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I'm basically asking -why does it take special equipment (or does it?) to split an atom? Is it nature's way of keeping us from blowing ourselves up? There isnt always a bad reaction. Fermilab has been annihilating atoms for years with no ill affects.-- Sunburned Baby ( talk) 01:37, 16 April 2008 (UTC)
Also, an atom is a tiny nucleus surrounded by a large cloud of electrons. To split an atom, you need to get at the nucleus. Imagine the previous poster's comment about loaves of bread, but imagine that there is a frozen pea in the middle of each loaf. Splitting the atom is more like splitting that pea. -- Slashme ( talk) 09:08, 22 April 2008 (UTC)
The forces holding atoms together are far stronger than the forces holding atoms to each other in a molecule, which are far stronger than the forces holding molecules together in a cellular structure in a wood fiber, and so on. Ziggy Saw dust 23:40, 22 April 2008 (UTC)
Since gravity is defined as known to be a bending of space-time, why should it be mediated by
bosons? Bosons mediate forces, and it doesn't seem that a bending or curvature of something is an actual force.
In M-Theory and string theory, are the strings described composed only of energy? If not, what else are they composed of? Zrs 12 ( talk) 01:57, 16 April 2008 (UTC)
How can one domino initiate a 'process' on a single, compact Rube Goldberg machine that is on a flat surface? --hello, i'm a member | talk to me! 05:06, 16 April 2008 (UTC)
Your article on Real time kinematic GPS positioning contains the statement "This integer ambiguity problem can be addressed to some degree with sophisticated statistical methods that compare the measurements from the C/A signals and by comparing the resulting ranges between multiple satellites."(integer ambiguity) in red.
I would like a more comprehensive (but readable) account of this subject. From other research, I have found that explaination of this topic are illusive, but perhaps Wiki has the resources to find what I (and others) need.
Thankyou if you can help.
RH. Astrogoose ( talk) 05:43, 16 April 2008 (UTC) Retitled for clarity AlmostReadytoFly ( talk) 09:29, 16 April 2008 (UTC)
How far is the earth from the sun? How has this distance changed in last 10 /100 years? Should we fire retro rockets to alter this distance? —Preceding unsigned comment added by 82.68.203.150 ( talk) 09:28, 16 April 2008 (UTC)
I'm learning about Environmental Impact Statements in class, and I was wondering, (because I find biology to be fun and fascinating) who writes these exactly? What would be the title of that profession? 69.16.91.28 ( talk) —Preceding comment was added at 09:56, 16 April 2008 (UTC)
Take an Extension cord and plug it into itself. The powr shud then go round and round and come ot of the other sockets. —Preceding unsigned comment added by 213.38.213.226 ( talk) 10:24, 16 April 2008 (UTC)
You can't just plug an extension cord into itself. You have to plug it into the mains until it fills up with magic smoke, then plug it into itself before any of it leaks out. 206.252.74.48 ( talk) 13:11, 16 April 2008 (UTC)
Now assume the extension cord is superconductive. Does that change the answer?
Edison (
talk) 02:45, 17 April 2008 (UTC)
(Sigh). Assume good faith. In general, the consumers ( plugged into the cord) expect a continuing source of power. When you remove the original power source by unplugging the extension cord, you remove that power source. Even if you assume a theoretical switching time of zero, the amount of energy in the closed system is constant, so the energy will fall over time. For practical circuits, the voltage will fall to zero in less than one second._ Arch dude ( talk) 03:30, 17 April 2008 (UTC)
A couple of years ago, I heard masturbation burned an inordinate amount of calories and/or fat. Is this true, or did I step in hip-deep bullshit? This IS a serious question. -- AtTheAbyss ( talk) 12:48, 16 April 2008 (UTC)
My japanese maple tree (red w/8 - 9 points on the leaves) apprears to have been grafted with a root of a weed. The tree has taken on characteristics of the weed and the maple. The top half of the tree is green like the weed, the leaves of the new growth now have 4 points. I can see there the green from the weed has grown inside the trunk of the maple. Probably a time where the viny weed attached itself to the trunk of the maple. My question is, can I cut the top half of the tree down so I only have the maple left. Will this give me a permanent fix or should I just cut the tree down? Enduranceprincess ( talk) 13:19, 16 April 2008 (UTC)
I was reading about the current oil crisis and was wondering about the effects that the rising cost of petroleum will have on industrial and consumer goods. We're talking about a 300 $/gallon barrel in a few years from now. ADM ( talk) 13:31, 16 April 2008 (UTC)
A slightly different take...
- There may be a dip but it is hard to say - the difficulty with the prediction is that any decline in developed nations might be surpassed by increase in developing nations
- They already are. The problem is their recycle rate. You have to look at the full life-cycle of a product. The site i was going to link to ( http://www.ilea.org/) seems to have been replaced which is odd - but the research suggest that it depends on what % are recycled as to whether it is better or worse than paper/canvas bags for the environment (and again their respective recycling affects it too)
- I suspect this will very much depends on tax policy country-by-country. Whether they rise faster than the increasing wealth of people in each nation is perhaps a more difficult question to answer.
–
- Well coal production already exists on a massive scale, i'm sure some movement to coal will happen where economically viable
- Water prices already rise and fall according to market expectations of utility-companies/real-costs of their business, it's unlikely this will change in the future
- It depends on what oil is used, I doubt demand will outstrip supply enough to make these things vastly more expensive
- The optimist's theory is - yes. As oil becomes expensive the viability of alternative increases. That new fuel that is too expensive to compete might suddenly become more attractive, it might attract more attention of investors/scientists/inventors etc. The governments of the world can help by giving incentives to invest in sustainable fuels and by giving short-term tax-breaks until new technologies replace old at which point the tax can increase (this is why so many people moan about "you got us hooked then increased the tax" - yes they did because it was a policy designed to move you from X to Y and once that was achieved the established technology could pull in valuable tax)
- Of course, though 'without oil' is not what is likely to happen. Likely the last barrels of oil will never be taken, but the world will adapt to the replacement that comes our way - that much is pretty certain. The doomsayers over-estimate the flexibility of mankind. It'll be tough, and I agree it is likely to lead to more international instability, perhaps even wars over energy/food/water as we adapt, but in the long-term things will progress. ny156uk ( talk) 21:25, 16 April 2008 (UTC)
What kind of molecules catalyze RNA splicing? I can't find an answer that I understand. Thank you. -- Freiberg, Let's talk!, contribs 16:29, 16 April 2008 (UTC)
Let's say you've got a chemical solution; some reaction takes place and small bits of a solid form in the solution. If the solid bits float to the top of the liquid instead of sinking to the bottom, is it correct to call this precipitation? I usually think of precipitation meaning falling. Is there a better word for the situation I've described? ike9898 ( talk) 17:17, 16 April 2008 (UTC)
by this definition, it does not matter whether the result's density is greater or lesser than the density of the remaining solution. The result is still precipitate. - Arch dude ( talk) 03:16, 17 April 2008 (UTC)
There is a clip from family guy in which Brian demonstrates to Peter that Peter has gravitational pull. Before long, an apple, a picture frame, a glass of ice water, and a tv set are all in orbit around Peter. Just how fat would Peter have to be for this to actually happen? -- Omnipotence407 ( talk) 21:36, 16 April 2008 (UTC)
If we ignore atmospheric effects and the confounding effects of earth's gravity (say we put Peter into deep space), you can calculate the needed mass with the formula given at Orbital mechanics#Circular orbits. v = sqrt(GM/r) or M = r*v2/G If I remember the clip correctly, the objects orbited at arms length or so (say 1 m), with a period of 5 seconds or so. The velocity of the orbiting objects was thus 2*π*r/t (one circumference per orbit) or v ~= 1.26 m/s. Plugging into the above equation, we get M ~= 2.4 × 1010 kg, a little less than one tenth the mass of all people on earth, or about 4 Great Pyramids of Giza (according to Orders of magnitude (mass)). -- 128.104.112.85 ( talk) 18:26, 17 April 2008 (UTC)
Hello. I am in grade 12 high school (last year before university). Our chemistry teacher told us that a mass spectrometer is used to determine the relative mass between isotopes of the same element. However, our article indicates that the exact atomic mass of an element can also be determined by a mass spectrometer. How does the two techniques differ? To find the exact atomic mass, does the spectrometer have to find the volume and density, and therefore mass, of the particles or something? Peace. Applefungus ( talk) 21:30, 16 April 2008 (UTC) (moved by BrainyBabe ( talk) 22:33, 16 April 2008 (UTC))
An "element" does not have an exact atomic mass. A particular isotope of an element does have a precise atomic mass. The "atomic mass of an element" is actually the weighted average of the atomic mass of its isotopes, weighted by the relative prevalence of the element's isotopes as found in nature. This definition of atomic mass is used because chemists were measuring atomic mass before there was any way to separate the isotopes. A mass spectrometer is the ideal instrument to separate the isotopes of an element. It can determine with absolute accuracy the ratios of the isotopes of an element in a particular sample, for example the ratio of carbon 12 to carbon 14 in a particular ancient tree ring. The atomic mass of pure carbon 12 is fixed by the laws of physics. The same is true of the atomic mass of carbon 14. The atomic mass of "carbon" is a number negotiated by humans, based on a consensus as to the ratio of carbon 12 and carbon 14 in a "natural" sample of carbon. - Arch dude ( talk) 01:45, 18 April 2008 (UTC)
Hello, this is a bit dry, and maybe a long shot. But I'm looking for information (preferably a study) on the variation of Young's (i.e. elastic tensile) modulus with degree of purity for a metal (preferably copper). Any ideas?
Eth ( talk) 23:30, 16 April 2008 (UTC)Eth
My father ordered me some very strange things on eBay and seems to have forgotten what they were actually used for. They are two lead cylinders with bottoms and removable tops. They each weigh around 10lbs apiece, I estimate. He claims they have something to do with atomic research. Any guess as to what they are? They look like they could hold radioactive sources in them or something like that. Should I be concerned about keeping things inside them now? I guess I could take it in and see if someone could run a Geiger counter on one of them... sigh. Any thoughts? -- Captain Ref Desk ( talk) 23:55, 16 April 2008 (UTC)
OK, I figured it out. They are lead pigs. Very odd. I imagine I should not store things in them but otherwise they are probably as safe as any other 10lb chunks of lead? -- Captain Ref Desk ( talk) 23:59, 16 April 2008 (UTC)
If there ia any contamination, then somebody broke the law before they showed up on eBay. Depending on where you live you can probaly find a local university lab that will asses these for you at no cost. If not, and if you are paranoid, then simply bury them and go to the local HomeDepot, buy sheet lead, and roll it into cylinders. - Arch dude ( talk) 03:06, 17 April 2008 (UTC)
Smack them together and if you find yourself instantly transformed into a cloud of plasma, they might be a bit radioactive... :-) Ilikefood ( talk) 22:21, 17 April 2008 (UTC)
Luxosus ( talk) 14:36, 19 April 2008 (UTC)
Science desk | ||
---|---|---|
< April 15 | << Mar | April | May >> | April 17 > |
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. |
I'm basically asking -why does it take special equipment (or does it?) to split an atom? Is it nature's way of keeping us from blowing ourselves up? There isnt always a bad reaction. Fermilab has been annihilating atoms for years with no ill affects.-- Sunburned Baby ( talk) 01:37, 16 April 2008 (UTC)
Also, an atom is a tiny nucleus surrounded by a large cloud of electrons. To split an atom, you need to get at the nucleus. Imagine the previous poster's comment about loaves of bread, but imagine that there is a frozen pea in the middle of each loaf. Splitting the atom is more like splitting that pea. -- Slashme ( talk) 09:08, 22 April 2008 (UTC)
The forces holding atoms together are far stronger than the forces holding atoms to each other in a molecule, which are far stronger than the forces holding molecules together in a cellular structure in a wood fiber, and so on. Ziggy Saw dust 23:40, 22 April 2008 (UTC)
Since gravity is defined as known to be a bending of space-time, why should it be mediated by
bosons? Bosons mediate forces, and it doesn't seem that a bending or curvature of something is an actual force.
In M-Theory and string theory, are the strings described composed only of energy? If not, what else are they composed of? Zrs 12 ( talk) 01:57, 16 April 2008 (UTC)
How can one domino initiate a 'process' on a single, compact Rube Goldberg machine that is on a flat surface? --hello, i'm a member | talk to me! 05:06, 16 April 2008 (UTC)
Your article on Real time kinematic GPS positioning contains the statement "This integer ambiguity problem can be addressed to some degree with sophisticated statistical methods that compare the measurements from the C/A signals and by comparing the resulting ranges between multiple satellites."(integer ambiguity) in red.
I would like a more comprehensive (but readable) account of this subject. From other research, I have found that explaination of this topic are illusive, but perhaps Wiki has the resources to find what I (and others) need.
Thankyou if you can help.
RH. Astrogoose ( talk) 05:43, 16 April 2008 (UTC) Retitled for clarity AlmostReadytoFly ( talk) 09:29, 16 April 2008 (UTC)
How far is the earth from the sun? How has this distance changed in last 10 /100 years? Should we fire retro rockets to alter this distance? —Preceding unsigned comment added by 82.68.203.150 ( talk) 09:28, 16 April 2008 (UTC)
I'm learning about Environmental Impact Statements in class, and I was wondering, (because I find biology to be fun and fascinating) who writes these exactly? What would be the title of that profession? 69.16.91.28 ( talk) —Preceding comment was added at 09:56, 16 April 2008 (UTC)
Take an Extension cord and plug it into itself. The powr shud then go round and round and come ot of the other sockets. —Preceding unsigned comment added by 213.38.213.226 ( talk) 10:24, 16 April 2008 (UTC)
You can't just plug an extension cord into itself. You have to plug it into the mains until it fills up with magic smoke, then plug it into itself before any of it leaks out. 206.252.74.48 ( talk) 13:11, 16 April 2008 (UTC)
Now assume the extension cord is superconductive. Does that change the answer?
Edison (
talk) 02:45, 17 April 2008 (UTC)
(Sigh). Assume good faith. In general, the consumers ( plugged into the cord) expect a continuing source of power. When you remove the original power source by unplugging the extension cord, you remove that power source. Even if you assume a theoretical switching time of zero, the amount of energy in the closed system is constant, so the energy will fall over time. For practical circuits, the voltage will fall to zero in less than one second._ Arch dude ( talk) 03:30, 17 April 2008 (UTC)
A couple of years ago, I heard masturbation burned an inordinate amount of calories and/or fat. Is this true, or did I step in hip-deep bullshit? This IS a serious question. -- AtTheAbyss ( talk) 12:48, 16 April 2008 (UTC)
My japanese maple tree (red w/8 - 9 points on the leaves) apprears to have been grafted with a root of a weed. The tree has taken on characteristics of the weed and the maple. The top half of the tree is green like the weed, the leaves of the new growth now have 4 points. I can see there the green from the weed has grown inside the trunk of the maple. Probably a time where the viny weed attached itself to the trunk of the maple. My question is, can I cut the top half of the tree down so I only have the maple left. Will this give me a permanent fix or should I just cut the tree down? Enduranceprincess ( talk) 13:19, 16 April 2008 (UTC)
I was reading about the current oil crisis and was wondering about the effects that the rising cost of petroleum will have on industrial and consumer goods. We're talking about a 300 $/gallon barrel in a few years from now. ADM ( talk) 13:31, 16 April 2008 (UTC)
A slightly different take...
- There may be a dip but it is hard to say - the difficulty with the prediction is that any decline in developed nations might be surpassed by increase in developing nations
- They already are. The problem is their recycle rate. You have to look at the full life-cycle of a product. The site i was going to link to ( http://www.ilea.org/) seems to have been replaced which is odd - but the research suggest that it depends on what % are recycled as to whether it is better or worse than paper/canvas bags for the environment (and again their respective recycling affects it too)
- I suspect this will very much depends on tax policy country-by-country. Whether they rise faster than the increasing wealth of people in each nation is perhaps a more difficult question to answer.
–
- Well coal production already exists on a massive scale, i'm sure some movement to coal will happen where economically viable
- Water prices already rise and fall according to market expectations of utility-companies/real-costs of their business, it's unlikely this will change in the future
- It depends on what oil is used, I doubt demand will outstrip supply enough to make these things vastly more expensive
- The optimist's theory is - yes. As oil becomes expensive the viability of alternative increases. That new fuel that is too expensive to compete might suddenly become more attractive, it might attract more attention of investors/scientists/inventors etc. The governments of the world can help by giving incentives to invest in sustainable fuels and by giving short-term tax-breaks until new technologies replace old at which point the tax can increase (this is why so many people moan about "you got us hooked then increased the tax" - yes they did because it was a policy designed to move you from X to Y and once that was achieved the established technology could pull in valuable tax)
- Of course, though 'without oil' is not what is likely to happen. Likely the last barrels of oil will never be taken, but the world will adapt to the replacement that comes our way - that much is pretty certain. The doomsayers over-estimate the flexibility of mankind. It'll be tough, and I agree it is likely to lead to more international instability, perhaps even wars over energy/food/water as we adapt, but in the long-term things will progress. ny156uk ( talk) 21:25, 16 April 2008 (UTC)
What kind of molecules catalyze RNA splicing? I can't find an answer that I understand. Thank you. -- Freiberg, Let's talk!, contribs 16:29, 16 April 2008 (UTC)
Let's say you've got a chemical solution; some reaction takes place and small bits of a solid form in the solution. If the solid bits float to the top of the liquid instead of sinking to the bottom, is it correct to call this precipitation? I usually think of precipitation meaning falling. Is there a better word for the situation I've described? ike9898 ( talk) 17:17, 16 April 2008 (UTC)
by this definition, it does not matter whether the result's density is greater or lesser than the density of the remaining solution. The result is still precipitate. - Arch dude ( talk) 03:16, 17 April 2008 (UTC)
There is a clip from family guy in which Brian demonstrates to Peter that Peter has gravitational pull. Before long, an apple, a picture frame, a glass of ice water, and a tv set are all in orbit around Peter. Just how fat would Peter have to be for this to actually happen? -- Omnipotence407 ( talk) 21:36, 16 April 2008 (UTC)
If we ignore atmospheric effects and the confounding effects of earth's gravity (say we put Peter into deep space), you can calculate the needed mass with the formula given at Orbital mechanics#Circular orbits. v = sqrt(GM/r) or M = r*v2/G If I remember the clip correctly, the objects orbited at arms length or so (say 1 m), with a period of 5 seconds or so. The velocity of the orbiting objects was thus 2*π*r/t (one circumference per orbit) or v ~= 1.26 m/s. Plugging into the above equation, we get M ~= 2.4 × 1010 kg, a little less than one tenth the mass of all people on earth, or about 4 Great Pyramids of Giza (according to Orders of magnitude (mass)). -- 128.104.112.85 ( talk) 18:26, 17 April 2008 (UTC)
Hello. I am in grade 12 high school (last year before university). Our chemistry teacher told us that a mass spectrometer is used to determine the relative mass between isotopes of the same element. However, our article indicates that the exact atomic mass of an element can also be determined by a mass spectrometer. How does the two techniques differ? To find the exact atomic mass, does the spectrometer have to find the volume and density, and therefore mass, of the particles or something? Peace. Applefungus ( talk) 21:30, 16 April 2008 (UTC) (moved by BrainyBabe ( talk) 22:33, 16 April 2008 (UTC))
An "element" does not have an exact atomic mass. A particular isotope of an element does have a precise atomic mass. The "atomic mass of an element" is actually the weighted average of the atomic mass of its isotopes, weighted by the relative prevalence of the element's isotopes as found in nature. This definition of atomic mass is used because chemists were measuring atomic mass before there was any way to separate the isotopes. A mass spectrometer is the ideal instrument to separate the isotopes of an element. It can determine with absolute accuracy the ratios of the isotopes of an element in a particular sample, for example the ratio of carbon 12 to carbon 14 in a particular ancient tree ring. The atomic mass of pure carbon 12 is fixed by the laws of physics. The same is true of the atomic mass of carbon 14. The atomic mass of "carbon" is a number negotiated by humans, based on a consensus as to the ratio of carbon 12 and carbon 14 in a "natural" sample of carbon. - Arch dude ( talk) 01:45, 18 April 2008 (UTC)
Hello, this is a bit dry, and maybe a long shot. But I'm looking for information (preferably a study) on the variation of Young's (i.e. elastic tensile) modulus with degree of purity for a metal (preferably copper). Any ideas?
Eth ( talk) 23:30, 16 April 2008 (UTC)Eth
My father ordered me some very strange things on eBay and seems to have forgotten what they were actually used for. They are two lead cylinders with bottoms and removable tops. They each weigh around 10lbs apiece, I estimate. He claims they have something to do with atomic research. Any guess as to what they are? They look like they could hold radioactive sources in them or something like that. Should I be concerned about keeping things inside them now? I guess I could take it in and see if someone could run a Geiger counter on one of them... sigh. Any thoughts? -- Captain Ref Desk ( talk) 23:55, 16 April 2008 (UTC)
OK, I figured it out. They are lead pigs. Very odd. I imagine I should not store things in them but otherwise they are probably as safe as any other 10lb chunks of lead? -- Captain Ref Desk ( talk) 23:59, 16 April 2008 (UTC)
If there ia any contamination, then somebody broke the law before they showed up on eBay. Depending on where you live you can probaly find a local university lab that will asses these for you at no cost. If not, and if you are paranoid, then simply bury them and go to the local HomeDepot, buy sheet lead, and roll it into cylinders. - Arch dude ( talk) 03:06, 17 April 2008 (UTC)
Smack them together and if you find yourself instantly transformed into a cloud of plasma, they might be a bit radioactive... :-) Ilikefood ( talk) 22:21, 17 April 2008 (UTC)
Luxosus ( talk) 14:36, 19 April 2008 (UTC)