Wikipedia:Reference desk/Archives/Science/2010 January 25

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January 25

why is THF called THF?

It seems to me that you're adding TWO equivalents of hydrogen across the furan ring... not four. Shouldn't it be called dihydrofuran? Shouldn't the current (2,3) dihydrofuran be called (mono)hydrofuran? I mean, I don't think you can add more than one H2 molecule across a double bond... John Riemann Soong (talk) 06:17, 25 January 2010 (UTC)

Two equivalents of dihydrogen (H₂) are added. The "hydro" means "a hydrogen atom", not "the molecular form of that element". Like hydrohalogenation, hydroformylation, etc., each add "one hydrogen atom, one other thing". But the real why is because, just like the answer to any "why is some standard used". Something had to be agreed, and even if it is completely nonsystematic and makes no sense to anyone, it is how it is, and asking "why" doesn't lead anywhere useful (though in this case it sort-of does). [1] DMacks (talk) 06:47, 25 January 2010 (UTC)

name of those fenced-in forests of powerlines and insulators etc?

Do you know the places I mean? What are they called?

Thanks Adambrowne666 (talk) 13:04, 25 January 2010 (UTC)

Are you talking about an electrical substation? -- kainaw™ 13:10, 25 January 2010 (UTC)

it is indeed; thanks, Kainaw Adambrowne666 (talk) 20:51, 25 January 2010 (UTC)

Menstrual period pregnancy

is it possible to get pregnant during menstrual period? —Preceding unsigned comment added by 119.95.22.212 (talk) 13:20, 25 January 2010 (UTC)

Yes. The Feminist Women's Health Center has a rather nice article describing the full 28-day cycle here. -- kainaw™ 13:38, 25 January 2010 (UTC)

As an aside, there are some studies out there saying that women are not "born with all the eggs they will ever use", but continue to produce eggs after they are born. I'm not sure if that has been conclusively proved or not, though. Clear skies 146.74.230.82 (talk) 01:20, 26 January 2010 (UTC)

The FWHC site has mostly accurate information but really provides no info about incidence of fertility during menstruation other than the bald statement that "it could happen". The FWHC site is badly in need of copyediting: it's full of mistakes in spelling, capitalization, syntax, and the common but annoying failure to grasp the difference between adjectival mucous and nominal mucus. It also mixes western folk physiology and medicine in with the science-based information, though it has no trouble properly identifying as such the folk traditions of some other cultures. It also appears to promote consumer sexism by advising its readers to buy products from companies owned by women. Other than those small quibbles, a great site. A much better reference would be this one: [2]. alteripse (talk) 14:46, 26 January 2010 (UTC)

In practice, a body temperature measurement of the female is done first thing in the morning, and a certain change of a fraction of a degree indicates ovulation. The date can be off if something else, like a bit of fever, affected the basal temperature. Menstruation can similarly be mistaken for bleeding from other causes. Edison (talk) 05:56, 27 January 2010 (UTC)

Circadian rhythm studies

Hi,

I was told that many early studies into human circadian rhythms had not been careful enough about letting outisde light in, and this screwed up their results. Does anyone know any examples and can lead me to a paper or 2?

Cheers, Aaadddaaammm (talk) 15:23, 25 January 2010 (UTC)

I'm not really familiar with that objection. In the 1930s Nathaniel Kleitman was already conducting isolation experiments in caves in Kentucky, which would seem to give pretty good control. He had also conducted other isolation experiments as far back as the 1920s that might not have been as convincing, but I don't know much about them. He published a book called Sleep and Wakefulness in 1939 that summarized his findings, but I haven't read it. Looie496 (talk) 19:15, 25 January 2010 (UTC)

Sleep#Timing may be of interest. ~AH1^(TCU) 20:23, 27 January 2010 (UTC)

wind turbine generator manufactures

I have patented a "Electric Power Train" this is for generating electricity from one of the forces (pressure)generated from automotive/railway traffic on road and rail.What I am looking for is someone who could give me the specks on the genrator/alternator being used on wind turbines at present.To name a few speck's I am looking for are how much force is needed to turn the shaft without the blades,what RPM is required to get the best results,I know you will be asking me what size generator or how much electrisity do I want to generate.I cannot say at this stage,but I do want a medium to large,For example one of wind turbine being used on the wind farm's,that will give me a good start and something to work from.If I could get contact details of a manufacture that would be good.I am based in the UK so one as neer as possible would be great. Thanks Pierre —Preceding unsigned comment added by 86.163.87.199 (talk) 15:23, 25 January 2010 (UTC)

If your plan is to mount the wind turbine on the car or train, you will be wasting more energy than you are creating by adding drag and decreasing fuel efficiency. You would do better to simply tap off the engine power directly with an alternator. This is already commonplace. If your plan is to mount the generator near the roadway or railway to collect wind from passing trains or cars, I think you will find that the amount of extractable energy is not cost effective (it will probably be darn near zero watts). In specific answer to your questions, there is no way we can answer details about force, torque, and RPM, unless you tell us your desired specifications. Perhaps you might take a look at wind power, which gives an encyclopedic overview of present technologies. If you're unfamiliar with engineering design in general, it may be worth reading up on that before you start a major venture and contracting manufacturers. Nimur (talk) 17:08, 25 January 2010 (UTC)

How did you get your patent without specifications? Perhaps I don't understand how you propose to generate your power. What pressure force are you planning to use? Here [3] is a manufacturer of small turbines who might be able to help you. Dbfirs 17:36, 25 January 2010 (UTC)

What country have you patented your invention in, and what is the patent number? Or did you mean simply "invented" or "thought up an idea?" Edison (talk) 21:26, 25 January 2010 (UTC)

Perhaps the OP's idea is to harness the recurring downward pressures of road and rail vehicles passing over a flexible roadway. Cuddlyable3 (talk) 21:44, 25 January 2010 (UTC)

That would produce even less energy! Really, though, the OP specifically said that he/she wanted to use a wind turbine, so we can safely assume that he/she is planning to harness the boundary layer created by passing cars/trains. (Oops, sorry, I just looked, the OP is definitely a he, based on his name.) Not that it would be any more cost efficient. And another objection to the OP's proposal: if he wants to use a wind turbine of a comparable size to the ones used on a wind farm, then (1) there won't be enough roadside/trackside space where to put it, (2) if the turbine is to be mounted low enough to catch the slipstream, then the blades will strike the ground, and (3) even if the turbine was somehow mounted low enough, only the very tips of the turbine blades will ever be exposed to the slipstream -- the rest of the blade will remain idle! This is clearly an impossible and even borderline ludicrous proposal, and I'm very astonished that the UK patent office has issued a patent for this contraption. Clear skies 146.74.230.82 (talk) 01:37, 26 January 2010 (UTC)

To be fair to Pierre, during the last year or so I have read in New Scientist magazine of schemes to recover energy from the pressure of foot or vehicular traffic on walkways and roadways, as Cuddlyable3 surmises, and I believe a couple of experimental setups are or have been trialled, though I can't find anything from hasty googling. One criticism of such schemes is that most of the energy they would recover would be extra energy that the person or vehicle would have to expend to negotiate such a surface, which otherwise would not be required: thus, they would in effect be using the vehicle's engine or the person's muscles as the generators and recovering the extra energy rather inefficiently.

It may be that Pierre only wants the specifications ("specs", not "specks," Pierre!) for wind turbine generators in order to crunch some comparative numbers - I can't see how such machinery could be repurposed for surface energy recovery if that's the idea, though the specification in his Patent application should make everything clear - could we have the Patent Office and Application number please, Pierre? 87.81.230.195 (talk) 03:02, 26 January 2010 (UTC)

Google energy from speed bumps will find some articles (not necessarily the New Scientist article). Mitch Ames (talk) 06:40, 26 January 2010 (UTC)

volumetric display using microscopic hemispheres? Has this been thought of yet?

Would pixel size hemispheres coated with red,green and blue phosphors with a pinhole on the flat side, inside a CRT allow holographic television. Or would the pinhole have be too small for the wavelength of light to allow standard or high definition images? Could such structures (transparent to let the phosphor colour through be constructed on such a small scale?Has anyone though of this or made a large holographic television with full vertical/horizontal parallax, (preferably with the quality of a good CRT) yet, and if so, where and when can I expect to buy one at a reasonable price? [[File:http://www.imagekind.com/services/frame_engine_https.ashx?IMID=568d016e-066a-4f08-b914-bb6e7ae59693&frameId=602&glazingId=4&topMatId=1324&topMatSpacingTop=2.5&topMatSpacingBottom=2.5&topMatSpacingLeft=2.5&topMatSpacingRight=2.5&middleMatId=-1&middleMatSpacingTop=0.25&middleMatSpacingBottom=0.25&middleMatSpacingLeft=0.25&middleMatSpacingRight=0.25&bottomMatId=-1&bottomMatSpacingTop=0.25&bottomMatSpacingBottom=0.25&bottomMatSpacingLeft=0.25&bottomMatSpacingRight=0.25&IMIDArray=&IMIDCropArray=&IMIDRotateArray=&typeId=-1&cropLeft=0&cropTop=0&cropRight=0&cropBottom=0&sizeId=1&materialId=1&maxWidth=200]] —Preceding unsigned comment added by Trevor Loughlin (talk • contribs) 15:29, 25 January 2010 (UTC)

For the second part of your question: Nobody has made any kind of holographic television yet... and even if you had one, it's not like all of your 2D television would suddenly be 3D. The signal just does not carry that information most of the time.

That being said, see 3D television. There are apparently a number of stereoscopic TVs (you wear funny glasses like in the movies) expected to hit the market this year, and ESPN is apparently starting the first full-time 3D channel, or something along those lines. These are not holographic—they are 3D in the same sense as a 3D movie. You can't look around at every angle, they just provide a little parallax.

I know SteveBaker has much to say about volumetric displays, so I'll definitely wait to see what he says about the first part. --Mr.98 (talk) 16:30, 25 January 2010 (UTC)

He probably said it last time Mr Loughlin asked about them.

I think what Loughlin is describing is a type of Lenticular display, Where each hemisphere/pixel shows a different color depending on the angle it's viewed. Certainly this idea has been thought of. (Everyone working on 3d displays thinks of this idea.) But it's just not practical. (Consider the number of pixels needed, multiplied against the number of angles each pixel could be viewed!) All that said, the technology is just now within grasp. Barely. I saw one at SIGGRAPH 09. It looked very primitive, but it was actually using a tremendous amount of computing power, and very expensive display elements to maintain the illusion. (If I recall correctly, it also had a serious overheating problem.)

I'll see if I can quickly find the reference.

APL (talk) 17:22, 25 January 2010 (UTC)

Found it. It's called the gCubik. See a (poor quality) video here. The paper on it is here, but I can't find a free copy. APL (talk) 17:27, 25 January 2010 (UTC)

Here's a better video [4]. APL (talk) 17:38, 25 January 2010 (UTC)

To get a hologram you are going to have to control the phase of waves between the pixels, and to get a wide angle view, your pixels will have to half a wavelength or less. This will be of order of a megapixel per square millimeter, or about a terapixel for a square meter display. The information required is more because you need phase as well as brightness for each pixel, to get an uncompressed TV picture you will need around a petabyte per second of data. Graeme Bartlett (talk) 00:10, 26 January 2010 (UTC)

We have to be very careful to define what we mean by a 3D display. They come in roughly four kinds:

1. Single viewer (you have to be sitting in the right place) - hence a very limited view direction - but no special glasses needed. Lenticular displays are like this.
2. Multiple viewers - but all of whom get the same view - with special glasses (that's what you get in a 3D movie or using red/cyan glasses or a head-mounted display).
3. Multiple viewers in multiple locations - all getting the correct view for where they are standing without glasses or anything. Holograms are pretty much it.
4. Multiple viewers in multiple locations - all getting the correct view for where they are standing...but with one horrible drawback (the kind of thing our OP is describing, bubble tanks, spinning grids of LED's, vibrating mirror displays, etc, ad nauseum).

The problem with the OP's idea is that you can't control transparency. You can't stop light from the back of the object from shining through to the front - or from the left through to the right - and vice-versa. So everything looks ghostly. You can't ever display a realistic picture - period.

So - we're back with holograms - which are still ruinously expensive to generate in realtime. But we're getting there. Graeme is technically correct about needing a petabyte per second to broadcast raw volumetric data at hologram densities - but that's not the plan. You can send (for example) octree-encoded data about the shape of the objects and use on-the-fly wavefront reconstruction to generate the hologram. That blows away the bandwidth issues (well, relative to a petabyte per second at least!) - and shifts it into doing crazy high numbers of calculations. But that's actually more do-able. So I think it's possible that we'll see animated, interactive true holographic 3D displays in our lifetimes - but it's not certain.

Bottom line then: We're stuck with glasses until we get crazy amounts of CPU time...and sadly, the OP's idea isn't gonna cut it. Vibrating or spinning mirror displays can do the same job better, cheaper and much more easily. SteveBaker (talk) 01:50, 26 January 2010 (UTC)

I would dispute the transparency claim, the hemisphere has an opaque flat side with a pinhole, it would be like looking through a tiny hole in a fence from all angles, except there could be a lot of them, too small to see. I think opacity would occur, but the other practical problems including data rates are grim. —Preceding unsigned comment added by Trevor Loughlin (talk • contribs) 03:50, 26 January 2010 (UTC)

So you're saying that you build a cube packed with these hemispheres - each of which can produce light in any color and has a hole in it to allow light from behind to come through it? Your explanation is less than clear and the image you linked to doesn't help! SteveBaker (talk) 14:54, 26 January 2010 (UTC)

I really think you're describing something similar to the gCubik device I mentioned above. It worked on little hemispheres. It looked like a toy, and had serious problems, but it pushed the limit of modern technology.

Incidentally, I think you would have really enjoyed the "Emerging technologies" section of the SIGGRAPH 09 show. Besides the gCubic, there was this, which is very similar to what you described last time you asked. However, there's still nothing even close to the quality that you described the first time you asked.

Of course, you're the one with a direct communication line to the future, why don't you tell us what the future holds for 3d displays? I'd very much like to know. :-) APL (talk) 05:37, 26 January 2010 (UTC)

The gCubik is just a standard 'lenticular' display (a small improvement on the prismatic 3D display that's been used in things like 3D postcards for 50 years or more). Each display produces a 3D image - but only over a relatively small field of view. By gluing them onto the six faces of a cube, you hope that people concentrate only on the side that's facing towards them - ignoring the other sides that aren't making much sense from this angle. So the limited lenticular display only has to produce a fairly small field of view (out to maybe 90 degrees) through each side of the cube to make something that's kinda-sorta useful. SteveBaker (talk) 14:54, 26 January 2010 (UTC)

gCubic is lenticular, but it's lenticular in two directions, it's the only display I've ever seen that's like that. The lenses are not linear prisims, they're (roughly) hemispherical dots. Loughlin's post is not entirely clear to me, but this device uses clear "pixel size hemispheres", to create a coherent 3d image that is roughly correct (Within 5 degrees or something. So, let's say 'very roughly'.) when viewed from any angle. Then they built it into a cube, creating a heat management disaster. APL (talk) 16:17, 26 January 2010 (UTC)

Anyway, my real point in bringing it up, and I think I didn't make that clear enough, was that this obvious idea ("What if we made pixels that looked different from every angle!") isn't really practical. The absolute cutting edge, state of the art is nothing more than a fun tech demo, and the technology requirements go up asymptotically with your resolution. So it will probably never be practical for high-def, almost certainly not in our lifespans. APL (talk) 16:24, 26 January 2010 (UTC)

I was about to ask a question about the '3D' glasses as used to see the movie Avatar in 3D. But I looked up the relevant article and here's the link for anyone interested. RealD Cinema 220.101.28.25 (talk) 09:54, 26 January 2010 (UTC)

For clarification, the type of 3D glasses used to see Avatar depends on which cinema you go to. Different cinemas have adopted different technologies, and of course these are compatible enough that the studios or distributor can easily make versions suitable for whatever technology the cinema uses and for a mass release like Avatar they do since there's no reason they're going to limit the movie to a subset of cinemas but just sell it to whoever wants it. I personally watched it with Dolby 3D and there's also a local Imax 3D cinema that had it (for NZ$3 more). Nil Einne (talk) 08:21, 28 January 2010 (UTC)

Thanks for that info. Nil. I was expecting the lenses to be polarised at 90° to each other, (which apparently doesn't work well in practice) didn't think of opposite circular polarisations. I wonder which system (Dolby 3D vs RealD) is best? Dolbys system sounds more complex. And if I go back to the same theatre to see Avatar again will they make me pay for another set of 3D glasses? (I kept mine) Almost certainly!...220.101.28.25 (talk) 12:07, 29 January 2010 (UTC)

(NOTE TO RESPONDENTS: In case you missed APL's reference to our OP having a 'direct communication line to the future', Trevor has asked about 3D displays here on WP:RD/S a couple of times in the past (see APL's links above) - but he also claims to have built a practical device that can predict the future using "retrocausal data transfer".) SteveBaker (talk) 14:54, 26 January 2010 (UTC)

Voltage divider

I had a question about the voltage divider article, specifically the derivation of the formula V_out=V_in*R_2/(R_1+R_2). I see that V_in should be I(R_1+R_2), and that therefore the potential after the first resistor is IR_2. But when a path for the output voltage is provided, why should the current running through the first and second resistors be the same? —Preceding unsigned comment added by 173.179.59.66 (talk) 19:18, 25 January 2010 (UTC)

By definition if R1 and R2 are in series, the same current flows through them. The formula is for ideal conditions, and does not assume any of the current through R1 flows through a physical voltmeter instead of R2. In practice a modern digital voltmeter has an input resistance of perhaps 6 megohms. Older cheap analog voltmeters could load down very high resistance circuits and affect the measured voltage appreciably. Whatever the input resistance of the voltmeter, it could be modelled as a parallel resistor across R2. If R2 has less than 1/100 of the resistance of the voltmeter, then the voltage would be off by less than 1%. A Potentiometer (measuring instrument) (in the older sense, rather than a variable resistor in the modern usage of the term) can be used to measure voltage without extracting any current once the adjustment is complete, by having a very sensitive galvanometer between the point and a known voltage, with the known voltage adjusted until no current flows through the galvanometer. A potentiometer I used had a standard cell, with a pretty constant known voltage, from which almost no current was ever drawn, and a slidewire, where a resistance wire of known composition and known resistance per unit length was tapped by a slider. By the bridge circuitry, an unknown voltage could be measured by tapping the key which conected the galvonometer into the circuit and adjusting the slider until there was no deviation of the galvonometer. This 19th century technique was still used in the late 20th century for calibrating some telemetry circuits. Edison (talk) 20:46, 25 January 2010 (UTC)

extrasolar planets

I did not note any mention in the article, but have there been any extrasolar planets discovered in binary star systems? Googlemeister (talk) 19:57, 25 January 2010 (UTC)

Yes. There are at least three planets in the Upsilon Andromedae system, for example. Algebraist 20:01, 25 January 2010 (UTC)

Alpha Centurai#Possibility of planets mentions Gamma Cephei also. —Akrabbim^talk 20:03, 25 January 2010 (UTC)

With the Upsilon Andromedae system, how can they tell the difference between a planet proper, and a red or brown dwarf star? Googlemeister (talk) 20:08, 25 January 2010 (UTC)

Our theories tell us the minimum mass of a brown dwarf and the observations of Upsilon Andromedae give estimates of the masses of the planets, and they are well below the brown dwarf threshold. Our article only gives lower bounds for the masses of the planets for some reason, but upper bounds will also be known. --Tango (talk) 22:11, 25 January 2010 (UTC)

Not necessarily, observations of gravitationally induced wiggling generally constrain the product M*sin i, where M is the mass and i is the inclination of the orbit. So you get a lower bound if the orbit is perfectly aligned for our viewing and sin i = 1, but it is unbounded in the upper limit since the planetary orbit might be directly skew to what we hope to observe. And there is no direct way to constrain i from wiggling alone (usually). You'd need to follow up gravitational detection with some other method to find an upper bound and that hasn't yet been done in many cases. Dragons flight (talk) 22:50, 25 January 2010 (UTC)

If there is just the one planet, then that's true. In this case, it's a whole system of planets and the interactions between them put constraints on the inclinations. The article mentions this. --Tango (talk) 23:40, 25 January 2010 (UTC)

What if we had a planet rotating around the center of gravity of the binary system? Is that possible? ~AH1^(TCU) 20:22, 27 January 2010 (UTC)

Laws of Thermodynamics

What are some everyday examples for all the Laws of Thermodynamics or how can I explain these laws to a kindergartener? --Reticuli88 (talk) 20:35, 25 January 2010 (UTC)

On At the Drop of Another Hat, is the song "First and Second Law" by Flanders and Swann. Its annoyingly catchy and a fun way of teaching kids that basic concept. a brief search of the web will let you hear it for yourself. Rockpocket 21:02, 25 January 2010 (UTC)

Try it with something like lego blocks. The first law says that nothing is created or destroyed, it only changes form. Any legos you use can't be used to build something else. If all of your legos are part of a house, and you want to build a car, you need to take some legos from the house. Legos are thus, conserved. The second law says that things just become messier unless you do something to clean it up. Hence, the legos don't pick themselves up! The room would just get messier and messier unless you spend some time to pick up the legos and put them away. However, time spent putting legos away means you can't do something else during that time. So you can't get something for nothing. Either the room gets to messy to play in, so you can't play with anything because its a complete mess, OR you spend time cleaning it up, and then you don't have any more time to play. Either way you can't play all that you want. Entropy is a mean bitch that way. The third law is a bit tougher, but basically it's the cabinet where you put your toys away. The third law simply tells you where all the toys go when you pick up the room. Or, as someone eloquently put it to me:

• The first law says you can't win or lose, you can only tie.
• The second law says that you can't even tie, you can only lose.
• The third law is the rules of the game.

Just some ideas bouncing around my head.--Jayron32 21:18, 25 January 2010 (UTC)

The third law is that you can't quit the game. --Anon, 22:42 UTC, January 25, 2010.

You might like to try the 'simple English' Wikipedia article.

I like the idea of a Lego analogy - but I think we could do better (and list all four laws):

0) If I have six lego bricks and you have six lego bricks and your best friend has the same number of bricks as you - then she also has the same number of bricks as me.

1) You only have just so many bricks. No matter what you build or how you put them together, there are always exactly the same number of bricks. Even if you lose bricks down the back of the sofa or your dog eats some - the bricks still exist...somewhere!

2) If you make a nice tidy pile of lego bricks - carefully arranged by size and color - then if someone shakes them up - they never get any tidier. It takes a lot of work to make a tidy pile of lego bricks - but hardly any effort for your little sister to mess them up again.

4) 3) If you had a small box that was only just big enough to fit all of the lego bricks inside - they'd have to be really, really tidy to fit inside! If you jumble them all up - they wouldn't fit properly.

Physicists call untidyness "entropy".

SteveBaker (talk) 00:31, 26 January 2010 (UTC)

0, 1, 2, 4? Thermodynamics is weird! ;) --Tango (talk) 03:21, 26 January 2010 (UTC)

Binary counting perhaps? 2, 4, 8, 16, 32, 64 etc. :-) 220.101.28.25 (talk) 05:36, 26 January 2010 (UTC)

I never liked rule 3 and it's too hard to do with Lego - so I invented my own rule #4....or it was a typo...you choose! SteveBaker (talk) 13:58, 26 January 2010 (UTC)

I don't see the point in teaching such abstract concepts. Small children should be encouraged to be inquisitive of knowledge, appreciative of nature, and skeptical of any claims. 66.65.139.33 (talk) 02:24, 26 January 2010 (UTC)

Yeaaah. Who says we can't build a perpetual motion machine ? Scientists ? What do they know ? I bet they just haven't been inquisitive enough. Let's try flying a kite in a thunder storm ... Gandalf61 (talk) 11:00, 26 January 2010 (UTC)

Certainly, if anyone ever does build a perpetual motion machine, it'll be with Lego. :-) SteveBaker (talk) 13:59, 26 January 2010 (UTC)

I hope you don't mind my being forward, but I must wonder what the purpose of explaining thermodynamics to a five year old would be. Even if they are prodigal and could understand it, I shouldn't think they would have the intellectual curiosity to understand it. Vranak (talk) 14:52, 26 January 2010 (UTC)

You said it better than I did. 66.65.139.33 (talk) 15:15, 26 January 2010 (UTC)

While it's probably unlikely that they'd really grasp the concepts enough to appreciate your answer, they would learn something much more important - that such things can be questioned. My daughter was 6 when I started showing her Eureka! episodes. While she obviously can't get out of it what a high school student would, she's at least familiar now with concepts such as "entropy" and "atoms". Young kids are smart - never doubt it for a moment; a five year old has a better grasp of using English than any programmed AI system and can run and climb better than any robot - and they do it almost entirely without instructions of any kind. Matt Deres (talk) 17:14, 26 January 2010 (UTC)

do E. coli process cellulose?

If so, if you eat lots of pure fiber, can you get drunk off the EtOH they produce? John Riemann Soong (talk) 21:16, 25 January 2010 (UTC)

Probably not. Remember that if it worked that way, someone before you would have thought of it. Plus, intestinal flora (of which E. Coli is but one part) produce prodigious amounts of CO2 during the ethanol producing process. So, anything which could produce enough ethanol in your gut to make you drunk would probably also produce enough gas to make you painfully crampy and bloated to the point that being drunk wouldn't be worth it. If you REALLY want to make booze and don't care much about the enjoyment of drinking itself, then it's just best to let the fermentation go on outside of your body. See pruno for a simple recipe. --Jayron32 21:23, 25 January 2010 (UTC)

Wouldn't that just mean I would fart a lot? For why it's not been thought of yet (or why it's not popular), people usually don't eat pure fiber. And other sugars would be digested before it could get processed into ethanol.

And the main idea is to get drunk without tasting a single drop of alcohol. John Riemann Soong (talk) 21:33, 25 January 2010 (UTC)

In theory, I suppose an alcohol enema would work. But the alcohol would hit the bloodstream fairly directly, I reckon, and you wouldn't have the safety of gradual absorption or vomiting to prevent acute alcohol poisoning. Much safer and more pleasant to just drink it. Brammers (talk) 21:40, 25 January 2010 (UTC)

Naturally, Wikipedia has an article (section) on this: Enema#Rectal drug administration. Comet Tuttle (talk) 22:07, 25 January 2010 (UTC)

Very few organisms can digest cellulose -- our termite article discusses this a bit. Looie496 (talk) 21:42, 25 January 2010 (UTC)

"Designated drunk: Can you get intoxicated without actually drinking alcohol?" APL (talk) 22:53, 25 January 2010 (UTC)

The kind of E.coli that you got inside your azz do not digest cellulose, as far as I know. That said, there are some mutant / genetically engineered strains of E.coli that do convert cellulose to ethanol -- I've studied those firsthand for the oil company's cellulosic ethanol project that never got past the lab studies stage. You really wouldn't want to drink the product, though, because of the high concentration of fusel oil -- not unless you wanna get really drunk really quick and don't give a dam about the horrible taste or any tummyaches you might get later. You can burn the stuff in a car engine, though, but it won't be cost-effective in the current energy market. Clear skies 146.74.230.82 (talk) 01:49, 26 January 2010 (UTC)

If there were bacteria capable of efficiently digesting cellulose, why wouldn't they very quickly reduce all trees, woods, grasses into a bubbly slime? 95.115.188.228 (talk) 07:59, 26 January 2010 (UTC)

Plants have their own defences. John Riemann Soong (talk) 11:30, 26 January 2010 (UTC)

Even inside the lifeless wood of the trunk? 95.115.188.228 (talk) 17:13, 26 January 2010 (UTC)

Well there you start to get lignin, and plus all those tannins are kind of acidic. John Riemann Soong (talk) 18:55, 26 January 2010 (UTC)

indonesia plate

Is Indonesia part of Eurasian plate or Australian plate. Since Scotese map concludes indonesia will collide with Australia, but the map we have Eurasia in green shows indonesia is not in that county but in orange this shows Indonesia is part of Australian plate. how can Indonesia collide with Australia when the sense is like "taking a train to school" and "what you ate for lunch". This is strange when something inside a plate collides with something inside a plate. --209.129.85.4 (talk) 20:54, 25 January 2010 (UTC)

In fact there are some smaller plates involved (at least in some versions), most of Indonesia lies on the Sunda Plate, a tiny part near Aceh is on the Burma Plate while the eastern part is part of a complex mess of microplates. None of Indonesia is on the Australian Plate. However, the Sunda Plate is actively colliding with the Australian Plate at its eastern end. Mikenorton (talk) 21:48, 25 January 2010 (UTC)

Here's a link to microplates. ~AH1^(TCU) 20:20, 27 January 2010 (UTC)

And here's one to tectonic microplates. Mikenorton (talk) 20:37, 29 January 2010 (UTC)

how do I get rid of awful vibration artifact in my speaker setup?

Just to be clear that this isn't some "audiophile" mumbo-jumbo, I'm not speaking of some subtle effect that's bothering me on a subconscious level, I'm talking about a really clear, awful sound that's really as clear as day. The sound I'm talking about is this awful vibration sound that you usually get when you record something and for example yell into the microphone much louder than it can support. Problem is, I'm not playing anything that has that sound in it, and further, I am NOWHERE NEAR the limit of the speaker set up -- it could be way, way louder (WAY louder). So my question is: how do I get rid of that awful noise? Like, am I supposed to turn the line out (playing from a music device/my computer) down, or up, or almost completely up, etc. The setup is: computer -> remote (with volume control) -> speaker system (with separate sound volume on the back, independent of the volume knob). Is there some way to set these to get the desired effect? THanks! —Preceding unsigned comment added by 84.153.202.229 (talk) 23:31, 25 January 2010 (UTC)

Your speakers are farting. Possible cause 1: you are over-driving them. From your description, this seems unlikely. Possible cause 2: one or more cones is physically damaged. The general cure for that is reconing them or replacing them entirely. To assist in the diagnosis, are you able to detach the speakers from the current setup & drive them from some other set-up (to see whether the problem stays with the speakers, or is associated with the PC/Remote setup?. And in any event, think yourself lucky. I've spent half an evening under my desk trying to get my PCs headphone socket working, with no joy :( --Tagishsimon (talk) 23:38, 25 January 2010 (UTC)

The artifact you report might be clipping due to overdriving the system with too high an input. If you have a friend with an audio oscillator(signal generator) and an oscilloscope, it might be possible to input sine waves (pure tones) at varying frequencies and amplitudes and determine when the objectionable sound comes out of the speaker. If the recorded and played back sounds are free of clipping, then maybe the fault is somewhere between sound source, amp, and speaker. Perhaps the speakers are damaged, as mentioned above. Try borrowing and listening to good speakers, while keeping the volume below a level which would damage them. The square waves resulting from clipping can damage speakers. Edison (talk) 02:29, 26 January 2010 (UTC)

I've noticed I can get clipping (audio) on my headphones, plugged directly into the computer, if I have the computer's volume turned way down low and the volume on the media player turned up high... or was it the other way round? Anyway, worth considering that sort of internal clipping, whatever it is. 81.131.17.2 (talk) 11:16, 26 January 2010 (UTC)