The cyclic universe theory predicts no gravitational waves from the early universe.

The Planck satellite may detect the imprint of the gravitational waves predicted by inflation. This would be quantum gravity written across the sky.

For years, my early work with Roger Penrose seemed to be a disaster for science. It showed that the universe must have begun with a singularity, if Einstein's general theory of relativity is correct. That appeared to indicate that science could not predict how the universe would begin.

When we understand string theory, we will know how the universe began. It won't have much effect on how we live, but it is important to understand where we come from and what we can expect to find as we explore.

If we do discover a complete theory, it should be in time understandable in broad principle by everyone . . . . Then we shall all, philosophers, scientists, and just ordinary people be able to take part in the discussion of why we and the universe exist.

If we find the answer [the unified theory], it would be the ultimate triumph of human reason -- for we would know the mind of God."