Tides on a cosmic shore

Abstract

The sea shares a kinship with space. Standing on the shore, staring out to sea, the limitlessness strains the senses. If you’ve ever been on a ship out of sight of land, the endless ocean makes even the largest ship shrink into insignificance. The same is vastly truer of space of course. Even here, with feet planted firmly on Earth, how many people feel small standing under a truly starry sky for the first time? How many let their imaginations run wild when they wonder what’s out there; whether it’s the dark depths of space or the equally dark ocean depths? In both cases, the impenetrable seems unknowable.

The surface of the Earth is the shore of the cosmic ocean. ... Recently, we have waded a little out to sea, enough to dampen our toes or, at most, wet our ankles. The water seems inviting. The ocean calls. Some part of our being knows this is from where we came. We long to return. Carl Sagan, Cosmos