Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: grainy universe?

Learn more physics!

Most recent answer: 10/22/2007
Q:
In our math classes we spend much time investigating the properties of continuous functions. Is there any reason to believe that any of the variables of physics e.g. ’time’, are continuous in this (mathematical) sense? Or is it more likely that the universe is fundamentally ’grainy’?
- Chuck
shasta college, Redding California
A:
The best reason for guessing that spacetime is continuous is that we have wonderful equations (General Relativity and quantum mechanics) which work beautifully as differential equations, treating the underlying spaces as continuous.

The best reason for guessing that spacetime is not continuous is that directly combining GR and QM leads to nonsense if one takes the equations literally on an arbitrarily small scale.

Nobody knows quite how it will all turn out.

Mike W.

(published on 10/22/2007)

Follow-up on this answer.