network profile
| bio | website | |
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| age | ||
| visits | member for | 7 months |
| seen | May 17 at 4:46 | |
| stats | profile views | 101 |
I am a physicist,
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Apr 22 |
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Robot controling pouring process from a bottle it is a very complex problem involving turbulence, unless you can make the robot to start pouring slow enough at the beginning (but it might not help). My suggestion, is unless your thesis requires to use fluid mechanics, use some easier algorithm based of feedback instead, it will be simpler and closer to what a human do. |
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Apr 17 |
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Paradox with Gauss' law when space is uniformly charged everywhere thanks, now I've got it! |
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Apr 17 |
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Paradox with Gauss' law when space is uniformly charged everywhere I agree with you that it is "physically" impossible, or at least dependent on the physical process. But mathematically, you do not need to build anything, it reduces to a mathematical problem: give a space, a metric, some second order equations, and the problem should be either well defined or not. Apparently Newton's law does not define a well posed mathematical problem for the case of homogeneous density and infinite space. |
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Apr 17 |
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Is Newtonian gravity consistent with an infinite universe? @Chris thanks for the attempt, I'll answer my doubts below your answer. |
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Apr 15 |
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What happens at the interface between two universes with opposite thermodynamic arrows of time? assume the two universes are disconnected for most of their history, and become connected at some point in the middle for a finite amount of time (trough a wormhole?). It doesn't matter if you name it a single universe or two, what matters is that the thermodynamic arrow of time is in the opposite direction between them, at least when they are not connected |
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Apr 14 |
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What happens at the interface between two universes with opposite thermodynamic arrows of time? Thanks! I'll read it! |
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Apr 13 |
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Is Newtonian gravity consistent with an infinite universe? The best I could bet from the redirected question is this quote: "However, the mass can't be negative and the energy density is positive. This would force a violation of the translational symmetry in a uniform Newtonian Universe". It still doesn't give a satisfactory answer. For instance: how is that symmetry broken if we assume that there is no noise nor small density fluctuations in the system? How can you choose then the absolute "origin" that will break the symmetry? Still doesn't make sense to me. |
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Apr 11 |
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Is Newtonian gravity consistent with an infinite universe? Thanks, I'll try to find that, in the meantime is there any reference that you can give me? I would be very happy to accept your answer if that seems to be the mistake in my argument! |
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Apr 11 |
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Is Newtonian gravity consistent with an infinite universe? @Ben, I already mentioned homogeneity (I know the system is unstable). What I am not sure to understand and you could have a good point is that sums are not associative (and why are they not? I am not sure to understand that). But I am not sure on what part you apply that argument. |
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Apr 11 |
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Is Newtonian gravity consistent with an infinite universe? I thought about that, but in an infinite universe, event if euclidean, is translation invariant. And you can always define spheres as large as you want. Then what it is left outside, can also be divided into spheres. If I am not wrong, this is pretty common assumption when we make infinite integrals, either in math or in physics |
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Apr 11 |
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Is Newtonian gravity consistent with an infinite universe? Thanks! but I tried to make clear that I was only interested in a purely theoretical issue (which doesn't apply to our universe because it is not Newtonian). Plus no fluctuations. Think as if I had asked this question in Newton's time! |
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Feb 20 |
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Is it really possible to walk on water? the most common trick is the one mentioned by Nijankowski V.in his comment, transparent invisible catwalks just under the pool's surface. But dont get tricked, they had prepared the pool in advance, even if it looks not so. They make it look that they just got there by chance and started walking, but take him to another pool of your choice and he will sink! |
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Jan 27 |
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How does Boscovich's argument show that force must act at a distance? I am not that sure you can imagine that (I mean, you can assume it, but imagine it it is a bit different!) just remember what Kant thought about euclidean geometry |
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Nov 29 |
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How does Boscovich's argument show that force must act at a distance? you are right, a small deformation of the objects as they enter into contact is another plausible explanation to the apparent paradox (which arises from assuming totally rigid objects). Actually, the cloud of electrons deforms as they approach each other, so in this sense the compressibility explanation is not only another alternative, but one of the aspects of what actually happen |
