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jfy4
Jul18-11, 06:03 PM
Hi,

Is a metric signature of (-,-,-,-) unphysical?

Thanks,

bcrowell
Jul18-11, 06:40 PM
You can flip all four signs in the signature, and it doesn't mean anything in terms of connection with observation. For example, my favorite signature is +---, but much of the literature uses -+++. They don't mean anything physically different.

So ---- would be physically identical to ++++, describing Euclidean four-space. Such a space has no time dimension, just space.

jfy4
Jul18-11, 06:43 PM
You can flip all four signs in the signature, and it doesn't mean anything in terms of connection with observation. For example, my favorite signature is +---, but much of the literature uses -+++. They don't mean anything physically different.

So ---- would be physically identical to ++++, describing Euclidean four-space. Such a space has no time dimension, just space.

Thank you very much.