Wikipedia:Reference desk/Archives/Science/2007 July 18

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July 18

Relationship between electron affinity and ionization energy levels

Is the ionization energy of an atom related to it's electron affinity? For example, chlorine has an electron affinity of 349 and a first ionization energy of 1251 (in kJ/mol). But would the first ionization energy of Cl+ be equal to 349 kJ/mol? Likewise, would the electron affinity of Cl- be related to that first ionization energy of Cl neutral? Thanks! Delta 02:44, 18 July 2007 (UTC)

You are correct in that there is a relationship, but I think you got the specifics wrong. The electron affinity of Cl would be equal to the first ionization energy of Cl-. Why? Because the reaction for the electron affinity of Cl is as follows: Cl + e- --> Cl- (-349 kJ/mol), while the exact reverse of that reaction is the first ionization energy of Cl-: Cl- --> Cl + e- (energy is therefore the opposite, or +349 kJ/mol). ugen64 06:19, 18 July 2007 (UTC)

Frequent Urination

Since yesterday, i have been urinating a lot. I don't have diabetes and I've been cutting down on my fluids, but I'm still going a lot. Any ideas why? BTW, my urine is clear if it makes a difference.71.218.37.80 04:22, 18 July 2007 (UTC)

We have an article on this at polyuria. However, Wikipedia cannot offer a medical diagnosis, so if you are concerned about the frequency of your urinations, please consult a doctor. Someguy1221 04:44, 18 July 2007 (UTC)

Any pharmacy (chemist) sells little test strips for detecting sugar in urine. Just saying. Edison 01:26, 19 July 2007 (UTC)

Diabetes mellitus says that Type 2 diabetes can go undetected for years, with intermittent symptoms. Unless you have seen your doctor since the onset of the abnormally frequent urination, you probably are not justified in stating that you do not have the condition. Edison 18:07, 19 July 2007 (UTC)

See a Dr. first. Second you might have prostrate problems if you are male that is. Frequent urination but not in large volumes is a symptom of enlarged prostrate (it might even be cancer, I pray not for you! amen). Best wishes! TripleBatteryLife 15:43, 23 July 2007 (UTC)

Waterdrops- Perfume spray

Always when I was spraying the perfume (aerosol metallic tin) I was noticing some thing unusual.. after spraying some drops are being accumulated around the nozzle even though I wiped it away it was appearing for second time..why this was happening? Temuzion 06:56, 18 July 2007 (UTC)

It could be due to the depressurising gas in the aerosol being very cold due to adiabatic expansion. This will chill the nozzle, which will get condensation from humidity in the air. GB 07:17, 18 July 2007 (UTC)

Yes the expansion of the gas will take lot of heat from the can therefore making it cold and encourages condensation. Don't do this on someone (they can get frostbite from it) but if you tip the can upside down the gas bypasses the heatsink of the can and gives out very cold aerosol, which will create a mist-like stream coming out of the nozzle. --antilived^{T | C | G} 07:34, 18 July 2007 (UTC)

A more noticeable effect can be demonstrated by letting air out of a car tire. Since the air is under pressure and it expands after being let out, according to the Ideal gas law there should be a corresponding drop in temperature. You can feel the nozzle drop in temperature as you let out the air. (Just don't let anyone catch you giving them a flat tire.) -- JSBillings 13:18, 18 July 2007 (UTC)

Excess drinking of water!

Since one week I was drinking high amounts of water..even though I'm not thristy I was forcing myself to pour in some litres of water every day..when ever I remember water I was drinking minimum 1&half litres of water..in that way I was intaking some 6-8 lts of water daily..& similarly i was urinating very frequently.. which kind of effect will be shown on my body by this new habit? I hope it'll be definitely +ve..! Temuzion 07:03, 18 July 2007 (UTC)

A) Wikipedia cannot give medical advice. B) Water intoxication is a potentially fatal condition brought on by drinking too much water too quickly. Dragons flight 07:11, 18 July 2007 (UTC)

The font of all medical knowledge, House, showed that this can mess you up real bad. All I remember is that the guy had crippling muscle cramps - It doesn't say much about this, but the episode was House_vs._God, I think. Aaadddaaammm 07:57, 18 July 2007 (UTC)

In the end it turned out he had herpes; he was drinking the excess water in an attempt to 'cleanse' himself of his guilt and the virus, nothing to do with water intoxication. Lanfear's Bane

Except that his symptoms are that of the water intoxication, so it has everything to do with water intoxication. Capuchin 09:00, 18 July 2007 (UTC)

See Jennifer Strange. Not a nice way to die. --S.dedalus 22:00, 18 July 2007 (UTC)

See the Q & A about "Frequent urination" above. Edison 18:08, 19 July 2007 (UTC)

Number of Perpetual Motion Machine Patents?

Hello,

Is there anywhere it is possible to find out the number of patents for perpetual motion machines that are filed in a given year?

--91.104.48.234 07:24, 18 July 2007 (UTC)

I'd guess so. The WIPO maintains the International Patent Classification (IPC) which it used by patent offices around the world to classify patents. The purpose is, of course, to help in searching: you can quickly look up what patents have been filed or granted in a certain subfield. A quick look at the IPC's index ("catchwords" in their lingo) shows you that there are four keys for "perpetua mobile, alledged". Now, you just have to find out how to search for all patents with a given ICP classification key on one of the public web sites offering access to patent databases (on the USPTO, for example, or with Google Patents) and count. There is only one catch: If you search in a database for granted patents, you won't find much, because in most jurisdictions patent offices may refuse to deal with perpetua mobile and reject them by default. So, you have to find a way to search through the database of filed applications, not of granted patents. This information is public, too, but maybe not as readily accessible. Have fun and tell us what you found. Simon A. 07:47, 18 July 2007 (UTC)

Yes, you cannot be granted a patent for something which defies the known laws of physics. Capuchin 07:50, 18 July 2007 (UTC)

I am not arguing for the perpetual machine here (I know it can not be built), but out of curiosity: How can they not grant patent for something just because they don't understand what it is or how it works, just because it does not conform to the known laws of physics? It is always possible for someone to come up with something which defies all known laws. Take the example of the idea of matter waves or the theory that sun is at the center of the solar system. Till these were proposed, people had different ideas. What is the rationale behind refusing patents? -- WikiCheng | Talk 09:57, 18 July 2007 (UTC)

This is exactly the problem that steorn is facing. They have had to patent each part of their device seperately, as they cannot patent the device as a whole. They claim that it creates energy, but have yet to form an explanation of how it works. I must admit, this is the only example that I have knowledge of patenting free energy machines from. (They have yet to demonstrate it in public, and i'm fully expecting for the source of the energy to be found, if it does indeed work). I would be happy to be proved wrong. Capuchin 10:21, 18 July 2007 (UTC)

A patent is essentially a trade between the inventor and the government: the government grants a temporary monopoly, and in return, the inventor teaches the public how the invention works, or more precisely, provides a description that allows a person skilled in the art to practice the invention. Ordinarily patent offices take the inventor's word that the invention will work, but in exceptional cases, can demand working prototypes. So you can't invent a perpetual motion machine and at the same time keep secret how to build one that works. Also, inventions must be useful. A perpetual motion machine that merely moves, but does not allow one to extract any energy from it, might not be considered useful. --Gerry Ashton 13:26, 18 July 2007 (UTC)

It's actually a tough thing about patent offices and always has been — on the one hand, they are expecting the devices to be on the cutting edge and thus not necessarily conforming to standard understandings; on the other hand, they are also on the lookout for tricksters, hucksters, and frauds, all of whom could exploit a poorly granted patent for their personal and economic gain, at the expense of others. That's why the patent office has its own experts who are trained to examine patents to see if they would work, to see if they have obvious fallacies in them, to see if they are just preposterous or not. Patents are supposed to be written in a way which means that anyone skilled in the art can understand how they work, and the patent examiner is presumably skilled in the art. Does it always work? Of course not — there are a lot of factors going into whether a patent is granted (according to these guys, the US patent system today grants patents far too easily because the examiners are overburdened and only get punished if they don't grant enough patents, not if they grant too many bad ones), but that's the general idea. --24.147.86.187 13:51, 18 July 2007 (UTC)

The biggest problem in finding such things is that since the USPTO explicitly says it won't grant patents on perpetual motion machines, no patentee with half a brain would make it clear that this is what they were trying to patent. They will try as hard as possible to make them look like standard electrical/mechanical devices, and to cloud the fact that they apparently violate the first law of thermodynamics (conservation of energy: it's not just a good idea, it's the law!). So you're basically looking at something which will be, rationally speaking, deliberate obfuscated. Which isn't impossible — but it's not easy! --24.147.86.187 13:57, 18 July 2007 (UTC)

Our article on Motionless Electromagnetic Generator gives a link to one such patent. So I count 1. Capuchin 14:09, 18 July 2007 (UTC)

"Yes, you cannot be granted a patent for something which defies the known laws of physics." - actually, as described in our article, with the specific exception of prepetual motion machines, you can: With the exception of cases involving perpetual motion, a model is not ordinarily required by the Office to demonstrate the operability of a device. If operability of a device is questioned, the applicant must establish it to the satisfaction of the examiner, but he or she may choose his or her own way of so doing. - http://www.uspto.gov/web/offices/pac/mpep/documents/0600_608_03.htm I can't remember where I read it, but a non-trivial percentage (something like a quarter) are for things that do not work. Raul654 14:09, 18 July 2007 (UTC)

Great, thank you for correcting me! Capuchin 14:10, 18 July 2007 (UTC)

Raul654, thanks for taken over the job of clarifying this mess. A few additions: A Raul correctly points out, the patent office's job is only to check whether the invention is new, i.e. that there is no prior art and that it is sufficiently non-obvious. There is no need at all to check, whether it would work, and there is no point to checking that. After all, if the state grants the inventor a monopoly in exploiting a useless invention in exchange for the inventor's paying patent fees to the state, this is no loss for the society and only the inventor's problem. Given that most patents are filed as soon as the idea is there, before it has been worked out sufficiently in details to even think of making a prototype, it would also be hard to show conclusively that it works. Now, the fact that most countries' patent laws explicitly exclude perpetua mobiles from patenting is, of course, an exemption to the rule that checking the soundness of an invention is not the patent office's business. The reason for this exception is, I think, just a courtesy to the poor patent examiners for whom the amusement value of having to deal with cranks might wear off pretty quickly. Furthermore, it is rather hard to judge whether one pertuum mobile is an invention that goes beyond another pertuum mobile invention in a non-obvious way, if the person having ordinary skill in the art would find both inventions equally stupid, and asking courts to check such jedgement would be quite a waste of time. So, the original poster was quite right in asking not how many patents on pertua mobile are granted but how many are filed. Given that all filed patent applications are made public already before they are examined by the patent office, it should be possible to count all the declined perpetuum mobile claims. Simon A. 17:00, 18 July 2007 (UTC)

TRUE PERPETUAL MOTION IS IMPOSSIBLE because even the sun will eventually run down (billions of years from now). BUT Psuedo PM is possible of a sorts. Example there is a clock in the smithsonian that runs perpetually on the motion of the earth. Solar cells can perpetually provide power as long as the sun rises everyday. Ocean tide generators , same, as long as there are tides. ect .ect. Beware the snamp (new word = snake x scam) who would separate you from your bank acct. lol TripleBatteryLife 15:48, 23 July 2007 (UTC)

Kent Couch - Lawn Chair Balloons - did he really go up to 13,000+ feet?

I saw Kent Couch, on a nightly talk show explaining his journey over Oregon and he said he got to altitudes of 15,000 feet. However, several articles I read online stated he got up to 13,000. I do not doubt that he made this trip in his lawn chair, but I am hightly skeptical of the altitude. He claims he used no supplumental oxygen at all. Some of the articles also stated that despite being so high he could even hear cows mooing. So, was he really that high? Would he be able to breath fine and not be sick during an 8 or 9 hour trip up in the air? Also, isn't it quite cold up at that altitude? I'd appreciate any references or further information. Thanks.

Have you looked at our article on Kent Couch? It gives his altitude as 3 miles (15840 ft). A lot of the information that is useful to you can be found in the outer space article. This has a list of the important point in the atmosphere. It gives 15,100ft as the point in the atmosphere where the FAA requires supplemental oxygen. It's not until 26,200 ft that you reach the death zone. Altitude sickness can occur at 6,500ft. I don't know if he was affected.

This page shows that it would be about 3 degrees celcius, so not too cold (that's not exactly a reliable source, but I couldnt be bothered to find a better one). I think it's certainly plausible. There's even more information and lots of sources on Larry Walters, who also went up to 16,000 ft in a lawnchair. Capuchin 08:19, 18 July 2007 (UTC)

Speaking from personal experience, I've been to the summit of Mauna Kea in Hawaii as part of a tour ([1]) a number of years ago. The summit is at just shy of 14,000 feet (4200 m), and most people have no trouble with it. (The tour operators reject visitors with heart or lung conditions, pregnant women, the morbidly obese, and children under 13—though the last group may just be because kids would get bored on the long drive up the mountain.) So yes—it's certainly quite possible and reasonable to breathe comfortably at that altitude.

Of course, as Capuchin notes it's apt to be cold. In Hawaii, in August, we were all glad to have warm fluffy coats when we were at the summit. It was above freezing, but not by much. TenOfAllTrades(talk) 13:31, 18 July 2007 (UTC)

Also note that international badass Reinhold Messner climbed Mount Everest (29,000 feet) with no oxygen, and presumably you need a lot more oxygen to climb a mountain than to sit in a lawn chair. --TotoBaggins 15:17, 18 July 2007 (UTC)

15,000 feet isn't too high - there are several towns in the world up at this altitude (Le Riconada, Peru is at 16,700 feet). Mt.Everest is 29,000 feet - so you're a long way from that kind of problem. He's not exactly exerting himself - so oxygen ought not to be a problem. It would be pretty cold though. The rule-of-thumb is that you get a temp drop of 6.5 degC per 1000m of altitude. So he was looking at a temperature drop of maybe 30 degrees C - it would be freezing - but he'd be OK if he was properly dressed for it. SteveBaker 18:36, 18 July 2007 (UTC)

IT was 1,300 feet not 13,000. (newspaper article). TripleBatteryLife 18:54, 24 July 2007 (UTC)

Arctic Fox

My daughter needs to do a project on hibernation and the Arctic Fox was presented by her teacher as one example of an animal that hibernates. I don't find a sigle reference to the hibernation of the Arctic Fox and infact, found an article indicating that the Artic Fox does not hibernate - can you kindly clarify. Thanks.

You are correct, the Arctic Fox does not hibernate. In fact the article has pictures of its different seasonal coats. Lanfear's Bane

I'm pretty sure that only the hibernating animal in the arctic is the Arctic Ground Squirrel. Some say that pregnant female polar bears hibernate, but it is debatable whether this is hibernation in the true sense. --GTPoompt(talk) 12:59, 18 July 2007 (UTC)

Perhaps you could tell your daughter's teacher that she/he made a mistake. Hibernation is a form of defense against cold, harsh weather; the Artic Fox is suited for cold weather, so it would never hibernate. Cheers!!! --Zacharycrimsonwolf 13:39, 18 July 2007 (UTC)

Why would an animal that hibernates change its coat color to match the snow? Gzuckier 19:02, 18 July 2007 (UTC)

This page says:

black and brown bears are just two of the seven mammals that curl up in dens or burrows or otherwise slumber through Alaska’s cold, dark season. The others are Alaska marmots, hoary marmots, woodchucks, arctic ground squirrels and brown bats, according to Loren Buck, a professor of biology at the University of Alaska Anchorage.

, but I don't know which of those critters occur in Alaska's sliver of Arctic.

Separately, a note of caution: I have encountered both in my own education and in my daughter's some teachers who do not appreciate being corrected on any subject. It's unfortunate, but true, so I would advise tact and discretion on your daughter's part. --TotoBaggins 15:26, 18 July 2007 (UTC)

Yeah - I can definitely agree with that whilst you have a responsibility to get to the truth, it's going to be painful. We've had long and hard arguments with teachers - extending up to principals when my son has given the correct answer and the teacher (and very often the textbooks) are wrong. It's not so bad when the teacher is wrong and the textbook is right - or vice-versa - but when both teacher and textbook are wrong, you're in for a hard time! (eg: Here are a whole bunch of triangles, list which triangles are isocelese, list which triangles are equilateral. My kid listed the equilateral triangle in both the equilateral list AND the isosceles list. The teacher said "No" that's an equilateral triangle - it's not isoscelese. The teacher's answerbook agreed with her. It took a month, three letters (one backed up by a college math professor!) one meeting with the teacher and one more with the principle to get them to agree and to change his grade. Then we had "Which is the odd word out: Orange, Apple, Pear, Tomato" - the official answer was "Tomato"...because "it's a vegetable"...well, I'm sorry but a Tomato is a fruit just like the others. My son not only knew this but chose "Orange" as the answer because "All of the others have rhymes - but nothing rhymes with orange". When told he was wrong he offered "Apple" because it's the only word that doesn't have an even number of letters and the only one with two successive identical letters - but conceded that perhaps "Pear" might be correct because it's the only word whose first letter is not symmetrical - and the only one that doesn't end in a vowel and the only one with two consecutive vowels. When he said it was an ambiguous question he got kicked out of class for being disruptive. (The question was "Which word" was the odd one out - so arguably the question wasn't about fruit anyway.) SteveBaker 18:32, 18 July 2007 (UTC)

Hahaha, I had that happen before. A teacher that insisted Mexico was part of South America, amongst other things I don't remember. I've had stupid teachers, but they weren't totally wrong that often. What your kid did though, Steve, is just plain awesome :D --L^augh! 18:38, 18 July 2007 (UTC)

Funny, and fun, and perfectly correct, but you might also want to inform him that "how to jump through the correct hoops" is also a valuable life skill. A teacher could be forgiven for finding a child's assertion that the object at right is called a "rectangle" to be deliberately obtuse, especially when multiplied by 20 kids in the class or whatever. --TotoBaggins 18:57, 18 July 2007 (UTC)

I remember my eighth grade science teacher informing us that ultraviolet light was yellow in color. Even in eighth grade I figured, WTF? Gzuckier 19:08, 18 July 2007 (UTC)

That's an unfortunate fact of life; "bright" kids, i.e. intelligent and/or original, can see a bunch of patterns, not just one. It would be vastly different if the question had some kind of point to it; i.e., "Which is the odd word out: Orange, Apple, Pear, Tomato, if you were writing a poem?" Just visited a classroom in a pretty good public school, but compared to a pretty good local private school, you can still tell the difference. Teacher in the public school classroom: "We're going to decorate these now. What's a nice shape to decorate with?" Happy, eager kindergartener: "Snowflakes!" Teacher: "But we don't see snowflakes in the summer. How about something else?" Gzuckier 19:08, 18 July 2007 (UTC)

I particularly enjoyed the textbook in year 6 which is now correct, sort of. The book, my teacher and everyone else on my table insisted that Mercury was the smallest planet. How I gloated, months later, when we got new books in secondary school that backed me up. If the book had just missed Pluto out altogether you could use it today :/ And in Britain at least, it's not a private/state thing I think. On the other hand, I knew someone at a private school who got their teacher in serious trouble through a reverse of this; the teacher kept marking their work as correct without checking, so they started making things up to see what would happen. What happened was terribly embarrasing. Skittle 21:42, 18 July 2007 (UTC)

On that last point, see this news story. --Anonymous, July 19, 02:54 (UTC)>

It is the duty of the student

Without question to be prudent.

If smarter than the teacher, tact

Demands that he conceal the fact.

-- Hilaire Belloc [I think --scs 17:18, 20 July 2007 (UTC)]

I had to face the wrath of my math teacher in 8th standard for arguing that the diagonals of a square cross at right angles. She had mentioned that rhombus is the only quadrilateral with this property. She did not seem to be in a mood to appreciate the fact that square is a rhombus, exactly because of this property. Needless to say, I didn't get a chance to prove what I said -- WikiCheng | Talk 06:29, 19 July 2007 (UTC)

Her original statement was wrong. A "kite-shape" (any quadrilateral composed of two isosceles triangles sharing a base) has perpendicular diagonals. Any rhombus is a "kite-shape", and any square is a rhombus. -Arch dude 12:48, 19 July 2007 (UTC)

Isn't even "kite-shape" is an incomplete answer? Stop restricting yourself to where either of the two diagonals bisects the other and you have...an irregular mess. Could be a quadrilateral with no pairs of congruent or parallel sides and no right angles or pairs of congruent angles. DMacks 13:24, 19 July 2007 (UTC)

That's true - I suspect she meant to stipulate that the diagonals had to bisect each other at their midpoints and at right angles. That's what gets you a rhombus - but she's still in trouble for not knowing that a square is merely a special case of a rhombus. That business of special cases not being allowed to take the name of the more general object was my kid's problem with isoscelese triangles and equilateral triangles. The trouble is that once you accept that, nearly all of the class must now be told they got it wrong even though the textbook says they are right. Teachers must just hate smart kids! (Erm...and we've strayed a bit off-topic here haven't we!) SteveBaker 21:48, 19 July 2007 (UTC)

night in the northern hemisphere

Is it possible for the whole of northern hemisphere to have night at the same time ? -- Myth (Talk) 13:25, 18 July 2007 (UTC)

no. the south pole would have to be pointing towards the sun. that will not happen unless something HUGE happens to change the way the Earth rotates. Capuchin 13:33, 18 July 2007 (UTC)

I suppose if you could tilt the whole earth so the north pole points away from the sun ... -- JSBillings 13:35, 18 July 2007 (UTC)

Actually, I suppose a comet or asteroid of sufficient mass could strike the earth at an oblique angle and send it spinning off in to space, so at one point it could have it's north pole facing away from the sun. It might even end up in a stable orbit, and have a tilt like Uranus.

And in that case, we won't be here to care :) Capuchin 14:06, 18 July 2007 (UTC)

(Edit conflict) Yes, but it probably won't be pretty for us on Earth when that happens. The comet would compress the Earth, and all the pent-up gas in the Earth's crust will be released, causing a huge blaze, and practically roasting everything on the Earth's surface. The shockwaves would also pretty much change the entire face of the planet. In fact, Earth might not even make it. And even if she did, it would take thousands to millions of years of years for the ecosystems on Earth to form again, and another million years for primapes to evolve into humans (or our equivalent). --Zacharycrimsonwolf 14:07, 18 July 2007 (UTC)

The Earth would not fall apart because of a mere comet. It would take something with much more mass to do that. Clarityfiend 17:15, 18 July 2007 (UTC)

Indeed - but a 'mere comet' couldn't flip the earth's axis to a noticable degree either (unless it was moving insanely fast!). But something big enough to change the earth's axis would certainly be enough to wipe out all life on the planet in the process. No - to address the OP's question: The answer is a categorical "No". SteveBaker 18:09, 18 July 2007 (UTC)

And any impactor with sufficent mass to significantly change the angular momentum of the earth would likely liquify the earth's surface in the process, making it an interesting fluid dynamics problem with no one around to solve it :) Unless of course, we can find a way to move to our similarly-created neighbor-RunningOnBrains 22:59, 18 July 2007 (UTC)

I think it's unfair to say the answer is "No". It is possible for it to happen, even if it kills every living thing on the planet, and in fact, it has happened to another, much larger planet in our own solar system. -- JSBillings 11:22, 19 July 2007 (UTC)

Actually, even if the south pole were aimed 100% accurately at the center of the sun - you still wouldn't get night over the entire northern hemisphere because (a) the sun is a lot bigger than the earth so it shines over more than half of the planet no matter how it's turned and (b) refraction through the atmosphere makes the sun appear higher in the sky than it really is - so even after the sun has mathematically 'set', it's still not dark - so you wouldn't get a full hemisphere of darkness - it would be a lot less. Still - if we're allowed to postulate catastrophies of earth-twisting proportions, let's just relocate the earth close to a neutron star and blow away all of the atmosphere - or maybe just move it so far from any star that it's "night" all the time, everywhere. Well - that's all well and good - but the "fair" answer is "No" - so let's not confuse the OP by saying otherwise. SteveBaker 21:37, 19 July 2007 (UTC)

Alternately, we could just redefine "Northern Hemisphere" to mean what "Eastern hemisphere" means now . . . Eran of Arcadia 17:21, 19 July 2007 (UTC)

How does that help? SteveBaker 21:37, 19 July 2007 (UTC)

Well, I don't reaslly have a reply, but I wanna ask, what does OP stand for? —Preceding unsigned comment added by Zachary crimsonwolf (talk • contribs) 11:37, 20 July 2007

See here. —Steve Summit (talk) 12:41, 20 July 2007 (UTC)

Is it possible...

...that the sun never sets on Russia? If their furthest west point is that little land-island that use to be Prussia (I think), and the furthest East is Diomede... has this been gone over before? 68.39.174.238 15:01, 18 July 2007 (UTC)

The sun never sets "on" any location on Earth. It is too far away to make physical contact. -- Kainaw^(what?) 15:12, 18 July 2007 (UTC)

Don't give stupid responses to straightforward questions.--138.29.51.251 15:14, 18 July 2007 (UTC)

It is not a stupid response. The question is not straightforward. A straightforward question would be "Is it possible that the sun is always visible from somewhere in Russia throughout the day?" Instead, the question is "It is possible that the sun never sets on Russia?" That question is vague. There are sunsets visible all over Russia every day. By simply using some intelligence in asking a question, it is easier to get an intelligent response. -- Kainaw^(what?) 15:46, 18 July 2007 (UTC)

Kainaw, the OP is no doubt referring to the concepts in The empire on which the sun never sets, or perhaps the British Empire, about which was said "the sun never sets on the British Empire". The idea is that a country and all its colonial possessions could encompass a sufficient number of widely-spaced territories on the Earth that the sun would always be above the horizon in at least one of them. Please don't assume that the OP is asking about the sun physically setting down on some piece of land—it's not polite to assume that degree of cluelessness without good cause. TenOfAllTrades(talk) 16:28, 18 July 2007 (UTC)

Thank you. 68.39.174.238 19:20, 18 July 2007 (UTC)

Our Russia article says the Russian Federation spans 11 time zones, which implies (roughly) that it covers not quite half of the span of longitudes, so clearly at some point (in the winter) the Sun is on the opposite side of the earth. You can see in this map that, even counting Kaliningrad, Russia does not span the more than the 180 degrees that would be necessary to have the sun never set.

I see... thanx. 68.39.174.238 19:22, 18 July 2007 (UTC)

You can play with [http:// www.daylightmap.com/ one of Google's toys] to see what is day vs night on a map. DMacks 15:53, 18 July 2007 (UTC)

Kainaw is perhaps not familiar with the old saying "The sun never sets on the British Empire," which was an observation of vast imperial geographic footprint, rather than a trivial astronomical fact. Edison 16:16, 18 July 2007 (UTC)

...which was also noted in can't-remember-what-humor-book with the explanation something like "this is because Britain is in the east, and the sun sets in the west". DMacks 16:54, 18 July 2007 (UTC)

Anguished English ? 68.39.174.238 19:22, 18 July 2007 (UTC)

Because the sun isn't a dot - it actually covers some angular extent, and refraction through the air means that that you can see the sun when it's technically below the horizon. According to Sunrise equation you get an extra 0.83 degrees at sunrise and sunset. Hence you don't quite need to cover 180 degrees of the earth's surface to get this result - but 178.4 degrees (OK - that's still not enough!). Also, our article on Antarctica says that Russia "reserves the right" to claim a part of that continent as it's terratory. Since it also owns parts of the earth very close to the north pole too - is it possible that between those two places that the sun never sets? It's a bit of a stretch though. The answer has to be "very nearly never sets". SteveBaker 18:06, 18 July 2007 (UTC)

Simply having Antarctic territory, without getting land somewhere in the 200° longitude not covered by Russia, would be insufficient. In the time frame around the equinoxes you can basically ignore the midnight sun effects of the polar regions, and you're left with the "not enough longitude" problem. For that matter, I don't think even some Antarctic land in the uncovered longitude is sufficient. My gut suggests that land sufficiently south (say, below 83°S or so) could still be under 24-hour night before the northernmost reaches of Russia (81°52') get 24-hour day. This, however, is a fairly fuzzy assertion. I'm quite confident that the problem would be simpler if we could talk territory outside the Antarctic Circle, and I'm pretty sure it would work out if Antarctic territory at the appropriate longitude were no further south than their antipodes were north. — Lomn 18:37, 18 July 2007 (UTC)

Further pedantry: 1) Kamchatka is both very easterly, and has a volcano 16,000 feet tall, so that might make the sun rise a bit earlier there. 2) According to this page, Russian modules on the International Space Station may be considered Russian territory for certain purposes, so that might affect the outcome, depending on its orbit (seems doubtful, though). Atmospheric lensing and the oblateness of the Earth should also not be ignored! --TotoBaggins 19:15, 18 July 2007 (UTC)

As a large portion of northern Russia is within the Arctic Circle, I thought of an interesting follow-up question: How long of a span during the summer does at least some part of Russia receive sunlight? Just a few days in June? Most of spring and summer? I don't have the right equations to do the calculations, just curious. -RunningOnBrains 22:51, 18 July 2007 (UTC)

Well, Extreme points of Russia says the northernmost point of Russian land is Cape Fligely. Plugging its coordinates into this web page along with various dates in 2007, I find... hmm, an anomaly. It shows sunrise and sunset on April 8, but neither sunrise nor sunset on April 9. Anyway, clearly the midnight sun starts about then. Then sunset will be on September 4, so that's about 149 days of daylight. --Anonymous, July 19, 2007, 03:18 (UTC).

Ah, this companion page shows sunrise at 20:22 UTC on April 8. I bet the other page just didn't look fr enough back into the preceding day. --Anon, July 19, 03:57 (UTC).

Stupid responses to legitimate questions such as Kainaw's are becoming increasingly more frequent in the RD. Perhaps we should warn about this somewhere. --Taraborn 17:22, 23 July 2007 (UTC)

Mould and Toxins

I'm writing a dissertation on coffee, and back when I started it I had access to a paper that said something along the lines of 'moulds undergoing temperature fluctuations produce more toxin than if they had been kept at a steady temperature' (specifically Ochratoxin A). Now that I have nearly finished, I find I cannot locate either the name or the address of this paper. While it appears to be common knowledge in the right areas that not only do fluctuating temperatures increase moisture levels, they stress mould into producing toxins, I cannot find a paper to use as a reference. Help!

I'm really hoping someone knows of, or can find, a decent thing I can use as a reference. I have access to a library, but I'm not subscribed to any places that offer papers. If it mentions it in the abstract (which I can view), that would be nice, or in a book, or anything that looks properly referencable. I'm having real trouble finding anything other than Geocities sites that actually mentions what I need to say I read D: Getting a bit desperate....

Thanks for any help. Skittle 16:04, 18 July 2007 (UTC)

• Production of Penicillic Acid and Ochratoxin A on Poultry Feed by Aspergillus ochraceus: Temperature and Moisture Requirements C. W. Bacon, J. G. Sweeney, J. D. Robbins and D. Burdick Appl Environ Microbiol. 1973 August; 26(2): 155-160
• Journal of Applied Microbiology Volume 97 Issue 2 Page 429-438, August 2004 Modelling the effect of temperature and water activity on growth of Aspergillus niger strains and applications for food spoilage moulds R. Parra and N. Magan

And many others.--Stone 16:42, 18 July 2007 (UTC)

And here's another:

"Under alternating temperatures OTA production was higher than at constant temperature, and alternating temperatures indirectly favoured OTA production due to condensation and a subsequent rapid increase in moisture content and water activity of the coffee beans." The production of ochratoxin A by Aspergillus ochraceus in raw coffee at different equilibrium relative humidity and under alternating temperatures (Palacios-Cabrera, et al. Food Control. Volume 15, Issue 7, October 2004, Pages 531-535) link

-- MarcoTolo 16:46, 18 July 2007 (UTC)

Thank you sooooo much! My saviours! :D Skittle 16:54, 18 July 2007 (UTC) In fact, I think Marco's one is the very one I initially had, right back at the beginning. Hooray! Skittle 17:00, 18 July 2007 (UTC)

greying eyes

I have dark brown eyes and they are actually changing to a greyish blue from the outter rim inwards and i am still young so I called my doctor and he told me that it was normal, then i was talking to my friend the other day and she said it's a loss of pigments and it happened to her brother (freaky!) so what exactly is the cause of losing pigments then?

There is discussion of this in Eye color. SteveBaker 16:55, 18 July 2007 (UTC)

Remove Scratches in Leather

Not sure if this belongs in Science Help Desk, but it's as good a bet as any. Does any one know how to get a fine scratch out of leather? It is a top quality leather sofa and the scratch is very fine (as if gently scraping your fingernail against the leather) -- yet noticable. The scratch is perhaps 1-2 inches long. Any suggestions on whether or not it can be "removed" or doctored up to be less visible? Thanks. (JosephASpadaro 20:05, 18 July 2007 (UTC))

http://www.google.co.uk/search?hl=en&q=leather+remove+scratch&meta= - apparently there are repair kits for these sort of small scratches commercially available. My first thought was a little shoe polish of a similar colour, but you might wish to try shop bought product first. Lanfear's Bane

Thanks. (JosephASpadaro 21:31, 19 July 2007 (UTC))

You might try something like an exact color match in a shoe polish (remember they use shoe polish for similar reasons other than just to make a shoe shine .. it covers over some of the scuffing scratches etc) afterwards try using a rag to get as much of the polish back off (leaving only a residual amount ideally in the scratch itself). Just a thought. TripleBatteryLife 15:59, 23 July 2007 (UTC)

Thanks for the ideas. (JosephASpadaro 05:13, 24 July 2007 (UTC))

Wholemeal v. wholegrain in the UK

Is there any difference between the two in the UK please? The article treats them as both the same, but I seem to rember reading about a difference at least in the UK. Thanks. 80.2.221.87 23:18, 18 July 2007 (UTC)

Wholemeal is meal (flour) made from whole grains of wheat, wholegrain is the whole grains of wheat etc. DuncanHill

How come you get wholegrain bread then? 80.2.192.45 11:02, 20 July 2007 (UTC)

Wholegrain bread has whole grains in it. DuncanHill 11:07, 20 July 2007 (UTC)

Harmone receptor question

What is Harmone receptor positive and Harmone receptive negative?72.76.142.100 23:37, 18 July 2007 (UTC)

I think you may mean Hormone receptor. There is some information in that article, but it is written in quite technical language. DuncanHill 23:41, 18 July 2007 (UTC)

I'm guessing you may be referring to how oncologists classify types of breast cancer. Patients with estrogen receptor (a type of hormone receptor) positive tumors will typically receive a hormone therapy treatment such as Tamoxifen. These treatments are ineffectual in hormone receptor negative tumors. Rockpocket 04:52, 19 July 2007 (UTC)

Parrot/Conure ID needed

I very nearly bought a parrot (poss. conure?) on a complete and utter whim today. This is a story that'll sound familiar to many pet owners - I saw it sat alone in a cage at the pet shop, looking very bored and it came up to me and let me stroke it when I tapped on the bars and made kissing noises. Very cute little bird - though I have no idea what species it was/is (never seen one like it before). Very, very tempted to take it home with me, though in the end I saw sense and decided to think it over.

It was a similar size to a cockatiel, though slightly 'wider', mostly olive green with some grey/brown on the head/neck and red feathers on the belly, a long darkish tail, black beak and white skin around the eyes and nostrils. It was completely silent the whole time I was there.

Anyone have any suggestions what kind of bird this is? The kid at the counter was only a part timer and she didn't know. --Kurt Shaped Box 23:45, 18 July 2007 (UTC)

Kurt, oh fellow bird lover. Don't do it! It sounds like a Sunday Conure, but there are several similar species. Parrots, especially Conures can be incredibly rewarding pets, but they take a great deal of commitment and time. After all they can live for 40-50 years or more! That said, go ahead and do some research and if you are ready to make the leap and are well prepared, then go for it! I highly recommend subscribing to the magazine Bird Talk (it is however, an American magazine and you may not be able to get it in Great Britian).--Eriastrum 00:24, 19 July 2007 (UTC)

I've owned/looked after a few different types of parrots before, so I do know what I'd be getting myself into - which at the moment is something I don't want to be doing. :) I have a few budgies at present (some in an aviary, one lone 'indoor budgie') - but they don't need a huge amount of one-to-one attention if you have several. Even the little guy seems to prefer to be left to his own devices (and his toys/beloved mirror!) most of the time. It's just so tempting when you see them in the shop, isn't it? I made that mistake once, with a lovebird when I was a kid - and the little thing ran me ragged for most of my teenage years (even though she was great)... --Kurt Shaped Box 01:07, 19 July 2007 (UTC)