On Friday, June 20, 2025 at 3:32:22 PM UTC-6 John Clark wrote:
On Fri, Jun 20, 2025 at 4:19 PM Alan Grayson <[email protected]> wrote: *>>> **What Wheeler says is BS for the masses. Surprised you can't see it, or the issue I have raised.* *>> Are you also surprised that none of Wheeler's physicist colleagues can see the "issue" you have raised either? What exactly is the "issue" by the way? I thought you said the word "local" resolved your confusion.* *> I changed my mind* *You must've changed your mind and become re-confused just a few minutes ago. I wonder what your opinion will be a few minutes from now. * *> when I realized that separate observers in different enclosures, with different measuring devices, could reach different conclusions about finding tidal forces,* *If the enclosure was large enough, you would be able to detect tidal forces. * But you still need accurate measurements (depending on the magnitude of the tidal forces), a fact you earlier denied. AG *Do you really believe that Einstein and his colleagues weren't able to figure that out? * I haven't made any such claim. I suppose they were/are very happy with GR and the fact that the EP motivated Einstein to develop it, so I doubt they would have been troubled by the fact the P in EP is an overstatement of what it is. AG *It's also true that** the tidal force near a supermassive black hole would be very low, title forces wouldn't be strong enough to start tearing your body apart until after you have passed the event horizon.* *>I have no idea what Wheeler's colleagues think about this issue, nor does it really matter.* *Because you know far more about General Relativity than all the professors who have spent their entire careers studying it?* More abuse from you. Maybe you're not retarded; just abusive? AG * > **I think it leaves a lot of unresolved issues to claim that geometry alone explains motion for free falling objects, without specifying exactly how geometry interacts with material objects.* *But Einstein's field equation of General Relativity does exactly that! The equation is: * *G_μν = (8πG/c⁴)T_μν* *Left of the equal sign is the Einstein Tensor which describes the shape of spacetime which is geometry. And right of the equal sign is the Stress-Energy Tensor which describes the matter density, the energy density, the pressure, the stress, the tension. and the momentum flux; which are all material things. And "specifying exactly how geometry interacts with material objects" is what you asked for!* The equation does no such thing. It just tells you how to calculate one quality, curvature of spacetime, when you know the other (energy / matter distribution). It doesn't specify any physical process for the calculation it describes. AG *If I had to summarize what that equation is saying in just 12 words I would say "Matter tells spacetime how to curve. Spacetime tells matter how to move". * * > **At the end of the day, you seem to support the "shut up and calculate" school of thought, or philosophy. AG* *Speaking of philosophy, can you tell me of one new philosophical problem that General Relativity introduced that Newtonian physics didn't already have? I can't think of one. * Sure, that's easy; time dilation, length contraction, muon clocks, the fact that spacetime has curvature, etc. Oh, I can anticipate your response. These phenomena have nothing to do with "philosophy". AG *John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis>* efq -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/df03b6eb-3b9e-48ca-81cf-1bd9ff57a7e5n%40googlegroups.com.
