On Wednesday, February 20, 2019 at 12:16:31 PM UTC-7, Brent wrote: > > > > On 2/20/2019 8:42 AM, [email protected] <javascript:> wrote: > > > > On Wednesday, February 20, 2019 at 7:09:10 AM UTC-7, John Clark wrote: >> >> >> >* Newton "explained" * >> >> >> Why did you put explained in quotation marks? If you can predict what >> something is going to do then you've explained it, the better the >> prediction the better the explanation. I don't know what else the word >> could possibly mean. And in science no explanation is perfect, but some are >> less wrong than others. >> > > *QM better illustrates the justification for quotes. Many interpretations > that make the same predictions. AG * > >> >> *> why a body at "rest" can start moving, via the application of "force"* >> >> >> And Einstein explained that a body moving in a geodesic through 4D >> spacetime will take a path that is not a geodesic if a force is applied. >> The Earth is moving in a straight line (aka a geodesic) through curved >> spacetime; the reason Earth's orbit looks elliptical to us is due to map >> distortion, the same reason that in a flat map of the curved surface of the >> Earth Greenland looks larger than South America and is almost as large as >> Africa. Except that it's even worse, in one we're projecting the 2 D >> curved surface of the Earth into the flat 2D surface of the map, but with >> Einstein we're projecting a curved 4D volume into a flat 3D volume. >> >> *> What does "rest" mean in GR * >> >> >> In General Relativity moving in a geodesic is as close as you can get to >> the traditional idea of rest, but as long as time passes you're going to be >> moving through 4D spacetime. >> > > > *If you're at spatial rest in spacetime in the presence of a gravitational > source, how does GR explain the subsequent spatial motion? AG * > > > When you were at "spatial rest" you had a force applied to you. Removing > it allowed you to follow a geodesics path through spacetime....also known > as "falling". > > Brent > > *So it seems that GR doesn't explain motion; rather, it assumes motion is a natural state of things. AG *
> >> *> what causes "motion" from that pov?* >> >> >> Force, same as with Newton. >> >> John K Clark >> > -- > 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 post to this group, send email to [email protected] > <javascript:>. > Visit this group at https://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > > > -- 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 post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
