A new way to measure nearly nothing: Ultracold trapped atoms to measure pressure
(PHYSorg.com Physics)

Many semiconductor fabricators and research labs are under increasing pressure from, of all things, vacuum. These facilities need to remove greater amounts of gas molecules and particles from their setups as new technologies and processes demand lower and lower pressures. For example, the vacuum chambers in which microchip manufacturers lay down a series of ultrathin layers of chemicals step by step-a process that must be utterly free of contaminants-operate at about one hundred-billionth of the air pressure at sea level. Some applications need pressures at least a thousand times lower than that, approaching the even more rarefied environments of the Moon and outer space.