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DrRocket

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Everything posted by DrRocket

  1. neither Go read Foundations of Analysis by Landau.
  2. [math]\int \frac{dy}{4y} = \int \frac{dx}{x} \Rightarrow \frac{1}{4} ln{\mid y \mid} = ln{\mid x \mid} + c [/math]
  3. If you find yourself catching up and actually understanding owl, then may I suggest that you immediately seek competent professional help.
  4. The key to effective application of mathematics in any field, physics included, is precision. In fact the approach as you stated it makes very little sense, and if taken as you state it, would result in nonsense-- trying to base a power series at (m+dm), whatever that is supposed to mean. So while the OP may know what he intends to do, your suggestion only muddies the waters and would confuse any innocent lurker. I is generally better to say what you mean and mean what you say than to speak in riddles and hope the listener can puzzle out something that makes sense.
  5. Maybe you learn what the theory actually says and not rely on your feelings. You have written quite a bit and not one iota of it is either correct or makes any sense at all. Pure gibberish. You might be "on your way" to understand it, but you have progressed no more than a couple of inches on a journey of thousands of miles. It rather appears that you are going backwards, as most of what you "know" is false.
  6. Quantum mechanics is not based on the uncertainty principle. That is a necessary part of the theory but hardly the basis. Special relativity actually requires two postulates, and the invariance of the speed of light is one. The other is the invariance of the equations of physics in all inertial reference frames. While the equivalence principle gets a lot of press, and it was philosophically useful to Einstein, it is not the true basis of general relativity and in fact it is pretty much logically irrelevant in modern treatments of the theory. One key problem with string theory is that no one really knows what it is. There are deep conceptual issues associated with quantum field theories, but they pale in comparison with the issues in string theory. Another problem is that string theory has yet to produce a single new testable prediction. It may eventually become a viable theory of nature, but it is quite far from any such status at this time. But the biggest problem with string theory is the totally unsubstantiated assertions made by some proponents in popularizations -- statements that they could never get away with in from of a knowledgeable and critical audience.
  7. Yes. I know that my e-mail to a mathematician was culled out by the spam filter when I e-mailed him that I was in town and would stop by for a visit. It was not that he ignored it, but that he never saw the e-mail. That was more than confirmed when I saw him. (He has since fixed the filter.) Snail mail, the telephone or just dropping by in person are more likely to be successful.
  8. http://en.wikipedia.org/wiki/Two-photon_physics
  9. True, but that is your personal problem. Go read the book.
  10. Your misconceptions and misrepresentations are too numerous to merit individual consideration. Go read the damn book.
  11. Get a beter book. Read it, as often and as slowly as necessary, and understand it this time. I like quantum mechqnics just fine, thank you very much. What I have no use for is the crap that constitutes your understanding of quantum theory. Read a real book. For something accessible and written by one of best quantum theorists ever, try volume 3 of The Feynman Lectures on Physics.
  12. Look at swansont's links. To add to that you need to note that analog signals operate on one of two methods of modulation -- amplitude modulation (am) or frequency modulation (fm). The 98.5 MHz which you reference is the carrier frequency, and it is the carrier frequency to which a radio receiver is "tuned". But the actual signal is not a pure sinusoid, due to the modulation. It is via the modulation that information is encoded on the signal. A radio receiver does two primary things. First it isolates one signal from among many by means of tuning to a band centered on the carrier frequency. Second it recovers the information from the modulated signal and converts it to a signal at audible frequencies that is used, after amplification, to drive a speaker of some sort. For more information you can consult electrical engineering texts on signal analysis or communication theory. Howevr, be aware that such texts assume a facility with linear system theory and in particular with the use of the Fourier Transform. The Fourier Transform is particularly important since virtually all of communication theory work is carried out in the "frequency domain" (i.e. the time domain differential equations are converted to algebraic equation in the frequency domain by means of the Fourier Transform). One text that you might consider is Modern Digital and Analog Communication Systems by B.P. Lathi.
  13. And if you did you would likely die. That would be really dangerous. Thermite in a pile on a lab table under controlled conditions is one thing. Thermite powder in a connfiguration in which it could be dispersed and ignited is quite another.
  14. Your two equations are equivalent. They are also equivalent to PV=nRT.
  15. String theory does not really predict the extra dimensions. Rather the theory requires the extra dimensions else it is demonstrably not self-consistent. One problem is that no one has yet really been able to clearly define what string theory is. But apparently, whatever it is, it requires extra spatial dimensions -- the precise number being dependent on the particular string theory or M-theory. As far as prediction go, string theory has yet to produce a testable prediction. Maybe someday it will, and maybe someday it will become a viable physical theory. But this is not that day. Analogies are pretty useless with string theory. It is a VERY abstract and mathematical theory.
  16. Maybe if you draw a Venn diagram you can see an answer. You are looking for everything that is in two of p,q, and r but not in all three.
  17. This is absurd. Learning science requires more than reading comic books and posting inane questions the responses to which you ignore. You need to get past pop-sci and buzz words that you don't understand and learn some real physics. I suggest that you start with The Feynman Lectures on Physics by Feynman, Leighton and Sands More gibberish. Now go read a book.
  18. But it doesn't make much sense mathematically. A Taylor series is normally spoken of as "expanded around a point" . In this case you want to expand the series arount the point m. It makes little sense to expand f(m+dm) around 0, when in fact the radius of convergence when expanded near zero may not even include m. Since we are talking about, in essence the reciprocal of the square root, it will not even be expandable around 0. It blows up near 0.
  19. Of course a single atom has an average kinetic energy. When you average over a single data point, that point IS the average. However, what you are grasping to say is that temperature is normally used to describe the statistical behavior of a large number of particles, and hence temperature is not really germane to the description of a single particle. Also you have to be rather careful when considering a single particle, as kinetic energy is a frame-dependent quantity. In statistical thermodynamics, it is implicitly assumed that one is working in a reference frame in which the net momentum of the system of particles under consideration is zero. In engineering thermodynamics (which considers open systems as well as closed systems) one has to be careful to specify what means by "temperature" so when gas dynamics enters the picture you have "stagnation temperature" or "static temperature" and the two can differ by literally thousands of degrees in problems of practical interest. You are also confusing the general, classical kinetic theory with quantum theory. They are not the same thing and the classical theory does not consider quantum effects. That is simply not true. The internal energy of a monatomic gas, like hydrogen, in classical statistical thermodynamics is just the translational kinetic energy, and it is very easy to pick a reference frame in which the energy of any single atom is zero. When you invoke quantum theory the situation is a bit more muddy. In fact at the quantum level the notion of kinetic energy as distinct from potential energy rather loses meaning. In fact "motion", given the uncertainty in position, is not particularly well-defined. What you have are quantum states, and "energy" is part of what is necessary to define a quantum state. Nope. You are trying to impose classical notions on quantum mechanics. That doesn't work. This makes no sense. Of course a measurement is different from a particle. A measurement is not a physical thing, but rather is an action taken by someone. It is also true, and equally relevant, that a horse is not a political principle. It is you, not others, who is not recognizing what is going on. You are also confusing the second law of thermodynamics -- which in one form states that no system not already at absolute zero can reach absolute zero in a finite number of thermodynamic steps -- with the idea that "0K is impossible". The concept of absolute zero is crystal clear -- either in the abstract language of classical thermodynamics or in the slightly more concrete language of quantum mechanics in which it is the lowest possible energy state of a system (which by the Pauli exclusion principle is not a state of zero energy).
  20. The question as to the mechanism that results in the observed asymmetry in abundance of matter and antimatter is not completely settled. However, it is generally believed that it is the result of the known violation of CP symmetry in quantum field theories. http://en.wikipedia.org/wiki/CP_violation
  21. Expand the inverse of the square root as a (truncated) Taylor series, around the fixed point [math]m[/math] that is your mass. That gives you [math] f(m)[/math], once you have accounted for the constants in your equation. Then look at [math] f(m+\Delta m) - f(m)[/math] for small values of [math] \Delta m[/math]. The number of significant figures will be determined by the value of [math]m[/math] and the number of terms in the truncation of the Taylor series.
  22. You can't without more information. A LOT more information. To get a force-time curve you would need to know, in gory detail, the properties of each and every material in the car and the specific geometry of each and every part. Even then it would require a very complex computer code to handle all of the dynamics and material response calculations. The guts of the problem is the time duration that you don't have, but to be absolutely correct the force will not be constant over any period of time, so the time duration would only allow you to calculate the time-averaged force, if you calculated the mass (which with velocity gives you momentum which is force x time ) from the given kinetic energy.
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