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If space is expanding, what physical entity, if any, is doing the expanding? Rephrasing the question, at the planck scale, is space made up of something?
- Kenneth (age 45)
That's a good question, and your rephrasing is very helpful in sharpening it. Unfortunately, the best answer that I know of is that we suspect space is made up of something on the Planck scale, but it isn't really known what yet. We're not even sure what dimensionality spacetime has on a small scale.
(published on 09/26/09)
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