On Saturday, July 11, 2020 at 5:05:02 PM UTC-6, Brent wrote: > > > > On 7/11/2020 12:54 AM, Alan Grayson wrote: > > > > On Tuesday, July 7, 2020 at 10:06:44 PM UTC-6, Alan Grayson wrote: >> >> >> >> On Tuesday, July 7, 2020 at 8:50:50 PM UTC-6, Alan Grayson wrote: >>> >>> >>> >>> On Tuesday, July 7, 2020 at 8:05:28 PM UTC-6, Bruce wrote: >>>> >>>> On Wed, Jul 1, 2020 at 4:18 PM Alan Grayson <[email protected]> >>>> wrote: >>>> >>>>> How, exactly, is the Principle of Equivalence used by Einstein to >>>>> develop GR? TIA, AG >>>>> >>>> >>>> >>>> This lecture by Sean Carroll should answer all your questions: >>>> >>>> URL: https://wp.me/p2WMeM-3vl >>>> >>>> Bruce >>>> >>> >>> I'll watch it tonight, but I think I've figured it out; specifically, >>> the EP implies space-time is curved by the presence of mass/energy (and >>> this is independent of the need to express the laws of physics in a >>> coordinate independent way via tensors). AG >>> >> >> Here's my reasoning regarding the EP; if an observer is in a box subject >> to uniform acceleration, a beam of light starting on the extreme left side >> (moving transverse or perpendicular to the acceleration vector), will hit a >> lower point on the right side, showing that uniform acceleration results in >> curved paths in space-time. But if this result is identical to gravity, >> locally, it means that curved paths in space-time are produced by, or are >> equivalent to gravity. >> > > That makes no sense. You're saying that because curved paths can be > produced two different ways then they must always be produced the second > way. > > > BUT gravity is only observed in the presence of mass/energy. ERGO, the EP >> implies mass/energy curves space-time. AG >> > > And that's not even true. Gravitational waves can propagate thru the > vacuum. The Schwarzschild solution is for empty space. De Sitter space is > an empty cosmos. >
Light can propagate through empty space, but it can't arise from nothing. Same presumably for gravitational waves. AG > > Brent > > > For Bruce; so far I've gotten about two-thirds through Carroll's video. > Will complete it this weekend. I sense a flaw in GR, suggested by the > inclusion of G, the gravitational constant. How can a constant inferred > from an approximate theory of gravity, Newton's Theory of Gravitation, be > included in a presumed perfect theory of gravity, General Relativity? Don't > you think something very subtle is awry here? 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] <javascript:>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/ffbbc9e9-1ba7-4410-8009-d76cf4ec12e6o%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/ffbbc9e9-1ba7-4410-8009-d76cf4ec12e6o%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > > -- 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 on the web visit https://groups.google.com/d/msgid/everything-list/793952a7-da65-47aa-aa41-256deeceac8eo%40googlegroups.com.
