20-pound brick

Physicists are getting a good laugh after reviewing the government's case against terror suspect Jose "Dirty Bomb" Padilla. The government says Padilla was plotting to blow up a uranium based dirty bomb in an American city. Experts who have reviewed the evidence in the case say radiation from uranium isn't dangerous and that both the government investigators and the terrorists are incompetent.

"I used a 20-pound brick of uranium as a doorstop in my office," American nuclear physicist Peter D. Zimmerman, of King's College in London, said to illustrate the point.