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swansont

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Everything posted by swansont

  1. Superconductors actually reject magnetic fields, which is how you can levitate magnets above them (Meissner effect)
  2. But of you don't understand cars, you can't differentiate between a legit answer and a bogus one. That's another danger of not being even minimially informed, or learning to think critically: you leave yourself open to being conned by being forced to trust specialists.
  3. It's an interesting problem. The body would recoil, but not according to the standard formula — it would not depend on M; you'd have to model some sort of "reduced mass" of the large object. Essentially you have to consider it's not one object, but a series of connected smaller objects. IOW, rewrite the terms so that the original assumptions would hold. The rotation case might be easier to model, because you have a much better defined torsion propagation, and in only one direction.
  4. And our pre-civilization ancestors seldom got into the situation where obesity-caused heart attacks and diabetes were an issue. They would rarely have gotten that fat, nor live long enough for the problems to manifest themselves.
  5. swansont

    About LED

    The color is going to depend on the voltage, since you need a larger bandgap as you move from red to blue. There's some addtional overhead in the circuit, too, but a 1 Volt drop can't give you more than 1 eV, which is a wavelength of ~ 1240 nm. Here is a chart of colors vs voltages of a sample of different LEDs.
  6. But is it surprising that within any minority division you might choose, that there is still a diversity of opinion on any given topic?
  7. It would light up, briefly, but that's a load on the system. You run into trouble postulating zero resistance; you can't assume that and solve any standard problems like this. Superconductors have peculiar behaviors.
  8. From that aspect we have many components in society that are elitist. Mechanics are elitist because they know how to fix my car, which is now too complicated for me to fix. But where is the burden? In an apathetic society, you are putting too much on the shoulders of the scientists and not enough on the rest. I think a lot of scientists are willing to explain what they do, but they are not willing to grind the information into mush and spoon-feed.
  9. The neutrinos come from the fusion reactions. At various stages you are getting protons changing into neutrons, and a neutrino comes out of that reaction. At terrestrial densities they penetrate quite well, but not at the densities in the supernova environment.
  10. You might notice this: Questions asked about mainstream physics don't get moved. It's explanations that are contrary to standard physics to which people object. As Atheist said, they do not belong in the science fora. ——— If one plugs v=c into the equations, the results are undefined. v=c is not a valid inertial reference frame.
  11. You may be looking in the wrong place for similarities. Rather than interference, you might investigate bifurcations in chaos theory.
  12. Data suggests that the field strength was relatively stable between 1590 and 1840. Kinda smacks around the Barnes/YEC claim of a smoothly decaying field as evidence of a young earth, and points to the danger of irresponsibly extrapolating your data.
  13. So is this representative of the scenario? A small object of mass m and speed v strikes a large rigid object of mass M. The assumed elastic collision itself takes a time t, but the large object has a diameter that exceeds ct, so that the force exerted during the collision, the small mass can't possibly "sample" the entire mass M of the large object. So the usual conservation of momentum results can't possibly give the right answer.
  14. You have the frequencies of the two normal modes, but you've already noted that they must be either in the same or opposite direction. That's zero phase, or 180 degrees out of phase. What happens if the relation is different? e.g. one lags the other by 90 degrees, so that one has zero displacement when the other has maximum displacement?
  15. Emphasis is on scholarly papers because that's one way of justifying getting more money to do additional research. The research part of science is a system in which you spend several years studying and doing research to get your degree, and then several more as a postdoc, and then you go off and do more research. The best and brightest usually end up doing the best research. Of course it's elitist. Educational ventures tend to be. Perhaps what you meant was that it isn't very acessible. In that regard, part of the problem is that there is often little motivation for scientists to explain their work in lay terms, but also some of the problem is that the people who don't understand the science don't understand any science. If the advanced research takes 12 years of study to get to the point of doing the research, it's really hard to explain the work to someone who has never bothered to acquire any math or science skills.
  16. Pressure is a macroscopic measure that relates to how often the collisions occur. It doesn't play a part in the individual reactions.
  17. It's better to segregate topics, and as Tycho? said, read other posts. They abound on the topics you have mentioned. [disembodied Obi-Wan voice]Use the search function[/voice]
  18. You keep using density, but as I had previously pointed out, this does not correlate well with mechanical properties you are discussing. Some of the stronger/stiffer materials are low density (and very useful as a result), e.g. titanium alloys. The connection to density simply isn't there.
  19. Did you read the link that Starry.Skies gave? I'm not sure what "fusion caliber energy" is supposed to mean.
  20. Can't comment without an example of 100% efficiency, but I suspect it is used when that's a limiting, or ideal case, like the limit of zero friction. Infinite rigidity is a limiting case in classical physics, but the solutions are only valid for a range of problems, i.e. if you have a collision, you assume the collision itself takes zero time, so your answers won't be valid for extremely small values of t after the collision (characteristic time would probably be d/c, where d is the size of the object colliding); solutions are valid only if t is large compared to that. But your scenario requires relativity, and is also in the range where the solution would not be valid, i.e. you want to know what happens in a time short compared to d/c.
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