Are Humans Significant in the Cosmos?
Humanity occupies a very small place in an unfathomably vast Universe. Travelling at the speed of light 671 million miles per hour it would take us 100,000 years to cross the Milky Way. But we still wouldn't have gone very far. By recent estimates, the Milky Way is just one of 2 trillion galaxies in the observable Universe, and the region of space that they occupy spans at least 90 billion light-years. If you imagine Earth shrunk down to the size of a single grain of sand, and you imagine the size of that grain of sand relative to the entirety of the Sahara Desert, you are still...