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Alfred Centauri

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Alfred Centauri last won the day on May 24 2012

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  1. @bob333, if you're arguing that, according to Objectivism, it is improper for the government to stop person A from doing this to person B, either you think that (1) person A is not infringing the rights of person B or (2) you think that person A is infringing the rights of person B but that person A somehow has a right to do so. If (1), then you must show how it is possible that the actions of person A do not infringe the rights of person B when, on the face of it, they do. If (2), then you must show how it is possible to have a right to infringe rights when, logically, this seems impossible.
  2. First, make the distinction between the common usage of "altruism" and "ethical altruism". Ethical altruism is essentially the doctrine that we exist for the sake of others. Comte coined the term and wrote: The crucial point here is that justifying actions that benefit others on the basis that this will in turn benefit you is not proper in the context of ethical altruism. According to ethical altruism, you are obligated to serve others regardless. An argument that you ought to act in a way that benefits society for the reason that you will receive long term benefit is an inherently egoistic argument, not altruistic. Second, keep this Rand quote handy:
  3. The question in the abstract is not particularly interesting to me but what is concerning to me is the misrepresentation of the actions of characters in the novel. There's too much false information already "out there" and I certainly don't expect it here. Wyatt invented a process to extract oil from "exhausted" wells. Whatever oil he burned was recovered through that process (how else would it have been available to burn?) and was his to use or to dispose of. So the answer to your question "Did Wyatt have a right to torch the oil [that his process of extraction made available] on his land" is yes, he did.
  4. In the novel, Wyatt did not destroy the immense reserves of the oil that he had not extracted from the "exhausted" wells, period. Those reserves were left intact, in the ground, just as they were before he began extracting from them. Are you seriously suggesting otherwise?
  5. As I read (and hear) it, Wyatt did not destroy the oil, he destroyed his property that he used to extract the oil. He left the message: "I am leaving it as I found it. Take over. It's yours." The oil shortage that followed wasn't because Wyatt destroyed the oil, it was because the government "scientists" were unable to understand and recreate the method Wyatt invented for extracting the oil. "... You see, it is a matter of reconstructing the special method of oil extraction what Wyatt had employed. His equipment is still there, though in a dreadful condition; some of his processes are known, but somehow there is no full record of the complete operation or the basic principle involved, That is what we have to rediscover." .. "Have you produced any oil?" "No, but we have succeeded in forcing a flow from one of the wells, to the extent of six and a half gallons."
  6. With respect to the extension of fundamental particles, we have to keep in mind that the only way to "probe" a fundamental particle is with... a fundamental particle. That is, we cannot, even in principle, determine the spatial extent of a fundamental particle with arbitrary precision. Why? This is related to Grames comment about infinite energy density but it doesn't require the density to be infinite. In order to probe smaller and smaller regions of space, we need fundamental particles with larger and larger energy. If I'm not terribly mistaken, there is a limit to how energetic our probe, e.g., a photon, can be and that limit is when the wavelength of the photon is of the order of a Planck length. To quote, gulp, Wikipedia: Because the Schwarzschild radius of a black hole is roughly equal to the Compton wavelength at the Planck scale, a photon with sufficient energy to probe this realm would yield no information whatsoever. Any photon energetic enough to precisely measure a Planck-sized object could actually create a particle of that dimension, but it would be massive enough to immediately become a black hole (a.k.a. Planck particle), thus completely distorting that region of space, and swallowing the photon. The point here is that, if we accept that our current physical theories apply at this scale, there is simply no physically meaningful way to speak of spatial extent "smaller" than a Planck length.
  7. It is, unfortunately, the case that, as usual, media can't seem to get their science anywhere near right. CCC does not claim that "the current universe will condense again and re-ignite another big bang". Penrose is very clear on this in his book and, in fact, goes to great lengths to distinguish CCC from other "oscillating universe" theories. Yet, in this recent article, we read: The research by Penrose, who was awarded the 1988 Wolf Prize along with Stephen Hawkings for adding to our cosmic knowledge, adds evidence to the theory that the universe has expanded ('the Big Bang') and contracted ('the Big Crunch') many times. No, in CCC, Penrose identifies the "big bang" of an aeon with the remote future expanded state of the previous aeon. No "big crunch" and he explains why very clearly in his book. If you don't want to buy it, then read this. Physically, we may think that again in the very remote future, the universe “forgets” time in the sense that there is no way to build a clock with just conformally invariant material. This is related to the fact that massless particles, in relativity theory, do not experience any passage of time. We might even say that to a massless particle, “eternity is no big deal”. So the future boundary, to such an entity is just like anywhere else. With conformal invariance both in the remote future and at the Big-Bang origin, we can try to argue that the two situations are physically identical, so the remote future of one phase of the universe becomes the Big Bang of the next. This suggestion is my “outrageous” conformal cyclic cosmology”
  8. http://en.wikipedia.org/wiki/Conformal_Cyclic_Cosmology I've got his book "Cycles of Time". It's a fascinating read.
  9. I would expect that taking a longer path would also result in taking more time to travel You're not thinking "relativistically", i.e., in terms of spacetime. You're thinking in terms of paths in space rather than in terms of paths in spacetime. Research "spacetime interval" and take some time to think it through. It will become clear but developing a relativistic intuition takes time. Regarding force: are you familiar with the term "fictitious force"? Essentially, a genuine force cannot be "transformed away" by a coordinate transformation whereas a fictitious force can. Fictitious forces arise in accelerated coordinate systems. In GTR, it is always possible to find a coordinate transformation in which the spacetime of the (infinitesimal) neighborhood of an event is flat, i.e., in which there is no curvature, i.e., in which the gravitational field is zero. In other words, it is always possible to "transform away" the gravitational "force" with an appropriate coordinate transformation. For that reason, within the context of GTR, gravity is not a genuine force.
  10. On a Riemmanian manifold, a geodesic is the shortest path. However, spacetime is a Lorentzian manifold, i.e., the norm of a 4-vector in spacetime is not positive definite so a Lorentzian manifold is a pseudo-Riemmanian manifold. Don't forget, the "distance" between events in spacetime is a combination of distance through space and "distance" through time. And, the distance through time carries a different sign than distance through space. Because of this sign difference, a (timelike) geodesic is a path of largest elapsed time. Anyhow, if you had Googled "geodesic general relativity" instead, you might have found this at Wikipedia: A geodesic between two events could also be described as the curve joining those two events which has the maximum possible length in time — for a timelike curve — or the minimum possible length in space — for a spacelike curve. Actually, this should not be surprising if you are at all familiar with STR and the so-called "twin paradox". The twin that takes the ride on the spacecraft must reverse direction, i.e., must accelerate, to return to home while the twin that stays at home does not. As a result, the twin that stays at home is older (more time has elapsed) than the twin that returns to Earth.
  11. There is a technical reason why gravity cannot be a force as force is understood in physics. The following is a bit technical but, for what it's worth... Associated with a force field is a potential. In the case of Newton's theory, the gravitational force is associated with a scalar gravitational potential. In the case of Maxwell's theory of electromagnetism, the electromagnetic force is associated with a 4-vector potential (the scalar electric potential and the vector magnetic potential are components of a 4-vector). If we wish to model gravity as a force in a Lorentz covariant way, i.e., in a way that is compatible with STR, we find the following: (1) A gravitational force field from a scalar (spin 0) potential (where the potential couples to the invariant mass-energy) does not bend light. (2) A gravitational force field from a 4-vector (spin 1) potential (where the potential couples to a 4-current as in EM theory) predicts that waves in the gravitational field carry negative energy and, like the scalar theory, does not bend light. (3) A gravitational force field from a 4-tensor (spin 2) potential (where the potential couples to the stress-energy tensor) that does bend light and has positive energy gravitational waves doesn't mathematically exist, i.e., the theory is self-inconsistent. Ultimately, in trying to fix (3), one is led to GTR. Loosely speaking, the difficulty is that a linear theory of gravity as a force field in spacetime doesn't exist because a gravitational field, possessing energy and momentum, must itself gravitate! If you add a term to account for this in (3), you find that you must add another and another and another ad infinitum. When you "sum" this infinite series of corrections, you get the equations of GTR. A related problem occurs when one tries to quantize a spin 2 field in the same way that the EM (spin 1) field was quantized. Essentially, to renormalize a spin 2 field requires an infinite series of infinite counter terms which means that the theory would require an infinity of parameters!
  12. I've come across so many places where gravity is still referred to and treated as a force In the non-relativistic limit, gravity "looks" like a force so it's OK to consider it a force in most contexts. However, at cosmological scales, we leave the non-relativistic regime and, in that context, gravity is not a force. If I'm understanding what you said about "world-lines" correctly, another way to put it would be that the path traveled by an object in free fall is the same as it would be if the object were not accelerating at all. Is this correct? Understood properly, the above is correct. However, I suspect that you don't understand this properly. First, let's be sure we understand "free-fall" in the context of GTR. An object in free-fall is free from any external force (and remember, gravity is not a force in the context of GTR). Between any two events (points) in spacetime, there are an infinity of possible world lines that include those events. One of those possible world lines is special in the following way: the elapsed time between the two events along that world line is larger than any other, i.e., that world line is the geodesic connecting the two events. Originally, Einstein postulated that the world line of an object free from external force is a geodesic but it turned out that this actually follows from the equations of GTR. The world line of an object in free fall (free from external force) is a geodesic, i.e., path of largest elapsed time. Second, let's be sure we understand acceleration in the context of GTR. In particular, the relativity of acceleration due to gravity. In the Special Theory of Relativity (STR), acceleration is absolute. If an inertial observer observes that the motion of an object changes with time, it is the object that is accelerating. When it comes to acceleration due to gravity, however, things are not so clear. Imagine two spacecraft in deep space with an astronaut in each. Both astronauts observe that the relative motion between their spacecraft is changing with time. In one spacecraft, the astronaut observes that his accelerometers all read zero while the other astronaut observes that one of his accelerometers is non-zero and that his rocket engine is on. Within STR, we can say absolutely that the later astronaut's spacecraft is accelerating while the former astronaut's spacecraft is not accelerating. But, in GTR, it is the case that the later astronaut can equivalently claim that his spacecraft is at rest in a uniform gravity field (by virtue of the fact that his engine is on and thrusting in the direction opposite that of the field) and that it is the other spacecraft that is accelerating under the influence of the gravity field. So, back to your question: another way to put it would be that the path traveled by an object in free fall is the same as it would be if the object were not accelerating at all. Is this correct? If, by acceleration, you mean acceleration due to a force (and remember, gravity is not a force) then yes, you are correct. If, however, you mean acceleration due to gravity, then the phrase "not accelerating at all" is, as my two spacecraft example shows, ambiguous.
  13. Only a little? OK, the short version. In the context of the General Theory of Relativity (GTR), gravity is the curvature of spacetime and not a force in spacetime. The world-line (path through spacetime) of objects in free-fall are geodesics of the spacetime; the path through spacetime of an unaccelerated object. This explains why, in free-fall, no weight is felt, i.e., we feel no acceleration, no force, no "gravity". In the context of Newtonian gravity, there is inertial mass (resistance to acceleration) and gravitational mass (gravitational "charge", the source of the gravitational "force"). There is no reason for these two very different properties to be equal in Newtonian gravity but, observationally, they are. GTR neatly solves this unlikely and unexplained coincidence.
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