Friday Science: Does Time Flow?

Another Friday, another chapter in Brian Greene's, The Fabric of the Cosmos.

My first four summaries were:

a. Overview
b. Spinning Space Buckets
c. Relativity and the Absolute
d. Particles Separated at Birth

This chapter was a dud to me. As usual, there are two possibilities: 1) I didn't understand what he was saying or 2) what he was saying just didn't make sense. He tried to make an argument that time was basically frozen. We might experience change from one moment to the next but really it was all one big spacetime loaf.

I may not have understood what he was saying about an observer in a galaxy far far away but it seemed to me he was only making an argument about when light arrived at a certain place, not a true difference in the speed at which time itself moves relative to the earth. It seemed like more subtle positivist nonsense, but I could be wrong (the mention of Carnap makes me think I'm not).

More thought provoking were the following statements:

• "A particular moment can no more change in time than a particular location can move in space" (141).
• "Each moment in spacetime--each time slice--is like one of the still frames in a film. It exists whether or not some light illuminates it" (140).
• All points of time eternally exist. "They eternally occupy their particular point in spacetime" (139).

The idea here is that all of spacetime is something like a loaf. You can slice it up differently but it all already exists.

I'm not quite sure what to make of this, so I'll keep reading...