image credit NASA, ESA, HEIC, Hubble Heritage Team
We could have had a Universe without trees, without mountains, without our skies and without oceans. We could have had a Universe without planets like Earth, or planets at all. We could have even had a Universe where nothing that we know of - no particles, forces or interactions - exists as it does right now. Yet despite the endless possibilities for what could have been, this is the Universe we have.