Science desk | ||
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Welcome to the Wikipedia Science Reference Desk Archives |
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The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages. |
In space since there is no drag, could not one moderatly accelerate to speed of light? —The preceding unsigned comment was added by 75.162.132.156 ( talk) 01:05, 2 May 2007 (UTC).
d they work? ...are they dangerous? what is the scientific status of this stuff? what is the medical status? —The preceding unsigned comment was added by 75.69.194.105 ( talk) 01:10, 2 May 2007 (UTC).
I think that I will say that (b) possibly. Some herbs can cause damage.-- Kirby♥ time 02:44, 2 May 2007 (UTC)
Phytosterols do not work for male bodybuilders who wish to grow muscle. So by analogy I do not suppose herbal supplements that encourage female hormones will work. To expand your knowledge I would suggest looking at female hormones and causes of feamle cancers and then decide where you want to go. Paul
thnx, :) i'd rather stay flat :P
I need help identifying this rock. It was found (by my mother) a long time ago in England, and has spent many years in faithful service to me as a doorstop. It's fairly heavy/dense, and I was told by someone it could be a meteorite, although I don't know if I believe him. I've looked at many sites for identifying a meteorite, but am still not convinced either way. I know that identification through just an image is still shaky, and should probably still get some more info (density and compositional data ( XRF) data in particular). I'm also curious as to what it looks inside, although I don't want to break it open. More pictures, as well as much larger pictures, can be found at my personal website. Thanks -- Bennybp 03:23, 2 May 2007 (UTC)
I know my rocks, and that doesn't look like much, just a typical glacial cobble, probably composed of some sort of granite or gneiss, with some inclusions. -- Zeizmic 11:38, 2 May 2007 (UTC)
It looks exactly like a sarsen cobble to me - the same stone as the large trilithons at Stonehenge are made of. Some sarsen has an orangey-brown rind on it, similar to what's in your photo. If you ever get to go to Avebury, a lot of the buildings there are made of smashed-up megaliths of sarsen, and they look just like your stone (although some faces have been dressed for masonry). No, I'm Spartacus 11:54, 5 May 2007 (UTC)
I was wondering if light could beat in the same way sound waves do. If one had two slightly different colours shining at the same time, would they dim and brighten? Thanks in advance, Storeye 07:15, 2 May 2007 (UTC)
We know that a fuse wire melts due to overheating.But the practical resistance of a fuse is low. So how does that become equivalent to heat in melting the fuse, because P=i^2r? Also would it not cause a voltage drop?? 210.212.194.209
How does the voltage drop suddenly increase when the fuse is about to blow and its negligible when the fuse is operated under max current rating??Also any idea how do same value and different wattage restistace work??~~ —The preceding unsigned comment was added by 210.212.194.209 ( talk) 06:15, 5 May 2007 (UTC).
Any idea how hypersonic waves travel in straight lines??Also is it possible for the same phenomena to exist with electro-magnetic waves?? 210.212.194.209
Hi, everyone. I've asked this question before, so I'm sorry for asking it again. If you've already read it, please don't be angry. I just really want a good answer. So, the question: What proportion of land/earth's surface/plants/organisms have to survive temperatures below freezing (0 C)? If you know of any peripheral statistics around this question, they would be great too. Thanks very much for your help. Aaadddaaammm 08:30, 2 May 2007 (UTC)
Removed duplicate question. Answered on Humanities desk.-- Shantavira 18:20, 2 May 2007 (UTC)
why are you more likely to see a polar view in animal cells than in plant cells?
What is the lewis structure for Li2S (lithium sulfide)? —The preceding unsigned comment was added by 68.191.57.84 ( talk) 15:18, 2 May 2007 (UTC).
If the half life of a substance is 60 hours, how many hours does it take for that substance to clear the body completely?
It may never clear the body completely. There may still be a molecule or two left when you die. However, that doesn't matter, since it will have no effect once it drops below a certain level. For a general estimate, though, you could use this chart:
half lives elapsed hours elapsed days elapsed amount remaining ================== ============= ============ ================ 10 600 25 1/1,024 20 1200 50 1/1,048,576 30 1800 75 1/1,073,741,824
StuRat 17:10, 2 May 2007 (UTC)
the amount of something left after 'n' half lives is 5^n*10^-n+1 :) HS7 17:13, 3 May 2007 (UTC)
Forget that, a much easier way to work it out is 2^-n :) HS7 17:36, 3 May 2007 (UTC)
do you guys know non prescrition cream for the face that contains the following? : retinol, madecassol,alpha licolic acid and or vitamin C? thank u —The preceding unsigned comment was added by 75.69.194.105 ( talk) 17:35, 2 May 2007 (UTC).
Hi! I wonder if anyone help me with something for a school project? I read this article that said "if you drink milk and have meat in the same meal that you don't absorb the calcium from milk" is this correct please help i need it quickly! - Jen
(removed field coloring question since it was asked below under a proper header) --
Bennybp
21:59, 2 May 2007 (UTC)
How are the different colors of the grass on football fields created? Most football fields have different shades of green to help see when players are offside. How are those made? 83.250.67.227 19:19, 2 May 2007 (UTC)
Thats what I thought too but what would happen if someone did a sliding tackle on the grass, will it change color?
If you mean regular patterns you can see even not near the line of scrimmage (e.g., each 10-yard region alternating), then Ollie is right...same thing that gives stripes or checkerboards in the outfield of baseball. For a good time, google for field stripe mowing. If you mean something that always appears for a given play regardless of where that play is, then that's a computer-generated video effect. DMacks 20:00, 2 May 2007 (UTC)
10-yard line DMacks? I thought he was talking about real football (soccer). Anyway you see the same thing in baseball fields. I'm pretty sure its largely for decorative/visual appeal purposes. And its not the way its mowed, its the way its grown. its just two different turfs used to make the field. Adam2288 T C 23:56, 2 May 2007 (UTC)
Is the bond between the N+ and the O- in HNO3 considered ionic or covalent? I don't really understand how this bonding works. —The preceding unsigned comment was added by 63.249.102.46 ( talk) 19:23, 2 May 2007 (UTC).
Our article on nitrate sure makes it look like a covalent bond rather than an ionic bond. Look at all that shared electron density! See also the elements' electronegativity difference for a (perhaps outdated) way to determine bonding types. DMacks 19:50, 2 May 2007 (UTC)
Just a thought, but if you know how to make a Lewis Dot Structure.. this may lead you in the direction of how the bonds form between elements! Otherwise, the electronegativies is your best bet.
As far as I know to be an acid it must always be a covalent bond, other wise the O- ion will be free, and will thus be a base Bastard Soap 13:02, 4 May 2007 (UTC)
Is the rusting process of iron or steel actually a form of fire?
--email removed to prevent spam-- —The preceding unsigned comment was added by 63.65.152.94 ( talk) 19:26, 2 May 2007 (UTC).
Not really " fire" in the usual "heat, light, flame" sense. But fire and rusting are both examples of oxidation. DMacks 19:41, 2 May 2007 (UTC)
Lately I have been thinking about evolutionary psychology. I am especially interested in learning about the way that instincts presumably coded in genes become concious (or subconcious) desires. I am also curious about how belief systems, individual or shared, mesh with these instincts/desires.
Can anyone recommend some respected, popular-level books about these issues? Even some links to good articles, or research hints would be appreciated. Thanks -- Diletante 20:42, 2 May 2007 (UTC)
I have been conducting a lab with an acid and base, and the ending solution is basic. The indicator that I used was phenolphthalein, and at the end of the experiment, the color of the solution is a pale pink color. The question that I have is: Why are titrations typically set up so the ending apperance is colored and does not disappear? Is there a certain reason for this?
I have already read the page about this indicator, but its not quite what I'm looking for. Any comments will help! Thanks! —The preceding unsigned comment was added by 76.188.176.32 ( talk) 21:17, 2 May 2007 (UTC).
So is the only reason that titrations are usually set up to turn a different color.. because its easier to see..?
The whole basis for titration requires knowing when one has reached the endpoint. Need some clearly detectible change to occur, and the clearer the change and the more abruptly it occurs, the easier to detect reliably. "Colorless → colored" is easy, "blue → green" is harder; "precipitate starts to form" is easy, "no more precipitate forms" is hard; etc. DMacks 21:44, 2 May 2007 (UTC)
Thanks for the help!
Sometimes when I chew my nicotine gum, I get hiccups. This is listed as a possible side-effect of the gum and the WP article mentions it too (though I'd disagree with the 'excessive use in times of stress' line - I've never been particularly stressed when it's happened to me). What I don't understand is *why* this happens - i.e. how the nicotine works on my body to cause the hics. Anyone know? -- Kurt Shaped Box 21:23, 2 May 2007 (UTC)
Do you chew with your mouth open?? Don't suck the air in too fast now!
How come if you have a frozen bottle thats sealed (such as a 20 ounce coke bottle), if you take it out the freezer, wipe off the outside so you know theres nothing on the outside, and let it sit, you will see water drops on the outside, why does this happend? Where does the water come from? —The preceding unsigned comment was added by 76.167.159.75 ( talk) 21:26, 2 May 2007 (UTC).
The warm air will cause condensation to from on the cold outside of the bottle. The droplets are formed when the coldness tries to evaporate. Perhaps, the air bubbles escaping. They certainly don't like warm!
As light approaches a black hole, does it travel faster than the speed of light? Please repond on my talk page or let me know you or someone has reponded, thank you. 100110100 22:35, 2 May 2007 (UTC)
Light still travels at the speed of light, however, as it approaches the black hole it is blue shifted, so that the frequency is increased. This also applies to light approaching any object with gravity such as the earth, but usually the effect will be too slight to notice. GB 23:31, 2 May 2007 (UTC)
Allow me to play the role of a country bumpkin. Any particle traveling at speed S will accelerate further when it drops down a gravity well. So therefore a photon traveling at speed C will accelerate further if it drops downs a gravity well. So does the photon travel faster than the speed of light? 202.168.50.40 00:22, 3 May 2007 (UTC)
the speed of time changes near a black hole, instead of the speed of light.
Dear Ref Desk, I am very interested in knowing what structures or mechanisms are responsible for the variation in visual perception among different substances i.e. LSD produces a variety of patterns and while thats true they also happen to be very geometric with well defined shapes while psilocybe mushrooms produce organic shapes in the visual field and furthermore DMT can produce both?
http://www.pocketmagazine.net/album/wp-content/uploads/2007/05/unknownfruit.jpg
-- Sonjaaa 22:53, 2 May 2007 (UTC)
My Mother claims to be AB+ and on my birth certificate it says I am AB+. Seems to fit, however my father claims to be O. If my mother is AB and my father is O then I should be A or B. Is this possible? —The preceding unsigned comment was added by 75.74.140.121 ( talk) 23:12, 2 May 2007 (UTC).
Science desk | ||
---|---|---|
< May 1 | << Apr | May | Jun >> | May 3 > |
Welcome to the Wikipedia Science Reference Desk 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 on one of the current reference desk pages. |
In space since there is no drag, could not one moderatly accelerate to speed of light? —The preceding unsigned comment was added by 75.162.132.156 ( talk) 01:05, 2 May 2007 (UTC).
d they work? ...are they dangerous? what is the scientific status of this stuff? what is the medical status? —The preceding unsigned comment was added by 75.69.194.105 ( talk) 01:10, 2 May 2007 (UTC).
I think that I will say that (b) possibly. Some herbs can cause damage.-- Kirby♥ time 02:44, 2 May 2007 (UTC)
Phytosterols do not work for male bodybuilders who wish to grow muscle. So by analogy I do not suppose herbal supplements that encourage female hormones will work. To expand your knowledge I would suggest looking at female hormones and causes of feamle cancers and then decide where you want to go. Paul
thnx, :) i'd rather stay flat :P
I need help identifying this rock. It was found (by my mother) a long time ago in England, and has spent many years in faithful service to me as a doorstop. It's fairly heavy/dense, and I was told by someone it could be a meteorite, although I don't know if I believe him. I've looked at many sites for identifying a meteorite, but am still not convinced either way. I know that identification through just an image is still shaky, and should probably still get some more info (density and compositional data ( XRF) data in particular). I'm also curious as to what it looks inside, although I don't want to break it open. More pictures, as well as much larger pictures, can be found at my personal website. Thanks -- Bennybp 03:23, 2 May 2007 (UTC)
I know my rocks, and that doesn't look like much, just a typical glacial cobble, probably composed of some sort of granite or gneiss, with some inclusions. -- Zeizmic 11:38, 2 May 2007 (UTC)
It looks exactly like a sarsen cobble to me - the same stone as the large trilithons at Stonehenge are made of. Some sarsen has an orangey-brown rind on it, similar to what's in your photo. If you ever get to go to Avebury, a lot of the buildings there are made of smashed-up megaliths of sarsen, and they look just like your stone (although some faces have been dressed for masonry). No, I'm Spartacus 11:54, 5 May 2007 (UTC)
I was wondering if light could beat in the same way sound waves do. If one had two slightly different colours shining at the same time, would they dim and brighten? Thanks in advance, Storeye 07:15, 2 May 2007 (UTC)
We know that a fuse wire melts due to overheating.But the practical resistance of a fuse is low. So how does that become equivalent to heat in melting the fuse, because P=i^2r? Also would it not cause a voltage drop?? 210.212.194.209
How does the voltage drop suddenly increase when the fuse is about to blow and its negligible when the fuse is operated under max current rating??Also any idea how do same value and different wattage restistace work??~~ —The preceding unsigned comment was added by 210.212.194.209 ( talk) 06:15, 5 May 2007 (UTC).
Any idea how hypersonic waves travel in straight lines??Also is it possible for the same phenomena to exist with electro-magnetic waves?? 210.212.194.209
Hi, everyone. I've asked this question before, so I'm sorry for asking it again. If you've already read it, please don't be angry. I just really want a good answer. So, the question: What proportion of land/earth's surface/plants/organisms have to survive temperatures below freezing (0 C)? If you know of any peripheral statistics around this question, they would be great too. Thanks very much for your help. Aaadddaaammm 08:30, 2 May 2007 (UTC)
Removed duplicate question. Answered on Humanities desk.-- Shantavira 18:20, 2 May 2007 (UTC)
why are you more likely to see a polar view in animal cells than in plant cells?
What is the lewis structure for Li2S (lithium sulfide)? —The preceding unsigned comment was added by 68.191.57.84 ( talk) 15:18, 2 May 2007 (UTC).
If the half life of a substance is 60 hours, how many hours does it take for that substance to clear the body completely?
It may never clear the body completely. There may still be a molecule or two left when you die. However, that doesn't matter, since it will have no effect once it drops below a certain level. For a general estimate, though, you could use this chart:
half lives elapsed hours elapsed days elapsed amount remaining ================== ============= ============ ================ 10 600 25 1/1,024 20 1200 50 1/1,048,576 30 1800 75 1/1,073,741,824
StuRat 17:10, 2 May 2007 (UTC)
the amount of something left after 'n' half lives is 5^n*10^-n+1 :) HS7 17:13, 3 May 2007 (UTC)
Forget that, a much easier way to work it out is 2^-n :) HS7 17:36, 3 May 2007 (UTC)
do you guys know non prescrition cream for the face that contains the following? : retinol, madecassol,alpha licolic acid and or vitamin C? thank u —The preceding unsigned comment was added by 75.69.194.105 ( talk) 17:35, 2 May 2007 (UTC).
Hi! I wonder if anyone help me with something for a school project? I read this article that said "if you drink milk and have meat in the same meal that you don't absorb the calcium from milk" is this correct please help i need it quickly! - Jen
(removed field coloring question since it was asked below under a proper header) --
Bennybp
21:59, 2 May 2007 (UTC)
How are the different colors of the grass on football fields created? Most football fields have different shades of green to help see when players are offside. How are those made? 83.250.67.227 19:19, 2 May 2007 (UTC)
Thats what I thought too but what would happen if someone did a sliding tackle on the grass, will it change color?
If you mean regular patterns you can see even not near the line of scrimmage (e.g., each 10-yard region alternating), then Ollie is right...same thing that gives stripes or checkerboards in the outfield of baseball. For a good time, google for field stripe mowing. If you mean something that always appears for a given play regardless of where that play is, then that's a computer-generated video effect. DMacks 20:00, 2 May 2007 (UTC)
10-yard line DMacks? I thought he was talking about real football (soccer). Anyway you see the same thing in baseball fields. I'm pretty sure its largely for decorative/visual appeal purposes. And its not the way its mowed, its the way its grown. its just two different turfs used to make the field. Adam2288 T C 23:56, 2 May 2007 (UTC)
Is the bond between the N+ and the O- in HNO3 considered ionic or covalent? I don't really understand how this bonding works. —The preceding unsigned comment was added by 63.249.102.46 ( talk) 19:23, 2 May 2007 (UTC).
Our article on nitrate sure makes it look like a covalent bond rather than an ionic bond. Look at all that shared electron density! See also the elements' electronegativity difference for a (perhaps outdated) way to determine bonding types. DMacks 19:50, 2 May 2007 (UTC)
Just a thought, but if you know how to make a Lewis Dot Structure.. this may lead you in the direction of how the bonds form between elements! Otherwise, the electronegativies is your best bet.
As far as I know to be an acid it must always be a covalent bond, other wise the O- ion will be free, and will thus be a base Bastard Soap 13:02, 4 May 2007 (UTC)
Is the rusting process of iron or steel actually a form of fire?
--email removed to prevent spam-- —The preceding unsigned comment was added by 63.65.152.94 ( talk) 19:26, 2 May 2007 (UTC).
Not really " fire" in the usual "heat, light, flame" sense. But fire and rusting are both examples of oxidation. DMacks 19:41, 2 May 2007 (UTC)
Lately I have been thinking about evolutionary psychology. I am especially interested in learning about the way that instincts presumably coded in genes become concious (or subconcious) desires. I am also curious about how belief systems, individual or shared, mesh with these instincts/desires.
Can anyone recommend some respected, popular-level books about these issues? Even some links to good articles, or research hints would be appreciated. Thanks -- Diletante 20:42, 2 May 2007 (UTC)
I have been conducting a lab with an acid and base, and the ending solution is basic. The indicator that I used was phenolphthalein, and at the end of the experiment, the color of the solution is a pale pink color. The question that I have is: Why are titrations typically set up so the ending apperance is colored and does not disappear? Is there a certain reason for this?
I have already read the page about this indicator, but its not quite what I'm looking for. Any comments will help! Thanks! —The preceding unsigned comment was added by 76.188.176.32 ( talk) 21:17, 2 May 2007 (UTC).
So is the only reason that titrations are usually set up to turn a different color.. because its easier to see..?
The whole basis for titration requires knowing when one has reached the endpoint. Need some clearly detectible change to occur, and the clearer the change and the more abruptly it occurs, the easier to detect reliably. "Colorless → colored" is easy, "blue → green" is harder; "precipitate starts to form" is easy, "no more precipitate forms" is hard; etc. DMacks 21:44, 2 May 2007 (UTC)
Thanks for the help!
Sometimes when I chew my nicotine gum, I get hiccups. This is listed as a possible side-effect of the gum and the WP article mentions it too (though I'd disagree with the 'excessive use in times of stress' line - I've never been particularly stressed when it's happened to me). What I don't understand is *why* this happens - i.e. how the nicotine works on my body to cause the hics. Anyone know? -- Kurt Shaped Box 21:23, 2 May 2007 (UTC)
Do you chew with your mouth open?? Don't suck the air in too fast now!
How come if you have a frozen bottle thats sealed (such as a 20 ounce coke bottle), if you take it out the freezer, wipe off the outside so you know theres nothing on the outside, and let it sit, you will see water drops on the outside, why does this happend? Where does the water come from? —The preceding unsigned comment was added by 76.167.159.75 ( talk) 21:26, 2 May 2007 (UTC).
The warm air will cause condensation to from on the cold outside of the bottle. The droplets are formed when the coldness tries to evaporate. Perhaps, the air bubbles escaping. They certainly don't like warm!
As light approaches a black hole, does it travel faster than the speed of light? Please repond on my talk page or let me know you or someone has reponded, thank you. 100110100 22:35, 2 May 2007 (UTC)
Light still travels at the speed of light, however, as it approaches the black hole it is blue shifted, so that the frequency is increased. This also applies to light approaching any object with gravity such as the earth, but usually the effect will be too slight to notice. GB 23:31, 2 May 2007 (UTC)
Allow me to play the role of a country bumpkin. Any particle traveling at speed S will accelerate further when it drops down a gravity well. So therefore a photon traveling at speed C will accelerate further if it drops downs a gravity well. So does the photon travel faster than the speed of light? 202.168.50.40 00:22, 3 May 2007 (UTC)
the speed of time changes near a black hole, instead of the speed of light.
Dear Ref Desk, I am very interested in knowing what structures or mechanisms are responsible for the variation in visual perception among different substances i.e. LSD produces a variety of patterns and while thats true they also happen to be very geometric with well defined shapes while psilocybe mushrooms produce organic shapes in the visual field and furthermore DMT can produce both?
http://www.pocketmagazine.net/album/wp-content/uploads/2007/05/unknownfruit.jpg
-- Sonjaaa 22:53, 2 May 2007 (UTC)
My Mother claims to be AB+ and on my birth certificate it says I am AB+. Seems to fit, however my father claims to be O. If my mother is AB and my father is O then I should be A or B. Is this possible? —The preceding unsigned comment was added by 75.74.140.121 ( talk) 23:12, 2 May 2007 (UTC).