Too late!
Too late!
Oy!
The following paragraphs are from Don N. Page, Is Our Universe Likely to Decay within 20 Billion Years? (PDF format): Let us take the case in which the decay of the universe proceeds by the nucleation of a small bubble that then expands at practically the speed of light, destroying everything within the causal future of the bubble nucleation event. [snip] One might ask what the observable effects would be of the decay of the universe, if ordered observers like us could otherwise survive for times long in comparison with 20 billion years. First of all, the destruction of the universe would occur by a very thin bubble wall traveling extremely close to the speed of light, so no one would be able to see it coming to dread the imminent destruction. Furthermore, the destruction of all we know (our nearly flat spacetime, as well as all of its contents of particles and fields) would happen so fast that there is not likely to be nearly enough time for any signals of pain to reach your brain. And no grieving survivors will be left behind. So in this way it would be the most humanely possible execution. Furthermore, the whole analysis of quantum cosmology and of measures on the multiverse seems (at least to me) very difficult to do without adopting something like the Everett many-worlds version of quantum theory (perhaps a variant like my own Sensible Quantum Mechanics or Mindless Sensationalism [1, 36]). Then of course if there are “worlds” (quantum amplitudes) that are destroyed by a particular bubble, there will always remain other “worlds” that survive. Therefore, in this picture of the decaying universe, it will always persist in some fraction of the Everett worlds (better, in some measure), but it is just that the fraction or measure will decrease asymptotically toward zero. This means that there is always some positive measure for observers to survive until any arbitrarily late fixed time, so one could never absolutely rule out a decaying universe by observations at any finite time. However, as the measure decreases for our universe to survive for longer and longer times, a random sampling of observers and observations by this measure would be increasingly unlikely to pick one at increasingly late times. Although observers would still exist then, they would be increasingly rare and unusual. Of course, any particular observer who did find himself or herself there could not rule out the possibility that he or she is just a very unusual observer, but he or she would have good statistical grounds for doubting the prediction made in this paper that he or she really is quite unusual. In any case, the decrease in the measure of the universe that I am predicting here takes such a long time that it should not cause anyone to worry about it (except perhaps to try to find a solution to the huge scientific mystery of the measure for the string landscape or other multiverse theory). However, it is interesting that the discovery of the cosmic acceleration [37, 38] may not teach us that the universe will certainly last much longer than the possible finite lifetimes of k = +1 matter-dominated FRW models previously considered, but it may instead have the implication that our universe is actually decaying even faster than what was previously considered.