Wikipedia:Reference desk/Archives/Science/2007 December 4

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December 4

Guppy

My guppy that i think is a female has a pointy think sticking out of its but lol and i know its not poop because its been there a long time what is it? thanks --Sivad4991 03:37, 4 December 2007 (UTC)

Can you describe this "pointy thing" with more detail? It would cut down on guessing and specious answers. 70.57.229.74 04:43, 4 December 2007 (UTC)

Have a look at this [1] page and see if it helps. Richard Avery 15:20, 4 December 2007 (UTC)

Processor Cooling

My heatsink has a fan on its right side, would it be beneficial to put a fan on the left side also (mounted onto the heatsink) or would it be better to put it on one of the other sides or top? Thanks —Preceding unsigned comment added by 76.167.132.90 (talk) 05:13, 4 December 2007 (UTC)

I would be most efficient if the airflow goes in the same direction, so put one on the other side with the same orientation as the original. However, are you sure that your processor need an extra fan? --antilived^{T | C | G} 09:47, 4 December 2007 (UTC)

Trying to overclock the processor as high as it goes, so I want to keep it as cool as possible without spending a lot of money on a cooling solution (like water cooling). Thanks for the reply —Preceding unsigned comment added by 71.106.34.15 (talk) 16:12, 6 December 2007 (UTC)

Little fishes

What kind of little fishes school at the surface of the water near the bank in a river in subtropical brackish water and appear to breath air? (At a distance of 10 feet or so this activity appears to be bubbles coming from the bottom.) Is this behavior because the water does not have enough oxygen or is this some type of social or other natural behavior of the fish? —Preceding unsigned comment added by 71.100.1.143 (talk) 05:31, 4 December 2007 (UTC)

Bubbles? Schooling in a single place? Sounds like they're spawning. SamuelRiv 08:27, 4 December 2007 (UTC)

Individual fishes remain separated by 4 to 6 inches. Stop at the slightest move I make although I'm a tremendous 20 feet away.

Many fish feed on insects at or just above the surface of the water. Shooting on along that thought, you might want to see our article about archerfish.

Atlant 14:08, 4 December 2007 (UTC)

They are not archering.

Some extra information would be helpful. How big are these 'little fishes', one or two centimetres? or smaller. Where, geographically, are you talking about? In the meanwhile, subtropical brackish water is likely to be low in oxygen if the water is warm. In these circumstances some species of fish do come to the surface to try and augment their blood oxygen level. This may account for the disturbance you have seen. Richard Avery 15:15, 4 December 2007 (UTC)

Lat. 27. Water Temp. 72 Air temp 82. They are 1 to 2 inches long.

A picture is worth a thousand words. Someguy1221 20:17, 4 December 2007 (UTC)

The wiki did not come to mind until I was home. I shall return to the spot when it warms up (has dropped to the low fourties over night) and take pictures galore.

one scientist's take on evolution

I just spent another useless hour googling for this: I remember once reading in an interview with some brain/intelligence researcher where he stated a piece of opinion that went something close to "The biggest evolutionary leap lies within mankind". He was talking about differences in intelligence and illustrating his opinion that the difference between the most gifted humans and averagely gifted humans is far greater than that between the average human and other primates. I have googled off my finger-tips several times over now, but I just can't seem to find it online who that researcher may have been? I dorftrottel I talk I 10:17, December 4, 2007

I remember hearing something about this on a science podcast once, maybe in relation to Artificial Intelligence (and the singularity) too in a Raymond Kurzweil kind of way, but it isn't him...I even tried to Google search your problem myself, as everyone tells me that I seem to be able to find out anything, but alas it is a real stumper! I will be interested to see if someone has the answer. Maybe when people in North America wake up. I keep thinking of James D. Watson! So sad. There was just that report in the news the other day about Chimpanzees beating college students at short-term memory tests too. Good luck! P.S. Not that people in North America are smarter, just that a majority of them read English and like to come to the the Wiki! Saudade7 13:02, 4 December 2007 (UTC)

Here's the short-term memory story. And an important note to that study was that the chimps were faster in their recall abilities, but no more accurate. So saying "they had better short-term memory" isn't precise enough to say exactly what the study concluded. And I highly doubt it was Watson. He usually just makes controversial claims about race and intelligence.--droptone 13:28, 4 December 2007 (UTC)

The chimps were faster at entering their responses - but no more accurate. That could be that the humans were being overly cautious or something. What was impressive was further down that article where they started to reduce the amount of time for which the numbers were flashed onto the screen. At four tenths of a second, the chimps were still doing quite well when the humans were failing utterly. That might mean that their visual system is more acute. I don't think these tests show anything about intelligence. SteveBaker 13:34, 4 December 2007 (UTC)

Just to say that I was just kind of throwing out ideas...I didn't read that chimp story very carefully, I just read the headline and skimmed. And I don't actually think that Watson said it, I was just saying that it made me think of him given his recent public comments when I was in London. I'm sorry if what I said sounded purposefully misleading or wrong. I really hope you find out. Take care. Saudade7 19:37, 4 December 2007 (UTC)

The BBC TV news showed some video of the chimps performing - DAMN! - they were fast! It was quite utterly amazing that such a complex task could be done that fast. They started off teaching the chimps the numbers 1..9 and scattering the numbers at random across a computer screen. The game was for the chimp to use a touch-screen to touch the numbers in ascending order (as each one is touched, it disappears). Then they'd flash the numbers up - for some amount of time - then write white squares over where the numbers had been. The game is the same, touch the white squares in the order of the (now concealed) numbers. Finally, they'd leave out some of the numbers - so you might have 1,2,4,6,7,8 and 9. That's quite a hard task when you only see the numbers up there for less than half a second. It was easy to see that the chimps were both faster (MUCH faster) and more accurate than the humans. (What's more, they were doing this for treats - and the chimp was casually eating with one hand and playing the game with the other!) But I'm still not convinced that this is a demonstration of intelligence - dexterity and 'photographic' memory - yes, but IQ, no. I could easily program a dumb old robot arm with a webcam to beat both chimps and humans...and such a machine would have no intelligence whatever. SteveBaker (talk) 01:55, 5 December 2007 (UTC)

I don't think it was supposed to be about IQ (nebulous as that is), what was supposed to be amazing was that Chimps outperformed humans in an area of cognition (is this the word I want or is it too specific? 'using their brains' is what I mean) and that this could happen was pretty dismissable until now. After all, you can program a computer to calculate arithmetic considerably faster than chimps and humans, but it would still be amazing if young chimps were faster and more accurate at arithmetic than humans. Skittle (talk) 09:57, 5 December 2007 (UTC)

Yeah - I agree. I think it would be surprising if there weren't quite a few mental skills that Chimps have that can beat us. I'm just dubious about attaching this "intelligence" tag to what they do. After all, what they are doing isn't so different than (say) dogs doing scent tracking - but we don't put that down to intelligence because it's clearly sensory and motor skills...well, so was the chimp test. SteveBaker (talk) 04:39, 6 December 2007 (UTC)

Thanks for the replies, will keep looking then. ¶ dorftrottel ¶ talk ¶ 07:48, December 5, 2007

Iranian nuclear video

In reports about Iran's nuclear program, the TV news often shows a clip where there's some sort of large ductwork on a floor with a gap where you can see an orange flame moving right-to-left. What is that apparatus doing? --Milkbreath 12:03, 4 December 2007 (UTC)

Can you find a link to a video on YouTube or YahooNews or something that shows this object? Saudade7 13:11, 4 December 2007 (UTC)

I found one on BBC World News, but it's not a direct link. You have to go here and click on "Pictures from inside an Iranian nuclear facility". The apparatus appears at 35 seconds in. --Milkbreath 14:54, 4 December 2007 (UTC)

Here's an attempt at a direct link:

mms://a113.v373744.c37374.g.vm.akamaistream.net/7/113/37374/1.0/clipdownloads.bbc.co.uk/realmedia/news/media/avdb/news/world/video/134000/nb/134442_16x9_nb.wmv

Thanks goes to Firefox plugin UnPlug. How do I make it an ordinary link, btw? —Bromskloss 15:40, 4 December 2007 (UTC)

I don't think you can make a direct link with something that doesn't start with "http://" etc. - this link has to have another program open to view it. It is kooky but it worked! I don't know what that thing is however. Good luck. Saudade7 19:32, 4 December 2007 (UTC)

They are using gas centrifuge technologies for doing the separation of the necessary isotopes. One assumes that this entails vaporizing the uranium and keeping it gaseous as it passes through successive enrichment stages. The boiling point of Uranium is around 4100 degrees C. So I guess that could easily be one of the centrifuge heaters...but who knows? Maybe the factory just gets kinda chilly in the winter? SteveBaker 15:54, 4 December 2007 (UTC)

I don't think so: The gas centrifugation is done with uranium hexafluoride which has a boiling point lower than water. 193.171.121.30 19:05, 4 December 2007 (UTC)

Remember that even though the media focuses primarily on the centrifuge facility (of which to my knowledge there is only one picture on the 'net of the insides), there are actually many facilities and plants required for their nuclear program. Anyway, I've seen some of those photos before from a trip made by the FARS news agency, and I believe it is of the Uranium Conversion Facility at Isfahan, at least judging from the color scheme and the orange staircases. See this group of slides for more pics. I don't know a huge amount about the many processes and equipment necessary to convert yellowcake into uranium hexafluoride, but some idea of some of the ways it is done can be gleaned from this document (a DOE-produced handbook of things not allowed to be exported to Iraq in 1996, specifically the chapter on uranium conversion technology). --24.147.86.187 (talk) 19:01, 9 December 2007 (UTC)

Emotional music

I'm trying to understand why most people have such a strong emotional response to film music (the kind you get in blockbusters and Disney movies). Why do we loose control of our emotions when hearing overwhelming violins and a few timbals? Not sparing myself for scientific experimentation, I rented a Hans Zimmer CD and I'm getting the expanding lungs, tingely heart thing as I type this so the film is not needed for the music to work. Why is it so effective? Keria 15:26, 4 December 2007 (UTC) and I have to add insistant wind instruments to the list.

In the case of music-for-film, it's easy to explain. Human memories are stored 'holistically' - we don't remember things the way a computer does by tucking one memory away in a little box with a label on it. Instead we remember by connecting every little bit of information with every other little bit. This makes it impossible to hear the music without (possibly subconsciously) recalling the movie it was attached to. This is sometimes very annoying...but it's how our brains work. Consequently, I cannot listen to the "Dance of the Sugar Plum Fairy" without thinking of chocolate with nuts and raisins in it because the tune was used for a particularly memorable series of UK television adverts a few decades ago. So I presume, the music is evoking the memory of (and emotions relating to) the movie. SteveBaker 15:47, 4 December 2007 (UTC)

By "film music" I only meant the type of music. I guess you could call it a certain type of classical music (the only example I can think of would be Carmina Burana). In the example of Zimmer, I haven't seen any of the films yet the music as a strong emotional impact. I'm pretty sure, for example, that it increases my heart rate, which feels like it's being crushed yet is all tingely at the same time; eyes go moist etc. This doesn't happen with most music. I can be excited and appreciate a good rock record but it hasn't the same direct emotional impact (maybe I'm wrong in calling it emotional). I guess this might happen with martial music too. Keria 15:59, 4 December 2007 (UTC)

This is a phenomenon that a lot of composers use, not just Hollywood composers. It is created by playing a chord of three notes (a triad), and then playing some other chords and notes that are dissonant to the original chord (called the root). This dissonance creates an uncomfortable feeling among the listeners. Eventually the composer then inserts a chord that will resolve or complete the root chord. This resolving chord may be a fifth or a seventh usually. This resolution to the dissonance creates a feeling of satisfaction and even euphoria for the listeners. For a more complete explanation of this, look at the wiki article called Seventh chord, with special attention to the section entitled "Dominant seventh". Saukkomies 16:09, 4 December 2007 (UTC)

It's not necessarily the music per se. You can listen to the same music on CD, radio or in a concert hall and not be affected by it to the same degree, or at all (although you might). It's the combination of the on-screen action with exactly the right music at exactly the right moment, that does the trick. This is not a new idea; for centuries, composers have been commissioned to write incidental music to plays (such as Grieg's music for Ibsen's Peer Gynt, Bizet's music for Alphonse Daudet's L'Arlésienne, Mendelssohn's music for A Midsummer Night's Dream, and hundreds of other examples). Stage managers cottoned on very early in the piece to the fact that audiences had a greater emotional reaction to the play when music appeared at judicious intervals to counterpoint the action; which would encourage patrons to come back and back, ie. put bums on seats. And of course, it's the entire basis of opera and modern day musicals, and try to imagine Swan Lake with dancing but no music. This doesn't help explain why it's so effective, but to show the idea has been around a lot longer than the movies. -- JackofOz (talk) 22:52, 4 December 2007 (UTC)

Level of inflammation determines speed of healing process?

Hi. Generally speaking, as an exercise question only. Suppose someone has a sprained foot. The body's natural healing process is to make the tissue surrounding the injury site inflamed. Thats called Inflammation. So, the patient takes Ibuprofen, a non-steroidal anti-inflammation drug. As I understand it, the body's purpose in making inflammation is to generate the replacement of injured tissue. The inflammation triggers this process, right? So, suppose patient A does take ibuprofen, and patient B doesn't (assuming the same kind of injury) I would imagine patient A will take longer to heal than patient B. Because patient A's inflammation will be less, and so the molecular replacement mechanism will be less intense, and stretch out over a longer period of time. Patient B will experience more pain, the inflammation will be more, but the injury will heal faster, because the repair signals are stronger. Right?

Thanks! —Preceding unsigned comment added by InverseSubstance (talk • contribs) 17:01, 4 December 2007 (UTC)

As noted at Inflammation#Inflammatory_disorders, not all inflammation is beneficial. Whether inflammation will help or hinder healing in any particular case is a medical question which should be directed to your doctor. The reference desk does not give medical advice. Dragons flight 19:47, 4 December 2007 (UTC)

There have actually been a number of studies on this, like this one, which found no significant increase in post-operative recovery with increasing dosages of anti-inflammatory drugs. Of course, these studies were operating only on approved dosage levels. Someguy1221 20:06, 4 December 2007 (UTC)

compass needle

what is the meaning of the phrase "needle point north to south" although a needle has two ends, how would we know which end is towards north and which is towards south?193.251.135.124 17:12, 4 December 2007 (UTC)

By convention, compasses are constructed such that the end that points north is marked in some way, often by being painted red. MrRedact 17:37, 4 December 2007 (UTC)

If I had to guess, I suspect that compasses were invented by people who lived in the Northern hemisphere and who didn't know that the South Pole even existed. For them, it pointed toward the North Pole - the back end pointed towards nothing in particular. SteveBaker 21:17, 4 December 2007 (UTC)

The compass was available well before most people had a concept of a globe in mind, and so it is doubtful whether those people even concieved of a "Pole" at all. I suspect there was a time when it was seen more as "one end points towards the cold lands and the other end points at the hot lands", at least in the early times. Dragons flight (talk) 21:25, 4 December 2007 (UTC)

For what it's worth, the compass was invented around 1000 and reached Europe around 1300. The idea of a Spherical Earth goes back to ancient times. More info on the general topic at History of navigation. The page on Christopher Columbus puts it, "the Earth had generally been believed to be spherical since the 4th century BCE by most scholars and almost all navigators". Pfly (talk) 21:59, 4 December 2007 (UTC)

Indeed. It's in our article, but in the interest of it becoming more widely known: Columbus' great idea was not that the world was round. His great idea was that the world was significantly smaller than it was then thought to be, and that he could thus sail all the way to Asia by going west. In this he was entirely mistaken, and was saved from mid-ocean starvation by running into the New World. Algebraist 22:26, 4 December 2007 (UTC)

{fact} Known certainly. Widely known and accepted by most scholars? I'd question the reality of that during the say the 12th century. Pre-renaissance there was a lot of old wisdom that wasn't exactly well known. Dragons flight (talk) 23:21, 4 December 2007 (UTC)

I too thought that statement was probably going too far -- but in a hurry I used it anyway -- the basic idea I was aiming for was that as the use of the compass spread through Europe, circa 1300-1400 or so, the people most likely to find them useful and practical would be navigators of the open seas (perhaps a rare breed at the time), who would probably already be familiar with celestrial navigation and methods of determining location that presumed a spherical planet. Just a minor tangent to the OP's question. Also, it amazes me that exploration voyages such as the Norse to Greenland and North America were done without the aid of compasses, relying on dead reckoning, measurements of latitude, and celestrial navigation. In any case, it may be difficult to determine how widespread the idea of a spherical Earth was in the late Middle Ages. The people most likely to make practical use the concept, sailors and navigators, tended to leave very little written record back then. Another grey area is in the three centuries between the compass's invention in China and its introduction to Europe. I know very little about what the Chinese and Muslim sailors of the Indian Ocean thought about the sphericity of the world -- though Medieval Muslim scholars were world's ahead, so to speak, than their European contemporaries on such things. But if we're talking about Europe, we're looking more at the 1300s and 1400s, by which time I think even among scholars -- at least scholars who cared to swell upon such topics -- the sphericity was becoming well established. Still I agree the statement on the Columbus fact was rather sweeping. Pfly (talk) 03:43, 5 December 2007 (UTC)

See Flat Earth. The early Christians were (as ever) dubious scholars, and no-one knows what the common people thought, but a recent study of medieval concepts of the sphericity of the Earth noted that "since the eighth century, no cosmographer worthy of note has called into question the sphericity of the Earth." And don't forget that the Polynesians achieved far greater (and much earlier) navigational feats than the Norse. Algebraist 16:55, 5 December 2007 (UTC)

ammonia

why ammonia is a gas even though it has three polar bonds? 122.163.139.129 19:12, 4 December 2007 (UTC)

One reason (or at least a devil's-advocate for your idea) is that the bond dipoles somewhat cancel each other, making the molecule as a whole less polar than "lots of N–H bonds" would suggest. DMacks 19:40, 4 December 2007 (UTC)

(ec) The polar bonding between ammonia is not nearly as strong as between water molecules. Firstly, oxygen is a much more electronegative than nitrogen, so the bonds are much more polar. Secondly, a water molecule has two lone pairs and two partially positively charged hydrogen atoms, whereas an ammonia molecule has one lone pair and three such hydrogens. Now, consider that a hydrogen bond can only be made between a lone pair on a partially negative atom (such as oxygen or nitrogen in these molecules), and a partially positive hydrogen. Since water has two pairs and two hydrogens, each water molecule can hydrogen bond to four other water molecules, and form a very strong nearly continuous lattice. (Indeed, at room temperature a water molecule is bonded to 3.6 other water molecules, on average.) An ammonia molecule can also make four hydrogen bonds, but the average over a large group cannot be four, as they contain disproportionately many hydrogen atoms to lone pairs. At best, a volume of pure ammonia could have each molecule make only one two hydrogen bonds. Combine this with that afformentioned weaker polarity, and the cohesive force holding ammonia molecules together is much weaker than in water. Someguy1221 19:42, 4 December 2007 (UTC)

The ammonia molecule is also closer to planar than a water molecule, which weakens its polarity further, thus weakening simple dipole-dipole interactions. I'll spare you the quantum mechanical reasoning for this. Someguy1221 19:47, 4 December 2007 (UTC)

Uhh, if I remember correctly, isn't ammonia sometimes a liquid? I remember, when we did experiments at my school, the ammonia was in the form of a liquid, at room temperature. Thanks. ~AH1^(TCU) 23:02, 4 December 2007 (UTC)

It can be liquid if stored at low temperatures and/or high pressures. It can also be dissolved in solution (ammonia is quite soluble in water), or dissolved as ammonium salts. It is also a product of many common chemical reactions. Someguy1221 (talk) 23:08, 4 December 2007 (UTC)

The "liquid ammonia" you used at school was almost certainly a solution of ammonia in water. You'll probably recall that the stuff smelled pretty strongly — that was the ammonia gas gradually evaporating out of the solution. —Ilmari Karonen (talk) 01:15, 8 December 2007 (UTC)

Gasoline-methanol blends?

From methanol:

The use of methanol as a motor fuel received attention during the oil crises of the 1970s due to its availability and low cost. ... As a result of its low price, some gasoline marketers over-blended.

How inexpensive can methanol be? How much would a gas station profit from over-blending? I mean, methanol has to be synthesized from simple organic molecules. The prices of these materials would also rise during an oil crisis because they are also fuels. Chemical synthesis adds to the costs of methanol. How could an over-blender profit from over-blending? If methanol is so cheap and abundant, why don't big companies build methanol burners to power their big factories? -- Toytoy 19:50, 4 December 2007 (UTC)

As of 2002 it cost 50 cents a gallon. However, this is the cost at very low levels of production (relative to global oil consumption). Someguy1221 19:56, 4 December 2007 (UTC)

The subsections on "production" and "automotive fuel" may also be enlightening. Methanol is not (primarily) derived from crude oil, and so its price isn't really tied to the 1970s oil crises. Over-blending builds the profit margin by substituting additional cheap materials for expensive ones. The section on "automotive fuel" (among other places in the article) notes that methanol is corrosive, damaging both metal parts and rubber seals. I'd think this a major reason that methanol burners aren't in vogue, and Someguy's note about production level's impact on cost is worth noting, too. Methanol may not be economically feasible if scaled up to crude oil demand levels.

As for profits, I'll pull numbers out of a hat for example purposes. I'll use $3/gal gasoline and $1/gal methanol. Pure gas costs $3/gal. The gas station decides that no one will notice their little "this gas contains methanol" sticker and substitutes 5% methanol without adjusting the sale price. They're now charging $3/gal for what's only worth $2.90/gal, pocketing the extra 10 cents on every gallon. Unscrupulous Gas Station X then decided to overblend to 10% methanol, charging $3/gal for $2.80/gal product. UGSX can even drop their sale price below the regular blenders (to, say, $2.95/gal) and still haul in a higher profit margin -- at the expense of their customers' engines. — Lomn 20:08, 4 December 2007 (UTC)

I wasn't aware of methanol as a gasoline additive, but we do have an article on Methanol_fuel. If it's like ethanol, my understanding of it being bad for engines is that this is merely a myth. You'll still find plenty of old timers who're convinced it's harmful to the engine, but I don't think this is really true today, if it ever was. Friday (talk) 21:21, 4 December 2007 (UTC)

Methanol/ethanol are solvents the designers of 1970's and 1960's engines did not plan for, and in a vehicle of mine, the blended alcohol destroyed the plastic float in the carburetor. Myth? I don't think so. Edison (talk) 22:47, 4 December 2007 (UTC)

Ethanol most certainly does destroy some OLD engines. It has three properties that are bad:

1. It dissolves rubber. So any car older than about 25 years that still has it's original rubber seals in the fuel path is in trouble. Even 10% ethanol ("E10") is enough to do this - and I can tell you that the classic car club I run has seen a MASSIVE increase in problems with various rubber seals since E10 was introduced into Texas. Retrofitting with modern seals fixes the problem - but for those who absolutely must keep their cars completely original, this is a major blow.
2. Ethanol conducts electricity - gasoline doesn't. At 10% (E10) it doesn't seem to be a problem - but it's anticipated that if/when we go to E20 or E25 in a few years time, then some gas gauge 'sender units' will misread or fail completely - as will some electric fuel pumps that are cooled by the gasoline. Again - not a problem for modern cars - bad news for classics and clunkers.
3. The combustion by products of high-ethanol mixtures are pretty acidic and will attack non-synthetic engine oil. So switch to synthetic and your problems are over - except that a very few old cars (of which my '62 Mini is one) use engine oil to lubricate the gearbox and synthetic oils aren't so good at that job. How big a problem that will be - I have no clue.

So yeah - it's mostly not a big deal - but the dissolving of rubber seals is absolutely real - and I have the rotted out 2 year-old seals to prove it.

I haven't heard of polythene parts in carb floats being destroyed yet - and I'm inclined to think this is a myth - but since my Mini has one - I'm going to keep a close eye on it! The '62 Mini has a float chamber that regulates the flow into the carb with a plastic float. If it jams in one direction, the engine is starved of fuel and stops. If it jams in the other direction the gasoline is over-pressurised and squirts out of an overflow hole in the float chamber - landing on all sorts of hot engine parts...it's quite exciting really!

SteveBaker (talk) 01:38, 5 December 2007 (UTC)

For anyone interested in ethanol-petrol blends, there's been a lot of hype and controversy about this recently with the recent launch of a 10% blend combined with the governments plans to mandate the introductions of such blends. New Zealand has a large number of used import cars, largely from Japan (which is rather late to the ethanol blend 'party' and isn't going to require all new cars to be compatible with E10 until 2010 and I think doesn't have much or any use of ethanol blends at the moment [2]) and the average age of the vehicle fleet is something like 12 years. Most imports are not carried out by the manufacturers so there are complicated liabity and COI (it's obviously in the manufacturers interest to claim most imports are unsuitable) issues etc. In any case, most manufacturers are reluctant to certify many of their imported cars as being suitable for anything greater then E3 (3% ethanol) while the government wants E5 and E10 and believes many vehicles should be fine. Some links which may be of interest [3], [4] & [5], [6], [7], [8] & [9] Nil Einne (talk) 11:05, 5 December 2007 (UTC)

Is it safe to say that gasoline blends with 10% methanol OR ethanol are not harmful to modern cars? Friday (talk) 15:26, 5 December 2007 (UTC)

I would say that 10% ethanol is OK for any car made in the last 20 years. Given the potential liability issues, it's hard to imagine how E10 could be sold in the USA if that were not the case. Here in Texas, ALL gasoline is E10 these days. But Nil Einne's evidence says otherwise. 'Harmful' is a tough word to use here...if E10 were to cause your oil seals to degrade after (say) 200,000 miles - is that "harmful"? I have less confidence with saying that is the case for Methanol. Switching to sythetic motor oil (which is a good idea anyway) is a wise thing to do - but it doesn't seem to be 100% necessary. It'll be a few years before we know for sure. SteveBaker (talk) 04:34, 6 December 2007 (UTC)

telescope type

Hi. I saw a telescope in the glass display case facing outside a store window. I want to know what type of telescope it is: refractor, reflector, or catadioptric. Sorry, I don't have an image, but if you want I might be able to upload one taken earlier. This telescope is about 4 inches in objective diameter, although the tube is about half an inch thick. It seems to have an objective lens, although it is about a centimetre behind the front of the telescope. The eyepiece is at the back of the tube, but sticks out of the tube vertically, sort of like in a Newtonian, further in front than the back of the telescope, but at the back. The finder seems to be a red-dot or reflex, but I'm not sure. It is computer-controlled, and has no counterweight. It's a Celestron. I estimate the focal length at f/5, but I'm not sure. I'm usually sort of a telescope "expert", but now this one confuses me. This is why:

refractor characteristics

• objective lens
• eyepiece at the back of telescope
• relatively small total size

reflector characteristics

• eyepiece jutting perpendicular from main tube
• relatively short focal length
• in-tube mirror may be needed to place the eyepiece there

So, any ideas to what type it might be? About how much would it cost if it were new and regular price? Thanks. ~AH1^(TCU) 22:57, 4 December 2007.

The people at the store ought to at least know what model number is written on the thing, if not the detailed specification. If you can't go back there and ask them, why not telephone them and ask? --Anonymous, 23:10 UTC, December 4, 2007. (UTC)

Possibly a Maksutov-Cassegrain or similar design? They are relatively short for their aperture. (Because the light path is folded, the real focal ratio is slower than the length would suggest, i.e. slower than the f/5 you estimate.) -- Coneslayer (talk) 00:36, 5 December 2007 (UTC)

It is probably a four inch Matsukov or Schmidt-Cassegrain. Those are about 300-400 dollars. You should go to the Celetron website and look up the pictures Website or on the Meade site. Saudade7 00:49, 5 December 2007 (UTC)

To tell what sort it is, look at the front of the scope. If there's a plain sheet of glass, it's a reflector. If there's a round object supported by a sheet of glass, it's a catadioptric of some sort. If there's a round or rectangular object supported by one or more wires, it's a reflector. --Carnildo (talk) 01:11, 5 December 2007 (UTC)

I think it's their 4" Maksutov-Cassegrain (NexStar 4SE). The eyepiece and prism looks like it's built into the rear plate which hides the actual path out the center of the rear mirror. It's actually an f/13 scope. --DHeyward (talk) 17:56, 5 December 2007 (UTC)

Hi. Uhh, how could you try to find out what is is if you don't know what it looks like? First of all, the telescope actually isn't for sale, and it's more of a used items store than a telescope or department store. Well, I only know the telescope by looking at the images, and there is a lens visible but even when photographed head-on, it's hard to see anything other than the lens. I don't think it is a NexStar 4SE, for many reasons. First, the telescope tube is much closer to the mount than that. Second, the eyepiece doesn't just look close to the tube, the hole for the eyepiece atcually juts perpendicularly through the top of the tube, closer to the back than the front. Also, It was impossible to see someting that resembled that white circle in the centre of the lens, as only the front lens was visible at all when the telescope was photographed head-on. If you want, I could probably upload a photo sometime later today. Oh, and the photo might suit the article for Celestron, Telescope, and the one for whatever classification it is. Thanks. ~AH1^(TCU) 18:36, 5 December 2007 (UTC)

Hi. I uploaded the image so hopefully you might be able to tell what type it is.

Here's the image! There's a lens at the front. If you look closely the eyepiece juts from the tube.

Thanks. ~AH1^(TCU) 23:23, 5 December 2007 (UTC)

Okay, look at the end of the tube nearest the camera and you'll see a brand name: it appears to be NexStar. Look on the Celestron website and you'll see that they have two NexStar lines. The telescope in the photo looks very similar to the NexStar 114 SLT or the slightly larger NexStar 130 SLT. Presumably the telescope in the window is an older model that was replaced by one of these; of course the differences might be enough to significantly affect the price.

I note also that the telescope in the window is pointed the wrong way! That's the mirror end nearest the camera. --Anonymous, 00:14 UTC, December 6, 2007.

Hi. Um, the end nearest the camera actually has a hole, and a lens behind it. I know it's hard to see on this image, but my other images show that there is glass at the end of the tube closest to the camera. I can't see where it says NexStar, and I know that if it were a reflector, the end nearest the camera would be closed, but actually that end has glass, and you could see to the other end of the telescope if you looked at it head-on. Thanks. ~AH1^(TCU) 01:05, 6 December 2007 (UTC)

The lettering is at the top of the tube, above the double wavy line. As to the construction, obviously I haven't seen the actual thing, but that looks like a mirror mount, and the layout looks reversed compared to the images on the Celestron site and I cited. --Anon, 01:55 UTC, Dec. 6.

Hi. Actually, nevermind. I checked the Celestron's site using the Internet Archive's wayback machine. The telescope seems to be a model from about 5 years ago, a NexStar 114. The new telescope doesn't really look like this, but the NexStar 114 from back then looks almost identical, although I can't tell if it's a GT or an HC. The new version sells for over $450, but the old one was probably cheaper, although I can't tell because the old version didn't have its price listed. Well, thank you all for helping me solve this mystery. Thanks. ~AH1^(TCU) 00:22, 7 December 2007 (UTC)

Mystery Vegetable

I bought some interesting produce from a stall outside a little shop, and I've worked out what everything was except for one root vegetable (my favourite was realising that the weird knobbly black things were chestnuts with complete outers). This root vegetable is white and about 30 cm long, 10 cm in diameter (with little tapering until the very end where it has a root which was not included in the measurements I gave). When cut it smelled like radish, and when nibbled it tasted like radish and had the same texture. I assume it's in the same family as radish, possibly it's just called 'giant white radish'?

Anyway, does anyone have any idea what this vegetable is? Thanks. Skittle (talk) 23:09, 4 December 2007 (UTC)

Could it be a Daikon? --TeaDrinker (talk) 23:13, 4 December 2007 (UTC)

Fantastic! (The introduction actually uses the phrase giant white radish :P If I hadn't thought I was suggesting something ridiculous, I could have searched the phrase) Hooray! Thanks TeaDrinker. Now, to learn! Skittle (talk) 00:18, 5 December 2007 (UTC)

Redirects are cheap. Giant white radish.  ;-) Dragons flight (talk) 00:23, 5 December 2007 (UTC)

Yes, but alas, the poor mangel-wurtzel has to make do with beet.... - Nunh-huh 00:28, 5 December 2007 (UTC)

Maybe you mean a Mangelwurzel? DuncanHill (talk) 01:25, 5 December 2007 (UTC)

No, I meant mangel-wurzel, the spelling which actually appears in my dictionary. Unfortunately a "t" got caught up in it. It's nice to know we have an article on my favorite strange vegetable, but it would be nicer if the redirect went from the wrong spelling to the correct one, rather than vice versa. :) - Nunh-huh 01:49, 5 December 2007 (UTC)

Those chestnuts did not have "complete" outers. When the chestnut falls off of the tree, it has a prickly husk about the size of a baseball ( about 100mm in diameter.) This husk is so prickly that you must be quite careful when you pick it up from the ground. The husk contains several of the covered nuts that you found in the market. You should use those nuts immediately instead of keeping them. roast them or boil them, or eat them raw. They may (and probably do) have insect eggs that will hatch into larvae that become evident if you keep them for more than about two weeks. This is not a health problem, but it is an aesthetic issue. take a look at this:

those nuts came from several of those prickly things. When they are still green the husks can be picked up carefully with your bare hands. They turn brown after about three days. At that point you will need either some good garden gloves or a high pain tolerance. -Arch dude (talk) 01:38, 5 December 2007 (UTC)

Whenever I see discussion of chestnuts, and eating them, I feel inclined to remind American readers that the tree and nut commonly called "chestnut" in the US is actually Aesculus hippocastanum, "horse-chestnut" or "buckeye", and can make you sick if eaten. I for one believed for years that the "chestnuts" we collected as kids were the same things one could "roast over an open fire". Essentially all the American Chestnut trees were killed by the Chestnut blight of the early 20th century. Just a friendly word of warning. Pfly (talk) 04:01, 5 December 2007 (UTC)

Yes, do not under any circumstances eat a buckeye. My comments were with respect to the Chinese chestnut which is now grown in many places in the United States. I have personally encountered trees planted in about 1945 in Tennessee and in about 1960 in Virginia. if you encounter a "chestnut" in the wild in North America, do not eat it. -Arch dude (talk) 02:25, 6 December 2007 (UTC)

I've actually been puzzling over this. When I said 'complete outers' I meant it; the shiny brown things were inside a shrivelled black layer, but the shrivelled black layer contained only one of them. I'm now wondering if they were water chestnuts, but I don't have much experience with water chestnuts except in certain take-away meals. I tend to think of water chestnuts as having a different texture and flavour, but perhaps that is only in the preparation? I boiled these and they tasted like chestnuts and had the same texture as roast chestnuts. Skittle (talk) 09:42, 5 December 2007 (UTC)

How can this thread POSSIBLY be complete without mention of the noble 'Conker'?!

British schoolboys have been using horse chestnuts (aka conkers) to play the game of Conkers since time immemorial. There is something wonderful about opening that shrivelled spikey green/brown husk and finding a beautiful, shiney smooth conker inside. Conkers were played obsessively when I was a kid in the 1960's. Truly great conkers (six'ers and better) were traded and competed in exactly the way the Pokemon cards are - the difference being that you could find your conkers lying in the street. Truly great, legendary twenty'er conkers were practically worshipped. People would give their lunch money just to be allowed some practice swings with such heroic nuts. The dozens of arcane and mysterious techniques for hardening conkers were passed on from father to son, from elder brother to younger. Debate over which techniques were fair - which acceptable - which worked and which didn't would consume all of our waking hours! The string could be improvised from a shoelace in an emergency - but the perfect, softest sting and the exact way to knot it was another subject for endless debate. People perfected their swings, complete with follow-through - with the verve of pro-golfers. SteveBaker (talk) 04:23, 6 December 2007 (UTC)

Um, I'd rather you'd passed on any experience you had of water chestnuts and chestnuts, how they are different from a culinary point of view and whether what I bought more closely resembles one or the other. I was not buying conkers. Skittle (talk) 18:55, 6 December 2007 (UTC)

Good, it would be immoral to buy conkers, totally contrary to the spirit of the game. DuncanHill (talk) 01:20, 8 December 2007 (UTC)