American scientists claim they have conducted nuclear fusion in a lab, raising waves of excitement worldwide. More energy was created in a nuclear fusion test than was expended in triggering it, scientists said, raising hopes that the technology can be scaled up. However, it's too early to celebrate. Thanks to prohibitive costs, scarce fuel and the potential to affect global disarmament, it may be a long time — if at all — before fusion energy becomes an alternative to fossil fuels and other sources of energy. These are just baby steps Scientists at the US government's Lawrence Livermore Laboratory in...