Wikipedia:Reference desk/Archives/Science/2006 August 20

What happens if the sun stops shining?
If the sun suddenly stopped giving out light and heat, what would happen? I assume that everything else about it is the same - that we still orbit around it and so on.

How cold would it get? How long would humans and other species survive for? 62.253.52.30 00:35, 20 August 2006 (UTC)


 * Damn cold very quick. Think how cold it is at night in winter with no cloud. Much Colder than that. Not very long at all for extinction (unless you had a heater)--Light current 00:47, 20 August 2006 (UTC)


 * It is also not possible for this to occur. Stars go through a specific process before they die. Check out Star. --liquidGhoul 01:05, 20 August 2006 (UTC)


 * Yeah we know that. We were just musing! 8-)--Light current 01:07, 20 August 2006 (UTC)


 * This question was asked before. See If the sun turns off, when does the earth freeze?.-gadfium 01:22, 20 August 2006 (UTC)

I wonder what would kill most humans and animal species first. Would it be hypothermia or starvation as plant food sources died. Would plants die from the frosts or the lack of sunlight. I wonder how long in practice humans could keep themselves alive. Heat would be less of a problem than growing food.

I expect those shrimps and other novel species who were discovered living next to very hot water vents in the deep ocean would survive perhaps until the whole earth cooled, since they are already in the dark. I think the heat from the earths core would be little affected by the sun closing down, since the earth is large and as far as I recall the heat comes from radioactivity and perhaps eddy currants.


 * Agree. Undersea life near hot vents would probably continue to exist. THe earths core would continue to generate heat.--Light current 19:04, 20 August 2006 (UTC)
 * Yeah, I'd imagine it could take tens of thousands of years for the undersea life to die off, or maybe longer. I think some undersea life depends on detritus drifting down from surface ecosystems - any life that depended on that interaction would probably disappear.  However, it could take a long time for some undersea geothermal ecosystems to be destroyed.  It's one of my fondest hopes for science that we may discover life under the ice of Europa when we eventually send a probe there.  It is thought that tidal heating of Europa's crust by Jupiter's gravitational field may maintain a significant liquid ocean in which recognizeable lifeforms might have developed.    --Bmk 19:55, 20 August 2006 (UTC)


 * All these worlds are yours except Europa. Attempt no landing there! (2010)--Light current 20:05, 20 August 2006 (UTC)


 * I love that movie! But 2001 was even better.  --Bmk 00:21, 21 August 2006 (UTC)


 * Yeah possibly! I think there were good bits in both. Presumably Jupiter was turned into a sun just in case the other one stopped. Is that right? But wouldnt Europa be far too close not to burn all life there?--Light current 00:23, 21 August 2006 (UTC)


 * See brown dwarf. Jupiter is nowhere near the critical mass needed to form a star (one that emits heat through nuclear fusion). I assume that all the mass in the solar system (excluding the Sun) wouldn't be enough to get form a star. However, if it were possible to make a red dwarf, it would emit just a fraction of the energy of the Sun, so Europa might be safe. DirkvdM 08:58, 21 August 2006 (UTC)


 * Ahh but you neglect the extra mass of all those monoliths!--Light current 17:18, 21 August 2006 (UTC)

We have forgotten to consider oxygen. With no light, no photosynthesis, no oxygen production. Humans, animals, and shrimps would eventually suffocate. I wonder how long this would take before the oxygen was used up or the levels of CO2 became toxic?

Even if humans could rig up lamps to grow plants under, we would need to live in hermatically sealed environments. Soon the earths atmosphere would be like some alien world's.

Any practical method for calibrating a bathroom scale?
Is there a practical method, using only easy-to-find items, that would allow one to determine the approximate error of a bathroom scale in a given range of nominal measured values?


 * If you have the info that came with the scale, it might have those in the specs. Then again, an old and mistreated scale might no longer fall within the specs.  Comparing it with a much more accurate scale would work.  But then again, if you have a much more accurate scale, you'd likely just toss out the less accurate one.  If you have a weight-lifting set, you could also use those to do the check. StuRat 01:53, 20 August 2006 (UTC)


 * Easy. 2lb bags of sugar! --Light current 02:48, 20 August 2006 (UTC)


 * Or, get a bucket, put it on the scale, note the weight, then put a liter of water in the bucket, as measured by some trusted measuring device, and make sure the scale increases by 1 kg. Or more water, if you can't accurately measure 1 kg on the scale.  --Bmk 02:58, 20 August 2006 (UTC)


 * Yes. A gallon of water weighs 10lb (approx)--Light current 03:00, 20 August 2006 (UTC)

Hey! "A pints a pound the world round" so a gallon of water weighs about 8 pounds. Or use the relation that the latest U.S. quarter coins weigh = 5.670g and count out 10 lbs, 20 lbs, 50 lbs, 100 lbs, and 200 lbs worth. then put them in a bucket and weigh them (being careful to tare the bucket).Edison 04:00, 20 August 2006 (UTC)


 * Not in the UK its not. A pint of water weighs a pound and a quarter. US and UK pints are different. See this from our article:

In 1824 the British parliament replaced all its variant gallons with a new "imperial" gallon based on ten pounds of distilled water at 62 °F (277.42 cubic inches), from which the UK pint is derived. --Light current 13:22, 20 August 2006 (UTC)


 * Weigh yourself on a beam balance scale in a doctor's office and then immediately drive home and well, you know. --hydnjo talk 04:05, 20 August 2006 (UTC)


 * Yes that would do a one point calibration check, but woukdnt check the whole scale.--Light current 13:22, 20 August 2006 (UTC)

[I am the person who asked the question.] Thanks everyone for the ideas. The best method that I have come up with so far is this:
 * 1. pack a number of boxes with books or other items so that the total weight of the boxes is in the target weight range
 * 2. go to a post office that has an accurate scale for parcels in the lobby
 * 3. measure and record the weight of the individual boxes
 * 4. re-weight the (whole stack of) boxes on the bathroom scale to be calibrated
 * 5. estimate the error

Please continue to share your ideas. --71.123.61.112 14:21, 20 August 2006 (UTC)


 * The thing people have missed is that weighing a human and weighing inanimate weights is different. When I was dieting, I soon noticed that slightly moving my position on the scales, such as positioning my feet half-an-inch forward or back, and also slightly leaning forward or back, would make several pounds difference to my weight. I solved this by recording both my maximum and my minimum weight at each weighing. If anyone knows of an inexpensive pair of bathroom scales that do not have this problem, please leave their brand-name here.


 * Weighing animate objects isn't different as long as they aren't moving. You just have a poorly constructed scale that is apparently sensitive to changes of the weight's position. - Rainwarrior 16:38, 20 August 2006 (UTC)


 * My scales behave in the same way!--Light current 17:53, 20 August 2006 (UTC)


 * Digital scales using load cell or strain gauge technology tend to be more accurate and repeatable than spring scales. The early ('90s) models however, using a single load cell and a suspension system to transfer the weight on the platform to it, were susceptible to shifting positions on the platform. Most of today's digital home scales use four load cells to support the platform and are accurate and repeatable to well under one pound. --hydnjo talk 15:11, 21 August 2006 (UTC)

a wierd question!!
who was the first person to commit a suicide??thanks

Anne Ty


 * Nobody knows. Mankind has existed for 200,000 years (longer if you count precursors of H.Sapiens) while recorded history goes back only about 5,000-6,000 years. After a quick search the earliest recorded suicide I found on Wikipedia is Aegeus in the 1230s BC though fact and fiction are hard to tell apart there. There is probably an ancient Egyptian stone tablet fragment somewhere that mentions in passing some non-notable guy killing himself. Weregerbil 11:53, 20 August 2006 (UTC)


 * If he was non notable, it wouldnt have been noted! 8-)--Light current 13:24, 20 August 2006 (UTC)


 * Did not Gilgamesh think of committing suicide ? That was very very before everything was written. -- DLL .. T 19:29, 20 August 2006 (UTC)


 * If it was before anything was written, how do we know? Did someone tell you?--Light current 19:42, 20 August 2006 (UTC)


 * Gilgamesh is the oldest surviving literary work, and was carved into a clay tablet. And I'm pretty sure it was a "legend" (ie, made up), so I don't think that really counts. Black Carrot 03:39, 21 August 2006 (UTC)


 * Why do you say 'legend' and not foot?--Light current 17:23, 21 August 2006 (UTC)

dispersal of seeds
pl.let me know if there is a seed by name barksia that disperse when fire is brought near? haima


 * Read Banksia. --Shantavira 10:55, 20 August 2006 (UTC)

Elbow injury
I have had chronic tendinitis in both elbows (inner side, epicondilitis, golfer's elbow colloquially speaking), but with drugs, weight training and patience, tendinitis has completely disappeared. But I still have a problem... a problem that I already had during my injury period and which appeared in the early stages of my tendinitis, probably due to it or just in parallel to it.

The thing is that, whenever I perform an eccentric exercise with my right triceps with heavy weight there's a perfectly defined point in the flexion of the arm where I get acute and strong pain. To give you an idea, exercises that cause me the pain I have mentioned are, among others, doing push-ups with weight in my back while I descend my body slowly to the floor. There's no problem while I lift the weight, just when I go down again (I've said push-ups with weight in my back because push-ups using only my body weight aren't enough to cause me pain, since I'm quite strong for my bodyweight).

It is quite uncomfortable in some situations. What can cause this? How can I cure myself? Any ideas? Thanks in advance.


 * Go see a physio!--Light current 13:25, 20 August 2006 (UTC)

The obvious advice is to cut back on the workouts, you're just wearing out your elbows from overuse. How about concentrating on your legs for a while and giving your arms a rest ? Then, once you get severe knee pain, you can switch back :-) StuRat 03:43, 21 August 2006 (UTC)

Breaking down of a polysaccharide
Hi! How does a polysaccharide break down in acid hydrolysis? More specifically how does it differ from hydrolysis using an enzyme? Or is there no difference? Thanks --203.54.74.30 11:19, 20 August 2006 (UTC)


 * Sounds like home work! look at links--Light current 19:35, 20 August 2006 (UTC)

LpH disinfectant
LpH is a germicidal detergents that use in my company as a disinfectant. I can't find what LpH stands for,I search almost everywhere on the internet.

Please help.
 * Perhaps LpH stands for low pH (as in acidic)?Sluzzelin 13:35, 20 August 2006 (UTC)
 * I think that's probably right, though it looks like their marketing department prefers the term "non-alkaline". - Nunh-huh 14:02, 20 August 2006 (UTC)


 * Low pH it is. If you're interested, here's a link to the material safety data sheet: ENVIRON LPH ST STERILE PHENOLIC DISINFECTANT--Mark Bornfeld DDS 14:23, 20 August 2006 (UTC)

corroding aluminum
I have a zipper that will not come apart. The large (when compared to the teeth) parts of the zipper that go together at the bottom have corroded together it seems. They appear to be made of aluminum but that's just a guess. Is there a solution that I might soak them in to break up the corrosion but not ruin the cloth around them? Dismas|(talk) 14:05, 20 August 2006 (UTC)


 * TRy a bit of light grease such as Vaseline and gently work it up and down (the zip that is)--Light current 19:10, 20 August 2006 (UTC)


 * From the OP's description, I don't think the parts can be moved to do that. Personally, I'd give it a good squirt of WD40, making sure to get it well into the gaps not just on the surface. I can't promise that it'll not do anything to the cloth, but it's fairly light and volatile so I doubt it would stain. PeteVerdon 13:15, 21 August 2006 (UTC)

No it sounded like the teeth of the zip were stuck together, but the slider was still sliding!--Light current 13:51, 21 August 2006 (UTC)


 * What I'd try is, using two pairs of pliers (that is, two instances of the same kind of instrument), to grip each of the two zipper "teeth" firmly between the teeth of the pliers (using one for each "tooth"), and to wiggle those gently in the hope the teeth will come apart from each other (without coming individually apart). --Lambiam Talk 01:10, 22 August 2006 (UTC)

aromatic plants-distillation
I desire to install distillation machinary of aromatic plants. would you please guide me some books/reading material as i will be totally new in this field.Or some popular feasibility reports in installing ditillaries.


 * In an episode of Food Jammers, the fellas built a smallish version of such a machine. You can see a cartoon of their setup here. So... just build something like that :) When trying to start out in a new field, it's generally best to find a local person who does a similar thing so you can learn from them... you'll learn faster and probably better than you would from a book. Try, e.g., the chemistry department at a local university. You could also ask your favorite search engine for something like "essential oil distillation". digfarenough (talk) 16:37, 20 August 2006 (UTC)
 * Sounds like fairly specialised machinery. Probably the manufacturer would provide a technician to show you how to use it. BTW if you're looking for a line on those 'aromatic plants', we've got a bumper crop up here in BC :wink wink: Anchoress 01:38, 21 August 2006 (UTC)
 * When you proceed, be careful about local regulations. For example, I believe it is illegal in the United States to use a still to do an alcoholic extraction without a license, even if you purchaced the alcohol as pure. -- 14:44, 29 August 2006 (UTC)

bowel movements
recently ive found myself passing stools quite frequently (about 3 or 4 times a day), only they`re not very big (i mean big enough to sit on for sure..... oh i'm so funny!!) anyway, seriously, is there are an Optimum Poo Frequency (OPF)? and is the fact that not alot's coming out a bad thing? thanks! (p.s. i`ll leave it to wikipedians to make sure that OPF catches on. i`m quite proud of it!) —Preceding unsigned comment added by 201.18.237.154 (talk • contribs)
 * Have you recently changed your diet? I once heard, many years ago, that the thing that varies most among humans is defecation rate. According to defecation, "Humans remove waste anywhere from several times daily to a few times weekly", so it looks as though it is true. I used only to go once every few days, but since a change of diet it is now once a day. More frequently certainly feels better to me. --Shantavira 17:24, 20 August 2006 (UTC)

Oh and you might want to check whether your stool type has changed, with this cool link.--Shantavira 17:37, 20 August 2006 (UTC)
 * OHH Gross! I find once every 12 hours is probably normal unless you have diarrhoea THen its anything goes (and quite frequently!)! --Light current 18:46, 20 August 2006 (UTC)

The normal range is from 3 times a day to once every 3 days, and that's the latest poop scoop. StuRat 18:56, 20 August 2006 (UTC)
 * Once every 3 days!!!?? You cannot be serious! Thats GROSS!--Light current 19:07, 20 August 2006 (UTC)
 * And that's with a normal diet. If you fast you may stop going altogether.  You could also get all the calories you need in a very small mass of food, if eating some dense calorie source, like very fatty meat.  While not a very healthy diet, this would lead to infrequent defecation.  Eat lots of salads, on the other hand, and you may find yourself closer to the 3 times a day limit. StuRat 03:40, 21 August 2006 (UTC)
 * On my trip to Australia, that was probably the longest I ever went. It must have been four days. I ate normally. — [  Mac Davis ] (talk)


 * That was probably due to the change in environment,climate, food,water, travel and your excitement at being on holiday.-- not normal tho!--Light current 16:18, 21 August 2006 (UTC)


 * I think if its that infrequent you just aint getting enough fibre! Studies amongst tribes in Africa showed that the low incidence of many Western diseases was probably due to the 'speed of processing' of food. It only took 12 hrs from mouth to.. other end in those people!--Light current 14:30, 21 August 2006 (UTC)
 * As someone who has several, uh, bowel issues, I'd like you to make sure that the type of your excretion has not changed. If it's become frequently very soupy or very firm, or if you vary from soupy to firm within a 24-36 hour span, please search WebMD.com forUlcerative Colitis, Crohn's disease, amd Irritable Bowel Syndrome to see if you may have other symptoms.  It's very important to diagnose these afflictions as early as possible.  Srose   (talk)  14:36, 21 August 2006 (UTC)


 * I think thats good advice. Of course drinking copious quantities of amber nectar or other alchoholic libation the night before can loosen the uhh.. stools quite effectively?--Light current 14:44, 21 August 2006 (UTC)
 * Good point. ;) Speaking from personal experience, I'd also like to note that the process of being diagnosed with any of those diseases (particularly Crohn's Disease and Ulcerative Colitis) is a long process, sometimes rather disgusting.  Srose  (talk)  14:52, 21 August 2006 (UTC)


 * Yeah I can imagine. Didnt mean to make fun of your condition. Best of luck with your treatment!--Light current 14:58, 21 August 2006 (UTC)

tempometer
I'm not sure if this is appropriate for the ref desk, but I read the article tempometer, mentioned in a post a few days ago, and at least part of it seems unsupported, and smells distinctly hoaxy to me, especially the part about it being "fixed to the luminiferous aether". Perhaps some of you could take a look and weigh in one way or the other? Thanks  --Bmk 16:46, 20 August 2006 (UTC)


 * I added a comment there. Seems delete-worthy to me. digfarenough (talk) 17:22, 20 August 2006 (UTC)


 * Okay, that's enough moral support that I think I can escape the appearance of picking on the author. The article is now up for AfD. Melchoir 19:21, 20 August 2006 (UTC)


 * Hang on a minute! Are you sure this was not once a legit device uses by someone?--Light current 19:31, 20 August 2006 (UTC)


 * It is theoretically impossible to be sure of that; all we know, and all we need to know, is that there is a reasonable good-faith search has found no evidence. As with any deletion, if a reliable source is uncovered in the future, it can be used to write a new article that is verified and free of original research. Melchoir 19:35, 20 August 2006 (UTC)


 * I think the proper way to deal with an article like that is to separate accepted scientific/historical facts from unjustified claims, and remove the latter. If tempomemter is not a recent invention of whoever created the article, and is part of history, I would recommend leaving the article there. If, at some point in the past, people had mistaken/unjustified/superstitious beliefs about the device, the existence of those beliefs is part of history, but they should labeled as such (and not be given a false appearance of a modern scientific description of the workings of the device). I have no idea if any of the historical descriptions is correct, but the Lorentz quote is arguably out of context (in the sense that a reader seeing more of the context will get quite a different impression of what the quote is about). I see no reason to accept the implied claim that a tempometer is "fixed to the classical ether", even when one adopts Lorentz's view about the obsolete hypothetical concept of ether. --71.123.61.112 22:10, 20 August 2006 (UTC)


 * See the discussion page. From what I can tell, it's a word made up by the creator of the page for the software s/he created and links to there. So I think there are no scientific/historical facts, those are covered at the astrarium page, which is what a "tempometer" is a new name for as far as I can tell (I am not an expert on these things). digfarenough (talk) 23:13, 20 August 2006 (UTC)

male/female speaking rates
Is the a study comparing the verbal speaking rates of men and women in different languages?


 * Women speak faster and change subject more often! (This is probably to confuse the opposition -- men)--Light current 18:44, 20 August 2006 (UTC)


 * Don't change the subject. (If that was the joke - this was clarification for those confused men who dind't get it :) ). DirkvdM 09:06, 21 August 2006 (UTC)


 * Im confused already: are you a woman?--Light current 16:20, 21 August 2006 (UTC)


 * I think you might want to search for "discourse analysis" and "conversation analysis" together with "gender." Also, if you can borrow a linguistics textbook from your library, check if it has a chapter on "Language and Gender." --Kjoonlee 16:26, 21 August 2006 (UTC)


 * Alternatively, there's a liguist who wrote some books on gender differences in language. I can't remember her name, but one of her books is titled You Just Don't Understand. --Kjoonlee 16:26, 21 August 2006 (UTC)


 * It's Deborah Tannen, but I don't think she goes into the subject of different languages (unless you consider Manspeak and Womanspeak to be different languages). --Lambiam Talk 00:58, 22 August 2006 (UTC)

Of course they bl***dy well are!--Light current 01:01, 22 August 2006 (UTC)

Yes, some of those liguists are quite cun devious!--Light current 18:26, 21 August 2006 (UTC)

Butterfly's life from the begginng to the last stage
196.207.47.60 20:06, 20 August 2006 (UTC)Molly.I need information about the creepy crawly.Specifically the Butterfly. From the beggining to the last.

Try the link. Also try caterpillar--Light current 20:08, 20 August 2006 (UTC)

skull fracture
Hello, Please can you tell me what the 'lasting disabilities/symptoms' are after suffering a fractured skull? Thank you for your help,  Janice


 * You turn into either a crackpot or a nutcase--Light current 21:11, 20 August 2006 (UTC)

Most fractures of the skull heal. Some more complicated fractures may need insertion of a protective plate; contact sports are sometimes forbidden is the skull does not heal to its original condition. However, the major problem after a skull fracture isn't the harm to the skull, but that trauma severe enough to fracture the skull may injure the brain below. Obviously the range of such damage is wide, from a concussion with no permanent effects to death from brain swelling. In between is every neurologic disability you can imagine as a possible consequence of fracture and brain injury. alteripse 00:05, 21 August 2006 (UTC)


 * Also, at times skull fragments from the fracture can be pushed into the brain. When a fracture this severe occurs, there is also a risk of infection to the brain. StuRat 03:33, 21 August 2006 (UTC)

Fractures of the base of the scull can lead to cerebrospinal fluid rhinorrhea if they fail to heal properly. See. --N·Bluetalk 13:26, 21 August 2006 (UTC)

Obviously someone who has suffered a skull fracture needs the advice of a physician, not postings by random persons of unknown qualifications on the internet. That said, with regard to the previous post about CSF leakage, cerebrospinal fluid is a clear liquid which may be tinted pink by blood if the leak is due to injury. It may be mistaken for ordinary sinus drainage, even by physicians. One test is the "bulleye test" wherein the fluid is allowed to drain into a piece of white gauze. The blood cells will produce a ring or halo on the gauze. This test does not work in the absence of a certain amount of blood in the CSF so it may produce a false negative. A more modern test see http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8818499&dopt=Abstract is to collect a sample of the fluid in a sterile sample bottle and have it analyzed for Beta-2-transferrin. This is pretty much unique to CSF. A middle ground is to use a diabetic's blood sugar meter to determine the glucose concentration in the fluid. Nasal secretions will generally test negative for glucose, while CSF may have concentrations close to the concentration in the blood. Anyone with chronic CSF leakage (it can go on benignly for months) is at high risk for meningitis a potentially fatal and often damaging infection of the brain and central nervous system. Signs of meningitis are 10 intense headache, 2) sensitivity to light, and 3) pain when the head is tilted down to the chest, 4)fever, and/or 5) vomiting. Immediate treatment is required. Edison 14:57, 21 August 2006 (UTC)