Wikipedia:Reference desk/Archives/Science/2008 July 29

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July 29

What was the last species to become extinct?

In other words, what species most recently became extinct? 71.181.253.33 (talk) 00:24, 29 July 2008 (UTC)

According to Holocene extinction event, the current rate of extinction may be as high as 140,000 a year, most of which will be species never discovered by humanity. Thus your question is unanswerable. Algebraist 00:30, 29 July 2008 (UTC)

In that case, what would be the most famous recent extinction? --Kjoonlee 01:29, 29 July 2008 (UTC)

Altho, I can't find a list directly has the information you want, you could figure it out from List of extinct animals & List of extinct plants. ---J.S (T/C/WRE) 01:46, 29 July 2008 (UTC)

(ec) The last documented species to be officially declared extinct is Begonia eiromischa. Using the crude equation 'famous'='I've heard of it', the last famous extinction is the Baiji (assuming it is extinct; a few might survive, but they won't last long if so). Algebraist 01:48, 29 July 2008 (UTC)

Probably the most famous extinction of the last century is the Passenger Pigeon, which not long before had migrated across north America in flocks a billion strong. Algebraist 01:53, 29 July 2008 (UTC)

To go from "probably extinct" to "extinct", the IUCN requires that no members of a species have been observed for at least 50 years. That uncertainty means that "recent" extinctions are necessarily not very recent. Dragons flight (talk) 03:52, 29 July 2008 (UTC)

Then let's ignore the IUCN list for the moment, since declaring extinction is distinct from actual extinction. --Kjoonlee 04:28, 29 July 2008 (UTC)

But that's precisely the problem. How do you know when the last Baiji died (presuming it really has died, which is easily not the case)? How do you know if it died before the last whatever other species you want to name (that was declared possibly extinct at around the same time, I'm obviously not talking about the dodo here) Nil Einne (talk) 15:28, 29 July 2008 (UTC)

Baiji was a recent probable extinction of a well known species-- declared "functionally extinct". Even if one or two remain they'd still almost certainly die out. And for the record, the IUCN Red List does not require 50 years -- but they do require "no reasonable doubt that the last individual has died." which means Baiji are still listed as Critically Endangered/Possibly Extinct [1] —Pengo 12:35, 29 July 2008 (UTC)

No baiaji have been taken into captivity? Usually I'm not for captivity, but when it's that or extinct... Pfly (talk) 02:42, 31 July 2008 (UTC)

There were attempts. Have a look at the article which lists 6 individuals. Note that for a population to sustain itself you generally need at the very least 100 individuals. That's to allow genetic diversity and avoid inbreeding. 60.242.139.27 (talk) 23:25, 31 July 2008 (UTC)

Organ Donation

which are the organs that can be donated by a brain dead person? why can't all organs be donated?Shraktu (talk) 05:07, 29 July 2008 (UTC)

All organs can be donated (for example, by leaving one's body to a medical school for dissection). But not all organs are useful for transplant. Most commonly, the organs and tissues used are corneas, skin, bone, kidney, liver, heart, lung. Take a look at Organ_transplant for other transplantable organs. - Nunh-huh 05:22, 29 July 2008 (UTC)

If the individual is "brain dead" then presumably they are still alive. I'm fairly certain it is considered unethical to remove someone's vital organs (without the intent of replacing them) until after their heart has stopped and they are definitively declared deceased, although this practice would almost certainly provide for more viable organs. Even Dr. Kevorkian didn't directly kill any of his right to die patients. I think they sometimes will push drugs that help preserve a brain dead patient's organs in anticipation of their death, though. --Shaggorama (talk) 08:01, 30 July 2008 (UTC)

On the contrary, in jurisdictions where "brain dead" has a legal meaning, a brain dead person is dead. A brain dead person on a respirator is a very common source of organs, and removing the organs is indeed done while the heart is beating. - Nunh-huh 12:00, 30 July 2008 (UTC)

Wow, that's uh...unexpected and scary. I take it the hospital pays for the time the individual is on life support then? I understand many amilies choose to keep "brain dead" individuals on life support for sometime in the hopes that they might come out of the coma. It does happen periodically. I'd feel pretty shitty if I found out I was paying to keep a family member alive while their liver was cleaved out of them. Mind finding some jurisdictions for me? I'd be interested in reading their policies and ethical discussions on this topic. --Shaggorama (talk) 09:47, 31 July 2008 (UTC)

Well, first: brain-dead people don't come out of comas. You're talking about people who are something other than brain-dead if there's any chance whatsoever they're revivable. Brain-dead means (there are slight variations from place to place, but in general:) irreversible end of all brain activity, including the inability to trigger a respirator, as measured by separate EEGs measured 24 hrs apart, and certified by more than one physician. It's something quite different from the so-called persistent vegetative state coma-patient cases you read about. Once someone's brain-dead, costs for the respirator and hospital are charged to the organ recipient, not the donor. Actually, looking now, we have articles on this: Uniform Determination Of Death Act (for U.S. jurisdictions), brain death, persistent vegetative state. - Nunh-huh 13:19, 31 July 2008 (UTC)

Feasibility of a vapor and vacuum-based engine?

I apologize if this is too far beyond the scope of the reference desk, but I'm hoping someone more versed in mechanics and fluid dynamics can entertain a thought that I had. Considering that one of the drawbacks of the standard steam engine is the necessity of a fuel source and therefore thermal waste, I imagined something a bit different, and I'm severely interested in knowing if there are similar ideas or instances out there.

In my version, a chamber filled with water or a low-boiling liquid is subjected to a vacuum created by the same liquid being forced over a liquid-impermeable membrane. The subsequent vapor is collected, perhaps with the encouragement of a turbopump, before it can escape into the flow system, compressed by an electric apparatus (but not to the point of liquification, which seems to work for the steam engine) and then injected (Is this possible? Can one inject air from a vacuum without condensation?) to the pistons, which also probably have to be under vacuum to eliminate the need for a high-pressure injector. Perhaps a timed mechanism could be used to vent the "spent" vapor, allowing the piston to fall, after which it is fed into a condenser and back into the vacuum flow--and eventually back into the tank.

Please forgive me if some part of this makes it a horrible idea in terms of thermodynamics.  :) Goodbyegravity (talk) 07:35, 29 July 2008 (UTC)

-The problem I see is that your process could hypothetically generate power in the reverse process also (the whole process ran backwards). Check out Sterling Engines on youtube and Stirling Engine here at wikipedia. The problem I see is that the vapor will strongly resist leaving the vacuumoid region that it entered upon leaving the liquid (or water your choice). You can't "suck it" out, you'd have to displace it with another gas, or if you wish to convert it back to a liquid (condensation) is a very costly chemical reaction. That is your bottleneck. Its a good idea though, creative and original, I like it. Sentriclecub (talk) 09:26, 29 July 2008 (UTC)

I didn't quite follow everything, but what I did did seem to make sense though the reversability of the reaction makes me question it a little bit. DISCLAIMER: I'm not a lawyer. However, you should know that because all content on Wikipedia is lisenced under the GFDL thereby putting your idea into the public domain for free use with unlimited changes as long as there is attribution to the original source. If I am interpreting correctly, I believe this makes your idea now non-patentable, but you should really ask someone more experienced. EagleFalconn (talk) 14:16, 29 July 2008 (UTC)

Aside from the energy input from the proposed pumps and compressors, it seems to me that you're hoping to use the semipermeable membrane as a sort of Maxwell's demon. If you're hoping to see more energy out than you put into the pumps and compressors, then you're going to be disappointed. TenOfAllTrades(talk) 15:12, 29 July 2008 (UTC)

Thank you all so much for your responses! I am not certain what is meant by the possibility of the reverse process; the main vacuum flow should be capable of receiving liquid from one direction, and liquid should not enter it where the flow leads into the containing tank, if that is to what you are referring. The condensation mechanism is indeed what I feared to be the bottleneck as well, but perhaps it would only have to be repressurized to change faces (this might make some other parts of this device useless). The page on Maxewell's demon is a little complex for this early in the morning, so I will check it out in a little while. And @ Eagle: if this idea pops up in some incarnation, I wouldn't wish it to be patented anyway. I want to leave a lasting impression on chemistry, not the automotive market. :) goodbyegravity (talk) 18:00, 29 July 2008 (UTC)

I think possibility of getting energy from the reverse process implies that it would be a perpetuum mobile, which proves that it can't work. But in any case, I think you would be interested in the Heat pump article and the articles it links to. Using the waste heat from engines or other temperature differentials to produce electricity is not a far-fetched idea. EverGreg (talk) 10:32, 31 July 2008 (UTC)

Teeth during pregnancy

Please see Wikipedia:Medical disclaimer : as such we cannot give medical advice.

• This question has been removed as it may be a request for medical advice. Wikipedia does not give medical advice because there is no guarantee that our advice would be accurate or relate to you and your symptoms. We simply cannot be an alternative to visiting the appropriate health professional, so we implore you to try them instead. If this is not a request for medical advice, please explain what you meant to ask, either here or at the talk page discussion (if a link was provided).

question and responses hidden

My wife is about three months into her pregnancy and has just discovered she has started growing a new tooth! Could this be related to the pregnancy or just coincidence? Iiidonkeyiii (talk) 09:26, 29 July 2008 (UTC)

Well, humans go through 2 sets of teeth in their lifetime. Pregnancy horomones like FSH and LH do not play a role, sorry. Sentriclecub (talk) 09:42, 29 July 2008 (UTC)

This is too much a request for a medical diagnosis to be answered. You have given a symptom (what you believe to be a new tooth and not a lodged popcorn kernel or bone tumor or one of many other things that have been thought to be a new tooth by people in the past). You have asked for validation of your diagnosis: pregnancy hormones leading to new tooth growth. We do not validate self-diagnosis. This is a reference desk. If you want references for studies on the effects of pregnancy hormones, please ask. -- kainaw™ 12:11, 29 July 2008 (UTC)

What ? Since when is growing a tooth a "medical condition" ? It's a normal part of human growth, and, in this case, most likely just the coincidental natural eruption of a wisdom tooth. Calling this a medical diagnosis is quite absurd. And suggesting that the poster can't tell a tooth from a popcorn kernel is equally absurd. StuRat (talk) 03:56, 30 July 2008 (UTC)

(Not answering because of diagnosis issue, just asking for clarification.) How many adult teeth has your wife had before? 28? 32? Some other number? —Keenan Pepper 13:16, 29 July 2008 (UTC)

Although I cannot say what's happening in your wife's case, I will note that wisdom teeth usually grow in during the teens/twenties, even if a person is not pregnant. At any rate, I would recommend consulting a Dentist, as the appearance of new teeth, even wisdom teeth, has implications for the alignment of bite. Teeth that grow in during adulthood (such as wisdom teeth) are usually removed as they may push against old teeth, forcing them out of alignment. Depending on how they grow in, they may not *need* to be removed, but only a licensed Dentist who can physically examine the patient's mouth can make a proper determination. -- 128.104.112.147 (talk) 17:57, 29 July 2008 (UTC)

I have heard of some people growing three sets of teeth in their lifetime. Cecile Adams will probably debunk me, but I'll have a look for a link. Plasticup ^T/C 19:04, 29 July 2008 (UTC)

Hyperdontia: growing more teeth than normal or even growing a third set of teeth. This happened to one of my relatives, but I forget what he did about it. A visit to the dentist is an excellent idea.--El aprendelenguas (talk) 20:36, 29 July 2008 (UTC)

Please note that a discussion on the talk page about whether this question constitutes medical advice may be found here: [2]. StuRat (talk) 05:28, 30 July 2008 (UTC)

Nature paper

I am doing some research for a paper about Wikipedia's reliability and I have come across this paper. However I do not have a subscription to Nature and am wondering if there is a copy stored on a Wikipedia server someplace? Or perhaps someone has the PDF? Thanks! P.S. Can you copy whatever answer onto my talk page? Bstone (talk) 10:56, 29 July 2008 (UTC)

Please note that Wikipedia is licensed under the GFDL. Because of this, placing a PDF of this article onto Wikipedia would violate the authors' copyrights by co-opting the article without their permission and placing it into the public domain. While academic fair use is common, particularly among peer reviewed journals, doing this would not fall within those terms. EagleFalconn (talk) 14:20, 29 July 2008 (UTC)

Minor quibble—material on Wikipedia is not by default in the public domain. That term has a specific legal meaning, and Wikipedia emphatically does not release its content in that way. The GFDL – under which our textual content is released – is a specific license enumerating the ways in which we permit our still-fully-copyrighted material to be (re)used. Care should be taken not to conflate or confuse 'GFDL-licensed' and 'public domain'. That said, EagleFalconn is entirely correct that Wikipedia does not can cannot host material that is not under a free license, and that posting an article without the copyright holders' permission would be an abrogation of their rights. TenOfAllTrades(talk) 15:04, 29 July 2008 (UTC)

From a quick Google [3], I found this [4] apparently legit reproduction (although I have my doubts whether Trevor was really supposed to make it publicly accessible but he is apparently a librarian so one would hope he knows what he's doing Nil Einne (talk) 15:11, 29 July 2008 (UTC)

(Why would one assume a librarian knows anything about copyright law? Usually they aren't any more informed than anyone else on such things. But it's his problem, not yours.) --98.217.8.46 (talk) 20:50, 29 July 2008 (UTC)

I would expect a librarian to be familiar with enough copyright law to know which things in their library it's ok to put under the photocopier. More than that, they probably aren't generally too knowledgeable. --Tango (talk) 02:06, 31 July 2008 (UTC)

I'm not talking about knowledge of copyright law, but knowledge of what stuff they may legally re-distribute, copy, etc and also the smarts to know who to ask when they're not sure. Perhaps I'm mistaken but I expect most would need this sort of knowledge because if not, they're the ones responsible when they screw up and given what they do. And actually, it is against wikipedia policy to post links to sites violating copyright violation and I avoid doing it as much as possible hence the reason I was unsure whether to post this. In any case, I would expect even if their knowledge is not sufficient, the average librarian is more informed then the average person about copyrights because it's something they do deal with to some extent whereas most people don't deal with copyrights much. (I mean how many people have you come across who think "if someone put it on the internet it's fine for me to copy it whenever and however I like"? For me the answer is a lot but I would expect most librarians at least have more knowledge then this.) Nil Einne (talk) 08:46, 1 August 2008 (UTC)

If you do use this article as a source, please also read the additional data subsequently released by Nature, Britannica's reply, and Nature's reply to Britannica's reply (all of which are linked from the Nature page). Despite its publication in Nature this study doesn't seem to have passed peer review. My subjective impression after reading the whole exchange is that the study was poorly conceived and executed and its results are scientifically valueless. -- BenRG (talk) 19:09, 29 July 2008 (UTC)

The study compares the Wikipedia you can get for free from the internet to the Britannica you can get for free from the internet. In this way its pretty reasonable, although Britannica has additional layers you can obtain for cash. WilyD 20:53, 29 July 2008 (UTC)

The question is whether it was reasonable to compare the two, but whether it was executed and formulated well. Personally I'm not so sure whether it was even reasonable—the sorts of things Wikipedia is good at are things that Brittanica is often bad at; the sorts of things Wikipedia is bad at are things that Brittanica is usually pretty good at. In any case, Brittanica and Wikipedia have very different approaches not just to content generation, but content epistemology: Brittanica wants to be correct, Wikipedia wants to report on what other people think is correct. There's a big difference there. --98.217.8.46 (talk) 22:57, 29 July 2008 (UTC)

Although it doesn't fall strictly under the scope of their project, in the future you may want to try posting requests for published material like this at Wikiproject Resource Exchange. It's only intended to assist research for wikipedia articles, but it's an incredibly powerful and underused resource, so I imagine any reasonable request you post will be answered. --Shaggorama (talk) 08:07, 30 July 2008 (UTC)

I actually took care of the OP request within about 30 minutes and should have posted to that effect here - but I was responding on the Help Desk, acting as a WP:WRE member.

I did mention the library at the help desk and I'll wholeheartedly second Shaggorama - powerful, underused and somewhat unknown resource where you can get copies of most everything. The more people who use it and the more people who provide to it, all the better! I've just now found that my library card gives me access to all kinds of previously costly resources, so I need to update my entry over there. Please everyone, the more we participate at the Resource Exchange, the more powerful it will be. Franamax (talk) 02:20, 31 July 2008 (UTC)

Different approaches doesn't really matter however since from a user's POV, all that matters is the result. Remember this isn't about politics. Also remember that Nature is a scientific journal. Their primary interest is science. I don't think it's surprising then that if they want to compare the two, they will do it on science, not of Pokemon or historic people or developing country politicians or whatever. This obviously isn't a complete comparison of the two, but a comparison of the two in a scope of most interest to the journal's audience. And I would say it is relevant. While encylopaedia's are usually not used in an academic context, they are useful on occasion sometimes even for student papers. If you're going to be rejecting use of wikipedia because it's inaccurate but accepting Britannica, then you want to be sure your view is correct. Also, most scientist's have interest in how well people understand science. As both wikipedia and Britannica are a big part of that, with wikipedia becoming even more significant, it's likely to be of interest to see how good, or poor, a job they are doing of it. Finally remember that most people I think when looking for something, if they are going to check an encylopedia are not going to have the detailed knowledge of which encylopaedia they should choose. Nil Einne (talk) 09:01, 1 August 2008 (UTC)

Organic chem

My daughter is 1 class away from graduation(organic chem). She must have this class and has twice failed it. Is there something like an organic chem form dummies textbook that would help?129.112.109.251 (talk) 14:36, 29 July 2008 (UTC)

You might try an online retailer or a large bricks-and-mortar bookstore. Organic Chemistry I for Dummies is in stock on Amazon.com. Also available is The Complete Idiot's Guide to Organic Chemistry, if you're looking for other humbling titles. (There is apparently an accompanying workbook available for purchase with the Dummies title.) Note that I haven't reviewed either book and can't offer a specific endorsement, but it appears (from Amazon's Customers Who Bought This Item Also Bought section) that there are a number of titles in this field—your daughter is by no means the only person to have difficulty with organic chemistry. TenOfAllTrades(talk) 14:58, 29 July 2008 (UTC)

I'm actually holding my Organic chemistry "Quick study guide" UPC 781572-225541 It is $5 from [here barcharts.com] and their phone number is 1800 230 9522 I never liked organic chemistry, so I used flash cards and laminate study guides. Sentriclecub (talk) 15:01, 29 July 2008 (UTC)

Find out why she failed. Organic chemistry, unlike other chemistry classes, requires the memorization of a lot of compound structures. If she isn't memorizing them, she won't have a shot at answering the questions on the exams. If she is memorizing them, she is failing in the interaction between compounds. Since those are two very different areas of learning (one is memorization, the other a functional understanding), you don't want to waste time focusing on one when the problem is the other. -- kainaw™ 15:01, 29 July 2008 (UTC)

Second Kainaw's point. I'm a free tutor for organic chemistry and so I see all types of people. One of the really common mistakes I see is people taking that point too far. While organic does, unfortunately, require some level of memorization its important to choose what to memorize and what to learn. Hopefully since your daughter has already taken the class twice she has at least a basic level of understanding of much of the material. Assuming she's taking a one semester course intend for biology majors or the like, the really important thing to memorize is nomenclature.

Outside of that, the vast majority of organic chemistry she'll encounter can be understood as lewis acid and lewis base behavior. Find the places of high electron density and find the places of low electron density, thats your nucleophile and electrophile respectively. Being able to identify those areas is really important. I suggest she review her general chemistry textbook on VSEPR theory. Our article is decent on the matter, but her textbook is probably better. Have her read our article on the Sn1, Sn2, Elimination reactions (for E1 and E2) and review her textbook on those reactions before the semester starts. A thorough, complete, detailed understanding of those four reactions is key. If she can understand those in terms of Lewis Acid/Base behavior, she can understand the rest of the class in terms of those reactions (with the notable exception of the Diels-Alder reaction). If she gets really gung ho, have her read all of [5]. EagleFalconn (talk) 15:34, 29 July 2008 (UTC)

One thing I've noticed about ochem (I'm still taking it; see my later question) is that a lot of stuff is quite difficult to derive from basic principles as opposed to inorganic chemistry. So like others have said, you do need to memorize. But you also need to be able to apply memorized concepts to new problems. I have found that the only way around it is lots of practice problems. Lots. Doing all the ones in the book might not even be enough, if she has failed it twice. --M1ss1ontomars2k4 (talk) 04:35, 2 August 2008 (UTC)

igneous rocks

igneous rocks are classified on the basic of what factor?

See Igneous rock and ask again if you don't get an answer in the first sentence. -- kainaw™ 17:27, 29 July 2008 (UTC)

do we explode in outer space?

Hi, if you were released into a zero pressure environment, like outer space without a suit, would you explode because of the greater internal pressure? Would your blood boil instantaneously? Thanks in advance, 202.89.166.179 (talk) 17:32, 29 July 2008 (UTC)

Please see Human_adaptation_to_space#Unprotected_effects. -- Coneslayer (talk) 17:35, 29 July 2008 (UTC)

Thanks very much for the link. I haven't read it in full yet, but it seems like a brilliant article, and pretty much on the way to featured status. Fascinating stuff. 202.89.166.179 (talk) 18:04, 29 July 2008 (UTC)

Follow up question

I just noticed that the article mentions barotrauma, but doesn't explain why the astronaut who was exposed rapidly to near-zero pressure didn't suffer/ die from it. The barotrauma article itself doesn't help much, either. Does anyone know what the reason might be? 202.89.166.179 (talk) 18:16, 29 July 2008 (UTC)

S/he doesn't explode because skin is tough enough to withstand a sudden drop from one atm of pressure to (near) zero pressure. See Explosive decompression and Cecil Adams' take here. --Sean 14:31, 30 July 2008 (UTC)

fast room cooling solution

Dear Wikipedians:

I love my little study upstairs. It is a small, cubic room that is enclosed (when I close the door). I loath to part with my study.

However, one big problem is that during the summer, the central A/C does not have enough power to keep my little study cool (and since warm air travels upwards, hot upstairs is a common problem that plague all north american houses). This gets especially bad in the afternoon when the sun shines directly into my study through the window. So I'm forced to flee my little study into my dad's study downstairs. And since it's my parent's house, there's no way that I can request the drilling of a hole on the wall of my study for me to install a window type air conditioner just for myself.

So I am wondering, is there any simple way to cool my study down fast? I am thinking of making big chunks of ice and put them into my study to absorb heat. But thought dry ice/liquid nitrogen might be faster for this purpose. From Michio Kaku's documentaries I know now that liquid nitrogen is as cheap as milk, so that's why I thought liquid nitrogen might be feasible for me, but I'm afraid I might asphyxiate if I don't do it properly.

I'm also wondering if there are small/portable air conditioners that don't require me to drill holes in walls in order to use them.

Any suggestions are much appreciated.

76.68.11.220 (talk) 20:38, 29 July 2008 (UTC)

How about just a fan? And are your parents really going to be that unhappy about the two small screws used for most window units? You could offer to spackle them over if they want to sell the house. (God knows that the two screw holes are going to be the least of their problems these days.) As for "alternative methods", I suspect it will be far too much hassle to try and cool your room with chemicals of any sort, and probably a losing battle in any case. --98.217.8.46 (talk) 20:47, 29 July 2008 (UTC)

First off, I'd recommend using curtains to block the sunlight coming in through the window. Judicious use of curtains can keep a room substantially cooler. Secondly, what sort of window is it? Can you install a (small) window air conditioner in it? If the window is too small, you may look into portable air conditioners. From ref 1 (McAfee) on that page: "Portable ACs are similar to the window units ... They suck the hot air from the room and send it outside through a flexible tube that looks like the bendy part of a straw, which you stick in a slat that seals up your window." I was able to find portable air conditioners for sale at the websites of several big home improvement stores in the US (Walmart, Home Depot and Lowe's). If the window is an odd shape, you may be able to cut an appropriate shaped plug from Styrofoam type sheet insulation. (Also conveniently available from home improvement stores.) Good luck. -- 128.104.112.147 (talk) 20:59, 29 July 2008 (UTC)

My window is those plain-vanilla type house window half-sealed with immovable glass, the other has a mosquito screen that cannot be opened. It's about 1.5 meters by 1.5 meters, the halves are vertical panes, and are therefore unsuitable for air conditioners.

Too much dry ice in an unventilated sunny room may actually kill you, or at least give you a very bad headache. 10% CO2 in air will kill you in minutes; for a 25 cubic meter room that is 4-5 kilogram of dry ice evaporated, maybe less if the air doesn't mix well. Don't do this with dry ice, ever. --Dr Dima (talk) 21:34, 29 July 2008 (UTC)

A portable air conditioner won't help you in a small enclosed space if you have no way to vent the heat ejected from the air conditioner exhaust.

If the air is reasonably dry, and you do have ventilation from the house, I recommend a portable swamp cooler. You fill it with water, and it blows air past an evaporator to cool down the air. We have one and we use it in the summer. ~Amatulić (talk) 21:45, 29 July 2008 (UTC)

Light doesn't result in a lot of heat. It is the actual heat from the sun that is heating up the room. There are many relatively cheap window coverings that block much of the heat without blocking the light. That is why most office building have that shimmery look on the windows - they all have reflective film on them that reflect heat without much light. As for the AC, if you are shutting your door and the room is relatively air-tight, then it won't benefit from a central AC system. You've basically closed off the vent. The air needs a way to make it to the return duct. In my house, there is a one-inch gap at the bottom of all the doors. It was easy to do and most people don't notice. I've seen vents directly through walls and little U-shaped vents going through the attic. The main goal is to ensure the room is not air-tight. -- kainaw™ 02:26, 30 July 2008 (UTC)

You might hose down the outside of the house in the vicinity of the study. This will evaporate and cool the walls before the heat finds it's way into the study. And, if you haven't considered it already, try closing (inasmuch as they can be closed) the vents in the rest of the house so more A/C will make it to you. Finally, I've got two window A/C units and never bothered to put the screws in. They are an important anti-burgler protection on the ground floor, but I would assume a burglar would need to use a ladder to get to your study, which would be rather too obvious for the average burglar to consider. I do, however, cut a chunk of wood to the proper size to keep the window from opening further, thus preventing the A/C unit from falling or being removed. StuRat (talk) 03:45, 30 July 2008 (UTC)

Eating and/or drinking something cold, while in minimal clothing, with a fan blowing on you, will also greatly reduce the need to cool the room. StuRat (talk) 03:48, 30 July 2008 (UTC)

Hosing off the house might cool down the walls of your study, but it would take some dilligent hose work to keep your study from heating up that way. I'd suggest saving the water and investing in curtains and a fan per the other posters. If the window you were complaining about can be openned, I'd suggest pointing a fan AT the window --with the door to your study open-- as an experiment. If you're lucky, you may be able to get enough negative pressure (if the fan is sufficiently powerful and aimed properly) to induce an air flow and suck some of the cool air from the rest of the house into your study. Consequently, this will also increase the load on your AC since you'd also be ejecting cool air from the house. --Shaggorama (talk) 08:21, 30 July 2008 (UTC)

Point the fan at a closed window ? That won't help. Did you mean to point the fan at the open door to the study to create suction in the room ? That might help, but pointing the fan directly at the person is likely to make more of a diff. If they have two fans, then one fan pointed each way might work. StuRat (talk) 13:42, 30 July 2008 (UTC)

Actually stu, I meant openning one window and pointing the fan at it with the door open. It's a firefighting trick called negative pressure ventilation. If you push air out the window and the fan is set up in such a way as to minimize churning air though the opening, then it creates negative pressure in the room, sucking air in from the doorway and creating a draft towards the window. Presuming the rest of the house is colder, it could bring some cool air into the room, although it will make the A/C work harder because he'd be stealing cool air from the rest of the house and sending some/alot of it outside. The effectiveness of this strategy for the OP's purposes depends on the position of their study in the house and the power of the fan they use, but it's still worth a shot. --Shaggorama (talk) 14:29, 30 July 2008 (UTC)

In the long term, creating a better microclima in the vicinity will reduce temperatures by several degrees. That's why cities with many trees (e.g. Berlin) have less problems in summer. --Ayacop (talk) 08:49, 30 July 2008 (UTC)

My previous house had a 10+ degree difference in the upstairs/downstairs temperature. I fixed it and lowered my electric bill by improving the insulation in the attic. I'm sure your folks wouldn't mind if you volunteered to do that for them! It only takes about a day (a very unpleasant day, but still). --Sean 14:37, 30 July 2008 (UTC)

Thanks for all the input. I appreciate it very much. I think that for now I will go with the fan suggestion, with a twist -- my mom told me yesterday to set a large chunk of ice in front of the fan and let the fan flow air around ice, then air will come out icy-cool like the air conditioning. I will try the portable and swamp coolers when I get the chance. Thanks again for all the help. 76.68.10.189 (talk) 15:49, 30 July 2008 (UTC)

I'd avoid any method that's going to increase humidity. It may actually be a lower temp, but that high humidity will make it feel hot and muggy. StuRat (talk) 23:37, 30 July 2008 (UTC)

Not in all cases. Swamp coolers have been around forever because they work. If the OP lives in a dry climate, they work even better. If it's humid, you need to bring in new air and exhaust the old. I can say our portable swamp cooler works reasonably well. ~Amatulić (talk) 00:08, 31 July 2008 (UTC)

Tallest mountain in Earth's history?

Mount Everest is obviously the highest point above sea level on Earth. I'm curious if there is any geological evidence of a taller mountain having existed at some point in Earth's geological past. What kind of evidence for prehistoric mountains might there be? Rocks showing signs of immense pressure? Reconstructions of collapsed volcanoes? Guess based on continental plate shifts?

Note: I've asked this question on some other forums and heard a lot of Chimborazo, Mauna Kea, and Olympus Mons. Those mountains are cool too, but I'm asking about a point on Earth higher above sea level than Everest.

192.12.16.65 (talk) 20:44, 29 July 2008 (UTC)

The maximum height of a mountain on any planet with a fluid interior is limited by isostasy, or the buoyancy of lithosphere material overlying denser mantle material. Think of an iceberg floating in seawater. Another limit is due to the finite material strength of rock in the brittle upper crust. On Mars, Olympus Mons rises nearly 25 km (80,000 ft) from the surrounding plain, more than 2.75 times the height of Everest. This sort of mountain is only possible due to the weak gravity and thick lithosphere on Mars; if you put Olympus Mons on Earth, it would collapse under its own weight due to isostatic equilibrium and structural failure. The total relief on small, icy worlds like Titan and Europa is typically less than a kilometer.

Good question. While I don't know the answer, I do have a suggestion about where to look. The largest current mountains are the result of the collision of the Indian Subcontinent Plate and Asia. This suggests that the collision of two full continental plates may produce even higher mountains. The major continental plates have collided many times in the past, as part of the supercontinent cycle. I would suggest that the initial impact points of the plates would likely be the location for the highest mountains.

The other source of large mountains, volcanoes, doesn't seem as likely to have produced the highest mountain, for a couple reasons. First, note that current volcanic mountains are not as high above sea level as those formed by uplift (although some are higher when measured from the sea floor). Second, note that supervolcanoes don't form a massive single cone, but many smaller surface ruptures. Meteor impacts might also form high mountains, but I'd expect that any that would form peaks bigger than Everest or K2 would liquefy the rock so that it would immediately collapse again. StuRat (talk) 03:30, 30 July 2008 (UTC)

According to Canadian_shield#Geology, the Canadian Shield once had mountains 12 000 m high. However, the article cites a grade 9 geography textbook as its source, and the textbook mentions only that mountains of that height covered the Shield during the Precambrian. I can't find any sources confirming the textbook's claim.

As for the evidence that mountains existed, rock deformation is the best indicator (see orogeny). --Bowlhover (talk) 09:23, 30 July 2008 (UTC)

Excellent, thank you for the answers. I also found a reference to 40,000-foot peaks from that same textbook, unsurprisingly I suppose, in the mountain article. The supercontinent cycle article also mentions that sea levels drop when the continental plates are pushed together into a supercontinent, so that may be another place to look, even if lowering the sea level seems kind of artificial. 192.12.16.65 (talk) 16:20, 30 July 2008 (UTC)

Mount Everest isn't the tallest mountain. It's the one with the highest peak. The tallest is Mauna Kea, which is much lower than Everest, to the point of being mostly underwater. Do you want to know if there was a peak higher than Mount Everest, or a mountain taller than Mauna Kea? 67.182.169.172 (talk) 15:56, 30 July 2008 (UTC)

The questioner made clear that he is interested in highest point above sea level. Nimur (talk) 16:48, 30 July 2008 (UTC)

Mount everest may be even taller, if you think of most of it as being underground (below sea level)! :-) --Itub (talk) 17:14, 30 July 2008 (UTC)

So I'm driving in my car

and picking my nose. Is this wise? If I have a car crash will I poke my brians out? —Preceding unsigned comment added by 86.144.124.43 (talk) 21:32, 29 July 2008 (UTC)

It is neither wise nor unwise. It just is.

The destination of your finger in a crash depends how you crash. ~Amatulić (talk) 21:41, 29 July 2008 (UTC)

I have a ten-minute comedy routine on this exact subject :) The airbag deploys with a lot of force. What would the hospital ward be like where they put the nose poking cases? There was an urban legend long ago that cellphones would set off the airbags in BMW's - I always wanted to drive around 'til I saw someone in a Bimmer picking their nose, then give them a call. I could go on... :) Franamax (talk) 22:24, 29 July 2008 (UTC)

Mind you, we are not allowed to give medical advice here! 93.132.155.253 (talk) 22:26, 29 July 2008 (UTC)

I'm tempted to suggest you fastrack poking your brain by poking your eye. So I'll resist. Julia Rossi (talk) 05:20, 30 July 2008 (UTC)

If you're picking your own nose, Brian should be fine. Remember, you can pick your nose, and you can pick your friends, but you can't pick your friend's nose. -- Coneslayer (talk) 11:27, 30 July 2008 (UTC)

Reminds me of another sketch that had the line: You can prick your finger, but don't finger your...

~Amatulić (talk) 00:03, 31 July 2008 (UTC)

Coroner: "cause of death is brain trauma due to involuntary nasal finger-poke."

Mom: "I told you if you kept putting your finger in your nose it would get stuck that way!"

Oh please shoot me now. I promise I won't post again to this thread :) Franamax (talk) 09:15, 31 July 2008 (UTC)

Missed or irregular heart beats

Is there any info on what may cause this phenomenon? —Preceding unsigned comment added by 79.76.156.194 (talk) 22:33, 29 July 2008 (UTC)

Our article on cardiac arrhythmia links to a lot of information and all of the key Wikipedia articles on the topic. TenOfAllTrades(talk) 22:46, 29 July 2008 (UTC)

...although I rather suspect that when people subjectively report that their heart "missed a beat" that in fact no significant physical or physiological event occurred, bar perhaps a little jolt of adrenaline. -- Finlay McWalter | Talk 22:49, 29 July 2008 (UTC)

Pathophysiologically, it's usually a result of coronary artery disease or electrolyte imbalance. However, missed beats and small irregularities are not uncommon in a healthy individual. Wisdom89 _{(T / ^C)} 00:44, 30 July 2008 (UTC)