On Friday, February 22, 2019 at 11:28:50 PM UTC-6, agrays...@gmail.com wrote: > > > > On Friday, February 22, 2019 at 9:12:02 PM UTC-7, Bruce wrote: >> >> On Sat, Feb 23, 2019 at 3:08 PM <agrays...@gmail.com> wrote: >> >>> On Friday, February 22, 2019 at 8:13:21 PM UTC-7, Brent wrote: >>>> >>>> On 2/22/2019 6:04 PM, agrays...@gmail.com wrote: >>>> >>>> On Friday, February 22, 2019 at 4:55:41 PM UTC-7, Brent wrote: >>>>> >>>>> >>>>> >>>>> On 2/22/2019 2:40 PM, agrays...@gmail.com wrote: >>>>> >>>>> Gravitons, as quanta of the metric field, are already relativistic >>>>>> particles and covariant. >>>>>> >>>>> >>>>> *I thought it's the equations of motion for the particular force, not >>>>> the mediating particles, that must be covariant. On a related topic for >>>>> this thread, where does GR depart from Mach's principle? That is, what >>>>> did >>>>> Einstein implicitly (or explicitly) deny about Mach's principle? TIA, AG * >>>>> >>>>> >>>>> Einstein thought he would develop a theory that satisfied Mach's >>>>> principle, but as it turned out GR doesn't. For example the metric of >>>>> spacetime is a dynamic field and transmit momentum and energy, as shown >>>>> by >>>>> LIGO. Mach's idea of spacetime as purely a relation between material >>>>> events couldn't do that. >>>>> >>>>> Brent >>>>> >>>> >>>> *Were you inferring covariance simply because the mediating particle >>>> for gravity, the graviton, travels at the SoL? * >>>> >>>> >>>> GR is a covariant theory. So it's quanta, gravitons, are covariant. >>>> >>> >>> *I could be mistaken, but I see gravitons as being part of a distinct >>> theory of gravity, which might give the same results as GR. In GR, the >>> paths are determined by geometry in the absence of forces, not by mediating >>> particles. AG * >>> >> >> GR, as a theory, implies the existence of gravity waves. Wave, when >> quantised, give particles: these are the gravitons of the theory. Exchange >> of such gravitons does not necessarily have anything to do with the forces >> in the theory, or the formation of geodesics. >> >> Bruce >> > > *Very clarifying. Then, since gravitational waves have been detected, it > must be that gravitons exist, but too low in energy to be detected. AG * >
That is news for sure! - pt -- 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
