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algore

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About algore

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  1. Galileo was the first person to solve those equations. Look up his "Discourses Concerning Two New Sciences", written in 1636. First he finds the average speed ((v+u)/2) then finds v^2 = 2as (supposing u=0, starting from rest). It's all done geometrically; this was before they invented modern algebraic methods. You may find the geometric reasoning helps make the physics behind the equations more intuitive. One reason for eliminating t from the equation was that his method of measuring time was very crude (water clock) so he could get more accurate answers using distance (rulers are much more ac
  2. What you say is very encouraging. It sounds like my view is out of date. I could defend the position that 2-3 decades ago (when I was still a theoretical mathematician, with a strong interest in physics) experimenters were looked down upon, but who cares? Apparently today they're finally getting the attention, respect and funding they deserve. I'll have to read up on LHC, about which I know nothing .. As for how much one person can or can't understand, if a young John von Neumann (or Leonardo da Vinci, or etc) comes along, he might be able to shed new light on the subject. Witten is brilli
  3. While you were transporting the cat, I suppose you had to feed her half as much food, and clean out her litterbox half as often, as usual? Leo32: A second step might be to influence the quantum state of the cat on one side such that the chances of it being found alive are much higher than they are in the original experiment, after the boxes have been separated. Some of the texts on entanglement make me think, and I'm not sure about this, that this increased chance of the cat being found alive is "transported" at a speed higher than that of light. In other words, the quantum state of the r
  4. Hi Severian, note that the divergence you describe between theorists and experimenters is a recipe for disaster. There's a crying need for more "generalists" who take an overall approach rather than specializing in narrow areas. I don't think it's impossible for "one person to follow it all". If a person of ordinary intelligence can master one branch of physics (ordinary in this context might be IQ around 140) then a real genius will be able to master the whole ball of wax (since an IQ like 200 is dozens of times more capable). The problem is that such people are steered into the most advanced
  5. swansont: "Sounds dogmatic" and "is dogmatic" aren't the same thing. - Agree. Similarly, "accidentally sounds rabidly iconoclastic when sounding off a bit" and "is rabidly iconoclastic" aren't the same thing either! swansont: As far as actual physics instruction, in which colleges or universities is the duality being presented without supporting evidence? - No one, I'm sure, instructs actual physics students about this duality without presenting the evidence. However laypersons are, I think, often instructed dogmatically. I took the trouble to look up the reference to Hawking's bo
  6. Swansont, I didn't say that matter doesn't have both wave and particle properties. In fact I explained exactly how it works: Schroedinger's eqn describes the probability wave, while observation collapses it so that the particle is seen. I even mentioned the 2-slit experiment. You can do this yourself at home using sunlight, exactly as Thomas Young first did it 200 years ago - it's very instructive and convincing. My point was, the way the particle-wave duality is presented to a layperson (like noz92) is often dogmatic. Simply "it's both a particle and a wave - believe it because I say so". The
  7. It's a good question noz92. A few decades ago it wouldn't have come up because back then physicists explained the whole picture .. today physics instruction has become pure dogma. "Particle is also a wave" "big bang universe was infinite in extent and also condensed into a point" "dark matter exists even though it's impossible to detect, just because we say so", etc. It's exactly like "God is a trinity, both 3 and 1" or "the Pope is infallible", or "6,301 angels can dance on the head of a pin" etc. You must have faith in your priest / physicist, who is the fount of all mystical wisdom. If you
  8. Maybe you're right philbo1965uk, but having examined van Flandern's arguments, I'm figuring that he's wrong (and every other physicist since Einstein is right): gravity propagates at light speed. Admittedly, it remains an open question .. so, what do you say is the most interesting thing about gravity? Is it, perhaps, the question "<i>why</i> does everything attract everything else?"
  9. Edisonian: "I have never really understood how space is supposed to never end." There are a lot of ways to approach this question; here's one which is compatible with both modern physics and common sense. First, suppose the universe has some definite age, say 15 billion years. (I'm not claiming that's the case, but it's plausible). Then the farthest we can possibly see is 15 billion light years. Hubble telescope is actually theoretically capable of seeing a very bright light source even farther out, for instance 30 billion LYs. Unfortunately there hasn't been enough time for that light to
  10. Thanks JHAQ, yes I see now how the binary pulsar example works. Turns out my old textbook (1980) mentions it also .. back then the data was more ambiguous but now it looks like it's been firmed up and is fairly definite. I found a reference from a "professional physics kook", Tom van Flandern, which does a great job of presenting some of the misgivings that have been rattling around in my head; he claims speed of gravity is >= 2*10^10 c. Makes a distinction between gravity radiation (which he admits the pulsar data confirms) and gravity waves, which he claims are unsubstantiated. Check it o
  11. Thanks swansont .. Yes, the binary pulsar data is significant, but are you sure it indicates that the "the results are consistent with the speed of propagation being c with a high degree of precision"? I had thought it only showed the likely existence of gravitational radiation, which would occur at any speed less than infinite; that's what was said in early reports, back in the late 70's. Perhaps the greater accuracy of the data obtained by continued observations has allowed the determination that it must be c. (Note that even Newton was dubious about gravity acting "instantaneously", so
  12. Yes, swansont, GR <i>predicts</i> that that gravity acts at c but the underlying point of my question was that prediction is not proof. Proof must ultimately come from experiment (according to Sir Francis Bacon, who invented the scientific method, and also according to common sense). If you review the actual experiments which ratify GR, none of them depends on the speed of gravity - that is, until the recent one 2 years ago that you cite (which I stupidly had overlooked; I should have googled before posting). I'm pretty sure one could formulate an "alternate GR", allowing instantan
  13. yourdadonapagos, there are two problems that I can see with your "proof" (I put the word in quotes out of respect for Kant . First, the restriction on speed of information is only a principle, or theory. You can't use a theory to prove an experimental fact; instead, it's the other way around. When I first asked this question, years ago, I argued (correctly) that gravity speed was still an open issue. Of course, as mentioned above, it turns out we now have experimental proof that it's limited to c (1.06 c, to be exact). This constitutes more (real) proof that the theory of limited informat
  14. Edward Duffy, thanks for your input .. I'd never heard of tensegrity and am not too inclined to study it, since it appears to contradict some pretty well-established facts. There are a lot of alternate theories out there which, if true, would turn modern physics upside down; some are much better supported than this one, and perhaps I'll discuss them on this forum another time. As I mentioned above modern physicists have gotten far ahead of actual experimental verification, leaving the field wide open to far-out speculations .. one of which might actually be correct. Many of the brightest physi
  15. Agree. But remember what Mr. Holmes said: ""It is a capital mistake to theorize in advance of the facts." If you're sure the butler did it you might not notice that the wife had a blood-stained knife in her dresser drawer .. Admittedly the last century of physics wouldn't have happened if they'd taken his advice literally. But I think his underlying point is still valid: go ahead and explore theories, but don't fall in love with them.
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