Space is not digital

The current SciAm asks is space digital?

Craig Hogan believes that the world is fuzzy. This is not a metaphor. Hogan, a physicist at the University of Chicago and director of the Fermilab Particle Astrophysics Center near Batavia, Ill., thinks that if we were to peer down at the tiniest subdivisions of space and time, we would find a universe filled with an intrinsic jitter, the busy hum of static. This hum comes not from particles bouncing in and out of being or other kinds of quantum froth that physicists have argued about in the past. Rather Hogan’s noise would come about if space was not, as we have long assumed, smooth and continuous, a glassy backdrop to the dance of fields and particles. Hogan’s noise arises if space is made of chunks. Blocks. Bits. Hogan’s noise would imply that the universe is digital.

The experiment is a variant of the Michelson–Morley experiment that was so crucial for the discovery of special relativity. Another variant is LIGO, which tries to detect gravity waves from another galaxy.

Philosophers commonly say that it was silly for physicists to repeat the Michelson-Morley experiment so many times in so many different ways in the early 20th century, because Einstein deduced relativity from pure thought. I guess they think of relativity as a believe system that is independent of empirical evidence. They are wrong about the origin of relativity, as I explain in my book.

I do think that the belief in digital space is strange and unwarranted. These new experiments are very unlikely to find any evidence for it. Contrary to some beliefs, quantum mechanics does not require digital space.