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May 22

If Earth was great big ball of magnetism

If the earth was magically replaced with a new earth made totally from a strong magnetic material like neodymium what sort of impact would that have on the solar system? I know that gravity is really weak compared to the other forces so i'm just curious would an earth of neodymium pull other planets towards it? Would it have any effect on the sun? Mike --87.112.183.70 (talk) 01:17, 22 May 2010 (UTC)

I don't think so -- at the sorts of interplanetary distances involved, the gravitational force would still be much more of a factor than the magnetic force. Keep in mind, too, that the other planets would still be non-magnetic. FWiW 67.170.215.166 (talk) 05:17, 22 May 2010 (UTC)

This is a terrific question that I know will have several people puzzling. I can't speak much to the change in Earth's natural magnetic field at all - I will defer to someone who knows more about it - and I'm not sure how the polarity is set up in those Nd magnets. That said, most planets have natural magnetic fields, and if the field lines from two bodies reinforce each other, they will attract according to the cube of the distance from each other. This tapers off much more quickly than gravity, but even if it didn't, Earth's field may be strong but even Jupiter's, the strongest in the solar system, is relatively weak and will likely not result in much orbital disturbance.

It takes two good fields to magnetically tango. When magnets pick up pieces of metal like paperclips they do it by inducing a temporary field in the paperclip, because the iron in a paperclip is something that can quickly align as a magnet and then fall back out of it, depending on what other fields are in the environment (so it can attract itself to either pole of a magnet by rearranging itself, for example). A planet is not made out of this "ferromagnetic material". Most of them have heavy cores of iron or nickel, but those are far too high temperature to hold an attractive arrangement together to attract itself to the Nd Earth. However, Nd magnets are strong enough to induce magnetic fields in even non-ferromagnetic materials, even humans, and thus can make for neat household tricks (try dropping one down an iron tube).

In conclusion, I don't think this giant Nd Earth will have much direct effect on other planets, though someone will probably prove me wrong. SamuelRiv (talk) 05:24, 22 May 2010 (UTC)

I think that the neat trick you're thinking of involves dropping a strong magnet down a copper tube. The magnet will simply stick to an iron tube. APL (talk) 07:42, 22 May 2010 (UTC)

Now you've got me curious. What happens? Vimescarrot (talk) 07:57, 22 May 2010 (UTC)

assuming you've not already google'd it - here's a youtube video of what happens. (http://www.youtube.com/watch?v=30oPZO_z7-4) ny156uk (talk) 09:13, 22 May 2010 (UTC)

Nifty! Vimescarrot (talk) 15:27, 22 May 2010 (UTC)

This super magnetic earth will have an impact on solar wind it will probably drag all the solar wind nearby and accelerate it to the magnetic pole. It might also attract iron asteroids - especially if given enough time. I think the first order of business is calculating just how strong the magnet would be. Ariel. (talk) 02:11, 23 May 2010 (UTC) well u see magnet can attract only magnetic substances around itself. grationational pull of earth could be the reason of its magnetic effect but not the only one . gravitational force is effective between masses, gravitones are smallest particle exchange which goes on between the masses. if earth would be a giant magnetic ball then its shape and size will deform itself under many time period(permanent magnet is always in shape of a bar). their are few forces we know so we can think of it but many more types of orce do exist whose effect we don't know.......for more questions mail me to champgamy@gmail.com

rust forceps

i bough some German stainless steel Surgical OCHSNER Forceps. i put them on my sink counter. a few weeks later a small amount of rust appeared. hows that possible. —Preceding unsigned comment added by Tom12350 (talk • contribs) 04:57, 22 May 2010 (UTC)

What's your sink counter made of? If could the rust have come from that and not the forceps? This used as a source in stainless steel only says that stainless steel rusts less easily than normal steel. I'm no chemist though, hopefully someone can explain in more detail. 131.111.30.21 (talk) 08:59, 22 May 2010 (UTC)

Stainless steel is very resistant to oxidation by oxygen gas, where it forms a thin protective layer of chromium(III) oxide. If there is acid, the coating dissolves, starting the corrosion (although the rust dissolves too). If there is strong alkali, the coating dissolves, and some rust forms which is insoluble in alkali (iron is not amphoteric). But you shouldn't have strong acids and alkalis on your sink. --Chemicalinterest (talk) 10:51, 22 May 2010 (UTC)

[1] [2] Rust spots on stainless steel happen, for a variety of reasons.77.86.62.107 (talk) 14:51, 22 May 2010 (UTC)

Weather recce

What's an aerometeorograph, and what atmospheric parameters does it measure? 67.170.215.166 (talk) 06:06, 22 May 2010 (UTC)

From here "A self-recording instrument used on aircraft for the simultaneous recording of atmospheric pressure, temperature, and humidity." APL (talk) 07:30, 22 May 2010 (UTC)

Cool, three essential parameters measured with one instrument! Now, does anyone happen to know its typical weight and size, and also whether it's a self-contained instrument or whether it has to be hooked up to the plane's static port or OAT gauge? Thanks for the info! 67.170.215.166 (talk) 02:53, 23 May 2010 (UTC)

Update: Just looked up some pictures of modern units, they're quite small (about the size of your typical battery-powered portable emergency radio). So no problem about the size; the only thing I need to know is, is it self-contained or does it hook up to the plane's instrument systems? 67.170.215.166 (talk) 07:17, 23 May 2010 (UTC)

Can the acoustic guitar hurt your hearing?

This question has been removed. Per the reference desk guidelines, the reference desk is not an appropriate place to request medical, legal or other professional advice, including any kind of medical diagnosis or prognosis, or treatment recommendations. For such advice, please see a qualified professional. If you don't believe this is such a request, please explain what you meant to ask, either here or on the talk page discussion (if a link has been provided). --TenOfAllTrades(talk) 13:40, 22 May 2010 (UTC)

TenOfAllTrades(talk) 13:40, 22 May 2010 (UTC)

Too fast to be an Iridium flare... so what was it?

I sat beneath the stars tonight for about an hour. I no longer have a grasp of the night sky, so all I can say is I was facing southwest (the Big Dipper was behind me somewhat). At one point, I saw what looked like a camera flash go off, but it was a pinpoint of light. It was extremely quick, no "few seconds" or "trail" that the Satellite flare article talked about. Then I noticed something peculiar... I kept staring at that spot and there was a second, almost imperceptible flash, just a hair to the left of the original flash. Huh! Anyway, time goes on and I'm staring to the northwest, closer to the Big Dipper, and again, there is a microburst of light way up in the heavens. This time I stared and stared, hoping to corroborate the secondary flash, and sure enough, after a few seconds, and just a fraction of some unknown stellar distance from the original flash was a second "pop" of light... What's up there, and is it rotating? I've seen dozens of "normal" satellites that are a constant reflection, a dot moving slowly across the night sky. I've never seen this before in my life. Any ideas? SR-71 taking pictures of me? :D – Kerαunoςcopia^◁_galaxies 09:17, 22 May 2010 (UTC)

It might be an airplane doing combat manuevers in the air. It also could be a meteor. Firecrackers? --Chemicalinterest (talk) 11:06, 22 May 2010 (UTC)

Without having seen it, it's hard to say for certain. It's also worth remembering that one's eyes can play tricks under low-light conditions. (For example, the second 'flash' might be just some sort of afterimage that you're seeing just because you're looking very hard for it. As well, to dark-adjusted eyes an object doesn't have to be particularly bright for it to look quite bright.) A couple of guesses: a meteor following a trail aimed almost directly at you, so that it didn't appear to move appreciably as it rapidly brightened and then disappeared. If the rock happened to break into more than one fragment, you might see a second flash. Another explanation could be tumbling space debris — the solar panels on a retired or 'lost' satellite, etc. That reflection would tend to have a much faster 'rise time' than an Iridium flare, and you might get a second flash as the satellite tumbled around. TenOfAllTrades(talk) 13:12, 22 May 2010 (UTC)

A fundamental problem we have here is not knowing how high was the artefact that caused the brief flashes. It could indeed be something as simple as a plane at altitude and you caught a solar reflection, you don't say how long after sunset this occurred. However the fact that it happened again in a different part of the sky makes me believe that it was some sort of image created by your eye or optic system. There are several non-pathological causes for the effect of "seeing stars" in a medical sense and I am not inferring that you have a medical condition that requires attention, I suggest this may be a possible reason for seeing microflashes of light. Richard Avery (talk) 14:59, 22 May 2010 (UTC)

It could easily be a satellite flare, just not an iridium reflection. There are other objects tumbling rapidly that could give a flash. If it is short you wont see a trail. Graeme Bartlett (talk) 22:09, 22 May 2010 (UTC)

Could it be a plane's anti-collision strobe lights? Many civilian planes have them, and they make bright white flashes every couple seconds. And if the plane was at high altitude (like an airliner at 30000 feet), then you can see the flashes but not hear the engine noise. FWiW 67.170.215.166 (talk) 02:58, 23 May 2010 (UTC)

If you remember the exact time, check the Heavens-above website. Count Iblis (talk) 16:56, 23 May 2010 (UTC)

Thanks, all. It wasn't an eye problem, it couldn't have been an airplane because I was watching for that, and beside, the night was absolutely crystal clear pitch black loaded with stars, and nothing was moving up there, and thanks for the Heavens Above website, but unfortunately I have no clue what time it was. Anywhere between 4 and 5 in the morning, but i have no watch. – Kerαunoςcopia^◁_galaxies 19:20, 23 May 2010 (UTC)

How many carbon black add in polypropelene polymers from protection SUN LIGHT

Dear, Plese, find answer headline and give me reply. thanks, Mr. jatin —Preceding unsigned comment added by Mjhirpara (talk • contribs) 12:14, 22 May 2010 (UTC)

More carbon black produces increased uv resistance.

This product [3] uses 3% carbon black.77.86.62.107 (talk) 15:03, 22 May 2010 (UTC)

See this book [4]77.86.62.107 (talk) 15:06, 22 May 2010 (UTC)

Iodine oxidation

Is sodium hypochlorite strong enough to oxidize elemental iodine (in its dilute state as household bleach)? --Chemicalinterest (talk) 12:19, 22 May 2010 (UTC)

Look up the reduction potentials for Cl⁺¹ → Cl⁰ or Cl^–1 compared to I⁰ → I⁺¹ to see which is stronger/able to oxidize or reduce which when you have these two redox half-reactions balanced. DMacks (talk) 15:06, 22 May 2010 (UTC)

There's a number of issues with this reaction:

• hypochlorite solutions are strongly basic - so the standard electrode potentials will need converting, or may not be applicable
  • particularily : Iodine disproportionates in alkaline solution to iodide and iodate
• Additionally Iodine reacts with chloride to form I₂Cl- and other reactions.

There's some more detail on iodine redox here [5] 77.86.62.107 , the chlorine potentials are also in this book a few pages before. (talk) 15:24, 22 May 2010 (UTC)

I never find the reduction potential for OCl^- + H₂O + 2 e^- → Cl^- + 2 OH^-; only see it for reduction to Cl₂. The iodide probably will be oxidized by NaClO when it is formed. --Chemicalinterest (talk) 17:04, 22 May 2010 (UTC)

It's in the above link, page 74 section C E=0.890V (in basic solution - not at [H+] = 1mol/dm3)

Probably the reason why it's never found as a standard E is that ClO- is unstable under standard (ie acidic) electrode conditions.87.102.18.191 (talk) 17:11, 22 May 2010 (UTC)

FWIW, "put a drop of solution on starch/iodide paper" is a standard test my students use for presence of hypochlorite in solution; turns dark if there is oxidizer available. See starch indicator and iodine test for some backround on what this might mean chemically. DMacks (talk) 18:55, 22 May 2010 (UTC)

Wembley Stadium grass - too dark?

Are the problems with the Wembley Stadium pitch simply due to the fact that the design of the stadium (high walls, roof) means that the grass does not get enough sunlight to grow properly? 92.28.248.33 (talk) 13:06, 22 May 2010 (UTC)

It seems unlikely, grass doesn't require a particularly high level of photosynthetically active radiation to grow. In fact at my house, the grass grows longer in the shade since there is more water available due to less evaporation. I'm not familiar with stadiums but I can't believe that Wembley is particularly different to any others and you'd think that they would have thought about it during the design stage. Reading this it sounds like it is more of a problem with it not being laid long enough before a game is played for a strong mat of roots to grow and form a good surface. 131.111.30.21 (talk) 16:33, 22 May 2010 (UTC)

The roof of Wembley was specifically designed to maximise the sunlight on the pitch, for the grass - that's why it's retractable. Vimescarrot (talk) 17:46, 22 May 2010 (UTC)

The stadium is in London, which is on the same latitude as Newfoundland, so it would not get as much intensity of sunlight as similar designs of stadium would in most parts of the United States for example. The grass is also 4 metres lower than it used to be, and the old design was less raked and roofless as far as I recall. 92.15.9.117 (talk) 18:04, 22 May 2010 (UTC)

dimple above penis

I have noticed that some men have a slight dimple just above the spot where the penis meets the pubis (this is normally only apparent if the pubic hair is shaved). Is this a medically recognised anatomical feature, and if so, what is it's name? Little radiolarian (talk) 13:14, 22 May 2010 (UTC)

Do you mean Apollo's belt? --Jayron32 04:25, 23 May 2010 (UTC)

Jayron -- I think he refers to the dimple in the midsagittal plane. It's a space between muscles that doesn't provide the support for the skin in that region as seen in the immediately surrounding areas -- anatomically, the space will fall in the midsagittal plane and will correspond to the skin and fatty tissue superficial to the suspensory ligament of the penis, just inferior to the pubic symphysis. DRosenbach ^{(Talk | Contribs)} 04:30, 23 May 2010 (UTC)

That certainly sounds like the same spot I'm describing. Would it be correct to describe this dimple as a surface feature of the pubic symphysis? If not, how would you refer to it (on the rare occasions one might have reason to)? Little radiolarian (talk) 15:25, 23 May 2010 (UTC)

I dreamt about this question last night, graphic imagery and all. Didn't even remember until I was passing through this question. – Kerαunoςcopia^◁_galaxies 19:16, 23 May 2010 (UTC)

According to the anatomy text I'm using (Moore), the pubic symphysis is too inferior to palpate -- probably because of both a low position and the erectile tissue being too massive to poke through. DRosenbach ^{(Talk | Contribs)} 01:28, 24 May 2010 (UTC)

The origin of life!!!!!!

I want to know how it was successfully verified that life on earth has arisen from complex molecules such as methane and oxygen was not present during the initial formation of life on earth? —Preceding unsigned comment added by Hitarth21 (talk • contribs) 14:58, 22 May 2010 (UTC)

Hi, your sentence is very confusing, can you rewrite it? Thanks. Beach drifter (talk) 15:00, 22 May 2010 (UTC)

Our knowledge and understanding of abiogenesis is very limited. There are some educated guesses about how it might have happened (see that article for details), but we don't really know. --Tango (talk) 15:50, 22 May 2010 (UTC)

TWO SCIENTIST DID AN EXPERIMENT: they took a round bottom flask, put two electrodes in it,filled it half with water, and put some rare gasses in same proportion they thought would have been present at the time of origin. they kept this setup for weeks at 100degree Celsius. electrodes are used for sparking mimicking lightning. and after weeks lo and behold1 TYHEY found key compounds needed to let life exist. THIS EXPERIMENT WAS CALLED MILLER'S EXPERIMENT ON THE NAME OF ONE OF THE GEEK. GOOGLE IT --Myownid420 (talk) 15:53, 22 May 2010 (UTC)

You're thinking of the Miller-Urey experiment. It was an important step in thinking about how life came about, though people today realize that the actual composition that they used probably wasn't very representative of Earth's early atmosphere. However, similar experiments have been done using other compositions, sometimes with interesting results. Buddy431 (talk) 16:23, 22 May 2010 (UTC)

Here are some of the problems with your original post:

1) Methane and oxygen aren't complex molecules, they are simple molecules (CH₄ and O₂). Oxygen, of course, is also a chemical element, O, but isn't normally found as a single atom.

2) The "complex molecules" you were probably thinking of are amino acids, the building blocks of proteins.

3) Then when you ask about whether scientists "verified that life on earth has arisen" from this process, you must realize that scientist can only propose a hypothesis that this is how it happened, as there's no fossil record of the original life forms. StuRat (talk) 16:30, 22 May 2010 (UTC)

The initial stages of the origin of life are still not clearly understood. To me it seems most likely that deep ocean vents are where the action took place. Regardless of that, there is very strong evidence that significant oxygen levels didn't show up until about a billion years ago -- the rocks that formed at the surface prior to that are not oxidized as they would be if high levels of oxygen had been present. Looie496 (talk) 16:52, 22 May 2010 (UTC)

AFAIK it is considered that oxygen was likely poisonous to early life. Vespine (talk) 22:55, 23 May 2010 (UTC)

Germ cell tumor

Whats the prognosis of a metastatic germ cell tumor —Preceding unsigned comment added by 24.97.164.250 (talk) 15:13, 22 May 2010 (UTC)

I assume you've read "Germ cell tumor#Prognosis"? Remember that Wikipedia does not give medical advice (see WP:MEDICAL). Gabbe (talk) 17:10, 22 May 2010 (UTC)

planets coming in align

in how many years does all planets come in one line. is it even possible or not? When they will align, will not it anyhow efffect Earth's life? if so then how.

<IN MY CLASS TEST ONCE I MADE ALL THE PLANETS IN ONE LINE AND MY TEACHER ASKED ME "WHAT IS THE PROBABILITY OF THIS". I SAID "MAY NOT IN COMING THOUSANDS OF LIGHT YEARS BUT SOME DAY IT WILL HAPPEN". I WANNA KNOW I WAS CORRECT OR NOT>

See Syzygy. How often it happens depends on how precisely you want them to line up. If you're happy with them just being in the same quadrant (ie. a 90 degree wide sector) then it will happen far more often than if you require them to be within a 1 degree sector, say. As for what effect it would have - none at all. About 70% of the combined mass of the planets is Jupiter, so all the planets acting together couldn't do anything significantly more than Jupiter can do on its own, which isn't much (as far as the Earth is concerned). --Tango (talk) 15:57, 22 May 2010 (UTC)

And when you consider the relative gravitational influence of solar system bodies on the Earth, you stop caring after the moon and the sun. Jupiter isn't even the most influential planet (it's 1/10th the effect of Venus), but none of them are meaningfully relevant. — Lomn 19:44, 22 May 2010 (UTC)

Ah, yes, I forgot it's tidal forces, not direct gravitational forces, that matter, so we need the cube of distance not the square. I believe Jupiter has the largest gravitational force out of the planets on Earth, just not the largest tidal force. Thanks for the link! --Tango (talk) 21:25, 22 May 2010 (UTC)

And a light-year is a unit of length, not of time. --Магьосник (talk) 16:37, 22 May 2010 (UTC)

Isn't there a particular name for this phenomenon?--Myownid420 (talk) 02:18, 23 May 2010 (UTC)

If you count Pluto as a planet, Neptune and Pluto "align" every 492 years ("align" = conjoin in geocentric celestial longitude -- it would be better to be heliocentric, but this is just for illustration). Uranus and Pluto align every 115 and 165 years, alternating. Uranus and Neptune align every 171 years. Saturn and Uranus align every 45 years. Saturn and Pluto align every 30-plus years, as do Saturn and Neptune. Jupiter and Saturn align every 29 years. And so on. Given that the solar system has been and will be around for billions of years, it's likely that at some point all nine planets will be within one degree of each other in heliocentric "longitude" because the product of all the periods is probably much less than several billion years. However, if you want alignment to within one arc-second, it seems unliekly that even the products of the periods will realistically indicate an exact nine-planet alignment, though I don't know the math for this. Anyone else? 63.17.50.130 (talk) 02:43, 23 May 2010 (UTC)

This data is based on short term observations. The solar system is basically an n-body problem; in the short term it can be predictable, but in the long term it becomes highly chaotic. So, we can pretty easily predict how often two bodies will be in line with the sun; but once we start waiting for three and four and five bodies to align in such a way, the time frame becomes long enough between occurances that chaotic effects take over and it literally becomes impossible to predict. --Jayron32 04:22, 23 May 2010 (UTC)

This happened about 5 years ago, all the red top papers in the UK were predicting workd disaster...nothing happened, just a normal day at the office. therefore, it does happen, rarely, but is of no significance to anyone. —Preceding unsigned comment added by 62.172.58.82 (talk) 14:24, 24 May 2010 (UTC)

I don't think anyone here would be happy to accept as evidence of multiple planet alignment, the word of red-top newspapers. --Tagishsimon (talk) 14:30, 24 May 2010 (UTC)

Solid phase extraction and Chromatography

Hi, I have just read both Solid phase extraction and Chromatography pages but I haven’t found the difference between techniques. I mean, they do the same thing and exploit the same principle or not? Thanks so much in advance, I ‘m studying Forensic pathology for next month exam.--151.53.91.218 (talk) 16:51, 22 May 2010 (UTC)

SPE deals with making the desired analyte specifically soluble/extracted or insoluble/stuck-to-solid-phase, the other starts and ends with the desired analyte in solution merely passed through. The key to SPE is where that article states "either the desired analytes of interest or undesired impurities in the sample are retained on the stationary phase" (emphasis mine) as opposed to the more general idea of chromatography "passing a mixture [...] through a stationary phase, [...] Subtle differences in a compound's partition coefficient result in differential retention on the stationary phase". Differential retention causes elution time to vary vs "retained or not-retained". DMacks (talk) 18:50, 22 May 2010 (UTC)

updates based on scientific fact

Shrimp are bottom feeders meaning their diet may include toxic substances including radioactive particles. However, since 1970 shrimp have been farmed in non-toxic environments. Consequently do any of the religions which in the past have excluded them from the diet now permit such non-toxic shrimp to be labeled "Kosher"? 71.100.3.228 (talk) 19:53, 22 May 2010 (UTC)

Toxins possibly being present in food has nothing to do with the food being or not being Kosher. Beach drifter (talk) 20:00, 22 May 2010 (UTC)

I think the toxin example is a bad one because it presumes to know the intent of the law, which would not sit with a religious person terribly well. (It assumes they have secular goals behind them; that is how an outsider views such things, not an insider.) But there are modern updates to things like kosher laws—for example, there is an entire industry of appliances designed to conform with Sabbath strictures as they are interpreted to apply to modern technology. See: Sabbath mode. In Judaism, there are rabbis who get together and debate whether or not, say, flicking a switch violates the strictures against "work", or whether setting an oven to heat up violates strictures against lighting a fire, and so on. --Mr.98 (talk) 20:52, 22 May 2010 (UTC)

To elaborate on Mr.98's concise post above, the laws of Judaism are immutable and the biblical violation of eating seafood that does not possess both fins and (easily scrape-off-able) scales (Leviticus 11:9) does not hinge on the toxicity or other physical uncleanliness of these organisms. DRosenbach ^{(Talk | Contribs)} 04:37, 23 May 2010 (UTC)

Okay then I'm really stumped here trying to explain why in this modern day why such ancient rules are not arbitrary but rather mandatory, unless they are intended to be arbitrary so they can serve more as test of obedience rather than anything else. If that is THE CASE and its just a matter of proving loyalty through compliance rather than compliance serving a practical purpose then not updating such laws makes more sense. 71.100.3.228 (talk) 07:54, 23 May 2010 (UTC)

"Why a religion has a certain rule" is not a scientific question. DMacks (talk) 08:13, 23 May 2010 (UTC)

Then what in your opinion is the purpose for a religion having rules? 71.100.3.228 (talk) 20:04, 23 May 2010 (UTC)

In any case, much of Judaism in particular is about doing what the law says even though you don't understand it. It is not and does not claim to be scientific. If you'd like a humorous send-up of Orthodox Jewish thought, which nonetheless gives a great (and entertaining) primer as to the logic behind it, I highly recommend Shalom Auslander's hilarious Foreskin's Lament: A Memoir. The basic philosophy is that you do what God says because God says to do it. As for whether the origin of the laws are based in some kind of secular purpose, well, there's been a lot of speculation about that, and that would be interesting for the anthropologist, but it would not be relevant to anyone practicing the religion. And I will note that my very reform cousins did not keep kosher at all, even at their bar mitzvahs and things like that (they served Hawaiian pizza, if you can believe it). There are multiple strains of thought within any religious heading. (I write all this as a nonreligious person myself, so if I offend anyone or have grossly caricatured a complicated thing, I apologize ahead of time.) --Mr.98 (talk) 12:53, 23 May 2010 (UTC)

What comes to mind are certain religious real world physical "journeys" in which the individual believer marks out the entire journey with a prone position to show devotion to its head. In any practical sense walking would be an update or flying in a plane but since the purpose is to show devotion to the religion's head by lying prone the entire length of the journey and walking or flying would not show this level of devotion they must be ruled out. From this perspective then I can see why religious rules would not be subject to update. 71.100.3.228 (talk) 20:12, 23 May 2010 (UTC)

Religious rules are subject to update - just, usually, not for scientific reason. Christianity is Judaism 2.0 (well, actually, a bag from 2.0 to 4.5 with plenty of mutually incompatible patches ;-) and Islam is essentially a merger of both rewritten from scratch. Looking at the early history of Christianity (which essentially started out as a jewish sect) shows significant debate of which laws apply to jewish Christians, and to gentile Christians. The laws given to Noah (don't kill, don't eat blood) were deemed to apply to all Christians (although the first has been very much rationalised away, and the second largely forgotten by now), but the Kashrut and circumcision were on the table for a while, too (with Paul being one of the strongest opponents of applying them to gentiles). --Stephan Schulz (talk) 20:46, 23 May 2010 (UTC)

Thanks for the Kashrut link. I have a friend who is developing meals that comply with individual diet plans which are based on varying amounts of commonly available foods which Kashrut will help guide. For instance, farmed shrimp was on the list until now. It would be nice in some cases though if the rules were updated to include farmed shrimp. 71.100.3.228 (talk) 20:59, 23 May 2010 (UTC)

(outdent) Religious observance is one of those things that really doesn't take kindly to an outsider trying to find technicalities or adjustments in how to apply or accommodate them. If you're trying to be polite and make certain populations feel welcome, you definitely take them on their own terms, however obsolete, confusing, nit-picky, or technicality/confusing-to-you they might seem. In fact, one of the tenets of Judaism and "follow its laws" I often hear is that you shouldn't try to find loopholes to excuse why you don't want to follow an observance (the flip side being whole movements that have taken a coherent look at deciding what observances are appropriate for modern-day). Or in a milder form, better to play it safe than to accidentally actually violate a law while trying to just tread close to the edge. Really, if you're trying to host an event where keeping kosher (to some level) matters (for some guests) ask them what they feel comfortable with. There's strictly kosher, who wouldn't even eat off your dishware and wouldn't drive to your venue on Saturday, there's "pretty kosher" who would be happy with a vegetarian option rather than putting you to the effort of cooking something really kosher, there's "kosher style" who would eat non-kosher beef but not a cheeseburger, etc. Just like there's vegan, lacto-ovo-vegetarian, "no red meat", etc. Actually, having a real vegetarian option (an actual entree, not just the side-salad) is a pretty good way to solve many different special diets (health, moral, religious). DMacks (talk) 21:45, 23 May 2010 (UTC)

I suppose the question arises from the use of the word "unclean" in reference to the different kinds of plant and animal that can be eaten as the basis for using a modern scientific designation of what is actually clean. Since shrimp are unclean from only what they eat it seems that if they are farm raised on only corn meal for instance that the designation of unclean simply cannot or would not apply. I'll ask the guests though from now on as the best strategy. 71.100.8.229 (talk) 03:15, 26 May 2010 (UTC)

Kashrut has nothing to do with unclean. Kashrut for animals is based on specific lists of things the animal needs to have. For a water-dweller (not just fish) it needs to have fins and scales. Shrimp doesn't. Unclean has nothing to do with it. Ariel. (talk) 11:38, 26 May 2010 (UTC)

magnetism versus temperature

what is the formula that relates and objects temperature to its magnetism? 71.100.3.228 (talk) 20:01, 22 May 2010 (UTC)

I'm not aware of one - maybe you were thinking of the Curie temperature .87.102.18.191 (talk) 20:25, 22 May 2010 (UTC)

So the state of magnetism undergoes a similar transition as state of matter phase change in which changes occur at junctures rather than continuously? 71.100.3.228 (talk) 20:49, 23 May 2010 (UTC)

Niel ?

I keep thinking I've heard of a "Niel temperature" - but search shows nothing. (Not Niels Bohr - I think it was a surname)

Is there a similarly name temperature or point - I'm sure it was a transition or phase change temperature.87.102.18.191 (talk) 20:27, 22 May 2010 (UTC)

Annealing temperature? --BozMo talk 20:34, 22 May 2010 (UTC)

:) (no) 87.102.18.191 (talk) 21:20, 22 May 2010 (UTC)

The Néel temperature is the temperature above which an antiferromagnetic material becomes paramagnetic. Cuddlyable3 (talk) 21:29, 22 May 2010 (UTC) Cuddlyable3 (talk) 21:29, 22 May 2010 (UTC)

Yes thanks. 87.102.18.191 (talk) 21:49, 22 May 2010 (UTC)

Resolved

What metals were thrown out by the icelandic volcano?

What heavy metals were ejected by the icelandic volcano?--92.251.177.211 (talk) 20:55, 22 May 2010 (UTC)

The material ejected by the volcano would have been basically basalt, which has metals in the form of silicates and oxides but none of the heavy metals are likely to be present other than in trace amounts, as far as I know. Mikenorton (talk) 21:26, 22 May 2010 (UTC)

Heavy metals are found in only trace amounts in basalt - but the overall effect of a volcanic eruption is to increase the levels of heavy metals in the surrounding area (in general) http://www.google.co.uk/search?hl=en&q=volcano+heavy+metal+emmision&meta=

In norway no effect had been noticed expected in this report http://www.niva.no/symfoni/infoportal/publikasjon.nsf/.vieEngInterForsideNIVA/1135331028BA9759C125770E00278CE0?OpenDocument&Category=&m1=News

[6] people are measuring this, but as far as I can tell the results aren't readily available as yet.87.102.18.191 (talk) 13:21, 23 May 2010 (UTC)

Is there any animal that can 'emit' fire?

Years and years ago I saw a wildlife documentary that featured a rainforest insect of some kind which (IIRC) as a defence mechanism was able to squirt a stream of *something* from its hindquarters which then spontaneously ignited in contact with the air, producing a small jet of flame. For some reason, I ended up discussing this with someone today, who insisted that I was wrong and asserted that there is no such and never has been any such creature. I'm open to the possibility that my memory is playing tricks on me and that I've mixed up something like a bombardier beetle (I looked that up first, thinking that it may have been what I was remembering) with Pokemon, or dragons - or that I saw it in a dream, or whatever.

So, does anyone know if there really is a bug, or anything else out there that can do this? --Kurt Shaped Box (talk) 21:05, 22 May 2010 (UTC)

I think you're just thinking of the bombardier beetle. There are no fire-breathing anything (other than people). --Mr.98 (talk) 22:07, 22 May 2010 (UTC)

Dragon —Preceding unsigned comment added by 79.76.233.61 (talk) 23:44, 22 May 2010 (UTC)

Animal, mythological creature. These are not equivalent, 79. Vranak (talk) 01:59, 23 May 2010 (UTC)

Salamanders are often associated with fire, though in reality they have very little to do with it. Buddy431 (talk) 04:12, 23 May 2010 (UTC)

It used to be thought that salamanders derive from fire, but it was later shown that they merely crawl from ground detritus when fire causes them to leave. See Slifkin's Mysterious Creatures (Targum Press 2003) ISBN 1-56871-248-0 (republished as Sacred Monsters) for a thorough review. DRosenbach ^{(Talk | Contribs)} 04:40, 23 May 2010 (UTC)

Any creature capable of setting fire to its environment would have made itself extinct by now.--Shantavira|^{feed me} 06:16, 23 May 2010 (UTC)

The conclusion being, any animal capable of emitting fire would have to live in a difficult-to-ignite environment. Vimescarrot (talk) 08:54, 23 May 2010 (UTC)

Or just be careful about what they ignite. I mean, humans are animals that are capable of setting fire to their environment. Yes, we've burnt ourselves a few times doing that, but it's hardly an evolutionary impossibility! --Mr.98 (talk) 18:49, 23 May 2010 (UTC)

Yes, but we've only been around for the blink of an eye. The (non-avian) dinosaurs still have about a factor of 1000 on us, and see where they are now. --Stephan Schulz (talk) 20:50, 23 May 2010 (UTC)

Not necessarily. Certain pines (I think Jack Pines are one), for example, need fire in order to germinate. If there isn't a periodic wildfire, they can be crowded out by other trees. (This has happened in portions of the western U.S., where there has been a "suppress all wildfires" policy for several decades.) Right now they require externally initiated fires, but one could easily imagine a hypothetical situation where a pine recognizes that it's being crowded by other species, so produces copious amounts of (fire-resistant) seeds, and then sets fire to the forest. Other species will be pushed out, and the seedlings now have ash-enriched soil to grow in. This might allow them to spread to wetter climates, where wildfires are not as wide ranging. -- 174.24.200.38 (talk) 17:48, 23 May 2010 (UTC)

A 2005 forum post [7] says: "There was an article a year or two ago in the NY Times, from a number of scientists who said that a fire-breathing animal was biologically possible." I haven't found the article. PrimeHunter (talk) 00:25, 24 May 2010 (UTC)

You're not thinking of fireflies, are you? (I wish I was a firefly I never would be glum Cos how could you be gloomy When the sun shines from your bum?)--TammyMoet (talk) 09:14, 23 May 2010 (UTC)

How about Bombardier beetle? RJFJR (talk) 17:42, 24 May 2010 (UTC)

The OP already mentioned the Bombardier beetle. --Tango (talk) 18:00, 24 May 2010 (UTC)

Black hole paradox

After watching an explanation of the black hole paradox from Leonard Susskind, the explanation made first at sense, but further thought has left me only more confused. First, a quick explanation of the paradox:

• When person 1 watching person 2 enter into a black hole, person 2 appears to freeze, and time for him stops due to the gravity. Person 2 will never progress beyond the event horizon from person 1's view.
• Time, however, does not stop for person 2; from his perspective, he will sail right past the event horizon.
• Point 1 appears to conflict with point 2. Thus anything done by person 2 inside of the horizon will be irretrievably lost to the outside world - this shouldn't happen though. Physics says that, in theory, person 1, with a perfect view of what's occurring, should be able to reconstruct person 2's past perfectly.
• The solution, as explain by Susskind and apparently mostly accepted by physicists, is that the information is stored on the surface of the event horizon, an unfathomably hot place where matter is squished into a two-dimensional (or essentially two-dimensional) plane.

What I don't understand is this:

1. For person 2, time on the outside world should go faster and faster. Right before reaching the event horizon, the world will speed up to infinite time. What then to make of what person 2 observes after passing the even horizon? (this situation, by the way, is far from just theoretical: the spaghettification on a smaller sized black hole apparently won't occur on supermassive black holes).
2. What of the matter towards the center of the collapsing star that becomes a black hole? That matter has no way of being "stuck" on the event horizon and as such wouldn't be visible as the event horizon slowly evaporates.
3. What happens to matter immediately inside the event horizon upon collapse? The gravity there would insist on a field faster than the speed of light. This seems to violate the laws of nature.

Magog the Ogre (talk) 21:25, 22 May 2010 (UTC)

I'm not sure what the problem is in your first question. Somebody falling into a black hole will see the outside world sped up (and massively distorted) and will observe things happening billions of years after they crossed the line in the few hours (at most) they can survive before being ripped apart, that's just the way it is. For your other questions, I don't think the problem exists since the collapse will happen from the inside out. The centre of the star will be the densest bit, so will become a black hole first and the rest of the star will fall into it. The event horizon will start out with very tiny diameter (you probably need a theory of quantum gravity to describe that bit) and grow. Your questions seems to be based on the assumption that the event horizon forms instantly at its final size, which isn't the case. --Tango (talk) 02:23, 23 May 2010 (UTC)

1. Remember that person 2 can only see what happens in his past light cone which will not include a infinite amount of the time of person 1
2. Tango answered question 2 pretty well above.
3. I'm not sure I understand your question, but be asured that any local observer (that is person 2) doesn't see any object passing by at a speed higher than the speed of light and light always is observed to move at the speed of light. He will, for instance, observe light rays moving outwards at the speed of light.

Dauto (talk) 02:45, 23 May 2010 (UTC)

Your bullet-point summary of the information paradox isn't really correct. "Losing" information behind an event horizon isn't a problem, because you can just say the information is on the other side of the horizon. Any surface that moves towards you at the speed of light behaves as an event horizon if you never cross it, including the unbounded redshift of objects falling through, the "gravitational" attraction, and even the Hawking radiation (though it's called Unruh radiation instead of Hawking radiation in some contexts). This is true even if you're out in the middle of nowhere and the "surface" is one that you just invented with no physical meaning whatsoever. Rindler coordinates has more information about this.

The problem with black holes is that they apparently can disappear completely by Hawking radiation, leaving nowhere for the lost information to go. People have proposed various unsatisfactory solutions to this, which you can find at black hole information loss paradox. The idea that infalling objects get "squished onto the event horizon" and then leave as Hawking radiation is the one called "Information gradually leaks out during the black-hole evaporation" in the article. The problem is that there's nothing physically special about event horizons, as I said above. You can define an event horizon anywhere, so the "new" physics should show up everywhere, unless you throw away the equivalence principle.

Susskind wants to solve this by having the "new" physics (where you turn into Hawking radiation) actually be mathematically equivalent to the ordinary physics (where you just fall through the horizon and nothing special happens to you). This sounds completely crazy, but there actually is a lot of circumstantial evidence for an equivalence ("duality") like this, and it's appealing because whereas the other solutions all break some nice physical symmetry (like unitarity or the equivalence principle) this one introduces a new physical symmetry, while preserving all the old ones.

I don't know why Susskind says that all physicists agree with him on this. Only a small number of physicists are interested in black hole information loss in the first place, and I've never had the impression that they agreed about much. I guess everybody now agrees that unitary is preserved (Hawking was the holdout, but changed his mind a few years ago). -- BenRG (talk) 21:44, 24 May 2010 (UTC)