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swansont

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swansont last won the day on November 9

swansont had the most liked content!

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6976 Glorious Leader

About swansont

  • Rank
    Evil Liar (or so I'm told)
  • Birthday May 12

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  • Website URL
    http://home.netcom.com/~swansont

Profile Information

  • Location
    Washington DC region
  • Interests
    Geocaching, cartooning
  • College Major/Degree
    PhD Atomic Physics Oregon State University
  • Favorite Area of Science
    Physics
  • Occupation
    Physicist

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  1. If relativity effects are small, you can ignore them. The theory breaks down when you can’t.
  2. How are you defining efficiency? Power or energy? If quantum computing is developed and applied to the problems it’s designed for, it’s sort of an apples vs oranges comparison. The quantum computer can solve problems a traditional computer can’t (in a reasonable time) so it must be more efficient. IOW, if your traditional computer will take ~3 years to solve a problem a quantum computer can solve in a few hours, the QC can draw 1000x more power and still be more efficient, since it still takes ~1/10 the energy (1/10 of a day vs ~1000 days). If the TC simply can’t solve the problem, then an infinite supply of energy can be wasted.
  3. As Sensei points out, terminal velocity means that the height doesn’t matter once you’re high enough to reach it. IIRC an airman survived a fall from many thousand feet in WWII. No parachute, plane on fire. Hit tall pine trees and deep snow. (pause to search) #3 on this list https://www.oddee.com/item_96967.aspx
  4. It’s the basis for time dilation and length contraction. It does need to be separately applied to solve the problems, true, but that’s true of lots of models. What if no field is involved? But it’s not a function of field strength. It’s there for weak fields, and for particles that aren’t unstable. And they aren’t “just so” as they can be derived from the basic principles.
  5. What is the point of doing the integral over only part of the spatial extent?
  6. It was not clear to me that this is what you meant by uniform. As you note, it’s not physical. In that case, yes, the melt would happen all at once. But there would be no situation where you had a water-ice mixture, so it doesn’t seem relevant
  7. That's a misapplication of the theory. Your link seems to assume a little bit of background, but even so it refers to "the mixture" which implies a system which is fairly homogeneous (the contents as well as the heat source or sink). A situation like a single chunk of ice in a swimming pool doesn't qualify. One of the more dangerous things in science is applying a model while ignoring the assumptions that went into deriving it. It's how we get nonsense like "according to physics, bumblebees can't fly" or the confusion you have shown here. Localized application of heat would violate the notion of a homogeneous system. The interior of the ice could remain colder. Melting only happens at the surface.
  8. And how do you know I mean it in another way? The object acted in a way that was unusual. In particular, the way it was lit (this was before dawn), and to some extent how it moved (I couldn't tell how far away it was, because I didn't know how big it was). But, it being the Washington DC area and it was along a commuting route, I knew I wouldn't be the only one seeing it. The local news tracked it down; I imagine they had gotten calls. OK, so you want to use the word in a way that's unlike anyone else. Kinda defeats the purpose of language, though.
  9. There are many instances where it’s been confirmed that the witness was not lying about seeing something they could not unidentify, so to me this is a non-starter. I’ve seen a UFO. I was able to later identify it.
  10. It’s assumed to be close to equilibrium. That’s what the stirring would do.
  11. The dipole moment depends on the charge and the separation distance (p = qd), so it would be related to the electronegativity and the size of the molecule. https://en.wikipedia.org/wiki/Electric_dipole_moment
  12. It tells you something about the thermal conductivity. It depends on heat transfer properties, area and the heat capacity of the object https://en.wikipedia.org/wiki/Newton's_law_of_cooling#Rate-of-change_of_temperature-difference_version_of_the_law
  13. Why not both? A lot of what appeals to the base on the left is actually a moderate position. It's just being painted as extreme by the opposition. Raising taxes on the rich is undo-ing an extreme move. A 70% marginal tax rate on top earners, for example, is actually a moderate position, in that it was the norm (or even be considered generous) for a long stretch of time. See also: https://boingboing.net/2019/03/13/they-were-socialist-invader.html
  14. A short story about when I was in my postdoc at TRIUMF and we were trying to trap K-37 atoms. K-37 is radioactive with a short half-life and nobody know its exact spectroscopic properties (nobody ever had enough around to study it), so the laser frequency needed to do this was unknown. We had a rough estimate, but had to search more precisely. After doing so for a few days (continually - 24/7 experiment), we saw a glow from the trap. It went away when we tuned the laser by several MHz. But that wasn't enough to announce we'd trapped it, because we still had to do systematic tests to show that the only conclusion was that the signal was from the atoms. We had to confirm that it wasn't scattered light, or some weird behavior of the detector, or anything else that might account for the signal. Only after we had done that did we announce, and write the paper to say we'd trapped the atoms. That's the kind of rigor I expect. And that's not even an extraordinary phenomenon. There are few parallels in science for UFOs. It's not something you can do in a lab. It's not something you can model — even one-offs like supernovae or (more recently) black hole mergers, where you can't predict where and when they will happen, you can at least compare the data to a model. And with those, you have instruments that are tailored to investigating the phenomena. Partly because you know what kind of signals to look for, and you can look just about everywhere. Which leave a pretty large gap between the evidence that has been presented, and Klaatu and Gort landing on the mall in DC. And it doesn't help that the strategy in presenting evidence has been quantity instead of quality. If you're trying to convince someone, a bunch of lousy evidence probably isn't the way to go, because what's the motivation to sort through mountains of poor evidence?
  15. It means we want to see some actual quantum mechanics.
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