mechanical devices that are designed to transduce electrical signals into acoustic signals. In that case, the unwanted electromagnetic signal is added on top of the desired electromagnetic signal, and that is why you hear it. This is common because a weak signal is usually amplified before it is played on a speaker.

In the exceptional case of very high currents, passive elements (like the wires themselves) can transduce electrical current directly into acoustic noise. The transduction of electric current into acoustic noise is mainly because such very large currents can create oscillating thermal changes, and because electrostatic forces cause the material to attract and repel other objects (including other parts of the same wire). These effects can result in mechanical movement of the bulk material. Essentially, in those cases, the wires are acting as a very poor-quality speaker. You are not hearing acoustic noise due to electrons impacting anything. Most of the time, you don't actually hear anything at all, until the energy is intentionally converted to acoustic vibrations.

Nimur (talk) 00:07, 31 January 2016 (UTC)[reply]

January_2016_East_Asia_cold_wave in Thailand.

Your article for the January 2016 East Asia cold wave reads: "Temperatures in Bangkok, Thailand fell to 16 °C (61 °F), and 14 people in Thailand died from the cold.". How the hell can 16 °C (61 °F) even kill people? it is not even cold. --Bidfevnörsk (talk) 14:50, 30 January 2016 (UTC)[reply]

The deaths weren't in Bangkok, The supporting cite is the second one, http://www.bangkokpost.com/news/general/840592/cold-wave-causes-14-deaths, which says the deaths were inChainat province, and Udon Thani, and Chai Nat, and Samut Prakan, and Nakhon Ratchasima, Sakon, and most of the victims had underlying health problems. The temperatures in these areas may have been lower than in Bangkok. IIRC, many homes in Thailand don't have heating, as it very rarely gets cold. LongHairedFop (talk) 15:20, 30 January 2016 (UTC)[reply]

I think it's all about the huge change from normal. It's almost always around 30°C, so 16 - and less - is a huge shock-to-the-system. And as stated, almost nobody has heating. — Preceding unsigned comment added by 81.108.18.234 (talk) 16:17, 30 January 2016 (UTC)[reply]

Note beyond the fact most of those affected probably experienced lower temperatures, already had health problems and the absence of heating, there's also likely to be an absence of clothing or even blankets (if they have any) suitable for lower temperatures. Remember that while sure, many people may be fine wearing just a thin t-shirt or shirt and if they're lucky think long pants (or similar), not everyone will be. And beyond the shock to the system of such an abnormally low temperature, there's also the lack of experience and understanding (including from friends, relatives and neighbours to keep an eye on the vunerable). It may be a bit easier than with a heatwave, still you get similar things where temperatures in the low 30s°C can be a significant concern in some places. Nil Einne (talk) 16:42, 30 January 2016 (UTC)[reply]

Bangkok is a city at sea level. Both of these facts raise the average temperature compared with the surrounding countryside. The average January temperature is five degrees lower in Phetchabun Province (still on the plain) and even colder in the northern mountains where there is sometimes a light frost. Dbfirs 18:09, 30 January 2016 (UTC)[reply]

Did it rain ? If you are soaking wet, those temps could contribute to making you sick. And they may have leaky houses and a lack of waterproof clothes, if the high temps normally make getting wet not an issue. Wind would also be a contributing factor. StuRat (talk) 18:24, 30 January 2016 (UTC)[reply]

Volcano

What kind of volcano is mount Konocti and mount Shasta? And Dormant? Extinct? 208.91.28.66 18:44, 30 January 2016 (UTC) — Preceding unsigned comment added by 208.91.28.66 (talk)

I linkified your Q. Please read those articles for answers. StuRat (talk) 19:14, 30 January 2016 (UTC)[reply]

(ec)Mount Shasta is considered by the USGS as a "very high threat volcano" [4], so dormant not extinct. Mount Konocti has a "high threat potential" according to the USGS [5], so dormant and not extinct either. Mikenorton (talk) 19:15, 30 January 2016 (UTC)[reply]

The Volcano article should answer your general questions. The two you mention would be stratovolanoes, and the difference between dormant and extinct is somewhat a matter of opinion. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:17, 30 January 2016 (UTC)[reply]

Although some volcanoes are definitely extinct! Alansplodge (talk) 15:36, 31 January 2016 (UTC)[reply]

Having an old castle on top doesn't necessarily mean it's extinct, as some volcanoes can lay dormant for thousands of years (700K for Yellowstone !). StuRat (talk) 03:45, 1 February 2016 (UTC) [reply]

I think that more than 300 million years is probably long enough to be sure. Mikenorton (talk) 09:47, 1 February 2016 (UTC)[reply]

You beat me to it! See Castle Rock, Edinburgh for the details. Alansplodge (talk) 11:08, 1 February 2016 (UTC)[reply]

January 31

Alkanes

What is the lowest viscosity alkane available, and would it be ok as oil for a sewing machine?--213.205.192.13 (talk) 01:17, 31 January 2016 (UTC)[reply]

Presumably the literal answer is methane, and no, it won't work.

If you mean the lowest-viscosity paraffin that's a liquid at room temperature, I expect that would be one of n-pentane, isopentane, or neopentane. Our article gives the viscosity for n-pentane but not for the other two. I doubt they would work as sewing-machine oil, but then I don't really know the requirements, so I can't say for sure. --Trovatore (talk) 02:51, 31 January 2016 (UTC)[reply]

I found the value for isopentane (it's less than that for n-pentane) in PubChem and added it to the article. PubChem doesn't have the value for neopentane. DMacks (talk) 03:52, 31 January 2016 (UTC)[reply]

Found some data about neopentane, but given it is a gas at room temp, it's probably not useful for your context (and also explains why our article doesn't list it). DMacks (talk) 04:53, 31 January 2016 (UTC)[reply]

KY

Can it have a laxative effect if swallowed in quantity?--213.205.192.13 (talk) 01:34, 31 January 2016 (UTC)[reply]

What do you mean by "KY"? Our KY page lists a bunch of topics, including a bunch of non-swallowable ones such as Kentucky and the Kyrgyz language. Are you perhaps asking about K-Y Jelly? Nyttend (talk) 02:26, 31 January 2016 (UTC)[reply]

A lubricant laxative coats the stool with slippery lipids and retards colonic absorption of water so that the stool slides through the colon more easily. It also increase the weight of stool and decreases intestinal transit time. Handbook of Nonprescription Drugs by the American Pharmaceutical Association mentions mineral oil which may decrease the absorption of fat-soluble vitamins and some minerals. In case of Constipation get qualified medical advice from a doctor and/or the directions given with an approved treatment because laxative abuse can lead to potentially fatal fluid and electrolyte imbalances, see Laxative#Problems_with_use. K-Y Jelly is a brand name rather than a specific formulation and it is not approved for laxative use. To do so amounts to medical advice that Wikipedia does not give. AllBestFaith (talk) 15:48, 31 January 2016 (UTC)[reply]

Cats and dogs

What causes cats and dogs to be mutually hostile? Is it body language? pheromones? or something else? 2601:646:8E01:9089:F88D:DE34:7772:8E5B (talk) 03:52, 31 January 2016 (UTC)[reply]

Body size of cats.
Sleigh (talk) 06:12, 31 January 2016 (UTC)[reply]

One suggestion is body language. The dog waves its tail happily, while the cat whips its tail in anger. Easy to confuse the two. Star Lord - 星爵 (talk) 14:21, 31 January 2016 (UTC)[reply]

Dogs are predators whose natural behavior is to chase and try to kill anything that isn't a dog. Cats naturally recognize a dog as an animal that is dangerous to it. Socializing these species by exposing them to each other from a young age can overcome these tendencies, but they often continue to some degree. In dogs that have not been exposed to cats, and cats that have not been exposed to dogs, the natural behaviors generally manifest with full strength. Looie496 (talk) 15:43, 31 January 2016 (UTC)[reply]

I strongly agree on the body-language thing.

A friendly dog will often greet others with a 'play bow' (front end flat on the floor - back end up in the air) - but that's the posture a cat adopts when it's about to pounce.
The contented purr of a cat probably sounds like an agressive growl to a dog.
A wagging tail means "happy" to a dog and "angry" to a cat.
Cats arch their backs in order to look larger when they feel the need to be agressive - dogs arch their backs like that when they are frightened.
Cats extend their claws when there is danger around - dogs can't retract their claws - so cats may well see extended doggy claws as a perpetual danger.
Dogs are pack animals - and if introduced to a cat as a member of the family "pack", they should be OK with that. But cats are much more likely to be highly individual - and the dog's immediate desire to understand who is a part of the pack and who isn't (and who is the 'alpha' pack leader) gets misinterpreted as getting too familiar too soon for the cat.

It's no wonder that they find it hard to get along. But dogs and cats that are introduced carefully - and preferably at a young age - they do seem to learn these differences and adjust accordingly.

When I recently introduced 'Drake' (our yellow lab) to a couple of cats whom we had to stay in the same house with for a few days - Drake wagged his tail, did a play-bow and then went towards the cats to sniff them out - that's what dogs do when they first meet. Both cats immediately took a bee-line to the most distant room in the house - where they hid for two days before venturing out a little at dead of night to investigate - again, very typical of cat behavior in the face of a gigantic threat animal invading their space. By the time the cats were ready to sneak out for a quick investigation, Drake had evidently decided that this was not the reasonable behavior of pack members - and all of that sneaking around was more likely the behavior of intruders. So, unsurprisingly he no longer saw them as potential friends and chased these non-pack-members back into hiding.

I'm not so sure about the 'predator' thing. Most breeds of domesticated dogs have evolved and been engineered by humans to be much more docile and relaxed around the house. When faced with another animal (or even a small child) - their reactions are more often curiosity and a desire to play than aggression. Cats are still fairly close to their wild counterparts - so they are more concerned about risk to themselves and opportunities to hunt.

SteveBaker (talk) 16:25, 31 January 2016 (UTC)[reply]

And that might be because the domestic dog is at least 33,000 years old while the cat is only 10,000, and even then the purpose was agricultural rodenticide first and cute later. Sagittarian Milky Way (talk) 01:17, 1 February 2016 (UTC)[reply]

Wikipedia articles: Cat behavior, Dog behavior. AllBestFaith (talk) 17:25, 31 January 2016 (UTC)[reply]

Our article at dog–cat relationship notes that it's the more generalized behaviour of the animals: cats are easily spooked and dogs like to chase things. A dog is going to be confused by cat purrs? Seriously? Matt Deres (talk) 17:36, 31 January 2016 (UTC)[reply]

Thanks, everyone! So it's not just the tail, but the whole spectrum of behavioral differences, right? 2601:646:8E01:9089:F88D:DE34:7772:8E5B (talk) 02:06, 1 February 2016 (UTC)[reply]

You may also enjoy reading Tolkien on the theme of Sauron--"Tevildo" in the form of a cat--and the speaking hound "Huan". μηδείς (talk) 04:18, 1 February 2016 (UTC)[reply]

Clashing colors.

We have an article complementary colors, but I haven't been able to find an article on clashing colors or any good google results. By clashing I mean something subjectively judged as unattractive, such as mixing brown and blue in your wardrobe, or such as at this blog. Thanks. μηδείς (talk) 04:29, 31 January 2016 (UTC)[reply]

Color_analysis_(art) is one article on a similar topic of wardrobe color matching, closest I could find quickly. DMacks (talk) 04:44, 31 January 2016 (UTC)[reply]

Yes, thanks, DMacks, that's closer in theme to the article I found. But what I was hoping for was an article or source that gave specifically clashing clothes--say--a pale, blue-eyed redhead wearing a charcoal shirt, a green vest, a navy jacket and an peach tie, that would explain why the colors clashed, and gave an example of explaining how changing one of the colors alone would bring the ensemble into harmony. μηδείς (talk) 06:12, 31 January 2016 (UTC)[reply]

Can you upload a picture of you wearing that combination? I'm having difficulty imagining it! Dbfirs 11:19, 1 February 2016 (UTC)[reply]

I don't think we have an article... we do have an articles on e.g. dissonance, so maybe we should. Then again Consonance_and_dissonance can be formalized in a way that matching and clashing usually aren't. Color theory is hard (and nobody will ever admit that's not really art or science, though it can be informed by both ;)

I think blogs may be your best bet for info. Outside of fashion, color clash also is discussed a lot with respect to print design [6], so you might use printing to narrow future searches. Here [7] is a freely accessible scholarly article that has some interesting empirical findings related to color clash. This one [8] is all about how single colors are interpreted in marketing, but the deconstruction into saturation,hue etc. make it a nice companion to the previous, I think. SemanticMantis (talk) 16:12, 1 February 2016 (UTC)[reply]

I believe what is interpreted as color clashes are to a great extent cultural. I have seen preferences for which colors clash change during my lifetime. If anyone starts an article with one theory or opinion about which colors clash, one should probably make early allowance for alternative opinions so that the article does not overly influence the subject it is trying to describe. Star Lord - 星爵 (talk) 21:31, 1 February 2016 (UTC)[reply]

Chemotherapy, Radiotherapy, Colorectal cancer and Ileus

Unfortunately I got a bad news just now. My friend told me that his father seems to have a Tumor, he asked me to search about "Radiotherapy, Chemotherapy and Colorectal cancer" to find out "could there be a cure for a level 4 Colorectal cancer and could Chemotherapy or Radiotherapy treat Ileus"? But his message is not clear and I don't understand, and unfortunately he does not answer my call. He previously told me that his father was a heavy cigarette smoker. This is all I know. Could you please help me? -- Bkouhi (talk) 07:21, 31 January 2016 (UTC)[reply]

Tell your friend that he should take his father to a doctor. We are unable to give medical advice.-- Jack of Oz ^{[pleasantries]} 07:33, 31 January 2016 (UTC)[reply]

Oh, I didn't notice that. Actually they are now in a hospital, in another city. I was so anxious that I didn't notice that there is an article for Colorectal cancer, I'm reading now. Thanks anyway. -- Bkouhi (talk) 07:50, 31 January 2016 (UTC)[reply]

Geodesics near a black hole

I have a question about matter in "freefall" near a black hole (timelike geodesics). First, an analogy. Suppose I take the surface of an ordinary round, positively curved, sphere, and I pinch off a small region into a bottle. This involves introducing a negatively curved region in the neck. The effect on the space of geodesics is rather dramatic: originally, geodesics were fairly boring, non-ergodic objects. But now a geodesic might fall into the bottle, becoming trapped there for a very long time (affine parameter), and then emerge much later.

Now, in the vicinity of some very high curvature region of space-time, it is conceivable that something similar might happen. One can consider (probably very non-physical) space-times which have precisely such bottles built into them, and matter can get stuck in the bottle for a long time before emerging from the other side. The twin paradox in such a scenario could allow a pair of twins A and B in freefall, such that twin A falls into the bottle and becomes trapped there for a very long proper time (in his rest frame), while twin B remains safely outside the bottle and sees twin A emerge just a few moments later. One can, amusingly, imagine a scenario where twin A will appear to have aged longer than the total age of the universe (from twin B's perspective).

Obviously, if such a scenario could hold in a physically reasonable universe, one would expect a black hole to form. I'm guessing the bottle would need to be something like the ergosphere. Assuming no physical principle rules this out (e.g., positive energy density), could matter whizzing about in the ergosphere of a black hole ever appear to be blueshifted? Also, is it ever possible for matter to appear blueshifted in a black hole without an ergosphere (i.e., Schwarzschild)? (Maybe this last is not quite the right question: I should ask, can a timelike geodesic acquire arbitrarily large proper time, relative to a static observer, by passing close enough to a black hole, and then coming back out again?) Sławomir
Biały 16:03, 31 January 2016 (UTC)[reply]

The ergosphere is a region located outside a rotating black hole in which it is theoretically possible to extract energy and mass from the black hole. The maximum radius of the ergosphere corrresponds to a non-rotating black hole's Schwarzschild radius at which the escape velocity is the speed of light, suggesting that no Doppler shift of light can be observed externally. Theories (for amusement?) about the Ultimate fate of the universe generally imply that all non-reversible entropy-increasing events, such as separated twins reuniting, shall have played out before the final curtain. AllBestFaith (talk) 17:59, 31 January 2016 (UTC)[reply]

None of this answers the question, however. This is a specific question about the behavior of timelike geodesics in Schwarzschild or Kerr. Obviously, the twin could not pass within the event horizon and reunite with the twin that remained static. What might be called the standard response is that the twin that become precipitously close to the black hole would appear redshifted relative to the the static twin. Thus, if the twins ever were to be reunited, the static one would be the older one. I'm asking if there is a scenario in which this standard response is actually wrong, whether because of something happening in the ergosphere, or some other global effect owing to the curvature of the spacetime. Certainly, the situation in Riemannian geometry is such that even tiny regions where the curvature becomes negative appear to have rather dramatic effects on the entropy of the geodesic flow. So it's not unreasonable to wonder whether such behavior is typical of the singular regions in a Lorentzian manifold. (Apologies, I am a mathematician...) Are there any "anomalous" blueshifts in light from quasars? Sławomir
Biały 19:50, 31 January 2016 (UTC)[reply]

Generally non-straight worldlines in spacetime are shorter, not longer as they'd be in a positive-definite space. My intuition (based on thinking about the metric in stationary coordinates) is that "most" worldlines (not just geodesics) that approach and then leave a black hole will be shorter than those of someone who hovers or orbits at a fixed distance, and none will be dramatically longer. I'm not sure what the spacetime analogue of your bottle would be exactly. I'm almost sure that it would be ruled out by standard energy conditions, but again that's just intuition, based on the fact that ordinary mass gives you gravitational time dilation and "time compression" would seem to require negative mass. There are geodesics that approach a black hole, circle it arbitrarily many times, and then leave again, but they take a long time (from the faraway stationary perspective) to do it.

Objects near a Schwarzschild black hole can appear blueshifted for a fairly uninteresting reason: if they're moving outward fast enough then the special-relativistic blueshift will overwhelm the gravitational time dilation. -- BenRG (talk) 21:45, 31 January 2016 (UTC)[reply]

Yes, this more or less agrees with the "standard response" scenario. I have heard that the energy density is negative in the ergosphere of Kerr, although perhaps that's not immediately relevant to your intuition regarding negative mass. (Of course Kerr, being vacuum, has vanishing Einstein tensor, so "energy" is possibly used in a different sense.) Sławomir
Biały 22:08, 31 January 2016 (UTC)[reply]

Here's an attempt to be more precise about my intuition. In a Kerr–Newman background you can write any causal worldline outside the event horizon as a function of t (even inside the ergosphere). If you write the metric as ds/dt = f(r, θ, dr/dt, dθ/dt, dφ/dt) and maximize it over dr/dt, dθ/dt, dφ/dt for fixed r, θ, you get (ds/dt)_max = g(r,θ). This function approaches 0 at the event horizon and 1 at infinity and I'm pretty sure it has no critical points. If that's true, then a stay-at-home twin that moves at nonrelativistic speeds far from the hole will be younger by at most a tiny GPS-correction factor than a travelling twin that goes closer to the hole where g is smaller.

For bottles in general, I really don't know. The best I can come up with is something like: if the twin that enters the bottle can return extremely old, it seems likely that they can return arbitrarily older for initial conditions approaching some asymptote. There would then (maybe?) be a causal diamond containing all of those geodesics and (maybe?) it would be noncompact, which would mean the spacetime is not globally hyperbolic. But that may be nonsense. Try asking at Stack Exchange or Physics Forums. -- BenRG (talk) 00:54, 1 February 2016 (UTC)[reply]

I am having a hard time picturing a "neck of a bottle" in the universe. I think there's something in the wormhole article about stabilizing a wormhole with negative mass, which I think might give that negative curvature, but I really don't understand this stuff enough to say, so just count that as a request: doesn't negative curvature require negative mass? Which is of course unknown, but even if it were known, I wonder if you only get your reverse effect if you use enough negative mass to outweigh the positive mass of the black hole, at least in terms of its effect on the passing twin ...? Wnt (talk) 00:17, 1 February 2016 (UTC)[reply]

What is World Health Organization's guidance on the longevity of Bti mosquito abatement strains?

I remember when Bti treatments for mosquitos were announced; they were supposed to live for five years in the wild, where presumably they would have a chance to flourish in ponds and lakes. But recently when I bought some on Amazon, they said they needed to be reapplied every month. I can't tell from e.g. [9], [10], or [11] what the expected environmental persistence of the live cells and spores (not the mosquito toxin which is often also shipped) is. Does anyone know? 75.166.29.132 (talk) 16:09, 31 January 2016 (UTC)[reply]

AIDS in the middle east

Why is AIDS less prevalent in the Middle East than in western countries? — Preceding unsigned comment added by I just registered a new account (talk • contribs)

This has some background material. At least part of the answer will be due to under-reporting. AIDS is still largely seen as a "homosexual problem" by many people, and so unworthy of broader concern. LGBT in the Middle East has a bit on that, with links. Those links often also deal with HIV/AIDS in particular countries. For example, here is the section on HIV in Saudi Arabia. There are also references there to follow to deeper answers. Matt Deres (talk) 18:04, 31 January 2016 (UTC)[reply]

The map on the right there dates back to 2009... but even 7 years later, many Middle Eastern countries aren't reporting HIV/AIDS data. The most recent UNAIDS report for the Middle East might help you - if you see page 85 you'll see that as Matt Deres says, many countries ignore (or actively repress) the LGBT population, and many also don't attempt to engage with drug users or female prostitutes either. So it's difficult to say for sure that it is less prevalent (per the report, "Given the gaps in HIV data, particularly related to key populations at higher risk, it is likely that the scope of the HIV epidemic and its impact in the region continues to be underestimated."). A more minor factor, which is also mentioned in the report, is "Nearly universal male circumcision in MENA could also act as an important biological factor which has potentially contributed to a reduced heterosexual transmission of HIV in the region." Smurrayinchester 14:59, 1 February 2016 (UTC)[reply]

LIST OF FAMOUS PEOPLE WITH MELANCHOLIC DEPRESSION

Hi, wikipedians i`m writing a novel, about a woman who is a personification of melancholic depression and want to know where on the internet i can find a list of people who suffer from it to say in the novel she made suffer from the disease. If any of you can also list some people who suffer from it that would also be helpful. THANKS — Preceding unsigned comment added by 96.250.231.111 (talk • contribs)

Your best bet would be List of people with major depressive disorder -- that's the clinical name for severe melancholic depression. Looie496 (talk) 17:57, 31 January 2016 (UTC)[reply]

Measuring the universe – Henrietta Leavitt

Seeing Silent Sky, a play about Henrietta Leavitt, I had two questions:

Why was it so hard to find the connection between frequency and distance?

According to Silent Sky, Leavitt pondered for years over the data she had already collected until she realized that frequency and brightness were related by a simple power law. This seems to be reflected in her paper, where the periods are mentioned almost merely in passing. That seems strange to me. Just like waves, any regularly variable phenomenon exhibits three characteristic quantities: The maximum, the minimum or the range, and the period. Why was that not an idea everyone had from the onset? — Sebastian 23:05, 31 January 2016 (UTC)[reply]

Lots of things that seem obvious in retrospect weren‘t so at the time … Without a set of measurements that were all from the same approximate distance, there was no way to compare the true luminosities of cepheids, even though the class had been recognized for quite some time. Most (if not all) of the members Leavitt identified in the Magellanic Clouds were being observed for the first time. Moreover a century ago practically nothing was known about astrophysics, stellar evolution, or galactic structure, so there was little context for any patterns that might have been perceived.—Odysseus 1479 01:23, 1 February 2016 (UTC)[reply]

I'm not asking about the 100-year view, but why Leavitt took so long, after she already had the data. And the truism that hindsight is 20/20 is just what I wanted to preclude with the sentence "Just like waves ...". — Sebastian 02:17, 1 February 2016 (UTC)[reply]

I can only speculate from a position of ignorance, but the fact that most of the periodic behaviour observed in ‘classical’ astronomy is orbital, rather than intrinsic to the objects involved, and therefore quite independent of mass or luminosity, might have something to do with it.—Odysseus 1479 05:43, 1 February 2016 (UTC)[reply]

How was the actual distance determined?

The 24-inch Bruce Telescope has a diffraction limit of about 1/3″, and the Magellanic clouds are over 50 kpc away, far more than could be measured by parallax. Consequently, the cepheids could only be used to provide relative distances. The absolute distance was apparently provided later by Hubble, but I don't see how he did that in the section The universe goes beyond the Milky Way galaxy or at the Science Oddysey referenced there. How did he determine the basic distance? — Sebastian 23:05, 31 January 2016 (UTC)[reply]

Is there a typo around "candles only provided gave relative" ? I can't parse it. StuRat (talk) 23:47, 31 January 2016 (UTC)[reply]

Yes, thanks for asking: The "gave" was redundant. It seems that even with that correction, the sentence was a bit to flowery, so I reworded it and the next one. — Sebastian 00:01, 1 February 2016 (UTC)[reply]

Harlow Shapley seems to get most of the credit for fixing the distance to one or two nearby Cephids, which is a start towards fixing them all, though even this doesn't make it clear to me. Anyway Cephids need not be well aligned in the cosmic distance ladder to understand that those seen in globular clusters are more distant than most, and those in M31 are many times more distant. Jim.henderson (talk) 00:15, 1 February 2016 (UTC)[reply]

Calibration of the distances was made possible by the identification of cepheid variables in our own Galaxy that are near enough for their distances to be measured by parallax (geometrical or statistical—see Ned Wright’s tutorial). These stars are not terribly common, so it was a quite a while before enough data were obtained. I guess an incomplete revision, where only one of “provided” and “gave” was intended to be kept. P.S. I should have got an edit-conflict here, but for some reason didn’t. Please ignore any consequent redundancy.—Odysseus 1479

Thanks, guys, that going in the right direction, good links, and the term "calibration" is of course what I should have used. Unfortunately, the numbers still don't add up yet: According to cosmic distance ladder, the closest globular clusters seem to be around 1kpc from us, which just recently gets into the range where we can use parallax. The cepheids near the center center of our own galaxy are even 10 kpc away. Not sure if there are some stray ones closer to home; unfortunately I couldn't find out which ones Shapley looked at. I checked a few candidates: Delta Cephei: 244 ± 10 pc, Eta Aquilae: approx. 400 pc. — Sebastian 02:17, 1 February 2016 (UTC)[reply]

The secular and statistical parallax methods applied to star-clusters have somewhat longer range than the geometrical parallax as used by terrestrial surveyors; the precision of radial-velocity measurements doesn’t fall off with distance like that of positional measurements, although the difficulty of obtaining individual spectra from a cluster must increase with its distance. I just browsed some of our articles like Astronomical spectroscopy, and could find nothing about the history of radial-velocity measurements aside from cosmic red-shift, but I believe it was all pretty new at the time. Ejnar Hertzsprung did a lot of the early work on cepheid ranging.—Odysseus 1479 05:18, 1 February 2016 (UTC)[reply]

The sixth satellite of Saturn

This question doesn't fit under the headline "Measuring the universe", but it's something I found incidentally: The same Harvard Annals, on page 33, also contain a very different mention of Miss Leavitt: "The required measurements [of the sixth satellite of Saturn] and their reduction were assigned to Miss Leavitt. It then appeared that in examining some of these plates on December 10 1904 she had already marked and measured the sixtli satellite but had concluded that it was probably an asteroid near its stationary point." Is that Phoebe, which is described at Moons of Saturn#Early observations as the ninth moon found? (The first to be discovered after the eight that had been found by direct observation.) If so, why does the Harvard paper credit Perrine at Lick, not Pickering or Leavitt, with the discovery? — Sebastian 23:05, 31 January 2016 (UTC)[reply]

I don’t know the specific history WRT Phoebe, but discovery credit generally requires that an object’s nature be identified, not just its existence. Galileo recorded a couple of observations of Neptune, but since he didn’t recognize it as non-stellar these aren‘t considered to constitute the discovery of the planet per se.—Odysseus 1479 01:37, 1 February 2016 (UTC)[reply]

February 1

Breached levee near town

Let's suppose, for argument's sake, that a 400-kV power line becomes submerged by a flood and somehow remains live (not very realistic, I know) -- how far away can it kill a person who is also submerged in the flood and is clinging to a metal object? (Question inspired by 911 First Responders mission #8, "Breached levee near town".) 2601:646:8E01:9089:F88D:DE34:7772:8E5B (talk) 02:10, 1 February 2016 (UTC)[reply]

High voltage electricity is very dangerous! A very tiny exposure can be instantly fatal - especially if the source is a high voltage transmission line. The general advice, even for emergency-crews, is to "avoid the area completely." But since you're asking for a little bit more of a quantitative answer, I looked around for some good sources.

From electrocution, you can find several references on the topic of electric shock. Sources vary in defining a level of current that is lethal or causes irreversible harm; but somewhere in the neighborhood of half an ampere at 100 volts is pretty much a guaranteed killer for a human. In some cases, a much lower current will be fatal. If the voltage is much higher or much lower, the lethal current level becomes very difficult to predict, and as a general rule, scientists haven't been able to collect great data on that.

So, how far away can you be from a live wire, and still get half an ampere? Well, it depends on the electrical path. You could be miles away from the wire, if you're touching a metal object that makes you the shortest path between high voltage to ground. If there is water or flooding, the electrical paths can become very difficult to predict. So, the answer is going to vary wildly.

The U.S. Department of Transportation publishes an annual HAZMAT Emergency Response Guidebook. (We even have an article: Emergency Response Guidebook!) That book is my go-to resource when I need to know how many hundreds of feet away from a hazard I need to stay - they publish standard safety-perimeter guidelines for all kinds of things, from fires to noxious gases to radiological hazards, and more!. Regrettably, they do not publish any guidance for a safe distance from exposed high-voltage wires. (If I may reiterate: any distance is hazardous if there is an electrical path from the high-voltage to you).

Here's a study guide from Los Alamos: Electric Hazard Safety Awareness. I read through it, and the short answer is, do not approach. Even trained professionals are instructed not to approach an unknown electrical hazard. Additional guidelines are prescribed for various levels of qualified/trained personnel, with- and without- personal protective equipment. For example, even a trained expert wearing PPE (protective gear) is instructed never to approach within 4 feet of a high voltage (230kV) conductor, even if it has no damage. In our OP's question, there is clear evidence of damage (due to flooding, and so on). The correct procedure - even for the emergency responders - is to "get the heck out of there!" The situation is very unsafe until we can be positively certain that the line is de-energized. After the line is shut off, and everybody is sure it is off, then the emergency crews can get in and start helping.

Here is a guideline aimed at the general public, from my local electric company: What to Do If You See a Downed Power Line. Again, the correct answer is get the heck out of there.

Nimur (talk) 03:22, 1 February 2016 (UTC)[reply]

Not sure if it would be miles. Perhaps if the water was all perfectly insulated from the ground and you were touching the only path to ground, but that doesn't describe the case of a breached levee. There are bound to be many paths to ground, over the course of miles, in all directions. So then the question is if your path to ground is still significant, compared with all those others, factoring in the resistance of the water over all that distance. I suggest that looking for empirical data might be the best approach here, of actual electrocutions at extreme distances from the source, during floods, rather than attempting a theoretical answer. (The "if can see it stay away" advice sounds good, though, as you couldn't see it from miles away.) I also imagine rescue personnel must have a guide they use, as the question of whether to attempt a rescue (that requires getting into the water some distance from live wires) has to come up. StuRat (talk) 03:35, 1 February 2016 (UTC)[reply]

This is going to have to do with the resistance of the actual soil and underlying rock in some way. Exactly what way, I can't guess... on one hand, if the ground is very conductive it should allow more current to dissipate deep downward, so the potential should fall off faster ... on the other, if the potential falls off faster, then your chance of actually getting a fatal shock crossing your body within that region should be higher. I imagine if the ground composition varies you might have a worst-of-both-worlds scenario - for example, you could have a pool of water lying on a big rubber sheet with a power line sparking, and the edge of that could be at almost the voltage of the live wire, but at the edge there is ground conductance and so there's a huge difference between your belly and your butt. Wonder if there's as much salt in the water as in your body...? don't know, but this seems like it needs a very specific solution for the exact scenario. Wnt (talk) 17:55, 1 February 2016 (UTC)[reply]

A more likely scenario would be a river that has burst its banks, and a downed power line somewhere in the floodwater (sort of like in the video I linked). So a fair approximation would be an inverted bell curve-shaped channel filled with river water, with the power line at the center of its upper (flat) surface. And the victims are either floating (floundering) in the water, or clinging to various objects (streetlamps, chain-link fences, trucks, etc. -- note that the 3 types of objects I listed are highly conductive), and are partly immersed in either case (let's assume up to their waist).2601:646:8E01:9089:F88D:DE34:7772:8E5B (talk) 09:59, 2 February 2016 (UTC)[reply]

I'd just like to address the bit about the "power line... somehow remains live (not very realistic, I know)". The overload protection on power lines is often not as quick-acting as household circuit breakers. For example, in this report on the Second Great Northeast Blackout, if you search for the word "seconds" you will find several instances where a trunk line did not trip out until several seconds after it was overloaded. In addition, power-line protection may be configured to automatically try reapplying power once or twice a few minutes after it has tripped out. So for both reasons, people in the danger zone, however large it is, will be at risk. --76.69.45.64 (talk) 04:56, 1 February 2016 (UTC)[reply]

In this mission, the power line actually remains live until you order your engineer to manually shut it off -- which is the part that's obviously bullshit. Take a look at this: https://www.youtube.com/watch?v=mUEKtRv3uxA&list=PLsQxuO6DkZTGC-_D2u7A_Nn3V3AyYSNRD&index=8 (from 0:49 to 1:36). 2601:646:8E01:9089:F88D:DE34:7772:8E5B (talk) 07:19, 1 February 2016 (UTC)[reply]

Actually that sounds quite reasonable from the responder's point of view. They don't know for sure how often the current might be reapplied... until they have an expert from the company tell them the line is securely disabled, they would be smart to consider it as live. Wnt (talk) 17:55, 1 February 2016 (UTC)[reply]

"Sleeping funny" and sore neck

In scientific, descriptive terms, what exactly do you do when you "sleep funny"? What is it that your sleep posture does to your muscles that causes sore neck the next day? --98.115.39.92 (talk) 04:12, 1 February 2016 (UTC)[reply]

Well, for one thing, if your neck is misaligned during sleep, then some of your neck muscles would be stretched, which is what causes the pain and soreness. FWIW 2601:646:8E01:9089:F88D:DE34:7772:8E5B (talk) 07:11, 1 February 2016 (UTC)[reply]

I suspect that the reverse is also true, and those muscles or ligaments that are shortened while you sleep take some time to stretch back to normal length, and during that time your neck is sore (which is to prevent you from trying to stretch them too quickly and tearing them). StuRat (talk) 08:04, 1 February 2016 (UTC)[reply]

Assuming that the connection between stretched muscles and soreness afterward is correct, how exactly does former cause the latter? What does being in a stretched state for an extended amount of time do to muscle tissues? How does the condition manifest as soreness? --98.115.39.92 (talk) 12:10, 1 February 2016 (UTC)[reply]

See cramp or Strain (injury) for some discussion of the possible causes. --Jayron 32 15:58, 1 February 2016 (UTC)[reply]

Do we have an article on tossing and turning? I find that helps alleviate the problem. It's only when I am highly medicated that I usually wake up in the same position in which I went to sleep. μηδείς (talk) 19:42, 1 February 2016 (UTC)[reply]

What is encoded?

Which of the following sentences is logically correct?

Gene XYZ is encoded on Chromosome 5.
The Protein XYZ is encoded in Gene XYZ on Chromosome 5.

The questions are - and both views/expressions are found in WP - "Are genes encoded?" or "Are Proteins encoded?". Thanks for comments. Play It Again, SPAM (talk) 08:41, 1 February 2016 (UTC)[reply]

Google finds roughly equal numbers of hits for "(XYZ) gene is encoded" ("The gene is encoded on murine chromosome 5") and "(XYZ) protein is encoded" ("The XK protein is encoded by a gene on the X chromosome"). I suppose either is valid - maybe "The gene is encoded" makes slightly more sense, since a gene is an abstract thing while a protein is a physical thing (like how "The selfie is encoded in this file" makes a bit more sense than "My face is encoded in this file"). A protein can also be "coded for" ("It is not known whether the terminal protein is coded for by a viral gene"), while I don't think genes are ever "coded for". Smurrayinchester 14:38, 1 February 2016 (UTC)[reply]

Unfortunately there's lots of loose terminology floating around, even from good sources. Smurray's description is reasonable, but note that a gene is locus or place in a strand of DNA. Whether a place is an abstract concept or a physical thing depends a bit upon the ontology and context you're operating in. But mostly, you'll do well to think of a gene like an address, and treat it grammatically the same as you'd treat at address.

I think this confusion in usage over encoding is related to the frequent conflation between genes and alleles. Pretend there's exactly one gene that determines human eye color, and that humans have eyes that are only brown, blue, or green. Then it is correct to say "there is a gene for eye color", but it is strictly incorrect to say "I have the gene for brown eyes". We should instead say "I have the allele for brown eyes". Even Nature gets sloppy [12], talking about genes. Anyway, linguistic descriptivism is fine for informal usage of natural language, and we can seek to not say how things ought to be and instead focus how they are.

But science ultimately seeks to codify and formalize its language - we don't like imprecision and vagueness, we want clear and concise nomenclature, sometimes lives depend on it! Thus, a gene is not encoded on chromosome 5, it is simply located on chromosome 5, just as my address is located on my street. SemanticMantis (talk) 15:42, 1 February 2016 (UTC)[reply]

In my opinion Gene XYZ is encoded... is incorrect and ought to be avoided. A gene can be located on a chromosome, but it is itself a piece of code, and to say that a piece of code is encoded would mean that the final product is encoded twice -- in other words I basically agree with SemanticMantis. Looie496 (talk) 15:52, 1 February 2016 (UTC)[reply]

Indeed. It's is the protein that is encoded by the DNA sequence on the gene. Fgf10 (talk) 17:15, 1 February 2016 (UTC)[reply]

I agree; "encoded" typically refers to the genetic code. An amino acid is represented by a genetic code in DNA; a gene simply is DNA and so is on a chromosome. However.... as always, there's a catch. Biology hates semantics... so do biologists... even so both use them with reckless abandon. An organism is full of "codes", as some author or other will use the metaphor; for example [13] the "cytosine methylation code". And so in that sense a gene is encoded in DNA and DNA modifications and histones and histone modifications and other DNA-bound proteins and so on. My feeling is that this is not the standard way of speaking but that is purely arbitrary; there's no majority vote over what metaphors to use and there is no way to know whose preferred metaphors will win out in fifty years. There is a certain historical appeal to the notion that a gene is encoded, however, since the definition of genes long predates the knowledge that DNA exists. Wnt (talk) 17:47, 1 February 2016 (UTC)[reply]

I am a biologist, and I love discussing semantics. People say "that's just semantics" to dismiss things all the time, but that doesn't make it a sound complaint. What they often mean is "let me be sloppy with my words and use them in inconsistent ways", and that can get us in to a lot of trouble with misunderstandings. Really, we need to agree on what the hell we mean when we use certain words if we have any hope of discovering, teaching, or learning things in science :) SemanticMantis (talk) 19:54, 1 February 2016 (UTC)[reply]

GLUT-4

What is GLUT-4? What is its role in biological system?

GLUT4, is a protein encoded, in humans, by the GLUT4 gene. GLUT4 is the insulin-regulated glucose transporter found primarily in adipose tissues and striated muscle (skeletal and cardiac). Wikipedia has an article about GLUT4. AllBestFaith (talk) 15:44, 1 February 2016 (UTC)[reply]

Interestingly enough, that first sentence is also a good example of how to write correctly about this stuff, related to User:Play It Again, SPAM's question directly above. SemanticMantis (talk) 15:46, 1 February 2016 (UTC)[reply]

Should be: GLUT4 is a protein encoded, in humans, by the gene GLUT4 (italics if it is human). Play It Again, SPAM (talk) 16:23, 1 February 2016 (UTC)[reply]

It is an awful example. It tells you exactly nothing, and is far too human focussed. The second sentence would be the correct opening one. Fgf10 (talk) 17:14, 1 February 2016 (UTC)[reply]

What source requires "italics if it is human"? The HUGO Gene Nomenclature Committee recommends "Proteins should be designated using the same symbol as the gene, printed in non-italicized letters." AllBestFaith (talk) 19:09, 1 February 2016 (UTC)[reply]

I don't see how one mention can make one sentence "too human focussed". The article may be too human focused, but I only wanted to point out that "XXX is a protein encoded by the YYY gene" is a good simple way to phrase these kinds of statements, and an example of WP doing it more or less correctly, as compared to the incorrect usage mentioned above. The sentence doesn't tell us nothing; it tells us precisely that that GUT4 is a protein, and it also tells us the name of the gene that encodes the protein in humans. And if you want to get critical, then the second sentence is a terrible opener, because it doesn't tell us what basic type of thing GUT4 even is. But issues of WP writing style are far off topic for this forum and post, as are issues of what things should be put in italics, so let's just leave this unless the OP needs further clarification on GUT4. SemanticMantis (talk) 19:48, 1 February 2016 (UTC)[reply]

Human protein X is encoded by human gene X? Well duh. What if people aren't even interested in human GLUT4 for starters? What is the number one thing anyone looking at the article want to know? What GLUT 4 does. But yes sure, let's not mention that in the opening sentence, you're perfectly right. Fgf10 (talk) 21:24, 1 February 2016 (UTC)[reply]

Whiskey warehouses

A wine cellar is a special type of cellar needed for the best production of wine. What about whiskey warehouses? Are they just warehouses in which the distiller stores whiskey, or are they an important part of the whiskey production process? The question arises from File:Rock Spring Warehouse from southeast.jpg, which depicts a whiskey warehouse. Nyttend (talk) 15:45, 1 February 2016 (UTC)[reply]

They are important insofar as aging of Whisky is important, i.e. very! Here are a few pages that discuss how temperature, humidity, and fluctuations of those affect whisky aging rate and process [14] [15] [16]. While an old shack might not look that impressive, my last link above specifically mentions how in many cases natural changes in humidity/temp like those found in an attic or barn are desirable, because this sort of "pumps" tasty wood molecules into the otherwise boring ethanol and water mixture. (This also applies for the real balsamic vinegar). I might be able to find more serious/academic refs if you need something more reliable than the links above. SemanticMantis (talk) 15:54, 1 February 2016 (UTC)[reply]

Why is air conditioning considered a luxury but heating is considered a necessity?

Don't people die from heat stroke just as often as hypothermia? Is this more of a political issue where land lords can merely use the excuse that air conditioning is a luxury to save money on not providing it? ScienceApe (talk) 19:31, 1 February 2016 (UTC)[reply]

What is the basis for your premise? ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:20, 1 February 2016 (UTC)[reply]

Heating has been around since before we were Homo sapiens. Air conditioning is relatively recent, and people who lived in hotter climes were usually better adapted to them, such as being longer-limbed and less broad-chested. Look at Allen's Rule and Bergmann's Rule. The insistance that air-conditioning is a luxury is usually a political one, see these articles. μηδείς (talk) 19:38, 1 February 2016 (UTC)[reply]

According to the CDC [17], it seems that there are more cold-related deaths than heat related deaths in the US (though the article is a bit of a dense read). Another way to look at it is mitigation methods. If it is too hot, there are a lot of recommended actions other than just "air conditioning," such as proper and frequent hydration, stick to shade and reduced activity, moving air/a fan, dressing down, etc. If it is cold, you can dress warmly, but that is about it short of some method of heating, be it burning stuff (dangerous or not an option in many residences) or having heat. --OuroborosCobra (talk) 19:42, 1 February 2016 (UTC)[reply]

I disagree. In cold climates, it's a trivial cost to buy a small electric heater and warm up whatever spot in the house you're at and passive insulation (clothing, blankets) allow you to trap body heat. You don't need "central" heating (although it may be desirable). When it's only mildly hot - you're right, there are possible mitigations. But when the air temperature exceeds body temperature - you are in trouble. Fans actually make matters worse and none of the tricks you describe are going to get you even modestly comfortable. That's something you can withstand for a day or two - but when the temperature stays above body heat for weeks - you need A/C. Small air conditioners are not very effective (and they're a lot more costly than small heaters) - so central airconditioning is something close to a necessity in seriously hot climates.

We should also consider vehicles. In a gasoline powered car, heat comes for free as a by-product of running the engine - but running the A/C requires extra energy and lots of expensive equipment. In that situation, heat is clearly not a luxury in any climate - but A/C is unnecessary in large parts of the world. (My wife's car has air-conditioned seats...that's a luxury...but really nice on a hot day!) SteveBaker (talk) 19:53, 1 February 2016 (UTC)[reply]

Air temps can exceed body temps without presenting any danger, so long as humidity is low. There are many inhabited parts of the world where this occurs each summer. In my location (Detroit), I can't see why anyone with water service should die from heat, since water delivered by underground pipes is cool enough, even on the hottest days, to cool you off. On the other hand, if gas and electricity was cut off in winter, I could see people dying from the cold. StuRat (talk) 04:09, 2 February 2016 (UTC)[reply]

True. I've walked at 104°F in the sun at low humidity (by forest biome standards) and it'd need to be somewhat hotter than that for that humidity level to be too much. If humans didn't sweat that would quickly lead to death (which is why pigs lie in mud and dogs pant). One of the most dangerous dew points ever recorded on Earth was near Green Bay, Wisconsin because the crops prevent the humidity from going down with the temperature rising (until the crops' water is exhausted). Sagittarian Milky Way (talk) 04:31, 2 February 2016 (UTC)[reply]

Yeah, the mitigation issue really seems to work the opposite way from OuroborosCobra's point. There's a saying in Canada: There's no such thing as bad weather, only bad clothes. The right clothes can keep you safe down to well below zero Fahrenheit.

But that only works for cold weather. In hot weather, your ability to adjust by way of clothing is pretty limited. --Trovatore (talk) 23:13, 1 February 2016 (UTC)[reply]

I think it depends on where you are in the world. When I lived in south-eastern England, you really wouldn't use air conditioning (A/C) for more than maybe a couple of days in the year. Having such costly systems just sitting there in house and car for the very rare occasion when it would have been useful was indeed a "luxury" that just about everybody managed perfectly well without. On the other hand, I now live in Texas - and just last Saturday (late January!) felt the need to turn on the A/C for a brief period of time to cool off the house. In the summer months, when temperatures always top 35 degC and usually reach 40 degC for one to two weeks, it's decidedly not a luxury! If I had to choose one or the other, I'd definitely choose A/C over central heating here in Texas because on the very few days you really need that heat, you can provide it with an old-fashioned fireplace and a handful of small spot-heaters.

Hence, your perception of whether A/C is a luxury or not depends entirely on where you live. Clearly there are some climates between that of south-east England and the heart of Texas where one might find considerable debate whether A/C is a luxury or not. SteveBaker (talk) 19:44, 1 February 2016 (UTC)[reply]

With the A/C in the UK You will dry the air with high humidity, in TX You are cooling it. --Hans Haase (有问题吗) 22:05, 1 February 2016 (UTC)[reply]

Many commodities that were perhaps considered "luxuries" at one time are now standard. Indoor plumbing, for example. Electricity. Telephones. Cars. On and on it goes. ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:22, 1 February 2016 (UTC)[reply]

I grew up in swamp country just 30 miles west of New Orleans, long enough ago that we didn't get air conditioning until I was about 11 years old. Before then, We made do with a large (three foot wide) ducted fan which drew hot air out of the house into our attic, where roof-mounted turbines vented the hot air outdoors. And we drank many glasses of water over ice, and we played outside a lot. We were aware of the danger of heat stroke, but we were also more commonsensical back then.

We knew to stay hydrated and, if we needed to be indoors in the heat, to lie as close to the floor as possible, where the cool air was (on sweltering nights, this worked very well). Workmen who had to be outdoors in the hot midday never went far from the large water cooler every work truck had as standard equipment. In fact, every home had one or two insulated coolers just for summer outings, because we knew we had to keep hydrated and as cool as possible. And I remember during heat waves that the television news always reminded us of these and other ways to survive extreme heat. Air-conditioning was a "nice to have" item, not a necessity, unless one had a medical issue.

In contrast, I've also lived in Indiana, about thirty miles north of Indianapolis, in a wood-heated farmhouse. It was "burn wood or die," because electric heaters are inadequate to winter nights where the temperature's in negative numbers in Fahrenheit OR Celsius. So are even multiple layers of warm clothing - without a good fire in your wood stove, you'll just be a heavier corpse for the rescue squad to pull out to the meat wagon. Heating isn't a luxury north of the Mason-Dixon Line, it's a vital necessity. loupgarous (talk) 23:58, 1 February 2016 (UTC)[reply]

We had this argument at work when some managers would set the temperature at 75, and others at 68. The question was, do yo want people who are too cold at 72 to put on more clothes, or do you want those who are too hot at 72 to strip naked. μηδείς (talk) 00:30, 2 February 2016 (UTC)[reply]

¿Por qué no los dos? --Trovatore (talk) 08:27, 2 February 2016 (UTC) [reply]

So basically, to summarise Vfrickey's argument, it's entirely possible (more difficult, but definitely not impossible) to function during hot summers without air conditioning, much easier than it is during winter with no heat. Consider that people in temperate and polar regions have always heated their homes (whether with open fires or with more sophisticated systems), but the tropics have been inhabited since time immemorial by people who didn't have air conditioning, which itself wasn't invented until the twentieth century. And Bugs, remember that "standard" and "necessity" are quite different; heating is absolutely necessary for human life (whether sun-provided, geothermal, or artificial heat), unlike phones and indoor plumbing, and Jim.henderson could tell you whether cars are a necessity. Nyttend (talk) 01:45, 2 February 2016 (UTC)[reply]

Technically, the only "necessities" are what keep us alive: food and shelter. Everything else is a "luxury". ←Baseball Bugs ^{What's up, Doc?} carrots→ 05:45, 2 February 2016 (UTC)[reply]

I think Vfrickey is wrong, though. It's mostly a matter of insulation. I simply don't believe the claim that you can't put on enough insulation to survive inside in an Indiana winter, without heating. I call bullshit. --Trovatore (talk) 01:55, 2 February 2016 (UTC)[reply]

See Igloos. Those are in far worse conditions than Indiana. Ian.thomson (talk) 02:09, 2 February 2016 (UTC)[reply]

For the record the hardiness zone map shows an average year reaching a hair under -10°F in that location and Indianapolis says the record low is -27°F. Maybe the cabin had no modern insulation or even was leaky and/or they didn't have much clothing. The point still stands that it's probably easier for healthy housemates without heat, thick clothes and cooling but with running water to die in coldish inhabited places than in the hottest. Sagittarian Milky Way (talk) 02:41, 2 February 2016 (UTC)[reply]

I'll put the lake effect snowfall in metro Indianapolis, when it got that far south, up against the worst that Buffalo gets. We're talking six feet of snow in a day. That's the sort of thing that doesn't show up on maps. Not too bad if you have a nicely heated home (having to dig your car out of a snowbank with a shovel is worth a few chuckles), but a definite challenge in a home without heat, which was my original point. Those healthy housemates would fare a lot better in the Gulf South on our hottest days without air conditioning than in central Indiana without heat, which was the original poster's question. Heat's more necessary in cold weather than air conditioning is in warm weather, all other things being equal. loupgarous (talk) 05:24, 2 February 2016 (UTC)[reply]

(edit conflict)I have to second SteveBaker's point that it depends on where you live. In my home town during the summer, the local news regularly goes on and on telling people to keep children and the elderly hydrated, and inside and air conditioned. Winter? Nothing unless it snows, and then it's only "these schools are closed, this gas station was caught mixing gas into their kerosene, and wow, everyone bought out all the milk, eggs, and bread like it's the end of the world or something." Yes, people managed to live there before air conditioning, but it was still by far more dangerous than winter (though most of the people dying were poor and/or black, which is probably why my older relatives don't think about summer being so dangerous). Ian.thomson (talk) 02:09, 2 February 2016 (UTC)[reply]

More so is the age of the home or building. People have lived in the desert and the arctic for much longer than either central air or heating. Structures were built with the current technology in mind so current structures support whatever climate control is available. A house built in the desert before air conditioning is quite different than today. --DHeyward (talk) 02:35, 2 February 2016 (UTC)[reply]

I'd like to revisit my remarks. I was one of the dads who actually went along with their kids on Scout campouts in that Indiana town, and was frankly incredulous (we'd just moved there from the Gulf Coast) that the troop would go camping in minus-10F weather. And we had thick clothing (I'd gotten my bachelor's degree in North Louisiana, where quilted overalls are standard hunting equipment, and still had them), but a lack of knowledge and confidence in how to deal with the cold. It turns out that two closed-cell foam pads under a winter-grade sleeping bag will actually keep you alive in a tent at those temperatures. And our farmhouse was indifferently insulated; the prior occupants apparently had plenty of wood, every winter, and that was a remarkably efficient wood stove at heating the rooms of that place we lived in.

And even so, I call bullshit on Trovatore's "bullshit". I was THERE. A drafty farmhouse with so-so insulation is a different matter than a tent that probably has a warmer air space by conserving the 500W or so body heat from each occupant in a small area.

Hypothermia is quicker to kill and harder to remedy than heat prostration. We got along better in the southern heat without air conditioning (though we got spoiled to the A/C in no time at all) for years, and the ambulances weren't zooming through the streets picking up the dead and dying from heat stroke. People probably deal better with what they're used to, our native Hoosier neighbors weren't fazed at all by the cold (though there were regular reports of hypothermia deaths in the local news).

People also tend to panic and do stupid shit in unfamiliar weather. A homeless man in New Orleans set a fire in the alcove of an office building on Canal Street (think "Broadway in New York") during last week's cold snap and wound up setting a six-alarm fire. I'm willing to believe that he wasn't the sharpest pencil in the box to begin with, but that the cold impaired his judgment and perhaps caused him not to do the sensible thing and visit the local Salvation Army shelter for the night. Fortunately, he survived the blaze, and no one else was hurt. loupgarous (talk) 04:57, 2 February 2016 (UTC)[reply]

Maybe the shelters were full and this action got him a warm place to spend the night, if only in jail. StuRat (talk) 06:47, 2 February 2016 (UTC) [reply]

White tube like things in poor quality diced beef.

Hello. tonight, I was eating some Iceland (supermarket) diced steak beef chunks for a stir fry, knowing that the quality was poor and full of gristle. I discovered upon biting a piece of the diced steak, that there was a small, white rubbery tube thing in the steak. I know this is hard to describe, but what could this be? It resembled some macaroni, but was it really a ligament or muscle fiber or something? --Commonîo (talk) 21:24, 1 February 2016 (UTC)[reply]

Probably a vein or an artery. --Jayron 32 21:26, 1 February 2016 (UTC)[reply]

Or a nerve, of course. Or a miscellaneous bit of fascia. Still edible, of course, if unappetizing. Tevildo (talk) 22:12, 1 February 2016 (UTC)[reply]

Nerves are like tubes? Anna Frodesiak (talk) 00:04, 2 February 2016 (UTC)[reply]

Ganglia (large nerve bundles) can resemble them, sometimes after processing. And perhaps it's best not to eat the white stuff in Iceland beef (I used to live in the UK for a few months, long enough to have shopped at Iceland myself, so I know what Commonîo means) - just on the off chance the cow it came from had BSE. The prions tend to be more present in nerve tissue. loupgarous (talk) 00:11, 2 February 2016 (UTC)[reply]

February 2

Cutting or bending Electronic paper displays

I'm trying to build a basic smart watch for fun, basically just hooking up a small electronic paper display to an Arduino clone, nothing too fancy. The problem is I can't find any e-paper small enough, and ordering a custom size e-paper display from a manufacturer is outside my hobbyist budget. So I'm thinking of re-purposing a larger off the shelf e-paper display:

1. Do e-paper displays still work after cutting them? Obviously I will leave the connector intact and try my best to minimize the damage while cutting it.

2. Do e-paper displays still work after bending them >=180 degrees? Googling "bending e-paper" shows that e-paper is fully functional even during bending, but in my application it's more like "folding" rather than "bending", since I would need to fold the excess portion almost 180 degrees to reduce its size. Would the display still function (the unbent portion of course) after folding it like that? Johnson&Johnson&Son (talk) 03:23, 2 February 2016 (UTC)[reply]