HomeBookmark Info.comMake Info.com your HomepagePlugins Visit other Info sites:
Info.com - Your independent search platform...
WebTopics
ResearchJobsFlightsImagesVideosShopmore


What is a black hole?

Find out what a black hole is and who coined the term.

A black hole is so dense that not even light can escape it. [©Jupiter Images, 2010]
©Jupiter Images, 2010
A black hole is so dense that not even light can escape it.

A black hole is formed when a star with a mass greater than about four times that of the sun collapses. In this event even the neutrons cannot stop the force of gravity. There is nothing to stop the contraction and the star collapses forever in an infinite curvature of time and space known as a singularity.

The material in the singularity is so dense that nothing—not even light—can escape. The American physicist John Wheeler, in 1967, gave this phenomenon the name black hole. Since no light escapes from a black hole, it cannot be observed directly. However, if a black hole existed near another star, it would draw matter from the other star into itself, producing X-rays as a result.

In the constellation of Cygnus, there is a strong X-ray source named Cygnus X-1. It is near a star and the two revolve around each other. The unseen X-ray source has the gravitational pull of at least 10 suns and is believed to be a black hole. Another type of black hole, a primordial black hole, may also exist dating from the time of the Big Bang when regions of gas and dust were highly compressed.

Related articles

Search the Web

We are not lawyers or legal professionals, nor are we financial counselors or professionals. The content of this Web site is intended to provide general information and advice. Prior to making any legal or financial decision, you should consult a licensed professional. For more information see Terms of Service/Usage Agreement.
Home   |   About   |   Media Comments   |   Legal & Privacy Policy   |   Tell a friend   |   Contact
Copyright © 2012 Info.com – All Rights Reserved.