According to the inflationary model, the entire universe could be created from less than a milligram of matter while preserving conservation of energy. During its rapid expansion, the patch of repulsive gravitational material from which the presently-observable universe originated doubled in size approximately every 10⁻³⁸ seconds. By the end of inflation, the region that was destined to become the now-observable universe was possibly only the size of a marble. In this demonstration, you can examine the approximate size of the inflating universe as it rapidly grew, comparing its scale to that of various objects.