via Physics Central
A vacuum is a space absolutely devoid of matter, at least according to the Merriam-Webster dictionary. But if you talk to a physicist you may get a different answer. According to quantum physics, even vacuums are not completely empty. Constant fluctuations in energy can spontaneously create mass not just out of thin air, but out of absolutely nothing at all.
“It’s like a boiling sea of appearing and disappearing particle pairs,” said James Koga, a theoretical physicist from the National Institutes for Quantum and Radiological Science and Technology in Kyoto, Japan. The pairs, made up of one particle and one antiparticle, exist for only moments. Koga is investigating the subtle effects caused by these fluctuations.
…[a group of] physicists are studying the same nothingness of vacuum, but with a different set of eyes. Instead of beaming light into the vacuum and looking for a glint, physicist Alejandro Manjavacas and his group at the University of New Mexico want to know if the fluctuations of vacuum can actually exert an invisible force on physical objects — as if they were being moved by Jedis.
The Casimir effect, named after Dutch physicist Henrik Casimir, describes the force that pushes two objects together due to surrounding waves. The effect exists for two beads on a vibrating string, or two boats in a wavy ocean, as well as two particles in a fluctuating vacuum. Much like Delbrück scattering, the Casimir effect was theorized in 1948 and has already been confirmed, in 1996. So, what is left to be discovered?
“Most of the work that was done on Casimir effect was for systems that weren’t moving, or if they were moving, they were moving in a uniform motion,” said Manjavacas.