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Samm

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    Australia
  • Favorite Area of Science
    Physics

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  1. I think quality shouldn't be sacrificed for speed. As far as I can tell, some of the people here on this forum seem incredibly knowledgeable within their fields (I'm definitely not one of these people). But they've got lives to lead, and don't really have a great deal of time for answering everyone's questions. Maybe it's a good idea to read good physics books. I know that when I get out of high school (this is the final year, the pressure is on!), the first things on my reading list will be penned by Richard Feynman.
  2. Looks like we're making progress. To be fair, you looked as if you were attempting to discredit General Relativity, by stating: As if that somehow meant something, other than General Relativity isn't 100% perfect. If temperature is the average kinetic energy of particles randomly bouncing off each other, in different directions, then no. Photons are the messenger particles for the electromagnetic force. Entropy and photons have little to do with one another. Entropy is just a measure of how much non "useful" energy there is in a system ie. how much energy can't be used to produce work. Or alternative the number of ways one can rearrange the atoms of an object and have the object still look the same, although I'm not too sure on that one. Wait... Are you confusing this with the idea of the heat death of the universe? A state where close to maximum entropy is reached, pretty much at the end of the universe. Supposedly all the matter evaporates into photons or decays into leptons No. There is a such a thing as zero point energy, which is the energy that a something has in its ground state.
  3. I think it's where the electrons or other charged particles travel faster through a medium than the speed of light in that medium. And then this produces radiation through some mechanism that I don't understand. Edit: On further research it has to be a dielectric medium. But I don't really know what that means either.
  4. Kinetic energy and quantum mechanics IS physics. What you're saying doesn't make any sense. It's not physics. I mean from what I can see, you're trying to establish that objects stop in time because measurements are events that don't occur continuously. As you're very keen to point out, measurements are distinct from the object. The measurement is just an image that we can see of what's going on, so... what does that have to do with any objects actually stopping in space, let alone time? And if a law of thermodynamics was disproved, it would be the largest science news was disproved, it would likely make headline news and be everywhere. I don't think we have yet seen that. General Relativity doesn't say "EVERYTHING IS RELATIVE". It doesn't. The laws of physics apply to all reference frames, to the same degree. It's just the way it works. Liquid helium is a superfluid under the correct conditions. Superfluids have high thermal conductivity, not infinite thermal conductivity. They are very strange, but it's not like they actually break any rules. They are frictionless, yes, but that is well documented and it doesn't actually void the laws of physics. It's funny that you say this because Dr Rocket seems to have the famous Nobel Prize-Winning Quantum Physicist Richard Feynman as his picture. Which would be odd for someone who doesn't know anything about Quantum Mechanics, now wouldn't it?
  5. I wouldn't agree entirely on that. If it is man-made and we are in fact causing global warming or climate change, we can actually take action to reduce greenhouse gas emissions and reduce hence future warming.
  6. Although somewhat speculative, Carl Sagan's Pale Blue Dot was excellent. Wonders of the Universe, by Brian Cox is probably my favourite book out of all the books I've read.
  7. That would be true if the car was on a frictionless road, driving in a perfect vacuum.
  8. Apologies for the missing equation. For some reason I can't edit the post, so here it is:
  9. About the transformer, I meant a power source which, while DC, could have its voltage changed. Sorry for the confusion. And yes, the pentiometer seems to fit exactly with what I remember about the circuit design.
  10. Lawrence Krauss once proposed something like that. He basically shows that the universe has no total energy (gravitational potential energy is negative) because it's geometry is flat. Now the interesting part is that with no total energy, the universe could have come from a quantum fluctuation; virtual particles popping in and out of existence.
  11. Now I remember distinctly that one of my science teachers described to me a circuit that one could use to measure the potential difference of a galvanic cell; it's E0 value, ie. it's electric potential where there is no current. It involved a transformer, a micro-ammeter, the galvanic cell and a rheostat. I want to know how it works and possibly get more info on the subject. Cheers.
  12. There's a formula for the force of gravity upon two objects: , Where: F = the force between the masses. G = the gravitational constant m1 = the first mass m2 = the second mass r = the distance between either mass. It's called Newton's Law of Universal Gravitation. If we're talking about an object falling towards earth, we can make the mass of earth m1 and the mass of the falling object m2. Now it just so happens that the acceleration of an object is equal to the force on it divided by its mass (a = F/m). So that means we can divide Newton's Universal Law of Gravitation by m2 (the mass of the falling object). So we get: And you'll notice that m2, the mass of the falling object has nothing to do with its acceleration. This equation will apply on pretty much any planet, moon, object etc. In fact astronauts on the moon have performed an experiment that supports this result:
  13. First of all, I'd like to point out that there is no such thing as an "energy particle". There are messenger particles of different forces which can transmit energy (eg. the photon), but inside them we don't find "energons". Energy is an abstract concept; the ability to do work. These particles merely possess that ability. You also seem to have a very strange understanding of Einstein's E=mc2 formula. It simply shows that matter and energy are equivalent that energy has mass and that matter has energy, and that you can change matter into energy and vice versa. If you're interested have a read of the wikipedia article here.
  14. It appears as if 2010 was the warmest year on record, equal with 2005, according to NASA and NOAA. It's interesting to note that the latter half of the year was actually influenced by a strong La Nina event, which is usually associated with cooler conditions. NOAA source NASA source
  15. First of all, it is not exactly the same. The most recent one lasted longer and warmed more than the previous periods of warming. And what are the odds of a non-linear chaotic system producing similar outputs if the most of the inputs remain much the same. I don't see it is as too improbable. Well, I can cite a paper that supports these statements. I can't prove it, I can provide evidence in it's favour. Here is a graph depicting the temperature rise due to the various different influences on climate. From Lean, J. L., and D. H. Rind (2008). Additionally, the "current lack of warming" isn't really doing the data justice. It's a currently lack of statistically significant warming, at the 95% significance level. Here's what Phil Jones would like to say: First of all, according to the graph above, the "current lack of warming", which isn't really a current lack of warming, can be explained by a decrease in the solar irradiance, and a decrease in ENSO forcing. The period of cooling seem between 1880-1910 according to the graph, appear to be due to volcanic aerosols and low levels of solar irradiance, coupled with a low level of anthropogenic forcing. Okay, I understand what you're saying. Natural influences appear to influence the short-term greatly, but over the long-term CO2 seems to win out. Any explanation that says it's only CO2, or only natural causes, behind any climate phenomenon, is likely to be wrong. I concede that solar irradiance, appears to have helped along the greenhouse effect (see graph), and feedbacks play a significant role. I'd consider it to be probably guilty. Not 100% sure, but it's definitely better safe than sorry. We'd have to figure out the actual rates of temperature rise for those spikes. Additionally, that is only one proxy, it doesn't invalidate reconstructions that either take it's data into account, or use a number of other proxies. Yes, true, however, my point is that you shouldn't base your conclusions on just one new paper, especially when it contradicts a whole number of others. Indeed. The former rather than the latter.
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