Introduction

Our Universe isn't just expanding, but the expansion itself is accelerating owing to the presence of a form of energy that doesn't dilute as the Universe expands: dark energy. Any individual object, like a galaxy, appears to recede faster and faster from any other as time goes on, driving unbound objects apart at ever increasing speeds. While these galaxies will become unreachable, the notion that they'll disappear from view is misleading, as more and more of the Universe becomes visible as time goes on. Here's the counterintuitive science of why.