I had a strange dream last night.
At one point, during an evening conversation with some classic car racing drivers, Dr. Who actor Matt Smith was talking about what he understood about time travel. I said that you can't know the future for certain because it can change, but you can know about the present. Then I thought that the present is then defined by a sharp shift in knowledge and I quickly drew a graph like two curves, one going up and one coming from the base, marked plus infinity to minus infinity, like this (this is all in the dream).
I realised that knowledge accumulates more and more until it reached the present, the time of maximum knowledge, then instantly falls of to zero, the immediate future being time of least knowledge. Knowledge of the further future becomes more certain as it can be predicted or anticipated. Knowledge of the past falls away gradually too, from the time of greatest awareness to a murky past of memory; the crucial moment is the present when a point of maximum awareness touched the point of minimum awareness.
The next day (again, in the dream), I was in some sort of dining room at breakfast, still thinking about the nature of the present and quickly thought that you can't have minus infinity, that's just zero. I lacked paper, so used an orange crayon and some light coloured gauze, like stocking material, stretched over a hoop to write down more. I started to write about it being 1800, and if it was, how would you know when it was, assuming that there were no clocks or calendars, to illustrate the question; how would you know when now is? The answer was information, that you would look around and gain more knowledge and thus determine your location in time. I drew a new graph with zero rather than minus infinities. The graph looked something like this; two upward curves, with the present defined at the point where the top of one curve (point of maximum knowledge) jumped to the bottom.
It was difficult to write much because of the chunky crayon. Then Matt Smith peered over the end of the hoop, trying to look at what I was writing. This annoyed me a bit as I wanted to focus on my work.
At that point I awoke.
