Measuring the pull of gravity on a micron-sized particle
Tjerk Oosterkamp of the Leiden Institute of Physics managed to do the first-ever measurement of gravity on a tiny particle - just 0.43 milligrams - where the quantum regime starts. He explains in Physics World why this is so challenging.
Gravity explains why apples fall to the Earth and why the Earth revolves around the sun. But when you look at the smallest particles, quantum forces take over. How gravity works on this scale remains one of the mysteries of physics.
Oosterkamp and his colleagues pushed the boundaries with their new experiment. They had to make sure the particle wasn’t moving due to anything other than gravity. ‘That turned out to be the most pressing challenge in our experiment,’ explains Oosterkamp. ‘But once we had succeeded in doing this, the motion of the particle that remained turned out to be so small that it was disturbed by gravity – and we could actually measure this.’
Read the full article on the Physics World website: Getting closer to measuring quantum gravity.