Scientists have many big questions to tackle about the universe, including how big it actually is. But even the proposed answers aren't straightforward.

Knotted structures once imagined by Lord Kelvin may actually have shaped the universe’s earliest moments, according to new ...

Will the universe keep existing forever? An astrophysicist explains how scientists aren’t entirely sure, but they can make predictions.

There is an important and unresolved tension in cosmology regarding the rate at which the universe is expanding, and ...

Gazing up at the stars at night, it’s easy to imagine that space goes on forever. But cosmologists know that the universe actually has limits. First, their best models indicate that space and time had ...

The surface of Earth is finite. We can measure it. If it was expanding, then its size would grow with time. And once again, good ol' Earth helps us understand what the universe might be doing beyond ...

In the beginning, the Big Bang happened, sending everything in the universe expanding outward and apart, from a dense hot point. Since then, all that matter and energy has continued to move outward, ...

Mathematical quirks of our universe have led some cosmologists to wonder whether the cosmos was actually born in a black hole. Parallels in the physics of the universe and that of black holes have led ...