The universe

1918

The universe

The book of science

Tom Sharp

Henrietta Swan Leavitt, Harlow Shapley, Edwin Hubble, Walter Baade astronomy

The universe

Cepheids

Standard candles

The span between us and the oldest and most distant observable objects in the universe might be only a fraction of what lies beyond, unless you assume that no space exists beyond our cosmic horizon. But even comparing ourselves to the observable universe, whose edge is perhaps under 47 billion light years from us, makes us very very small.

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