When the Apostles asked Christ when the end of the world would come, he responded:
It is not for you to know the times or periods that the Father has set by his own authority.
‘But about that day and hour no one knows, neither the angels of heaven, nor the Son, but only the Father.
Keep awake therefore, for you know neither the day nor the hour.
However, people have constantly been guessing at the day and the hour, and we hear of such guesses all the time. As far as the Catholic position goes, it is that we are closer today than we have ever been before, and therefore ‘keep watch’. Speculation, however, (at least about precise days and times) is simply not permitted because Christ said that it was not for us to know. Suppose, though, that somebody said that the end of the world would come before 2036 – since that person did not give a day or time, are they stepping over the line by saying what year they expect the end to come before? I think they are stepping over the line, but this leaves us with an interesting problem posed by modern science.
Since the expansion rate of our universe was found to reach what physicists call escape velocity, it is projected that the universe will die of heat death however many billions upon billions (upon billions) of years from now. I wonder if a Christian committing herself to that does something similar to the person who suspects that the world will end before 2036 – is there a qualitative difference? Existentially the prospective heat death is just too far off to be of any practical relevance, but suppose we were facing extinction by proximity to heat death in maybe a billion, or a few million years – wouldn’t it then become existentially relevant? We might start to feel that Christ was ‘slow’ to return. The closer we come to heat death, the more accurately we could guess at the time of Christ’s coming (if Christianity is true). What can we make of this problem?
First, we could say that the conjecture of heat death will simply be found to be incorrect in the ever advancing march of scientific knowledge. However, supposing that’s not the case, what other factors could help us retain the existential dilemma of never knowing the day or the hour of the end, and always being on guard waiting for it, all the while not having any date earlier than which that time must come?
One idea is perhaps that we could find a way, if the multiverse hypothesis is true, of moving from one universe to another, through infinitely many of them. This seems impossible given what we currently know, but it isn’t logically impossible (even if it now seems physically impossible) to go from one universe to another. That would dispel most of the existential angst which an obviously immanent apocalypse would cause for the Christian. I emphasise, however, that such a solution is looked upon today as being merely scientifically illiterate (and I agree that it is, but I’ll include it in the survey of possibilities regardless).
Another very speculative thought is that we could become able to travel backwards through time and settle on other planets in other solar systems. If we could do that, perhaps at that point we would have the technology necessary to engineer life-permitting solar systems anywhere in the universe and settle where we please. We would be able to diffuse the problem of an immanent end, at least for a while (for as ‘long‘ as there are corners of the universe which we could settle liveably at times which permitted life). However, this solution would only push the immanence of the ‘end’ back a step, since the universe is finite and thus there are only so many places and times which we could occupy before simply running out of room in the universe. Moreover, this suggestion would pose another existential problem: the problem of presumption; if we have travelled backwards in time 8 billion years, then we naturally suppose that the world will not end for at least that long, and thus the existential attitude which Christ recommends (to be ready) seems undermined. This problem may not be indissoluble – we need only to think of the end of the world as the human community coming to it’s proper end. Thus we could imagine Christ returning to the human community 2 billion years after we had travelled backwards in time 8 billion years. The ‘history’ of the world would then paradoxically include segments of time which would be ‘in the future’ relative to the apocalypse.
Another speculative idea is that we might find a way to counter-act the expansion rate for small pockets of the universe like our galaxy or some part of our galaxy.
All of this is extremely speculative, but it at least suggests ways in which we can get around treating the projected heat death of the universe as a marker for guessing at how soon Christ will come.