DanielLC comments on A case study in fooling oneself - Less Wrong

-2 Post author: Mitchell_Porter 15 December 2011 05:25AM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Comments (79)

You are viewing a single comment's thread. Show more comments above.

Comment author: DanielLC 15 December 2011 06:47:26AM 3 points [-]

The number of particles is discrete. As far as anyone can tell, the positions aren't. They might be if you look closer than we've managed, but that's beyond the realm of quantum mechanics.

Comment author: RolfAndreassen 15 December 2011 06:11:09PM 0 points [-]

Planck distance?

Comment author: DanielLC 15 December 2011 10:04:20PM 1 point [-]

Classical physics breaks down beyond this point, but the concept of distance does not. It's not meaningful to talk about the position of something beyond this accuracy because the position is blob that's bigger than that, but the blob itself has, as far as anyone can tell, infinite resolution.

Quantum physics is built on calculus. It doesn't work in discrete systems.

Comment author: Douglas_Knight 16 December 2011 04:45:38AM 1 point [-]

Your first paragraph is reasonable, but quantum physics works in discrete systems. The most extreme case is quantum computation, which often uses finite dimensional Hilbert spaces. But older and more mainstream is lattice gauge theory, which I believe approximates QFT with a discrete quantum system.

Comment author: DanielLC 16 December 2011 05:39:20AM 0 points [-]

You can approximate it with a discrete system. It's just not what quantum physics uses.

Comment author: Douglas_Knight 16 December 2011 06:08:12AM 2 points [-]

Maybe lattice gauge theory isn't what reality uses, but it's still quantum physics.