On Friday, February 22, 2019 at 11:28:50 PM UTC-6, [email protected] wrote: > > > > On Friday, February 22, 2019 at 9:12:02 PM UTC-7, Bruce wrote: >> >> On Sat, Feb 23, 2019 at 3:08 PM <[email protected]> wrote: >> >>> On Friday, February 22, 2019 at 8:13:21 PM UTC-7, Brent wrote: >>>> >>>> On 2/22/2019 6:04 PM, [email protected] wrote: >>>> >>>> On Friday, February 22, 2019 at 4:55:41 PM UTC-7, Brent wrote: >>>>> >>>>> >>>>> >>>>> On 2/22/2019 2:40 PM, [email protected] 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 [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.
