Science desk
< December 7	<< Nov \| December \| Jan >>	December 9 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

December 8

Ulysses butterfly

If the Ulysses butterfly is only found in Australia, New Guinea and the Solomons according to the article, then how did two of them wind up being photographed in Vienna as the main page picture says? 24.23.196.85 (talk) 02:10, 8 December 2013 (UTC)[reply]

Click on the picture. ([1]) It says it was taken at a butterfly zoo. This makes good sense from the point of a view of a photographer looking for beautiful pictures like this, because he can take shots any time of year, in comfortable circumstances, with freshly eclosed butterflies that don't have any nasty little nicks and faded spots. A purist might argue it is not a spontaneous ecological environment, however. Wnt (talk) 02:35, 8 December 2013 (UTC)[reply]

Native North American genetics

I was reading an article this evening and there was the following statement: " Natives possess a genetic marker that enables them to better endure starvation conditions. The same marker also makes them more susceptible to alcohol . . . "

The "drunken Indian" stereotype aside, is there any fact associated with this statement? 173.35.158.194 (talk) 05:23, 8 December 2013 (UTC)[reply]

Yes, in fact many American Indians lack liver enzymes that break down alcohol -- which means they get drunk easier, stay drunk longer and are more likely to become alcoholics. 2601:9:3200:467:5527:C9C7:A04:2CD5 (talk) 05:26, 8 December 2013 (UTC)[reply]

But I don't see why that would help them to survive long periods without food. StuRat (talk) 10:34, 8 December 2013 (UTC)[reply]

The "endure starvation conditions" sounds like the "thrifty gene hypothesis" purporting to explain the high prevalence of genes for diabetes (studies were performed on Native Americans, Inuits, etc., newly exposed to Western diets. But different genes are involved; it's not the same as alcohol dehydrogenase deficiency. And it's also not proven. Pima Indians are particularly affected. (And I'd like to note in passing that I think the original article was a little "loose" in the use of the term "marker": for me, a "marker" indicates a condition but doesn't cause it; it's something that correlates with the genetic anomaly being discussed, rather than being that anomaly per se.) - Nunh-huh 12:00, 8 December 2013 (UTC)[reply]

There seems to be some confusion in third thread, particularly in the first answer. Alcohol flush reaction is prevalent among East Asians particularly those of Han Chinese descent. I'm not aware it's prevalent among Native Americans nor does our article suggest it is. In particular, AFAIK and supported by the article it's not generally associated with increased levels of alcoholism rather reduced levels.

The most likely reason is because it makes the undesired effects of drinking alcohol much more acutely felt. In fact, as per our article, it possibly also ~~produces~~reduces (sorry that got screwed up in one of my edits) the desired effects of drinking alcohol in some cases (there appear to be multiple genes with multiple alleles involved).

From a few simple searches, I found [2] which suggests that Native Americans do not generally have the alleles associated with the flush reaction, and those that do often show the same trends, i.e. lower levels of alcoholism. Notably the study also suggests the reasons for the higher levels of alcholism among native American populations are not that well known and have no clear genetic cause. It was from 2007 [3] so it may be outdated (I didn't look much more) or it could be simply wrong, but my guess is it's probably still largely correct.

But even if we have better evidence now, given the possibly great diversity and complexity, it would be wise to be cautious with any research which appears to have identified a causal factor. Considering this, I don't think I would trust any source which talks about markers making them susceptible to alcohol. As Nunh-huh has said, the use of the term marker also seems rather unclear. (And I would note even if they had only identified a marker, nowadays it would not generally be that hard to find putative genes involved.)

And I'm further in agreement with Nunh-huh (as is our article) that the thrify gene hypothesis is still fairly contentious, and suggested to exist among several other populations besides certain native American ones. And I'm not sure that it's generally linked to higher levels of alcoholism.

Nil Einne (talk) 14:01, 8 December 2013 (UTC)[reply]

Endoplanet

I've seen exoplanets reported here and there. I was just wondering if there was such a thing as an endoplanet? Simply south...... eating lexicological sandwiches for just 7 years 14:36, 8 December 2013 (UTC)[reply]

An exoplanet is outside the Solar System so an "endoplanet" would be inside the Solar System, but the term isn't used. They are called Solar System planets, or usually just planets when the context is clear. PrimeHunter (talk) 14:45, 8 December 2013 (UTC)[reply]

For internal planets, see the hemorrhoid belt, inside the orbit of Uranus. μηδείς (talk) 01:09, 9 December 2013 (UTC)[reply]

Medeis FTW. I shot milk out my nose. And wasn't drinking milk. --Jayron32 03:38, 9 December 2013 (UTC)[reply]

That's not funny, Jayron. When I was in fourth grade, my best friend's little brother made me laugh so hard while I was eating over that I sprayed milk evenly over every surface in the kitchen, including the ceiling. The only thing that saved me from a fatal beating was that I was not a family member--I was simply sent home, and left gladly, and quickly. The tableau is burnt into my visual cortex. μηδείς (talk) 05:21, 9 December 2013 (UTC) [reply]

Repairing Things in Space

If you're on the International Space Station, chances are you may break something. How do you repair things? What kind of glue can you use?

I think most objects on the ISS are made of metal, glass, plastic or rubber. You may use Pritt to glue paper. But it can't be used on anything other than paper. Water-based white glue works well on woods. I guess there are no wooden chairs on the ISS.

Many other glues release solvents. They may be hazardous in a space station. Crazy glue has very low surface tension. It can form tiny floating droplets. I guess it is not a good idea. Rubber cement smells really bad.

Hot glue may be useful. However, they are very heavy and they may catch fire. On the other hand, they are not very strong. Epoxy glue takes much efforts to mix. This can be difficult when you're floating. -- Toytoy (talk) 15:04, 8 December 2013 (UTC)[reply]

Krazy glue (cyanoacrylate) comes in different formulations, some of which are pretty thick, and I think would be suitable. I don't know how they actually do it, though. Looie496 (talk) 15:19, 8 December 2013 (UTC)[reply]

The real answer is, by spending millions of man-hours designing parts that never break, because it's nearly impossible to repair things once they're on the ISS. Of course there are toolkits, zip-ties, replacement modules for critical pieces; but most stuff stays broken until a replacement piece arrives on the next cargo mission. Here's a NASA video about repairing a minor water-leak in a space suit: note how they keep mentioning "since last summer," because the leak didn't get fixed for months. I'll see if I can find a good interview or article about the ammonia leak that happened on ISS many months ago which was actually a potential risk to astronaut safety. Nimur (talk) 15:30, 8 December 2013 (UTC)[reply]

...Here we go, repaired after Expedition 35 arrived. And, WP:WHAAOE: International Space Station maintenance. Nimur (talk) 15:33, 8 December 2013 (UTC)[reply]

(ec) Regarding epoxys, you don't need to mix them manually. They make mixing nozzles (basically a tube with a bunch of internal back and forth wiggly bits [4]) that go on the front of dual syringe epoxy tubes . They're not ideal for your typical junk-drawer epoxy usage, as they're single use only (the glue will set inside), but if you're in a multi-billion dollar space station in zero-G using a specially formulated epoxy, having a single-use-only dispenser isn't all that much of a drawback. -- 162.238.241.136 (talk) 15:34, 8 December 2013 (UTC)[reply]

There's also the sort of 2-part adhesives used to repair and modify circuit boards in the electronic industry. These consist of the adhesive which comes as a viscous or fairly runny liquid depend on grade, and a spray on accelerator. Proviing the applied adhesive is kept to less than about 1 mm thick, the spray on accelerant works fine. No need for manual mixing. 120.145.176.236 (talk) 00:44, 9 December 2013 (UTC)[reply]

If selecting adhesives for ISS use, I would certainly be concerned about toxic vapors, such as come from the otherwise excellent adhesive E6000. Various companies advertise adhesives for space use, which work over a wide temperature range and do not outgas beyiond strict limits, See Masterbond, Wacker adhesives, An article by someone at Masterbond [5] notes that in low Earth orbit, atomic oxygen degrades adhesives used outside, and that cyanoacrylates are known for outgassing. The article discusses the use of various 2 part and one part epoxies in space. A distinction should be made between those to be used inside the craft and those outside, and use at high temperature versus room or low temperature, the exposure to solvents or acid, and the surface characteristics (porous or smooth). Adhesives for use outside might well be different from those to be used inside due to having to setup in vacuum and the high temperature range, as well as the UV radiation. RTV adhesive was used to hold space shuttle tiles in place, and if I recall correctly NASA had it in mind for possible in-spaced repairs. It can set up in vacuum and has a wide temperature range. Tape can also be handy. Duct tape was useful on the Apollo 13, to improvise a connection between different shaped air-handling components. It is still used in space, as is self stick Velcro, per [6]. Gorilla Tape seems to be a superior present-day duct tape. Rescue Tape is a self-fusing silicone tape useful from -65C to 230C and resistant to a wide variety of chemicals, so useful for patching hoses. Electrical tape could be useful for repairing and insulating conductors, as would heat-shrink tubing. A small kit of tapes and adhesives could be a lifesaver. Edison (talk) 01:43, 9 December 2013 (UTC)[reply]

Mir once tested a glue which could be used to seal tiny cracks in the hull. And of course there's Pritt: "successfully tested on board the International Space Station and was awarded Space Proof Quality". I assume they keep some aboard in case a Post-it note fails suddenly... Ssscienccce (talk) 08:26, 9 December 2013 (UTC)[reply]

And the NASA website says that Rubbn’Repair and Rec’Repair are the commercial versions of technology developed through a NASA partnership for repairs on board of the ISS. Quote: "To that end, NASA funded the design of a simple and reusable patch repair system for servicing structural components in space." Ssscienccce (talk) 10:40, 9 December 2013 (UTC)[reply]

Somewhat related, at least on the subject of how hard repairs are on the ISS, I rember watching the NASA channel as they were broadcasting the installation of some mundane piece of equipment live. It was something like a metal rail on an interior wall for holding another piece of equipment. They stripped one of the screws, and then it took at least half an hour (I think more) for them to decide the best course of action to continue the installation. If they had damaged screw more, then it could have ended up stuck there and drilling out a bad screw isn't something you want to do in microgravity. — Preceding unsigned comment added by Katie Ryan A (talk • contribs) 12:54, 9 December 2013 (UTC)[reply]

I recall that Apollo 13 carried duct tape (they call it "Grey Tape") which was the key to solving their famous air filter problem. Velcro is also used for some repairs. The ISS evidently has a sufficient supply of both.SteveBaker (talk) 15:15, 9 December 2013 (UTC)[reply]

Talking of 'quick' repairs, I have never seen the ISS astronauts on the televised down links -chewing gum – that ubiquitous substance that can pug almost any leak and stick all most anything together, on everything from the Enola Gay to a nuclear submarine. What has NASA got against chewing gum. It served the military so well for the last half of the century? NASA spent millions developing a pen that could write in space and the Russian's used a pencil. At least Chris Hadfield had the sense to take up an acoustic, sans tremolo arm nor wah-wah. --Aspro (talk) 17:48, 9 December 2013 (UTC) [reply]

That story about NASA spending millions on the space pen is complete and utter nonsense. The company that developed the pen had already spent the money doing the development of a very robust pen that would write upside-down, with no intention of them ever being used in space. NASA came along several years later and bought 400 of these already-on-sale pens at below normal retail price (less than $3 each - which isn't bad for a luxury pen!) The Russians (just like any other sane space-going people) did not give out pencils to their cosmonauts because in zero g, the dust and debris from a pencil would get into delicate switches and risk shorting them out - the Russians actually bought the EXACT same pens that the NASA astronauts carried - I don't know how much they paid for them. This is a great story - but just like so many others, it's complete bullshit. SteveBaker (talk) 21:57, 9 December 2013 (UTC)[reply]

Why the hysteria SB? I linked it to a Wikipedia section (did I not) which begins and I quote: A common urban legend states.... Also, 3$ for a pen! You where ripped off at even 2$. A Pencil... 25 cents.--Aspro (talk) 22:22, 9 December 2013 (UTC)[reply]

You said it was true - while linking to an article that (correctly) says that it's not true. I can only conclude that you didn't read the article you linked to until I told you that you made a mistake. No hysteria - just the facts. SteveBaker (talk) 22:30, 9 December 2013 (UTC)[reply]

No way did I say it was true. I gave a lead for those that where interest to follow up (with a come-on that YOU bit at)!

Oh! An' by the way. Your bit about the dust and debris from a pencil would get into delicate switches and risk shorting them out. Let's have the last word from Chris Hadfield. Not a US citizen... -one understands- but never-the-less a commander of the International Space Station – so he must know his stuff – yeah!? Quote: One user asks why astronauts carry pencils, to which Chris replies: 'pencils work in all attitudes and pressures, good in the cockpit. Unquote [7]. Trying to gain scientific knowledge through watching TV programs like Lost in space is not the way to go – after all, they where lost in space “Danger, Will Robinson -DANGER You are holding a pencil. If that graphite get into my circuits you will be doomed, to recording another 20 episodes.” (NASA has a channel where you can watch ISS pretty much constantly and see what their doing and what they are holding in their hands)--Aspro (talk) 23:32, 9 December 2013 (UTC)[reply]

So you expect us to believe that your editing strategy when answering questions is to write complete nonsense in the hope that this will provoke people to read your links? Either you're lying to cover your blatant mistake or you're one of the worst, most irresponsible editors we have here on the reference desks. You choose. SteveBaker (talk) 14:42, 10 December 2013 (UTC)[reply]

It is not complete nonsense. One theory as to why so meny Nobel prize winners where born and educated in Europe, is that their education system provokes students to question revived dogma. Many other people read WP Ref Desk and we don't wont to mislead them to believe every editors (not naming names) comments as the gospel truth -do we? You choose.--Aspro (talk) 17:43, 11 December 2013 (UTC)[reply]

If you'd read the article you'd linked to, you'd see that NASA was actually concerned about the exact things you just mocked Steve for describing! 75.69.10.209 (talk) 01:53, 10 December 2013 (UTC)[reply]

These were historic concerns. Like scientists of the 1800's saying a train will not be able to travel faster than 50 mph or the passengers will suffocate from not being able to breath. See my next statement.--Aspro (talk) 17:43, 11 December 2013 (UTC)[reply]

(purely speculation, but:) I assume NASA looks at very improbable risks and multiple levels of safety, potentially reconciling these statements. I certainly would not want to have to find a little piece of broken pencil lead that flies off in zero gravity, nor to absolutely guarantee that it can't possibly get crushed into a conductive layer when it gets caught in a dial as it is turned... Wnt (talk) 03:08, 10 December 2013 (UTC)[reply]

Exactly. A solid effort at improving the safety of spaceflight is to reduce every risk you can - even if it's a small one. Sure, the odds of a pencil shedding conductive material into a switch is small - but replacing a 50 cent pencil with a really high quality $3 ballpoint pen is a reasonable decision. I'd also point out that Apollo 11 nearly came to a very unfortunate end because of a broken lunar ascent motor circuit breaker - and was saved by using a pen tip to activate it. (There is some debate about whether it was one of the fancy "space pens" or just a regular felt-tip marker that did the job.) If they had taken pencils to the moon instead, there could very easily be two dead astronauts sitting on the lunar surface right now. It's no surprise then that NASA considers very carefully what goes into every gram of material we haul up into space and chooses the best option in every case. Sure, the difference between sending astronauts up with a $3 pen instead of a 50 cent pencil is small in terms of safety...but it's also negligible in terms of cost. Multiply that by the hundreds of thousands of similar decisions that they take for every mission and the results add up. Space travel is dangerous enough even with all of those careful precautions - but if they simply ignored them all, the total increase in mission risk would be appreciable.

I'd also add that for an investment of some $1,200 in "space pens" from NASA, the Fisher company who made them was able to promote the quality of that US-made pen throughout the world - they sold millions of them at a $40 to $60 price point - making tens of millions in profits - of which (presumably) a million or more was paid in taxes. This more than covered the $1,200 investment from NASA. So far from being a $1.2 million loss to the taxpayer (as the popular myth maintains), it was in fact more like a million dollar win for US taxpayers. SteveBaker (talk) 14:42, 10 December 2013 (UTC)[reply]

OK, Let use a pons asinorum: If an astronaut just floated in an aluminum can, s/he would soon suffocate in their own CO2 that they exhale. One of the soviet cosmonauts had this very problem when recommissioning one of their stations. So, orbital stations have air conditioning systems that create an air flow. That air flow brings most of the flotsam and jetsam to to air filters. The only thing that would attract this stuff to the circuitry is electrostatic force. Electronic surfaces are usually warmer than ambient, so that would repel this stuff. Also, they are coated with an electrically insulating epoxy lacquer. So any flotsam and jetsam – even iron fillings will not cause a fault. They have years to prefect this so that stray liquids, snot and stuff don't turn the lights out or worse (one can't send a repair man up at short notice to fix a problem like one can do on earth). The pencils I have seen them using on the ISS, appear to be chino-graphs – so no graphite dust problem there! Safety: A space pen cartridge is conductive and are pressurized. Of the pen and the pencil, which one offers the best failure mode? “And we've learned that the simplicity of the technology of the pencil is sometimes a more valid solution than the complexity of the highly capable, but more expensive, pressurized pen. [8]. So therefore, let us not mislead our other readers with unsubstantiated waffle. You choose and I will object and correct -if you choose more waffle.--Aspro (talk) 17:43, 11 December 2013 (UTC)[reply]

"Genetic code" - first mentioned in which "publication" ?

Who coined the term genetic code and published it for the first time? Erwin Schrödinger ist often mentioned in this context, but he used the terms „hededitary code-script“, „chromosome code“ and „minature code“ in his documented talks in 1943 (published as a book in 1944). Crick uses it 1962 in his (documented) Nobel speech. So the reading frame is 1944-1962. When was it published first - and where? Highly appreciate your input! GEEZER^{nil nisi bene} 15:16, 8 December 2013 (UTC)[reply]

Google Scholar is useful for things like this, because it allows searches of the scientific literature with a restricted date range. The earliest use I find is Waddington, C. H. "The mechanism of the genetic code of development." J Genet 1941.suppl (1941): 310-311. Of course he couldn't have meant the genetic code as we now understand it, since the structure of DNA was not known at that time. (By the way, your use of the term reading frame suggests that you probably don't understand what it means.) Looie496 (talk) 15:40, 8 December 2013 (UTC)[reply]

FWIW, I took Geezer's deployment of the term to be a deliberate contextual pun. {The poster formerly known as 87.81.230.195} 90.201.159.157 (talk) 17:52, 8 December 2013 (UTC)[reply]

Although a biochemist, I admit to occasional fits silliness... Thank you very much for the Reference (and for the acquaintance with C. H. Waddington,! Very interesting fellow...)! I'll look into that. GEEZER^{nil nisi bene} 09:08, 9 December 2013 (UTC)[reply]