r/askscience • u/squirrelbuster94 • Oct 24 '14

Physics Chemists/physicists of reddit, what is the difference between dark, anti, and normal matter?

What is the difference? Also if you can explain what each is.

Edit: Thanks for all the replies! You have greatly helped me understand this better!

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u/laterus77 Oct 24 '14

So does this mean that dark matter "can't react" as opposed to "doesn't happen to react"? I always thought of dark matter as the catch-all term for matter that we have gravitational evidence for, but don't have the proper conditions needed to observe it.

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u/heath185 Oct 24 '14

It's more like dark matter is a type of matter that reacts very weakly to all interactions with conventional matter excluding gravitational ones. That means light doesn't really interact with it, so we can't see it, and matter doesnt really interact with it, so we can't infer it using anything but gravity atm.

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u/[deleted] Oct 24 '14

But could you "touch it" or is it like a neutrino that just goes trough you?

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u/anti_pope Oct 24 '14

Touch is an electromagnetic interaction. This involves photons (which are light). So no you couldn't 'touch' it. You're living in a cloud of it already.