Raul Jimenez

In its first moments, the universe resembled dough beginning to rise. If the yeast is unevenly distributed, the rolls come out in different sizes. Astronomers are hunting for such 'clumps' in the oldest light and in the arrangement of galaxies to understand what the recipe was.

In the first moments after the Big Bang, the Universe expanded faster than light could cross it. This burst, which physicists call inflation, stretched tiny quantum jitters to the size of galaxies. It is usually assumed that after such stretching the jitters lose their quantum character and become ordinary, like ripples on water.