Two mathematicians have proved that a straightforward question—how hard is it to untie a knot?—has a complicated answer.

For decades, we have been taught that the universe is expanding faster and faster. That belief has influenced our view of ...

The universe's expansion may actually have started to slow rather than accelerating at an ever-increasing rate as previously ...

Genome size exhibits extensive variation across the life of a tree. Previous studies have predominantly focused on ...

For almost a century, we have known that the universe is expanding. For several decades, evidence has suggested that the expansion of the universe is accelerating. Crucial to those estimates were the ...