Editor's choice: Optical trapping and manipulation

Light has momentum, a fact that has been known since Kepler observed that the tails of comets did not point retrograde to their motion as was expected, rather they pointed away from the sun regardless of their direction of travel.  In 1970, Arthur Ashkin, who would go on to win the Nobel Prize for this work, was able to trap dielectric particles smaller than 1 micron in diameter using a simple objective lens to tightly focus a laser beam. Since then, optical tweezers, as they came to be known, have become essential tools in both the physical and life sciences.