Explanation: How different does the universe look on small, medium, and large scales? The most famous short science film of its generation gives breathtaking comparisons. That film, Powers of Ten, originally created in the 1960s, has now been officially posted to YouTube and embedded above. Please click the above arrow to see the nine minute movie for yourself. From a picnic blanket near Chicago out past the Virgo Cluster of Galaxies, every ten seconds the film zooms out to show a square a factor of ten times larger on each side. The video then reverses, zooming back in a factor...