On Tuesday, May 27, 2025 at 12:37:00 PM UTC-6 Brent Meeker wrote:
On 5/26/2025 10:16 PM, Alan Grayson wrote: On Monday, May 26, 2025 at 11:07:03 PM UTC-6 Brent Meeker wrote: On 5/26/2025 9:29 PM, Alan Grayson wrote: On Monday, May 26, 2025 at 7:44:59 PM UTC-6 Brent Meeker wrote: On 5/26/2025 2:51 PM, Alan Grayson wrote: On Monday, May 26, 2025 at 5:57:36 AM UTC-6 John Clark wrote: On Sun, May 25, 2025 at 3:33 PM Alan Grayson <[email protected]> wrote: *> I'm disagreeing with anyone, including you, who thinks the EP is an absolute, when in fact it's a relative, an approximation.* The Equivalence Principle, which is the foundation of General Relativity, states that at sufficiently small scales there is no way to tell the difference between a gravitational field and a simple acceleration. And it is not an approximation. But is it always correct? That is not certain because General Relativity does not take Quantum Mechanics into account, nevertheless so far at least the Equivalence Principle has easily passed every experimental test put to it. *Since the EP depends on measurement accuracy, it's mischaracterized as some absolute principle. That's pretty obvious regardless of contrary opinions, including Einstein's. AG * It was just an inspiring idea that Einstein had. It didn't need to have three digit accuracy. Brent *Sure, but inspiring how, in what way? No one seems able to put some beef on this. AG * He saw that gravity didn't need to be treated as a force, it could be treated as force-free motion in non-flat spacetime. This explained why all objects, whatever the material, fall with the same acceleration, something already determined experimentally by Baron von Etvos. It's sometimes referred to as inertial mass = gravitational mass. Brent *Interesting, TY, but does GR explain the acceleration? AG* I just wrote, "This explained why all objects, whatever the material, fall with the same acceleration,.." Brent *Change in position must occur because (I conjecture) geodesic motion depends on time, which is always incrementing. Doesn't this imply that every test particle has its own clock, or there's a universal clock which every particle can read? And why does acceleration exist; because the velocity vector changes direction due to the curvature of spacetime? TY, AG* -- 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/f191288f-9134-4c2a-a786-225e505a74a2n%40googlegroups.com.
