On Monday, July 13, 2020 at 11:57:50 AM UTC-6, Brent wrote: > > > > On 7/12/2020 11:50 PM, Alan Grayson wrote: > > There can be because it's consistent with the equations. A black hole >> doesn't include any matter. General relativity is non-linear, that's why >> there can be non-flat cosmologies that contain no matter. Of course there >> may be some different, better theory in which spacetime can't be curved >> without matter...but it seems unlikely since we have good evidence that >> gravitational waves exist. >> >> Brent >> > > Yes, good evidence that gravitational waves exist, but as far I know > they're always associated with material interactions such as collisions of > black holes. In the case of EM waves, I'd be more receptive of your claim > that they can exist independent of charges and/or currents, but as far as I > know there's no evidence of that. AG > >> > But a collision of black holes does NOT involve matter. Black holes (as > far as the theory goes) are purely geometric things, i.e. made of empty > space. > > Brent >
How then does the BH at the center of our galaxy weigh in at 4 million solar masses? 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 on the web visit https://groups.google.com/d/msgid/everything-list/fb7cfb37-313c-421f-aa6f-9a841db5b65fo%40googlegroups.com.

