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PeterDonis's latest activity
PeterDonis
replied to the thread
A
Dirac's integral for the energy-momentum of the gravitational field
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What's clear to me from that comment is that the integral (31.4) is taken over a 3-volume at a particular time, not over a 4-D...
Sep 12, 2025
PeterDonis
replied to the thread
A
Dirac's integral for the energy-momentum of the gravitational field
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Where are you getting that from? All I see in his (31.4) is integrating over a 3-volume. A conserved "total energy" over a 4-volume...
Sep 12, 2025
PeterDonis
replied to the thread
I
A sufficient condition for integrability of equation ##\nabla g=0##
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Because the orthonormal tetrad fields ##e_a## that appear in his calculation don't commute in any spacetime other than flat Minkowski...
Sep 12, 2025
PeterDonis
replied to the thread
I
A sufficient condition for integrability of equation ##\nabla g=0##
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Correct math is the basis for valid physical models of our world, yes. But only correct math.
Sep 11, 2025
PeterDonis
replied to the thread
I
A sufficient condition for integrability of equation ##\nabla g=0##
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Yes. Now go read my post #58, where I point that out, and then point out something else. Again, go read my post #58. In particular, the...
Sep 11, 2025
PeterDonis
replied to the thread
I
A sufficient condition for integrability of equation ##\nabla g=0##
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So far I haven't seen you give any valid "explanation" of anything. I just see you continuing to show math that leads you to results...
Sep 11, 2025
PeterDonis
replied to the thread
I
A sufficient condition for integrability of equation ##\nabla g=0##
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@ergospherical's calculation in post #10 doesn't make that assumption. Indeed, I don't think that assumption is even consistent with his...
Sep 11, 2025
PeterDonis
replied to the thread
I
A sufficient condition for integrability of equation ##\nabla g=0##
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Then it can't possibly support the two wrong claims you're making. I never said @ergospherical's calculation was wrong. I only said it...
Sep 11, 2025
PeterDonis
replied to the thread
I
A sufficient condition for integrability of equation ##\nabla g=0##
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@ergospherical is not making the two wrong claims you are making. He's not claiming that the Levi-Civita connection has zero curvature...
Sep 11, 2025
PeterDonis
replied to the thread
I
A sufficient condition for integrability of equation ##\nabla g=0##
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Not if your reasoning doesn't make sense to me. Your answer is obviously wrong because your answer is that the Levi-Civita connection...
Sep 11, 2025
PeterDonis
replied to the thread
I
Hawking After 54 Years Confirmed: BH surfaces don't shrink
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Note that this law only holds if energy conditions on the matter are satisfied. In the case of black hole mergers being observed by...
Sep 11, 2025
PeterDonis
replied to the thread
I
A sufficient condition for integrability of equation ##\nabla g=0##
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You were given a link to a Wikipedia article that shows this way back in post #2 of this thread.
Sep 11, 2025
PeterDonis
replied to the thread
I
A sufficient condition for integrability of equation ##\nabla g=0##
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They're not equal in any spacetime other than the flat Minkowski metric, since the whole point of the teleparallel connection is to put...
Sep 11, 2025
PeterDonis
replied to the thread
I
A sufficient condition for integrability of equation ##\nabla g=0##
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No, it isn't. They're two different things. No, it isn't. The Levi-Civita connection has nonzero curvature in any metric that's not the...
Sep 10, 2025
PeterDonis
replied to the thread
I
Follow-up Einstein Definition of Simultaneity for Langevin Observers
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No. "The same Langevin worldline" means a worldline that's one of those at the radius you're working with.
Sep 10, 2025
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