PAllen's latest activity
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PPAllen replied to the thread I Some confusion with the Binding Energy graph of atoms.I guess it is worth pointing out that if you have two nuclei with equal and opposite momentum collide perfectly and fuse, the initial...
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PJust think about that for a minute. You are standing by the road and a passing car turns on its turn indicator. How are you and the...
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PPAllen replied to the thread I The Einstein Clock aka Light Clock.Maybe it would help to imagine two flash bulbs, one in motion relative to the other. They both flash when one just passes the other. In...
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PPAllen replied to the thread I The Einstein Clock aka Light Clock.Let's stop right here. We will not get far by insisting that "we all must agree that 2 + 2 = 5". A given flash bulb (for example) has...
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PPAllen replied to the thread I The Einstein Clock aka Light Clock.I only have time for a quick reply now, just focusing on some issues with your first bullet: .. in the ship's inertial frame (assuming...
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PPAllen replied to the thread I Euclidean geometry and gravity.Well, arbitrarily close any horizon, irrespective of how mild the tidal forces are near the horizon of a supermassive BH, the...
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PPAllen replied to the thread I Euclidean geometry and gravity.From the thesis I referenced earlier is a notion of what embeddings are 'hard' versus 'easy'. 'Hard' implies you are likely only to get...
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PPAllen replied to the thread I Euclidean geometry and gravity.A smooth embedding is possible. Just try to think about a 2-sphere embedded in Euclidean 3-space. There is no curvature anywhere in the...
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PPAllen replied to the thread I Euclidean geometry and gravity.I found something right on point, but it is a thesis, so I don’t swear to its accuracy (I have not studied it in detail). Its results...
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PPAllen replied to the thread I Euclidean geometry and gravity.I don’t see that as relevant to the example. It was just to point out that there can be balanced forces unrelated to, and in different...
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PPAllen replied to the thread I Euclidean geometry and gravity.I assumed the beam was perpendicular to r, supported against gravity by external transverse force all along the bottom of the beam...
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PPAllen replied to the thread I Euclidean geometry and gravity.But I think the claim is simply that you can’t deduce balance opposing forces from proper acceleration; that doesn’t mean they don’t...
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PPAllen replied to the thread I Euclidean geometry and gravity.You can start here to look for references: https://en.wikipedia.org/wiki/Nash_embedding_theorems Also look at the Whitney embedding...
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PPAllen replied to the thread I Euclidean geometry and gravity.Yes, since you are looking for a cause of changed pressure. The final state by itself has no memory of how it originated.
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PPAllen replied to the thread I Euclidean geometry and gravity.Of course I meant number density and coordinate values. I note you haven’t commented on the second part of that post, which, to me...
