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swansont

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Everything posted by swansont

  1. A speedometer that measured passage of the trees/markers placed at regular intervals (as described earlier) would do this, if it were calibrated to the rest frame distance of the trees. i.e. your speed would be measured in trees-per-second, and converted to proper speed by knowing the rest frame distance between the trees. However, this is not how most speedometers are configured, and it would not be a true speedometer, since it is measuring this contrived "proper speed." It would be a "properspeed"-ometer. The obvious followup is: why would one bother to do this?
  2. Yes, and … ? "the hole decays into a spinon and a holon" The hole. i.e. the quasiparticle, which is a description of the absence of an electron, displays this behavior. Not the free electron.
  3. No, right answer. From your own source (emphasis added): "Under the worst of circumstances, the report said, the government's maximum exposure could total nearly $24 trillion … Much of the government assistance is backed by collateral and Barofsky's $23.7 trillion estimate represents the gross, not net, exposure that the government could face." You want to try again?
  4. By that metric, then, most government programs are failures. In fact, I think by that metric, all government programs are failures. I imagine you can find some aspect of society that does not benefit by any randomly chosen government program. Which pretty much makes it a useless metric for defining success. ——— Despite the anecdotes presented, the actual results thus far have been better: http://blogs.wsj.com/environmentalcapital/2009/08/05/cash-for-clunkers-an-expensive-environmental-fix/
  5. This is condensed matter physics — it's collective behavior of the electron and its surroundings (i.e. in a wire) that is being treated as a quasi-particle. This is not describing a bare electron.
  6. Why does it need to? That seems to be a contrived objection. Is that a problem the program promised to address? Because it's a strawman argument, since the goods aren't destroyed. The cars, except for the engine, are available as parts. If they get destroyed after six months of being unsold, how much of a market was there for them? New product, representing a larger increase in value of material, has been sold. Merged post follows: Consecutive posts merged If they were waiting, then they were not "in the market" to get a new car. If they were going to buy the new or used car anyway, they have not reduced the existing supply of used cars since they did not buy a used car; all you can say is that they did not add to the supply of used car by not trading one in. Bringing in the housing market and debt is a red herring. You have provided absolutely nothing to back that statement up. Stop it.
  7. The electron is not divided into charge and spin — the "quasiparticle" term refers to a collective behavior of electron and its surroundings that's being investigated.
  8. Let me clarify what I meant — a car that is traded in under the cash-for-clunkers program was not sitting on the lot at Bob's Beaters, waiting to be sold, it was owned by somebody. Bob has just as many cars on the lot for someone to buy. As for vehicles being sold by their owner, if they were going to then buy a used car, that's a zero-sum game. So again, no effect. They didn't sell their car to someone but neither did they buy a used car. So I'm not buying the argument that this program has removed a whole bunch of cars from the used-car supply. And, as you point out, since the parts other than the engine are stripped and an be sold, that points to an increase in supply of these parts, not a decrease, as claimed by navigator. Merged post follows: Consecutive posts merged Yes and yes. I intentionally try to be difficult — it usually makes the fact content of posts go up. And I had hoped for something more substantial than a few snippets in an NPR piece. "Chameides calculates that if you trade in an 18 mpg clunker for a 22 mpg new car (22 miles per gallon is the minimum mileage allowed for a new car under the program), it would take five and a half years of typical driving to offset the new car's carbon footprint. With trucks, it might take eight or nine years, he says." So, for cars, the worst-case scenario is 5.5 years to break-even for the carbon fooprint. Someone who buys a Prius gets break-even in less than 1.5 years (since 18 mpg < 20 mpg used in the story). Which means "buying a used car will reduce your carbon footprint compared to buying new" is only true under a limited set of circumstances, and not generally the case.
  9. A reference would be nice. And what are these numbers. Reference? No existing used cars were destroyed (i.e. used cars for sale, on a lot somewhere), so how exactly did the supply drop? And since people tend to buy used cars more often in a recession, this program has had the effect of reducing demand for used cars, thus easing any pricing pressure on them and making them more affordable. Decent goods? What part of "clunker" is giving you trouble here? We're talking about cars that got less than 18 mpg and were worth less than $4500 (otherwise you'd just trade in your car).
  10. Yes, they do (to the latter) — just barely. http://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/apollosites.html Also, check this out http://www.technologyreview.com/blog/arxiv/23205/ Faking that level of detail would be pretty impressive.
  11. If the other scientist had not yet made a measurement, allowing the particle to still be in a superposition, they would have to communicate this to you somehow. Which would require normal communication speed.
  12. One could do it that way, and one would NOT get the proper velocity given by the OP.
  13. What Diamond does is explain these environmental factors in some detail, and shows what the differences are in some superficially similar settings. e.g. it's not enough to have the same climate to expect two civilizations to advance in similar fashion — one needs access to other regions with similar climates, which was facilitated in Eurasia but prevented in Africa and the Americas.
  14. That's how you'd normally do it, and you'd get the wrong answer if you didn't take into account relativity. Which is the whole concept being applied here, apparently. I mean, a speedometer can show anything you want it to, if you don't wire it up properly. I've seen a speedometer which indicated 22 mph when the vehicle was standing still. BFD. The bottom line is that a true, relativistically accurate speedometer does not measure speed in the way that has been indicated. An accurate speedometer would calculate the wheels' circumference rather than using a measurement from the rest frame.
  15. The distance between the trees is not constant in your frame. The speedometer does not use the trees' frame to measure the distance. How would it "know" these distances?
  16. They are very different, indeed. If you shovel dirt into a regular hole, it fills up. If you shovel dirt into a black hole, it gets bigger (in terms of the event horizon)
  17. You know it has collapsed if you made the measurement — I don't think there's any way to tell if the particle was in a superposition beforehand or not. But it wouldn't do you any good for FTL communication anyway, because you don't know what state the particle would be in. You could measure polarization, which is a wave measurement.
  18. I read the book a while back — I think it's very good, other than Diamond's annoying tendency to repeat himself. (I'm currently reading Collapse, which suffers from the same flaw but is otherwise also very good)
  19. Opinion has nothing to do with it. Klaynos has already noted the failing of your recent example.
  20. You don't know what state the particle will collapse into. There's no information transfer in simply measuring state A or B.
  21. The point of contact is a point. That is the only part that does not contract; the rest of the wheel does, with respect to the road. The speedometer is not located on the wheel rim, at the point of contact with the road.
  22. You can't have it both ways. If the wheel contracts, then you can't just say that the length is constant. Show it.
  23. The point in contact with the road will not contract. You cannot say that about the rest of the wheel, since it does have a speed with respect to the road. What is the circumference of the wheel, measured in the road's frame?
  24. The speedometer will not measure the speed as you have described. The distance will contract, and you will get an answer that is < c
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