I was thinking about this recently. I'm a creationist (ducks to avoid the bottles and tomatoes flying through the air), and as such, am often considering the fundamentalist "thousands of years old" vs the contemporary "billions of years old" view.

When applied to the Universe, unless we have our distances wrong by a very large factor indeed, there are four explanations to what we see:

What's the problem with it simply being created a few thousand years ago? Simply this: most objects we have observed are more than "thousands" of light years away, so the light from them would not yet have reached us. If the Universe were created and left to propagate its own light, it would take about 100,000 years before we'd even see the full Milky Way. Most of the sky would be black, and every so often, a new star would pop into view. We certainly wouldn't have any pictures of other galaxies.

A few people have suggested that the speed of light could have changed over the years. However, the factor of change required combined with the intrinsic link between mass and energy (E=mc^2) does not give me any confidence in the suggestion (although see http://www.channel4.com/equinox/ein_transcript.html - thanks wertperch).

So we have two theories: that the Universe is indeed billions of years old; or that it is younger, and created with the light already in motion, giving the appearance of age.

This is going on my list of questions to ask when I enter into glory; it certainly isn't going to dent my faith down here!

Genesis 1
  1. In the beginning God created the heavens and the earth.
  2. Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters.
  3. And God said, "Let there be light," and there was light.
  4. God saw that the light was good, and he separated the light from the darkness.