If you were the Lord High Poo-bah of the Planet Xantar, and you wanted to banish someone to the farthest edge of the universe, here's a handy dandy instruction manual that ...
a) measures the size of the observable universe
b) points out that the part you can see is growing a little bit every day
c) tries to measure the whole universe, including the parts you can't see
d) and suggests, paradoxically, that you and the person you banish — both of you, in your very different places — are somehow simultaneously at the center of the universe.
I know, I know, banishments are so much more complicated than they used to be, but this animated video, "How Big Is the Universe?" is clear, fun and fascinating. It comes from Henry Reich, who, if I were Poo-bah of Xantar, would be my Most Royal Elucidator of Physics. Alas, times being rough, he has to spend his days writing, narrating and drawing Minute Physics videos at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario.
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