Where does it all end?

Cosmologists have put forward several different scenarios for where our universe ends

The universe goes on forever

The universe could be infinite in extent, endlessly continuing in all directions, on and on beyond our cosmic horizon with no edges or boundaries. If this picture is accurate then the universe has no edge, and it gives rise to the idea that eventually the same configuration of atoms would repeat in the universe. This means that there is another Earth and another you out there somewhere in the universe right now.

Other universes

If cosmic inflation really happened – the super-rapid expansion of our universe in its earliest moments – then it may have happened more than once, giving rise to neighbouring universes. According to Albanian-American cosmologist and theoretical physicist Laura Mersini-Houghton at the University of North Carolina at Chapel Hill, our nearest universe must be more than 1,000-times further than what we understand to be our cosmic horizon.

An event horizon

It is possible that what we see as our universe is the remnant of a black hole forming in another universe. One of the leading proponents of this idea is Polish theoretical physicist Nikodem Poplawski. If he’s right then just like the surface of Earth, our universe has no edge.

There could be nothing

There is no current reason to suspect that the universe ends with our cosmic horizon, just as we know that Earth doesn’t end just because the rest of the planet is hidden from view by its curvature. However, the universe could just stop.