Science Alert reports:

From the winding down of clocks to the death of stars, everything seems destined to eventually grind to a halt. But there’s one really, really big thing to which this doesn’t seem to apply, at all. That’s the Universe itself, getting bigger and bigger all the time.

According to our physical descriptions of how the cosmos should behave, that growth should be slowing down. Instead, measurements show it is speeding up, driven by a mysterious force known as dark energy. And it’s a dilly of a huge pickle.

But there’s something in the Universe that might explain it, some scientists argue: the massive, dense, growing concentrations of matter we call black holes.

“If black holes contain dark energy, they can couple to and grow with the expanding universe, causing its growth to accelerate,” says astrophysicist Kevin Croker of Arizona State University. “We can’t get the details of how this is happening, but we can see evidence that it is happening.”

We don’t know what it is, but calculations suggest whatever is responsible for the accelerated expansion it makes up an estimated 70 percent of the matter-energy distribution of the Universe.

What we see as expansion today also may not have always been consistent. [Continue reading…]