Nuclear Fusion Reactions Mark A 'Milestone'

Physicists create nuclear fusion reactions that produce more energy than was in the fuel involved — the power at work in the sun and other stars. It may be a step toward cleaner nuclear energy.

It took 192 lasers and a building big enough to contain three football fields, but physicists have finally produced a pair of nuclear fusion reactions that created more energy than was in the fuel to start with.

The reactions lasted less than a billionth of a second, and they released only a few thousand joules — enough to power a 100-watt light bulb for less than three minutes. But it marks the first time scientists have been able to harness the power of stars here on Earth.

"This is really an important milestone," said Warren Mori, a plasma physicist at UCLA who was not involved in the effort.