He also got angry when I told him I believed spacetime is positively curved. He said I should calculate the curvature tensor, since it would be zero if spacetime is flat. I responded, asking him why I should do that, since whatever I calculated, assuming I knew how to do it, wouldn't prove anything since the result would depend on my assumptions. He never replied -- a sad ending for me, for what I considered a friendship. AG On Sunday, February 16, 2025 at 10:07:58 PM UTC-7 Alan Grayson wrote:
> I'm sure you know him. RW. AG > > On Sunday, February 16, 2025 at 9:14:42 PM UTC-7 Brent Meeker wrote: > > What's his name? I still know a few people there. > > Brent > > > On 2/16/2025 6:07 PM, Alan Grayson wrote: > > > > On Sunday, February 16, 2025 at 3:33:29 PM UTC-7 Alan Grayson wrote: > > I got into a fairly heated argument with a Ph'D in physics from Brent's > alma mater, the University of Texas at Austin, concerning the construction > of the tangent vector space in GR. For this and other reasons we are no > longer in communication. He insisted on including particle paths of all > velocities passing through a point P on the spacetime manifold, aiming to > construct the tangent vector space at P. I objected since this would > violate one of the basic postulates of GR, which preclude particles assumed > to be exceeding light speed. I was berated for making such a criticism. > Initially I thought these faster than light speed particles were needed to > form a *vector space*, in order to satisfy the linear additive property > of a vector space under the field of real numbers. But suppose these > vectors are constrained to be added relativistically, so no pair when > added, can exceed light speed. Will this be sufficient to satisfy the > linear additive property of vectors in a vector space, without violating > the postulate of GR precluding faster than light speed particles? TY, AG > > > Since the LT is linear, I think it will work to restrict the velocities on > the tangent space to less than light speed. I'm puzzled why the physics > guru from the U of Tx adamently objected to my criticism and implied simple > fix for his obvious error. 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/16b0e331-f115-4264-9ed9-f2e7d679175fn%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/16b0e331-f115-4264-9ed9-f2e7d679175fn%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 visit https://groups.google.com/d/msgid/everything-list/b6aa804f-0273-4b6e-82c8-025a51074551n%40googlegroups.com.
