January 19, 2004

The black hole of christmas

A whole month has gone by, the black hole of christmas. Not that I've been idle, oh no. When the festive season was finally over I went to the Red Sea for a weeks diving. It's the nearest I'm probably going to ever get to floating in space. At night, with ones torch turned off and away from other light sources - divers, the boat etc - one is alone in space, floating. Floating in space, with all forces equal upon ones body, one could be in the black depths of intergalactic space . . . . well, sort of.

I re read Janna's book, "How the Universe Got it's Spots", and a lot of things seemed to make more sense than the first time. Some things I thought I understood I realised that I'd only taken in good faith. Like the fact that according to special relativity the faster one travels the slower time passes and objects become shorter. I'd never twigged that if time and space are not absolute and the speed of light is, then quite simply time and distance have to change the faster one travels. How thick is that ? Probably not too thick - it's easy when these things click, but it now seems so beautiful in it's simplicity.

The topological and spatial dimension stuff made more sense too, and I realised that in my musings over making model universes out of mirrors there was a fundemental flaw. If one lived in a universe that was a cube, with opposite faces identified - so that if you walked through the right hand face of the cube you'd reappear through the left hand one - you wouldn't see a mirror image of yourself, you'd see your back view. Light would travel round the universe from behind you and appear in front of you. If you looked up at the roof of the cube you'd see your feet.

So mirrors are not the way to make such a model. Probably have to do it with cameras and projections. If the size of the universe, the length of the cube was, say, 1 light second, then you'd see yourself as you were a second ago. And each second you'd see a new old you with the previous you receding - 2 seconds ago, then 3 and on and on . . . In this way it would look a bit like mirrors feeding back into each other. I think. Anyway I'm thinking that this could work : for each face you have a video camera pointing out from it with its output projected onto the opposite face delayed by the size of the space.(To be realistic in the size of space available it's probably a good idea to scale this. Call it x seconds for now. Otherwise the time lag will be too small to notice. Unless one projects onto the moon.) Then every x seconds cunning software starts playing back the buffered footage from x seconds ago, while all previous streams are moved further into the background. So you see what appears like ever increasing multiple versions of yourself getting further and further back in time as light circles the universe.

Actually projecting onto the moon could be pretty interesting, you could actually see a slight delay as light travelled there and back, see the speed of light.

Posted by Jem Finer at January 19, 2004 10:18 PM