2010, but interesting. “Who will be around then to be bored by this apparent overpowering eventual tedium?” A thought occurred. If, by then, only massless part

2010, but interesting. “Who will be around then to be bored by this apparent overpowering eventual tedium?” A thought occurred. If, by then, only massless particles are present (the rest having decayed), Penrose reasoned that eternity will pass in a flash since no proper time elapses at all for these voyagers along space-time light-cones. Edit: the review of Penrose's book is by Julian Barbour, who concludes with his own thought: Despite his great attraction to conformal geometry, Penrose still accords length a real physical role. But in fact we only ever observe angles, never lengths as such. Do we really need them? Or, as Pauli said, "Your idea is crazy, but is it crazy enough?"