|We started talking about the tiniest known particle, and now all of a sudden we are talking about the entire universe. One disorienting aspect of the BrainTime Big Physics Vacation is the tendency for topics to oscillate between A and C without passing through B: from neutrinos to the big bang without even a nod to the normal daily lives of human beings on the planet earth. Not only that, but extreme levels of abstraction seem to be also required. Some people are versed in the language of mathematics, but the rest of us must resort to visualisations and thought experiments in order to even begin to grasp the concepts of quantum physics. This is indeed a wilderness vacation.
Some physicists have been working on devising a quantum formula, a wave function, for the entire universe. One such person is James Hartle who has other skills besides physics, like his artistic skills. You can see examples of Hartle's excellent diagrams here.
Hartle worked with Stephen Hawking on a theory about the universe called the no boundary theory. When we start to try to diagram the entire universe we start to stretch the limits of what we can visually conceive. I've done my own version of Hartle's diagram above.
On the left, you see the universe as it is conceived traditionally, starting with the big bang at the bottom and following a trajectory forwards through space and time with the universe becoming more disparate and complex. On the right, you see a diagram of a quantum theory of the universe which has no singularity at its beginning, no big bang. What you see instead is a kind of curve, or a fold, and at that point there is no space/time there is only space/space.
This theory would take care of the troubling question, "What came before the big bang?" by eliminating the whole idea of a "before." The no boundary theory has not exactly taken hold, but the diagram is a success in that it gives us a mental picture for something otherwise utterly unimaginable.