Credit: NASA / ESA / B. Williams The Milky Way and Andromeda are part of a cluster of about 100 galaxies, held together by gravity, known as the "local group." ...

Galaxies merge when they are pulled toward each other by gravity, and the universe used to be more densely packed together. Over time, the universe has expanded, and more galaxies have combined ...

Galaxies merge when they are pulled toward each other by gravity, and the universe used to be more densely packed together. Over time, the universe has expanded, and more galaxies have combined ...

Galaxies merge when they are pulled toward each other by gravity, and the universe used to be more densely packed together. Over time, the universe has expanded, and more galaxies have combined ...

Astronomers witnessed two galaxies engaged in an intense deep-space battle for the first time. Watch the “cosmic joust” in action.

Astronomers witnessed two galaxies engaged in an intense deep-space battle for the first time. Watch the “cosmic joust” in action.

Compression would be expected. And law – that is, gravity – would be expected to emerge from these computational rules. We may not yet have definitive evidence that we live in a simulation.

Compression would be expected. And law–that is, gravity—would be expected to emerge from these computational rules. We may not yet have definitive evidence that we live in a simulation.

Compression would be expected. And law—that is, gravity—would be expected to emerge from these computational rules. We may not yet have definitive evidence that we live in a simulation.