Latest Issue of Science News


News

Energy-Saving Space Engines: Black holes can be green

Some seemingly quiet black holes are actually efficient engines that emit jets of high-energy particles. This finding, from the first study to directly measure the efficiency of black holes, offers a hint as to why the universe isn't more crowded with stars.

All black holes swallow matter and spit out energy. Their gravitational pull traps clouds of hot, X-ray–emitting gas, and the black holes spew radiation or jets of high-energy particles.

Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.

X
This article is available only to subscribing members. Join SSP today or Log in.