The FLRW metric doesn't conserve energy because it doesn't have a timelike killing vector field, ie it isn't a static spacetime. That is an invariant...
True, but when we're talking about using GR as a cosmological model we're talking about the FLRW metric which picks a preferred frame, namely one in...
Nobody else may have mentioned the effect of cosmic rays on computers and digital cameras, but that sure seems like an issue. Modern machines have a...