There has been plenty of discussion about May 21, 2011 being the end of the world.

Much of the doomsday conversation has been met with scoffing, and humor -- almost tailor-made for Stephen Colbert's mocking. But as many have heard the doomsday conversation, few seem to know much about the prognosticator.

The prediction was made by Harold Camping, who has made the prediction before back for September 1994. 

Camping is 89 years old, and a Christian-radio broadcaster. He was born in Colorado, but has lived in Northern California for most of his life, and currently resides in Oakland.

Helping found Family Radio in 1959, a 24-hour listener-supported radio network, Camping hosts Open Forum a TV and radio show. He recently announced he would no longer being doing the show, as the end of the world was near. He put out a $100-million worldwide advertising campaign, which was financed by the sale of his TV and radio stations. 

Camping believes that the Bible is the only word of God and teaches that hell and death are the same thing.

He uses bible-based numerology to make his predictions. When he was wrong about the September 1994 prediction, he said he made a mathematical error. As a graduate of University of California at Berkeley in civil engineering, Camping admits to having a fondness for numbers.

Camping believes only 200 million of the over six billion people will survive the rapture.

I know it's absolutely true, because the Bible is always absolutely true, Camping recently said.