Intense laser experiments provide first evidence that light can stop electrons

By hitting electrons with an ultra-intense laser, researchers have revealed dynamics that go beyond 'classical' physics and hint at quantum effects.

Whenever light hits an object, some of the light scatters back from the surface of the object. However, if the object is moving extremely fast, and if the light is incredibly intense, strange things can happen.

Electrons, for example, can be shaken so violently that they actually slow down because they radiate so much energy. Physicists call this process 'radiation reaction'.

This radiation reaction is thought to occur around objects such as black holes and quasars (supermassive black holes surrounded by a disc of gas). Being able to measure radiation reaction in the labwilltherefore provide insights into processes that occur in some of the most extreme environments in the universe.

Radiation reaction is also interesting to physicists studying effects beyond 'classical' physics, as the equations (known as Maxwell's equations) that traditionally define the forces acting on objects fall short in these extreme environments.
Now, a team of researchers led by Imperial College London have demonstrated radiation reaction in the lab for the first time. Their results are published today in the journal Physical Review X.