On Tuesday, July 14, 2020 at 10:32:59 PM UTC-6, Alan Grayson wrote: > > > > On Tuesday, July 14, 2020 at 4:27:35 PM UTC-6, Brent wrote: >> >> >> >> On 7/14/2020 2:36 PM, Alan Grayson wrote: >> >> >> >> On Tuesday, July 14, 2020 at 2:50:12 PM UTC-6, Brent wrote: >>> >>> >>> >>> On 7/14/2020 12:22 PM, Alan Grayson wrote: >>> >>> >>> >>> On Tuesday, July 14, 2020 at 11:31:42 AM UTC-6, Brent wrote: >>>> >>>> >>>> >>>> On 7/14/2020 3:34 AM, Lawrence Crowell wrote: >>>> >>>> On Monday, July 13, 2020 at 6:30:46 PM UTC-5, Alan Grayson wrote: >>>>> >>>>> >>>>> >>>>> On Monday, July 13, 2020 at 5:19:30 PM UTC-6, Lawrence Crowell wrote: >>>>>> >>>>>> On Monday, July 13, 2020 at 4:42:24 PM UTC-5, Alan Grayson wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Monday, July 13, 2020 at 1:42:49 PM UTC-6, Alan Grayson wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> 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 >>>>>>>> >>>>>>> >>>>>>> It's measured by observing the rotation rates of stars near the >>>>>>> galactic core, and not so small by comparison with other BH's at the >>>>>>> center >>>>>>> of galaxies, called Super Massive BH's. AG >>>>>>> >>>>>> >>>>>> It is unfortunately apparent that you are pretty highly confused by >>>>>> some of this. You need to sit down and read a comprehensive book or text >>>>>> on >>>>>> GR and related subjects. It is not going to be possible to clear this up >>>>>> with dozens of email posts. >>>>>> >>>>>> LC >>>>>> >>>>> >>>>> About the EP; I merely stated that it demonstrates that acceleration >>>>> is locally indistinguishable from gravity, and then I stated what >>>>> "locally" >>>>> means. This is what Wiki and other sources say. Yet you say I am >>>>> confused. >>>>> How so? About masses of BH's, I watch documentaries which feature >>>>> astrophysicists offering their opinions, and they *uniformly* claim >>>>> that BH's have mass. How could it be otherwise if they're remnants of >>>>> massive collapsed stars? Not one makes Brent's claim, that they're just >>>>> geometric manifestations. AG >>>>> >>>> >>>> I didn't say they lacked mass. I said they lacked matter. Thus >>>> countering your assumption that gravity requires matter. >>>> >>>> Brent >>>> >>> >>> I could have said that gravity requires mass/energy. What's the >>> distinction between matter and mass? TIA, AG >>> >>> >>> Some things, e.g. black holes, have mass without matter (at least as far >>> as GR goes). >>> >>> Brent >>> >> >> What's the distinction between matter and mass? AG >> >> >> What's your problem. Do you just want to argument semantics. I don't >> care if you want to call a black hole "matter", but nobody else does. >> Everybody else means localized packets of mass-energy in the form of >> fermions. >> >> Brent >> > > > Do I just want to argue semantics? No, of course not, But you seem to want > that. Otherwise, instead of trying to put me down, you could have just > assumed I meant MASS! IIRC, at some point above I did refer to E=mc^2, > which equates MASS with energy. AG >
But if I wanted to argue semantics, I could win! Can't fermions be considered "matter"? 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/26e863d3-997e-4af4-afa6-995ebc52e1d4o%40googlegroups.com.
