Wikipedia:Reference desk archive/Science/2006 August 4

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Humanities Science Mathematics Computing/IT Language Miscellaneous Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions at one of the pages linked to above.

< August 3 Science desk archive August 5 >


A question to Doctors.regarding my strainge chest pain.[edit]

All respected concerned health exeperts, would you please guide me the course of action I should take to takle my strainge pain which I am feeling for the last 4 to 5 days .I call it strainge as I AM QUITE NORMAL though at 66 of age my day to day activities are normal and Iam not experincing any kind of simptums other than this pain on the chest at right breast region.Pain is not consistant all through the day,I feel it when I sneege and or when I cough occasionally.If I sqeese the muscle on the breast Idont feel the pain but when I PRESS the right brest with my paw I feel the pain.Is it a impending heart problem ? Please adise me whether to ignore it as it might subside after few days or should I consult compintant Doctor.Iam male quite healthy at 66 of age except for slight hiper tension with reading 155 -86. I am vegitarian non smoker and active all through the day. Thank you yours loving s.k.pujar

There are many causes of chest pain. You should definitely see a doctor so that they can diagnose it. No one is going to be able to diagnose such a complicated thing well based on an online description, except to say, "It might be serious, go get it checked out." --Fastfission 03:11, 4 August 2006 (UTC)
You ask us Reference Desk editors to advise you whether to ignore your pain. Well, I advise you NOT TO IGNORE IT because we cannot give appropriate medical advice. A physician examining you can. Please do not hesitate to visit a doctor -- immediately if possible. --Ginkgo100 talk · contribs · e@ 03:22, 4 August 2006 (UTC)
Of all of the chest pains that are seen, chest pain which is on the right side and you can reproduce by pressing the chest wall is least likely to be related to your heart. Especially after five days of constant pain without other symptoms. However, just because it might not be cardiac doesn't mean that it can't be something else just as bad. Please, go get it checked out as soon as possible! InvictaHOG 03:26, 4 August 2006 (UTC)
I agree. See a doctor immediately. StuRat 05:18, 4 August 2006 (UTC)
Et tu, StuRat? DirkvdM 07:27, 4 August 2006 (UTC)
"The fault is not within our stars, but within our editors." StuRat 06:57, 5 August 2006 (UTC)

car cell phone charger[edit]

Do car cell phone chargers convert dc from the car to ac which the phone can charge on?

Is it the reverse of one of those big, heavy wall adapters?

You're assuming those wall-adapter chargers are supplying AC... DMacks 04:04, 4 August 2006 (UTC)
All cell phones charge on DC. The wall adapters convert AC to DC; the car adapters convert DC to a lower voltage DC (the car voltage is ~28VDC, while most phones charge at less than 5VDC). However, the DC to DC converter can do it by first converting to a high-frequency AC and then back to DC (and, in the same way, the wall adapters can convert AC to DC to high-frequency AC to DC; this is usually done in the smaller wall adapters, while the big heavy ones use a large transformer and a direct AC to DC conversion). So, your car cell phone charger might be in fact converting to AC (but only as an intermediate step). --cesarb 16:46, 4 August 2006 (UTC)
28VDC? My car's voltage is around 14V when running. —Bradley 17:21, 4 August 2006 (UTC)
Car batteries are intended to supply around 12 volts. Most cars supply this voltage. 48v 18:13, 4 August 2006 (UTC)
(edit conflict) Looks like I confused the voltages. Indeed, cars use 12VDC nominal, not 24VDC nominal. --cesarb 18:16, 4 August 2006 (UTC)
http://www.dcacpowerinverters.com/
A friend of mine bought one of these, plugged it on one end into the car and on the other end into his regular wall cell phone charger. Is this wasteful/silly?
While this solution will work, yes. It is both wasteful and silly. The power which the car privides is very near the voltage which the phone needs to charge, the car chargers provide only a charging circuit and a voltage regulator. Instead he/she is using an inefficient 'inverter' to try to simulate AC residential power. And then using a moderately efficient chargere to convert that voltage (110-120) back to what the phone needs (5-10.) Buying a car charger would be cheaper, simpler, and better for the car battery. 48v 04:44, 6 August 2006 (UTC)

Hearing pianos over the phone[edit]

Why can't you hear pianos clearly over cellphones? This problem doesn't appear to exist with other instruments, the guitar for example. Any ideas? Please answer on my talk page. Thanks for your help! MarkBuckles (talk) 04:49, 4 August 2006 (UTC)

I would guess it's the small frequency range on each piano note. They may fall into "frequency holes", which are omitted to fit more conversations into a given bandwidth in a highly compressed cell phone transmission. StuRat 05:14, 4 August 2006 (UTC)
Piano notes have a small frequency range? Most keys hit more than one string and they're in an encasing that gives them ample opportunity to give off all possible vibrations, resulting in many overtones. On top of that, the piano is the instrument with the widest tone-range. A telephone line is, however, restricted to the frequencies that are important for speech. Piano key frequencies range from 27 to over 4000 Hz. The range of the guitar is from 82 to less than 1000 Hz (way up on the neck). I can't find what frequencies are transmitted over a telephone (searching for 'telephone frequencies' only leads to radio frequencies the connections use, which is something different). But it may be in the hundreds of Hz (althogh I thought it was around 1000 Hz), which would explain why you can't hear notes above that. You could still hear lower notes, though, through the overtones. So same answer, just the other way around. :) DirkvdM 07:59, 4 August 2006 (UTC).
The standard sampling rate for telephony is 8000Hz, which due to the Nyquist–Shannon theorem means the highest frequency transmitted is 4000Hz (see Nyquist rate). If you use 8 bits per sample, you have a bitrate of exactly 64000 bit/s, which uses too much radio bandwidth (on POTS, however, you have almost the full 64000bps rate). To reduce the bandwidth, the sound is compressed using special speech codecs (which can vary from 13kbit/s to as low as 4.75 kbit/s). Of course, to reduce the data rate that much, some information is lost; these codecs are optimized to retain more information related to the human voice (and, sometimes out-of-band, DTMF tones), and less information related to everything else (including background noise and music; comfort noise can also be generated at the receiver). It's not a specific frequency being dropped (i.e. there are no "frequency holes"); these codecs actually try to predict the waveform using mathematical models (tuned to the human voice), and encode the resulting coefficients and residuals. --cesarb 16:22, 4 August 2006 (UTC)
So the explanation would be that (somehow) a guitar behaves more like a human voice? Might be interresting to test how different instruments and different notes on those instruments come across on a telephone. i just don't know who I might call who would be equally interrested in such an experiment. Ah come on, do I really have no interresting friends? Is that why I spend so much time here? Or is that the other way around? ... I will now just go and sit in a corner and feel sorry for myself. DirkvdM 19:04, 4 August 2006 (UTC)
You could try to find implementations of these codecs which run on a normal PC, convert a small sample of music (losslessly compressed if possible) to the codec and back to a normal wave file, and then do a blind a/b test (we seem to be missing either an article or a redirect here; any takers?). --cesarb 23:43, 4 August 2006 (UTC)
We do have Speex, ABX, Codec listening test, and double-blind test. --Kjoonlee 08:29, 6 August 2006 (UTC)

Part of the characterist sound of a piano is not the sustained tone alone, composed of a fundamental plus harmonics, but the initial attack as the key is struck. The 300 or 400 Hz high frequency cutoff in modern phones may allow the fundamental tones to pass, but block some of the harmonics. It may also cut off some of the envelope of the initial attack, which is somewhat percussive and may include more high frequencies. Edison 18:24, 5 August 2006 (UTC)

There's a high frequency cutoff at just a few hundred Hz? That explains a lot. If you're sure about this, could you add it to the telephone article? DirkvdM 08:50, 6 August 2006 (UTC)
No way it could be that low; plain lowpassing at 500 Hz gives an awful muffled sound with all sibilants unintelligible. --Kjoonlee 09:08, 6 August 2006 (UTC)
I assume Edison meant 4000 Hz, as cesarb mentioned above. --Kjoonlee 09:09, 6 August 2006 (UTC)

exhausting a portable air conditioner through the chimney flue[edit]

Is it possible to exhaust a portable air conditioner's exhaust through the chimney flue instead of the window? Would I be able to force the air out with a fan (after closing a furnace exhust vent) if the atmospheric pressure is too great?

Maybe. As you seem to already know, the exhaust from the A/C unit won't be sufficient in volume or heat to create a proper draft up the chimney. A fan at the chimney alone probably wouldn't be sufficient, either, as this would create a negative pressure in the house sucking the exhaust back down the chimney. If a second fan were added to force air into the house, this would probably do the trick. However, this would be blowing in hot air from outside which is going to fight the A/C unit. I suppose it still might cool the room containing the A/C unit, but the room in which the air enters the house would get hot. So, I recommend against this approach. Now, if you could rig up a long tube and route it up the chimney, and force the exhaust up the tube, that might work a lot better. A dryer vent hose might work. StuRat 05:08, 4 August 2006 (UTC)
Our toilet has such a ventilation shaft with a fan, so it should work. Air will easily get sucked in through all sorts of holes and chinks (is that the right word?) in the house. If it's hot and you create a lot of current that would be like having a fan for the whole house, so you can leave the ac off. It would have to be pretty strong, though. But then you wouldn't need the ac, which is begging the question. I suppose you'd better ignore this advise. DirkvdM 08:11, 4 August 2006 (UTC)
Of course, indoor Cannabis growers do this all the time. AllanHainey 14:46, 4 August 2006 (UTC)
I don't. I like the smell. DirkvdM 19:06, 4 August 2006 (UTC)
Every portable AC that I've had also drips water out the back. If you try to put it in a chimney opening, you'll end up with a puddle in your chimney. --Kainaw (talk) 14:48, 4 August 2006 (UTC)
The air conditioner doesn't really exhaust air; it exhausts heat. The fan on the hot side of an air conditioner is only there to increase the heat transfer not get rid of air. So, a single fan in the chimney would do very little as you need to be pulling cooler air into the condensing coils of the air conditioner. StuRat's idea of a tube within the chimney (a tube within a tube, effectively) to pull down cooler air and push out hotter air would be best. Modern wood-burning stoves do this. They pull the combustion air down the outside of a double-walled stack, burn the wood, and the combustion gases are vented up the middle of the stack. This prevents the stove from stealing your warm air in the house for combustion and pushing it out the chimney. In this case, you don't want the air conditioner stealing your cooled air to cool the condensor coil and push it out the chimney. —Bradley 17:16, 4 August 2006 (UTC)

Meteorite[edit]

Is it possible that a meteorite could hit the earth at an angle that would forever increase the speed at which our planet rotates on its axis. Thanks.

Sure, but not by a lot. Something the size of what killed the dinosaurs could change the angular velocity of the Earth by up to about a few milliseconds per day. Dragons flight 05:29, 4 August 2006 (UTC)
Just consider classical physics questions of momentum--the metorite would have to have a combination of mass*velocity (useful to visualize as a vector) that was non-negligable to the mass*velocity vector of the earth in order to detectably alter the earth's vector. I'd be more worried about massive global extinctions over resetting my Timex if something that large were to come our way... -- Scientizzle 07:45, 4 August 2006 (UTC)
Let's fill this in. Earth's volume is 1012 km3. A really really big meteorite could be 10x10x10 km = 103 km3. Assuming the same mass per volume, that would mean the meteorite's mass is only one billionth of Earth's. Earth has a rotational velocity of 465 m/s at the equator. Compensating for the fact that not all mass is at the surface, let's say 100 m/s. If the meteorite had 1000 times that speed (100,000 m/s or 360,000 km/hr - an enormous speed) then that would only constitute 1 millionth of Earth's rotational momentum. Also, just a tiny fraction would go into a rotational change - most of the energy would be absorbed (on this scale the Earth is quite elastic) and of the remaining energy, most will change the Earth's direction (and thus its orbit), not it's rotation, depending on the angle at which it hits. And that change would also be minute. DirkvdM 08:26, 4 August 2006 (UTC)
Let's just make some assumptions to simplify things here. a) Assume all the momentum transfered from the meteorite to the Earth is transfered to the Earth's angular momentum about the centre of mass (it hits a cliff). b) Assume the collision is perfectly elastic.
The angular momentum of a sphere is given by (2/5)MR^2 (the moment of inertia) multiplied by the angular velocity. For the Earth this works (I think) at about 2.5x1057. I'll leave you to come up with momenta for meteorites.
As DirkvdM says, in reality most of the momentum would be affecting the angular momentum of Earth's centre of mass (it's orbit), but as this is so much higher than the angular momentum about the centre of mass I would guess that (depending on the angle of collision) there would be a greater effect on the Earth's rotation (about its axis) than on its orbit.
What about a really really really big meteorite... But then again you might prefer to call a Mars-sized rock a "planetary collision" rather than a "meteorite hit". Weregerbil 09:46, 4 August 2006 (UTC)

One possible explanation for how the moon formed is as a result of a giant meteor collision with Earth. A meteor this size would likely have affected the rotation rate of the Earth by a significant amount. StuRat 07:45, 5 August 2006 (UTC)

Based on what StuRat said I'm not sure if it actually affected it's rotation but the metorite which hit the earth actually put the earth on a rotation (thus giving us the seasons). However, i think it can be possible if a metorite that large hit the earth and was that large could affect it's rotation speed. Probably much like the Metorite Apophis

--Agester 20:37, 10 August 2006 (UTC)

Some corrections are needed here. The seasons are caused by the Earth's tilt and revolution around the Sun, not by it's rotation. The rotation only causes day and night. Also, the Earth would have had an initial rotation, which comes from the rotation of the solar system. According to physics, as the diameter of a rotating object decreases, it spins faster to maintain a constant rotational momentum. Thus, as the Earth formed from a dust cloud, the rotation of the cloud would increase. I would think we could calculate the expected rotation rate of a planet based on it's size and distance from the Sun. Then, any deviation from the expected value would be from impacts since then (most of which might be tiny dust particles hitting the atmosphere). StuRat 17:46, 11 August 2006 (UTC)

Bullet[edit]

If I fired a bullet stright up into the air would it (technically) hit the ground at the same speed that it left the gun from. Assuming there is no wind etc.

Not likely, since most bullets are fired at speeds beyond terminal velocity. -- Scientizzle 07:29, 4 August 2006 (UTC)
If fired in a vacuum, however, it would. When dealing with speeds that don't approach the terminal velocity of the object in question, it's safe to say that upward release velocity will be essentially equal to downward falling velocity at the same height (with variations due to chaotic perturbations of the air and object, etc.). The nature of an atmosphere that provides non-negligable friction makes things slightly more complicated at higher velocities... -- Scientizzle 07:38, 4 August 2006 (UTC)
Don't try this at home. And if you do it outside, make sure to step aside. DirkvdM 08:30, 4 August 2006 (UTC)
See also MythBusters (season 3), Episode 50. It seems that if the bullet retains its spin, it will exceed its normal terminal velocity.--Shantavira 11:56, 4 August 2006 (UTC)
They also pointed out that the bullet would retain spin if it had any arc in the path. To keep it from spinning, you have to fire it straight up - which is nearly impossible to do. The gun, wind, spin of the Earth, and all will contribute to causing the bullet to go up at an angle, arc over (still spinning), and come back down.
Answering the question, though - no. It will not be at the same speed. Bullets do slow down as they pass through the air. Even though it will still be a lethal speed, it will be slower than the muzzle velocity. --Kainaw (talk) 13:30, 4 August 2006 (UTC)
The only real factor that would cause the bullet to have a different speed would be air resistance. Firing the gun from the surface of the Earth, it would be nearly impossible to get it to move in anything other than an arc due to the coriolis force caused by the Earth's rotation (which wouldn't be very much unless it was a very very powerful gun). This shouldn't effect its speed when it lands though as it wont travel any further coming down than it would going up. It's all about conservation of energy.
Mathematically, the velocity with which it would hit the ground would look something like:v = u - ((2Du + 2Dd)/2)½ where v is the final velocity, u is the initial velocity and Du and Dd are the energy losses on the ascent and decent respectively.


If he stood on the equator of the moon, facing in the direction of the moon's rotation and fired his pistol straight up (so no air resistance) at 300 m/s, would it go straight up and come straight down and (theoretically) land in the barrel of the pistol? The gun rotates with the moon surface at 4.63 m/s in a slightly curved path. The bullet along with its decelerating vertical velocity has an initial horizontal velocity of 4.63 m/s. At the moon's gravity of 1.622 m/sec squared, the bullet would rise for 185 seconds to its highest point. It would fall for another 185 seconds. If the shooter could see it, it would appear to move along the equator retrograde to the direction of rotation, and would land to the retrograde side of the gun. Not good enough at orbital mechanics to say exactly how far behind, but I am curious. Then assume he stood on the north pole of the moon and repeated the experiment. The coriolis effect due to the moon's rotation should be absent, but what effect would the orbital velocity of the moon about the earth and about the sun have?Edison 19:35, 5 August 2006 (UTC)

If he stood on the equator and fired the gun the bullet would land in front of him (doing a quick calculation) as the coriolis force causing the bullet to land in front of the firing point would have a greater effect than the rotation of the Moon causing the bullet to land behind the gun.
Taking the Coriolis force as F = 2mΩv you can calculate that the distance moved in the direction of rotation is (4Ωu²)/g and the (apparant) distance moved in the opposite direction is (2uΩ)/g you can see that it will always move further in the direction of rotation.
Standing on one of the poles, the effects of the Moon orbiting the Earth and the Earth orbiting the Sun would stop the bullet landing back down the barrel of the gun, but they shouldn't have a great effect (if you don't fire the bullet too high).

Energy consumption per country[edit]

We've got lists on just about anything, but I can't find a list showing the energy consumption per capita per country. All I can find is Image:Energyconsumption.jpg and Image:Energy per capita.png, but those don't show what I am looking for and only give vague indications. The latter has a list it's based on plus a source, but before I make that into an article I want to be sure there isn't already such a list (in a less obvious place perhaps) and also that I can use (and re-arrage) the data (no copyright violation). DirkvdM 08:50, 4 August 2006 (UTC)

Since you participated in the discussion, I assume you've seen of List of countries by electricity consumption, right? There is also List of countries by natural gas consumption. I don't think we have one on total energy consumption, which would be cool, although I'm not sure how it would be defined. --Bmk 15:35, 4 August 2006 (UTC)

When I worked in energy conservation 30 years ago, we we able to find figures for the "quads" of total energy used by the US and other countries. It should be easier now with the internet, but maybe you should visit a good sized library and have the librarian direct you to reference books on energy. We had a very small proportion of the earth's population and used a very large portion of the energy. Have things changed much? I don't think so, except that there are decreasing reserves of oil and increasing demand in developing nations. Don't forget to combine all sources of energy, and to allocate electricity to end users.Edison 19:40, 5 August 2006 (UTC)

Birds in Slovenia[edit]

Why are apparently very few birds in Slovenia. On a holiday in the region of Lake Bohinj, it was noticed that there was no dawn chorus, and few visible birds. Why is this? Thanks, --217.42.132.207 09:38, 4 August 2006 (UTC)

I believe this is because people take pot-shots at them for sport. It's much the same in many parts of eastern and southern Europe. One side effect is that butterflies etc flourish in places like this.--Shantavira 11:53, 4 August 2006 (UTC)
The same thing happens in Italy, people shoot them for food & sport when they migrate over & large numbers don't make it. There was a BBC Radio 4 programme on several months ago about this and the steps being taken to try to preserve the birds, such as legislation & bird reserves. I don't think that there has been a great deal of success in stopping the hunters. AllanHainey 14:28, 4 August 2006 (UTC)
Overhunting led to the extinction of the carrier pigeon. User:Zoe|(talk) 22:38, 5 August 2006 (UTC)

HD-DVD or Blu-Ray[edit]

At this point, which standard seems more likely to be adopted as the primary for consumers and studios?

I can't remember which way round it is, but one is supported by Apple and the other by Microsoft. I'd plumb for the one supported by Apple.
Really, we don't know. It is whatever hits The Tipping Point first. They both have their pros and cons. Sony is supporting Blu-Ray all the way, they already are putting out movies in DVD and Blu-Ray. If you just looked at the names, and they were the same thing, you would pick Blu-Ray. I've found I personally, and most people, like technology names to be less abstract. They prefer Mac OS Tiger, or Lisa over AOL version 10.2.3, or Microsoft XP SP3. — [Mac Davis] (talk)
I am holding out until Blu-Ray 2.0, then, just to be contrary!
Weird really. The whole point of the free market system and competing companies and technologies is that the consumers pick the ones they like so those manufacturers get an impulse to make more such products. Sounds good in theory, but in this case consumers just sit around waiting for which one will become the standard and only then go out and buy it. Which is the wrong way around. The central problem here is that the determining factor is the standard. So that should really be set by others, after which the manufacturers can then all use this open (!) standard and start competing with actual products. The openness of the standard is essential for this (the free market really works on the wrong level here). So who should set that then? The old answer would have been governments. But the new answer is the Open Source community. Any ideas how this could be brought about? Is it just a matter of some people deciding to come up with a standard and then presenting that to manufacturers? Or do the consumers need to be convinced to go for that one? DirkvdM 19:24, 4 August 2006 (UTC)
I don't know much about blu-ray/hddvd, but isn't it a fundamental hardware difference? How can open-source communities handle this? If it were up to open-source folks, there would be 10 different versions of the new DVD instead of two.
As a consumer, I don't really care about blu-ray or hddvd, I just want to consume video at a reasonable quality and reasonable availableness for the cheapest price possible. I don't want to invest and put in some mighty dollar votes for the newest gadgets. It's a means to an end and that's all.
The link you want is dollar voting. Make sure to also check out the talk page.
The open source community would converge on one standard. If you're thinking about the many Linux distros, that's exactly what I mean. There are many distros, but they all use the same Linux core. That's the standard. Commercial companies (and others) can then use that for their own version, thus putting the competition where it should be, but leaving the standard alone. DirkvdM 09:09, 5 August 2006 (UTC)

All the latest talk is about how HD-DVD is better in quality, and the players are 1/2 the price of a bluray. Given Sony's hysterical failings of making new standards I seriously don't see how they will ever succeed --mboverload@ 00:45, 5 August 2006 (UTC)

It's possible - perhaps likely - that the true successor to DVDs will be neither Blu-Ray nor HD-DVD, but instead will be online file-transfer, scrapping physical media altogether. The current competition between Blu-Ray and HD will hold everything up a long time, where as digital files have many more benefits to producers (there's essentially no cost to creating a new file, and if they use something like BitTorrent to distribute it, bandwith costs fall on consumers). In short - the average person shouldn't bother getting either Blu-Ray and HD-DVD for a long time, if ever. zafiroblue05 | Talk 01:13, 5 August 2006 (UTC)

The dirty truth is that we might not even need a new format. A movie encoded with H.264 or similar advanced codec can fit an HD movie on a standard DVD. In fact I have The Transporter in 720p HD in only 4 gigs, while standard movie dvds are 8. --mboverload@ 07:08, 5 August 2006 (UTC)
I'd like a new format, I will always think it's a good idea to back up my hard-drive on a read-only disc. And my hard-drive can only get bigger in the future.

priming fuel pumps[edit]

i wonder why internal combustion engines use centrifugal pumps for the fuel delivery system.this gives us the headaches of priming the pumps.isnt it possible just to use a positive displacement pump for fuel delivery since it needs no priming?why prefering the centrifugal ones.moreover i understand centrifugal pumps do not develop good pressure heads. --Chiwaye 13:48, 4 August 2006 (UTC)Chiwaye,04/08/06

Rabbit Internal Organs[edit]

Hello,

Can someone tell me what the, relatively, large white organ rabbits have, I've ruled out the heart, stomach & I think kidneys but I've no idea what it is. It's white with a few red flecks or thin veins & its ovalish. Any ideas? AllanHainey 14:22, 4 August 2006 (UTC)

The liver? --Ginkgo100 talk · contribs · e@ 14:32, 4 August 2006 (UTC)
A bladder shall be whiter than a liver. --DLL 15:21, 4 August 2006 (UTC)
Rabbits have a pretty big cecum, which kind of matches your description. Is it a hollow organ? --Joelmills 15:43, 4 August 2006 (UTC)
I didn't cut it open to see but it may be the cecum. Sounds like either the Cecum or bladder. Thanks. AllanHainey 07:22, 7 August 2006 (UTC)
Do you have a picture? The location in the body may give us a clue. - Cybergoth 20:37, 14 August 2006 (UTC)

lichen damage to trees[edit]

Can lichen, growing on the bark of trees, damage the trees? I have a Wigelia (tree form)that is covered with lichen and one branch has become so soft that it has twisted and flopped to the ground.

Thanks to everyone for any help you can give me. Antcathy

I wouldn't think so. Are you sure it's lichen ? StuRat 05:45, 6 August 2006 (UTC)

Oldest surviving sound recordings[edit]

Dear Wikipedia, I have tried searching on wikipedia for the oldest surviving sound recordings. Wikipedia provides a video file of the 'Roundhay Garden Scene' (1888); supposedly the oldest motion picture and also provides the oldest surviving photograph; 'View from the study window' (1826/27) by Niepce (I think that's how you spell his name). Wikipedia doesn't, however, seem to provide the world's oldest surviving sound recordings. I wrote to the British Library a while ago to find out more. Here is a copy of my question and their answer...

'Hello, my name's Russell and I may have an FAQ for you. I am interested in finding the world's oldest surviving sound recording.

I've heard that the first thing ever recored was Edison's 'Mary had a little lamb' from Decemeber 1877 but presumably this does not still exist.

I've tried searching on the Internet but can't seem to find out. If you could help I'd be grateful.

Kind regards, Russell.'

'Dear Russell,

Thanks for your enquiry. The earliest surviving recordings appear to date from 1888. For spoken word it is allegedly Lord Stanley's address in Toronto, see here http://radio.cbc.ca/programs/thismorning/lfnsound/sound_collectors/sound_collectors_092000.html. For music it is allegedly a recording of Handel's choral music http://www.nps.gov/edis/edisonia/very_early.htm . However, the recording on the following site can claim to be the oldest playable recording http://www.tinfoil.com/cm-0101.htm.

I hope this helps.

Yours sincerely,

Rod Hamilton

Reference Specialist (Sound Archive) Humanities Reference Service The British Library 96 Euston Road London NW1 2DB UK Email: <e-mail removed to prevent spam> Tel: +44 (0)20 7412 7676

I am no expert so I'm a little dubious about writing an article.

Thanks for doing the research! Sometimes on Wikipedia, in order to avoid knighting a thing as "the oldest X" where there is uncertainty or disagreement, we'll have a list of candidates. Then, if a candidate has an article, its claim to the title is linked to the list. Examples can be found in Category:World records. Perhaps it's time for an Oldest sound recording article, with a section for surviving recordings? Melchoir 20:08, 4 August 2006 (UTC)
I think you mean "dubbing", Melchoir. "Dubbed" can be applied to naming things generally, including making a man a knight. But "knighted" can only be used in that specific sense. JackofOz 12:34, 8 August 2006 (UTC)
If you want some historic wax in your ears try Tennyson's 1890 recording of The Charge of the Light Brigade or Robert Browning's How They Brought the Good News from Ghent to Aix from 1889. MeltBanana 23:11, 4 August 2006 (UTC)

I've heard Edison reciting Mary Had a Little Lamb, so some version of this recording still exists. StuRat 07:35, 5 August 2006 (UTC)

Someone was clever enough to make a backup? Ehm, ... on what? DirkvdM 09:12, 5 August 2006 (UTC)
Naw it was a hysterical re-enactment [1] MeltBanana 14:01, 5 August 2006 (UTC)

Edison's first phonograph was demonstrated to Scientific American editors in their offices and featured in the December 22, 1877 issue. IIRC, they included an illustration supposed to be an exact representation of a photo of the pattern of indentation in a tinfoil recording. That photograph or to a less accurate degree the illistration published would theoretically be one of the oldest "surviving" recordings. Actual foils are supposed to be too fragile to play, but a laser scan of one might produce reproducible sounds. A month or so later, tin the multi-volume collected papers of Edison, one of his assistants wrote he had made a plaster impression of a tinfoil recording which accurately reproduced all the indentations, and that he thought copies could be made from it. There is no sign this was done at the time, but maybe it is in a file somewhere. The phonautograph was pre-Edison and made accurate sound tracings on smoked glass cylinders. In fiction, they have been copied and played and perhaps could be in reality. There are urban legends of ancient pottery turned on a wheel and decorated with a wooden stylus having accidentally recorded sounds in the pottery shop, but the potter's hand would be far less effective than Edison's diaphragm connected to a recording stylus as a sound collector. Edison 19:59, 5 August 2006 (UTC)

about macbook (screen size 13.3 inches)[edit]

Have anyone seen the new mac book from apple which has a screen size of 13.3 inches? Is it big enough for anyone? Or is it just for students aged under 18? Is it good enough for adults? One more thing I would like to know What is the ideal distance between this monitor and our eyes while reading?

Thanks

I personally find that the bigger the screen, the better, because quality is not an issue with MacBook screens. I think if you're not a college kid without any money, you should get a bigger screen. I just checked the site, [2], and it says 13.3 is the only size for MacBooks!! I guess if you want a bigger screen you'll have to get a Pro. As for ideal monitor-eye distance, it is like the whole "don't sit too close to the tv Timmy, you'll hurt your eyes." You put your eyes where ever it is easiest for you to read. — [Mac Davis] (talk)
I think one good thing to check about a screen/computer combination is the refresh rate - try opening a window, then dragging it around the screen very quickly - if the motion looks choppy, you might want to look elsewhere. --Bmk 18:14, 4 August 2006 (UTC)
Just to get all pedantic on you, it's an LCD screen, so it doesn't have a refresh rate: it has a pixel response time. - Nunh-huh 04:32, 5 August 2006 (UTC)
Thanks for making time for that refreshing response. :-) StuRat 07:31, 5 August 2006 (UTC)
Screen size in laptops is usually directly correlated with weight. If you plan to carry this around with you a lot, a smaller size can make a lot of difference (I use a 12" iBook for this reason, it is large enough for everything I use it for). But if you have doubts you should go to an Apple retail store, where they will no doubt have many display units out that you can play with and see.--Fastfission 18:26, 4 August 2006 (UTC)
It really depends on what you're doing. When I'm programming, I find the 17-inch display on my laptop to be too small, but for reading ebooks, the 2.5-inch screen on my PDA is just fine. --67.185.172.158 04:23, 5 August 2006 (UTC)
Resolution is most of it for me, I had been using a 19xx by 16xx resolution for a while I think, I came back home, got on my old iMac, with a 1280x800 resolution, and everything seemed so fat. lol — [Mac Davis] (talk)

Freaky Plant Situation[edit]

Is it possible for two plants to get fused together or exchange genetic material just by being planted very close together? Because I have two plants, a green one and a purple one, and recently the greeen one's been getting streaks of purple in the leaves. The purple plant has vine-like stems and now the green plant is growing vines and it never did before. I have no idea what type of plants they are. It's sort of freaky, but I swear it's absolutely true. Is it possible the purple plant's a parasite or something? --Anakata 22:05, 4 August 2006 (UTC)

Also, another thing is that one of the abnormal vines on the green plant is actually growing through one of its own leaves, i.e. it poked a hole through it.--Anakata 22:14, 4 August 2006 (UTC)

There's something that sounds similar: see Chimera (plant) and Graft-chimaera. Melchoir 22:46, 4 August 2006 (UTC)
The Chimera thing could be the cause, but these strange purple streaks only started appearing very recently, like one month ago. Before that the plant was perfectly fine and green throughout. If it was a chimera, wouldn't it be like this from the start?--Anakata 23:02, 4 August 2006 (UTC)
Can you upload a photo? —Keenan Pepper 23:04, 4 August 2006 (UTC)

Are the two plants of the same species, and do the reproduce sexually (via stamen, pistols, and pollen) ? If so you may get a cross pollination between the two color phases. I've seen this in alyssum myself. StuRat 07:24, 5 August 2006 (UTC)

If the colouring is caused by some chemical, there need not be an exchange of genetic material, just picking up some of the other's juices. Just a guess DirkvdM 09:16, 5 August 2006 (UTC)

Reproductivity of results[edit]

What is meant by reproducibility of results in science? Why is this important in science?

--anonymous. —The preceding unsigned comment was added by 70.233.162.76 (talkcontribs) .

Never mind:)

ανωνυμία —The preceding unsigned comment was added by 70.233.162.76 (talkcontribs) .