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The Question

(Submitted February 12, 1999)

Can two areas of the Universe be so far away from each other that the light from area A can not reach area B?

The Answer

It is now believed that the Universe is large enough that there can be areas A and B that have not been able to exchange light.

This is a result of recent observations that indicate that the rate of the Universe's expansion is speeding up, contrary to what astronomers were expecting a couple of years ago.

David Palmer and Samar Safi-Harb
for Ask an Astrophysicist

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