A Force from Empty Space: The Casimir Effect

Credit & Copyright: Umar Mohideen (U. California at Riverside)

This tiny sphere provides evidence that the universe will expand forever. One tenth of a millimeter in diameter, the ball moves in the direction of a smooth plate, responding to energy fluctuations in the vacuum of empty space.

This forces is known as the Casimir Effect. Evidence is accumulating that most of the energy density in the universe is Dark Energy. The form and origins of dark energy is mostly unknown, but it is postulated that vacuum fluctuations similar to the Casimir Effect are generated by space itself. Dark energy appears to gravitationally repel all matter, thus it may the the force to cause the universe to expand forever. Understanding vacuum fluctuations helps us to better understand our universe. On a practical level, it helps micro-mechanical machine parts from sticking together.

See Astronomy Picture of the Day http://www.phys.ncku.edu.tw/%7Eastrolab/mirrors/apod_e/ap061217.html