The origin of the big bang

Once upon a time Little Grasshopper asked me to explain the origin of the big bang. I immediately answered. The future caused the big bang. Little Grasshopper asked how that could be.

I answered that it was quite straightforward, if not within the scope of present day technology. Consider the problem of implementing classical time travel. There are two desiderata:

(a) Some form of “backwards in time” causality. Uncomfortable as the thought may seem, reverse causality is consistent with modern physics.

(b) Encapsulation of the time traveller as it moves into the past. In classical time travel the traveller moves from the present into the past without interacting the universe during the trip. (English is such a poor language for discussing these things.) The resolution may lie within string theory. In some versions our “three dimensional universe” is a membrane in a larger dimensional space called the bulk. (That’s “bulk”, not “hulk” – there is no evidence that the macro universe is green.) The thought is that the traveller, like gravity, moves through the bulk.

So here is what may/might happen. In the rather distant future the sophonts of that era might discover that the universe needs to be, so to speak, jump started, that it could not have come into being on its own. They arrive at a solution. They construct a time machine and send back a bit of space-time to the time of the big bang. (Actually they send back nothing at all, relying on quantum effects upon arrival to produce something for a little bit.) That insignificant bit of quantum fluctuation is the beginning of the entire universe. Inflation takes care of expanding the microcosm into the macrocosm.

This exposition has left out a few technical details that can be easily supplied by an intelligent reader. One thought that occurs to me is to ask what happened to the sophonts that performed the experiment? Could it be that they no longer exist, that they have been erased by the changed course of history? I fear that they will have been, that Niven’s law applies.

If so, we are the children of parents who never will be.