On 17 veebr, 23:19, Erik Max Francis <m...@[EMAIL PROTECTED]
> wrote:
> George W Harris wrote:
> > Global conservation of mass/energy requires a
> > simply connected space-time topology.
>
> Actually, it's worse than that; even in a simply-connected spacetime
> topology, the concept of the total amount of mass, energy, momentum,
> angular momentum of the Universe is problematic in general relativity.
> You can talk about one, but those familiar with general relativity know
> that they're basically cheating.
>
> But more im****tantly, global conservation of energy is not in any
> meaningful sense true in general relativity. Indeed, our models of the
> Universe require that it be violated (namely, with cosmological red****ft
> -- photons traversing an expanding spacetime are losing energy, but the
> energy isn't going anywhere).
>
Photons encounter moving matter. Surely changing energy when changing
frames is a common phenomenon?
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