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About KipIngram

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  • Birthday 01/10/1963

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    Houston, Texas
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    Photography, history, science, digital privacy, beer brewing, genealogy, astronomy, cycling, movies / books, ...
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    PhD - Engineering, The University of Texas at Austin, 1992
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    Senior Engineer, IBM

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  1. I'm not really familiar with the circumstances of this case, but I ran across some interesting statistics the other day. In 2015 the Washington Post estimated that there were 350 million firearms in the US. That same year, the Centers for Disease Control reported that approximately 36,000 individuals died from gunshot wounds. I can't help noting that this implies that 99.99% of all firearms in the US in 2015 were not used to kill someone. A better analysis would include non-fatal gunshot wounds as well, but I didn't see that data. At any rate, it seems clear that the vast majority of
  2. Right - it was for the other angles (say, like 30 degrees off from the preparation angle) where he said there would be a superposition. For example, say we prepare at angle 0, then measure at angle 30. He said we'd then get a superposition of the 30 degree and 210 degree states (though he didn't say it like that). Just that we might get "no photon," which would imply the measured system aligned with the measurement field, or "full photon," would would imply it was 180 degrees out from the measurement field. I hope I'm describing this well enough - if anything sounds off the problem
  3. Hi guys. First, studiot, he said to neglect everything else about the electron and consider only it's spin - basically he said "imagine it's nailed down so it doesn't get away from us." Next, swansont, he did say that if we'd prepared the the electron in a certain direction, then there was 0% probability of finding it at 180 degrees to that preparation. He said if we re-applied the same magnetic field we'd used to prepare it, we would never get a photon, and that if we applied a field at 180 degrees to the original, we would always get a photon. Then if the measurement field was at any
  4. Ok, so I've been watching the lectures Leonard Susskind gave at Stanford that are available on the internet. He described a superposition of states sort of along the lines below. For purposes of this discussion we're assuming the position of the electron is "pinned down" somehow so that all we have to consider is spin. 1) Prepare the electron by applying a strong magnetic field. This will align the electron's magnetic moment with that field. I don't care whether a photon is emitted in this step or not - this is the preparation phase. 2) Now remove the preparation field, and apply
  5. Thanks, swansont. I thought so - just wanted to make sure I wasn't totally overlooking something subtle.
  6. Often I encounter materials online that motivate the mental picture of quantum uncertainty by describing it primarily as a measurement error. "Electrons are small, so to "see" them we have to use light of very small wavelength. But photons of such light have a lot of energy, and so necessarily disturb the momentum of the electron severely." Etc. I tend to find such descriptions very unsatisfying - they imply that the electron actually has both position and momentum, but that we are just unable to measure them both simultaneously because by making the measurements we disrupt the thing b
  7. Maybe it will help if I try to identify where I think my misunderstanding might be. After thinking about this, I believe I have assumed that it is necessary for a quantum of energy to reside in only one mode of a field - that if an entity is "many modes," as is necessary for it to be physically localized, it is of necessity many quanta. But this morning I'm thinking maybe that's wrong - maybe the two things have nothing to do with one another. Maybe a single quantity can still be a superposition of many modes, any one of which might be the one sampled by a momentum measurement, for instance
  8. I'm not sure my question is coming clear here. I already did understand the fact that in the real world there's never a perfect, infinite sinusoidal mode, and that all real wave patterns are combinations of sinusoids such that they do not extend to infinity and so on. The math nuances of Fourier theory I think I already understand fairly well. Let me try again. I've read many descriptions of experiments over the years (let's use the double slit experiment as a reference point), where mention is made of lowering the intensity of the beam until only single quanta move through the appara
  9. Hi swansont. Yes, that makes sense, but some of the discussions here on QFT led me to believe that's exactly what QFT field modes were - fully space-filling, sinusoidal structures that changed everywhere instantaneously when that mode gains or loses a quantum. I thought when a QFT field absorbed a quantum, that quantum was present everywhere in space per the shape of that particular mode. I admit I'm very weak in all of this still, though, and your comment furthers my feeling that I'm missing some important piece of all of this.
  10. Hi Rob. Thanks for the reply. Since reading Hobson's paper "There are no particles, there are only fields" I have, in fact, been operating with that as a working assumption. So references to particles and fields aren't quite in my thought sphere right now. Hobson describes arguments that assert the mere existence of an entity we could properly call a "particle" is incompatible with the combination of quantum theory and special relativity. I find those arguments compelling, and am willing to operate for now on the presumption that everything is fields. Schrodinger's paper pursued the same
  11. Hi guys. I've been away for a while - busy with work and family and so on, and I also got a little weary of the political and social narrow-mindedness that comes up here sometimes. But the quest continues - I've still been prowling the internet for good papers on quantum theory and so on. A few days ago I ran across Schrodinger's original 1926 paper, where he lays out quantum theory from ground zero, rather than via given axioms like most modern treatments use. I've found the connection with optics to be a VERY helpful mental image. So, if we start from the beginning and presume that
  12. Correct - the quotient of any two rational numbers is always a rational number. Say we have r1 = a/b and r2 = c/d, where a..d are integers. That's the definition of a rational number (quotient of two integers). So now r1/r2 = (a/b) / (c/d) = (a/b) * (d/c) = (ad)/(bc). The products ad and bc are both the products of integers, and thus are integers. The quotient of those two products is thus a rational number. The previous answers point out the misstep in your original reasoning.
  13. Well, I think there's truth in those words, but caution is in order. On the one hand, you have people like Einstein, whose imagination leads them to things that turn out to be right. Then on the other hand you have people who uncork the most ridiculous things. I don't think Einstein's words should be taken to defend anything that someone coughs up, because some people's imagination leads them thoroughly out into the weeds. I have no doubt that Einstein's imagination tended to stay "in bounds" because he also had knowledge. So I absolutely do not think he was saying "imagination is all
  14. It is a mess, and the software industry is as well. A large fraction of working programers don't, in fact, have familiarity with what's really going on under the hood of the systems they work on and also don't have familiarity with those "core" things I mentioned, like algorithm theory, basic data structure concepts, and so on. A lot of programming these days involves relying heavily on software libraries that hide all of that, and which have their own bugs and quirks which the programmer is likely unfamiliar with. On top of that, a lot of the day to day work involves either modifying softw
  15. There are components of a (good) computer science education that don't change. Algorithm complexity theory, data structures, standard classic algorithms like searching, sorting, hashing, and so on - those things don't change as technology changes. Proper application of them depends on the underlying technology, and so that changes. You are right up to a point, though - languages come and go, hardware changes, and so on - the usefulness of knowledge of that sort is ephemeral.
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