Attosecond Laser Pulses Illuminate Fleeting Dance of Electrons

Science : Like a prisoner trapped behind the wall of a fortress, an electron faces a huge barrier in escaping the confines of an atom. Yet when hit by a burst of intense light, it can set itself free in just a few hundred attoseconds (10-18 s), thanks to a quantum-mechanical phenomenon known as tunneling. In essence, it seeps through the barrier--the binding energy that normally holds it in place. Now, for the first time, scientists have seen this blindingly fast escape act happen in real time.