How cold are black holes?

The very idea that a black hole could have a temperature strains the imagination. I mean, how can something that absorbs all the matter and energy that falls into it have a temperature? When you feel the warmth of a toasty ...

Could Planet 9 be a primordial black hole?

For several years, astronomers and cosmologists have theorized about the existence of an additional planet with a mass 10 times greater than that of Earth, situated in the outermost regions of the solar system. This hypothetical ...

Is dark matter made of primordial black holes?

Astronomers studying the motions of galaxies and the character of the cosmic microwave background radiation came to realize in the last century that most of the matter in the universe was not visible. About 84 percent of ...

Could primordial black holes be dark matter?

(PhysOrg.com) -- “We know that about 25% of the matter in the universe is dark matter, but we don’t know what it is,” Michael Kesden tells PhysOrg.com. “There are a number of different theories about what ...

Black holes ruled out as universe's missing dark matter

For one brief shining moment after the 2015 detection of gravitational waves from colliding black holes, astronomers held out hope that the universe's mysterious dark matter might consist of a plenitude of black holes sprinkled ...

Gravitational waves: Why the fuss? (Update)

Great excitement rippled through the physics world Thursday at the announcement that gravitational waves have been detected after a 100-year search.

Did gravitational wave detector find dark matter?

When an astronomical observatory detected two black holes colliding in deep space, scientists celebrated confirmation of Einstein's prediction of gravitational waves. A team of astrophysicists wondered something else: Had ...

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