merrill@rex.DEC (12/10/84)
>The gravitational field does not "travel" at all.
If e=mc**2 and matter and mass are converted in an atomic bomb... shouldn't
something happen to the gravitational field of the "former" mass?jin@hplabs.UUCP (Tai Jin) (12/11/84)
> > >The gravitational field does not "travel" at all. > > If e=mc**2 and matter and mass are converted in an atomic bomb... shouldn't > something happen to the gravitational field of the "former" mass? well, when the theorists come up with super gut, we'll know what happens to it.
gjk@talcott.UUCP (Greg J Kuperberg) (12/11/84)
> > >The gravitational field does not "travel" at all. > > If e=mc**2 and matter and mass are converted in an atomic bomb... shouldn't > something happen to the gravitational field of the "former" mass? A common myth: mass is not conserved, energy is not conserved, but the sum of the two is. This myth is in part propagated by Isaac Asimov and other popular science writers. Now here's reality: Mass *is* energy, and it is conserved. In fact, one more conservation law was thrown in: momentum. Whereas B.E. (before Einstein), we had the conservation of mass, the conservation of energy, and the conservation of momentum, A.E. (after Einstein), we have the conservation of energy-momentum (energy being equal to mass). Energy can be thought of as "momentum in the time direction". --- Greg Kuperberg harvard!talcott!gjk "Strange women lying in ponds distributing swords is no basis for a system of government." -Monty Python
guy@rlgvax.UUCP (Guy Harris) (12/13/84)
> > > > >The gravitational field does not "travel" at all. > > > > If e=mc**2 and matter and mass are converted in an atomic bomb... shouldn't > > something happen to the gravitational field of the "former" mass? > > A common myth: mass is not conserved, energy is not conserved, but the sum > of the two is. This myth is in part propagated by Isaac Asimov and other > popular science writers. Now here's reality: Mass *is* energy, and it is > conserved. In fact, one more conservation law was thrown in: momentum. > Whereas B.E. (before Einstein), we had the conservation of mass, the > conservation of energy, and the conservation of momentum, A.E. (after > Einstein), we have the conservation of energy-momentum (energy being equal > to mass). Energy can be thought of as "momentum in the time direction". And, since the source of the gravitational field is energy-momentum (well, actually it's the stress-energy tensor, which more-or-less is to energy-momentum as electric charge/current density is to charge, so energy-momentum is actually the "charge" that generates a gravitational field), the "former mass" is still around, because the energy-momentum of the bomb before the explosion and after is the same (by conservation of E-M); therefore, the gravitational field may be changed but it doesn't "go away". Guy Harris {seismo,ihnp4,allegra}!rlgvax!guy
rcb@rti-sel.UUCP (12/17/84)
> > A common myth: mass is not conserved, energy is not conserved, but the sum > of the two is. This myth is in part propagated by Isaac Asimov and other > popular science writers. > How about a quote where the "Infalliable Isaac Asimov" propagated this myth. I've read most of everything he has written and have never seen an incorrect statement. Randy Buckland Research Triangle Institute ...!mcnc!rti-sel!rcb