Q.  Is the Universe really expanding?

A.  No. This idea is based on a misconception, that the red-shift of distant galaxies means they are moving away.

Q.  What is the red-shift of galaxies?

A.  Lines in the spectrum of light from distant galaxies show that the light has lost energy in its journey from its source -- the lines shift toward the red (lower-energy) side.

Q.  And these red-shifts vary with distance?

A.  Yes. As the light travels farther, it loses energy at a fairly steady rate with distance.

Q.  Didn't Edwin Hubble prove that the Universe is expanding?

A.  No, he showed that red-shifts occurred, and that they increased with distance. But he didn't believe that this had anything to do with galaxies moving away.

Q.  Where is this explained in more detail?

A.  Look at Refining the Zwicky Constant -- A new more soundly-based constant for inter-galactic distances, replacing the Hubble Constant.