Saturday, May 3, 2014

Meanwhile, in another universe...

I'm still working on the Rohonc transcription, but I thought I would post something amusing and light-hearted for a change.

I've always been bothered by the fact that time seems to only go in one direction, and to be orthogonal to the three spatial dimensions. Somehow it seems...arbitrary.

So imagine a universe where it worked differently: Imagine a four-dimensional universe where time moves outward from a central point, which I'll call the Origin. So, instead of the spatial universe being a three-dimensional slice moving through a four-dimensional space-time, instead it is more like the surface of an expanding hypersphere.

How would light move in a universe like this? If we require that the speed of light be constant in this universe, then the path of light must always be at a constant angle of deflection from a line radiating from the Origin. If the speed of light and the passage of time are constant, then light spirals away from the Origin, always bending at a constant angle of deflection.

What would it be like inside this universe? First, on a small scale, time would appear to be linear, the same way that the Earth appears to be flat, and gravity appears to go in only one direction. Second, on a larger scale, the universe would constantly be expanding.

Now, suppose light is deflected as a result of some influence exerted by the Origin, and that influence decreases the further from the Origin we get. (Maybe inversely proportional to the cube of the distance from the Origin). Since we require that the speed of light be constant, the actual rate of passage of time relative to distance from the origin decreases the farther out we get. Since the size of the universe is proportional to the cube of the distance from the Origin, but time passes increasingly slowly, we would perceive this as an accelerated expansion of the universe.

Chores call, so that's the end of this post.