That is the question that physicist Lawrence Krauss answers in his book, A Universe from Nothing. The book's trailer provides a little more context.
Everything we see is just a 1% bit of cosmic pollution in a Universe dominated by dark matter and dark energy. You could get rid of all the things in the night sky — the stars, the galaxies, the planets, everything — and the Universe would be largely the same.
And my favorite line from the trailer:
Forget Jesus, the stars died so you could be born.
(via open culture)
