Wikipedia:Reference desk/Archives/Science/2013 August 22

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August 22

if Mars still have more greenhouse effect like Earth

Before I didn't think planetary atmosphere and compositions are important in determining habitable zone but my college professor told me planetary atmosphere and composition are important to determine where the habitable zone will be, so if Mars have more greenhouse effect and atmosphere pressure roughly same that of Earth will it be much warmer than it is now? If it will be warmer than what will the average planetary temperature be? 23 F? If Titan didn't have any greenhouse effect will Titan be even colder?--69.233.252.198 (talk) 02:14, 22 August 2013 (UTC)

To determine the final temperature you'd have to know exactly how much greenhouse effect there will be. Venus is an example of a runaway greenhouse effect. The gas giants also have a pronounced greenhouse effect, although there they may be heated more by internal sources (radioactive materials, tidal forces, etc.). StuRat (talk) 09:12, 22 August 2013 (UTC)

The OP's question about Mars reminds me of what Carl Sagan had to say about the possibility of terraforming Mars and Venus. For Mars, you have to create greenhouse effects somehow. For Venus, it's the opposite - you have to introduce something that will somehow consume greenhouse gases. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:20, 23 August 2013 (UTC)

The immediately obvious solution would be to funnel enough of the gas from Venus to Mars.... 86.141.186.4 (talk) 12:53, 23 August 2013 (UTC)

Sure, a flexible, stretchable conduit of some kind, hundreds of millions of miles long. That shouldn't be too difficult to engineer. Kind of like a gigantic siphoning hose. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:34, 23 August 2013 (UTC)

Wormhole X-Treme! --Stephan Schulz (talk) 14:39, 23 August 2013 (UTC)

Heh, he's got a point. There are a lot of things that aren't too difficult to engineer, it's just the building part that gets you. :) But at least in fantasy you could use an elaborate system of momentum exchange tethers to exchange small packets of mass between Mars and Venus with relatively small energy investment total. Wnt (talk) 18:49, 23 August 2013 (UTC)

Do how old scientific articles matter the accuracy of informations?

Thistold me the article I linked were published in 1993 [1] and 1997 (Once and Future of the Sun) and is not a recent document. Do how old the scientific paper is published matters how accurate the information gets. Then why didn't the previous editors repost what their works in 1993 when the newer informations came up? I didn't thought the published dates matters that much. Or these authors are not require to repost information when new informations come up. Do these authors change their mind when the newer evidence comes up? I thought if they have changed their mind they suppose to repost their works they done in their earlier studies.--69.233.252.198 (talk) 02:38, 22 August 2013 (UTC)

Yes how the information is published does matter to how accurate the information is or at least how much you can trust it. If it's published in a refereed journal it means that someone else, who also works in the same field, has read it and not found errors within it. While if it's just put up on the web without being refereed it may well be correct but the information hasn't been independently scrutinised. As for the age of a paper, for a start computers are a lot more powerful now so you can enter more information. So with the same data you can get more accurate answers. Also the structure of the Standard Model of the Sun has changed quite a bit since 1992 with the lunch of SOHO. For new information a new paper would be written, submitted, reviewed and published. The old paper would be untouched after publication (there is only one publication run).Dja1979 (talk) 03:08, 22 August 2013 (UTC)

This is a largely subjective matter. It depends on the field of science or mathematics you're talking about. For example, Lord Kelvin's paper entitled "On the Age of the Sun's Heat engages in discussion on whether something made of coal could possibly be producing that much heat! Yet papers written by the exact same guy about the laws of thermodynamics in the exact same year remain as entirely valid and useful references, even today. Some fields just move faster than others!

As Dja1979 points out - recent spacecraft missions are still revolutionizing our knowledge of the sun - and papers from just a decade ago are unlikely to be of much use. Scientists working in a particular field tend to have a good knowledge of how far back they can reasonably refer without picking up on outdated information.

SteveBaker (talk) 13:53, 22 August 2013 (UTC)

It depends on the study done and the assumptions made. Sometimes a paper from a century ago can be a true pleasure to read, and as relevant today as the day it was written. There are even rare cases in which an ancient publication is found which was more knowledgeable than modern sources on a point (see Ge Hong regarding artemisinin) Wnt (talk) 14:38, 22 August 2013 (UTC)

Absolutely. It's not so much a matter of age, but a matter of what, if anything, has changed the scientific community's understanding since then. Math is not a science (in my view), but the results of math papers from e.g. 1900s are just as true now as they were then. Even in science, many old papers can be valid and useful for decades. If the OP is interested in specific examples in a given field, we could try to provide suitable refs. Of course, many old papers are outdated, because their findings have either overturned or improved (especially in younger subfields of e.g. computer science or genetics). This is generally held to be a good thing: it is how our understanding progresses, and is built in to the prevailing philosophy of science, specifically, Karl Popper's principle of falsifiability. (My WP:OR is that most currently practicing scientists are implicitly proponents of the Popperian view, even if they don't know it by that name, or don't think about philosophy of science much.) SemanticMantis (talk) 16:32, 22 August 2013 (UTC)

I'm not sure this issue got adequately dealt with in the responses above: scientists certainly do change their minds as new evidence comes up. This is central to science; without it, there is no science. Once a paper is published, though, it is not subsequently modified. Partly, this is because of the long history of paper publishing, where it is not so easy to 'repost' something that has been published. More importantly, it makes referencing clear: when one refers to a paper from 1993, one doesn't have to worry that the text might have changed by the time your readers go look it up. Instead of modifying the already-published paper, scientists publish new papers. An expert in the field would know what papers are still worthwhile and which are outdated. For the nonspecialist, it is best to rely on secondary sources such as books, which review and summarize material and put it in context. This is one of the reasons why Wikipedia prefers secondary sources to primary ones for referencing. --50.196.55.165 (talk) 00:11, 27 August 2013 (UTC)

How do I identify a new type of earthworm?

having been around for many years, raised on a farm, dug worms for fishing, and gardened forever, I have discovered a completely different kind of worm this past week. I live in northern Ohio and came accross an area which has a very strong and firm eartworm population of 3 to 4 inch red colored worms that go crazy when uncovered. They twist and turn rapidly, they are very hard to hold on to, and they move very fast. Their bodies are very firm almost like a snake and they flop all over the place. Diameter is large. They are really strong and not at all like the thousands of giant earthworms that I have encountered before. They can extend themselves like a regular earthworm but their ends are very pointed. Can someone tell me if this is an unusual worm and what it might be? — Preceding unsigned comment added by 184.59.176.230 (talk) 17:22, 22 August 2013 (UTC)

Any photos you can offer? I can't help you either way, but someone else might be able to if you have one. Mingmingla (talk) 18:15, 22 August 2013 (UTC)

Just a guess, maybe a red wiggler? As their name suggests, they are feisty, and if I recall correctly, they are rather firm. They prefer compost to ordinary dirt. Was anything else different about this patch of dirt? Also check for the characteristic putrid smell that red wigglers release when agitated. SemanticMantis (talk) 19:18, 22 August 2013 (UTC)

Getting a tattoo while tanned or burnt

My friend is plannning on getting a tattoo after a holiday in Spain. He likes to ta his skin and thinks getting a tattoo the week after will pose no problems. My logic is that this is a bad idea and could probably scar him if he gets sunburnt. Not to mention the chance of blistering and a longer healing time. Does anyone know anything on this matter? Thanks ツ Jenova20 ^(email) 18:16, 22 August 2013 (UTC)

Some would argue that this is a borderline medical advice request. I don't know anything about tattoos, and Googling produces conflicting advice from various sources. Bearing in mind the medical disclaimer we usually wheel out in such cases, I would suggest you persuade your friend to consult the tattoo artist he is intending to use, in advance of his holiday. A reputable professional will be happy to advise him. - Karenjc 22:57, 22 August 2013 (UTC)

Borderline maybe but it's a hypothetical. I was always told when i got sunburnt that you shouldn't scratch it. Someone getting a tattoo over sunburn and making the area bleed seems like it would at the least scar or cause issues with healing. I'm not looking for medical advice, i'm asking a hypothetical question and interested if anyone knows. Thanks ツ Jenova20 ^(email) 08:10, 23 August 2013 (UTC)

Your friend is thinking of getting a tattoo and you're asking if it's likely to cause a scar if his skin is sunburnt - in what sense is that a hypothetical question? Richerman (talk) 08:37, 23 August 2013 (UTC)

I suppose i didn't word that well. I'm not asking if he should get it done, i'm just asking if there are any issues or studies on sunburn and scarring, healing, etc, when the skin is scratched or damaged further while healing. I think there would be but the Sunburn article doesn't really mention skin damage other than cancer. It's hypothetical in the sense that i've made assumptions for a made up scenario. If we can't do that then every health question here should be tagged in this way as medical advice. In that way most health questions and topics on cancer or common ailments should be banned from here as medical advice. See the point I am making? Thanks ツ Jenova20 ^(email) 08:59, 23 August 2013 (UTC)

But you didn't ask about sunburn and skin damage in a general sense, you gave what sounded like a question about a very specific situation. You even include a time frame and a vacation place.Phoenixia1177 (talk) 09:56, 23 August 2013 (UTC)

Indeed. A hypothetical question would be "if someone with a recent suntan got a tattoo, could this cause any problems ?". Jenova20 (talk · contribs) gave too many specific details for their question to be treated as hypothetical. This question definitley looks like a request for Medical advice, and Karenjc (talk · contribs) has given the only response that we can in that situation. Gandalf61 (talk) 10:11, 23 August 2013 (UTC)

Never mind. Not that important ツ Jenova20 ^(email) 10:18, 23 August 2013 (UTC)

It's well established that the hepatitis-armed scribble artists who do these things are not part of the medical profession, so factors affecting the quality of their work are not medical advice. I imagine that even the slightest bit of actual sunburn would make their practice particularly unpleasant. But the aesthetic and practical issues are harder to judge. The practitioners deal with all shades and toughnesses of skin, usually, but if the thing is meant to be seen while tanned, would it help to do it while tanned? If not would it be improperly shaded for the lighter skin? I'm afraid my aesthetics is just don't: there must be 10,000 ugly marks for every one that isn't immediately unappealing. That's not an answer of course but it illustrates how hard an answer is. Wnt (talk) 18:44, 23 August 2013 (UTC)

I have a Toad in my house but I can't find him!!!

It was one of these guys!

Okay, so I'd just finished mowing the backyard, when I saw an Eastern American toad on my porch. Now, a lot of cold blooded things like to come up on my porch to get sun, lizards, toads, frogs, and insect you can imagine...so I usually just say hi and ignore them. Except...THIS ONE HOPPED IN THE HOUSE!!! I tried to catch it and put it back out but he got into the office. I searched everything, my boxes of cables, the papers on my desk, my cat's stomach, basically turned the whole place upside down...but I can't find him!!! I just know the poor little fellow will die of starvation or dehydration if I don't find him soon, is there anything I can do to lure him out? --Free Wales Now! what did I screw up?  18:38, 22 August 2013 (UTC)

Maybe make a toad home (google images here [2]), put in a moist sponge and hope it attracts the toad? I'd place one near where he was last seen, and another in the basement, if you have one. BTW, many toads, especially large ones, don't need much water on a daily basis, and only return to water to breed. So dehydration is not a big risk in the next few days, especially if you have a basement, which would also probably have toad food... SemanticMantis (talk) 19:13, 22 August 2013 (UTC)

It should be easier to hear and see him at night, since they're nocturnal. Might even try the same door it came in through. Like Mantis says, there's likely no immediate danger. Toads are generally much less susceptible to drying out than frogs, and cold-blooded animals don't starve so quickly. Cats generally hate the taste of toads, so I wouldn't look too hard into stomachs. A bit of damp grass may be tempting, if it's still there by tonight. InedibleHulk (talk) 19:34, 22 August 2013 (UTC)

They're pretty good at hiding. When I was a kid, one time my brother and sister and I were keeping a toad as a pet, in a cardboard box, and it escaped. For a couple of days we saw no evidence of it. But then in the middle of the night my dad got up to pee, went into the bathroom, turned on the light, looked into the toilet -- and there was the toad staring up at him. He made us get rid of it. Looie496 (talk) 22:04, 22 August 2013 (UTC)

Great story :) I hope the OP updates us if he finds it. SemanticMantis (talk) 01:40, 23 August 2013 (UTC)

In light of the above anecdote, might putting a pan of water someplace on the floor attract the toad? ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:31, 23 August 2013 (UTC)

The cat might not eat it, but may very well kill it nonetheless. You might want to lock the cat into a room far from where the toad was last seen, with water and a litter box, until you find the toad. Of course, if the toad squeezes under the door and sits in the cat's water bowl, I'd say his life expectancy will be substantially reduced. :-) StuRat (talk) 02:02, 25 August 2013 (UTC)

Let nature take its course. After all, your porch (and hovel) is not its natural habitat. Therefore, take comfort that local population pressure was probably high enough to drove him or it, to venturer into you humble abode to look for pastures a new. If your concerned about these little amphibians – then just think. If you spend -just a few hours- making your back-yard more amphibian friendly, then the demise of 'your' singular house bound ' toad will be made up handsomely by the increase in the local population. Maybe, in a few months time, your wife, whilst doing her spring cleaning ( if she still does these old fashioned household activities), may find a little mummified body of this toad in some back cupboard. Place it (the corpse) in a little glass jar to show your grand-children as a lead into explaining why these little amphibians mean so much... ecological-wise. Then show them how you have reformed your back-yard to become amphibian friendly. By then, these toads may have become so numerous that one can no longer step out onto to said porch without one of Kermit's relatives going 'crunch' under one's feet. As Stalin said: One death is a tragedy but millions of deaths are just statistics.--Aspro (talk) 15:20, 25 August 2013 (UTC)

Explanation for the acronym SWE

The phrase "SWE Stereo" appears on my television screen to reveal the audio utilized by a local TV station in their broadcast. The TV station is SLCCTV (Salt Lake Community College TV, channel 86-1701) located in SLC, UT. Directly below SWE Stereo is the resolution value "480i SD" (standard definition}. Thank you, Thomas J Tippett Tjtippett (talk) 19:10, 22 August 2013 (UTC)

Just a guess, but might it have something to do with Secondary Audio Programming? If you have an SAP button on your remote or set, try pressing it and see if you get Swedish. InedibleHulk (talk) 19:49, 22 August 2013 (UTC)

Another guess is it has something to do with this satellite terminal the station might use. Do you know if the station has any connection to the ABC 4 station? ABC is said to use this system. InedibleHulk (talk) 20:07, 22 August 2013 (UTC)

Effects of music while working & studying on performance

I listen to music several hours a day while studying (I'm a math student) and I wonder how much it affects my performances. Does the type of music (rhythmical/calm/powerful/..., vocal music or not, etc.) and genre (I hear mostly classical music and film soundtracks) matter? Thank you. 23:07, 22 August 2013 (UTC) — Preceding unsigned comment added by 84.109.248.221 (talk)

Mozart effect might be relevant. Googling "effect of background music" gave a few promising-looking links, including this (MS Word doc) on 'The effects of background music on learning, performance and behaviour' and this on 'The effect of background music and background noise on the task performance of introverts and extraverts'. AndrewWTaylor (talk) 08:35, 23 August 2013 (UTC)

I'm a high school teacher who moves around a bit between different schools. Just started in a new school for a four week stint. As usual, many students have asked if they could listen to music while they worked, insisting that they work better that way. (Some didn't ask, and DID listen. They won't any more.) Andrew - that study could be very useful. Might just print out that abstract for sharing with students. HiLo48 (talk) 09:28, 23 August 2013 (UTC)

It's a commons highschool science-fair project...comparing different styles of music (better students remember to analyze both style itself and alignment with subject's preference separately), different types of tasks, etc. It's rare that their background "research" consists of more than the popularized version of the Mozart effect--even if they cite the original study they obviously didn't read it--or any of the later publications strongly refuting the popular form. Sigh. DMacks (talk) 09:34, 23 August 2013 (UTC)

Temperature ranges of gas giant moons

When my teacher keeps telling me planetary composition, albedo, and atmosphere gases are also important to determine planet's and moon's surface temperature, I keep thinking these factors are not important. But Does the airless moon of gas giants have temperature ranges small or the global temperature of Jupiter, Saturn, Uranus' moon have wide temperature fluctuation between day and night. Enceladus (moon) Say the minimum surface temperature is 32 K and the maximum surface temperature is 145 K. I checked Europa (moon) it said the minimum surface temperature is 50 K and maximum surface temperature is about 125 K. --69.233.252.198 (talk) 23:12, 22 August 2013 (UTC)

You keep thinking the atmosphere is not important and keep being wrong. It's very important. To give you an idea, Earth's average surface temperature would be about 60 degrees Fahrenheit lower if the Earth didn't have an atmosphere. That's a significant change. Dauto (talk) 23:47, 22 August 2013 (UTC)

One other critical factor is tidal heating. Moons close in to gas giant planets can have rather large tidal heating, compared with solar heating. StuRat (talk) 01:57, 25 August 2013 (UTC)