How the Universe Will End

Billions of years from now, there will be so much dark energy pushing the universe apart, galaxies will be moving away from each other faster than the speed of light. Even with the most powerful telescopes, astronomers looking to the night sky would see only empty space—to them, the universe would appear to be a single solitary galaxy. And without distant galaxies to study, they’d have no idea about the Big Bang, dark matter, or even the dark energy that left them isolated and alone. But at least for now, we know these exist.