The coldest experiment on Earth
At 10:54 a.m. on June 5, 1995, inside a laboratory at JILA, physicists Eric Cornell and Carl Wieman achieved a temperature colder than any known natural place in the universe. They cooled a cloud of rubidium-87 atoms to 170 nanokelvin—just 170 billionths of a degree above absolute zero (-273.15 °C or -459.67 °F). At this extreme temperature, the atoms stopped behaving as individual particles and condensed into a single quantum state. This was the first creation of a Bose-Einstein Condensate (BEC), a new form of matter predicted 70 years earlier.
The theoretical foundation for this state began with Satyendra Nath Bose in the 1920s. He developed a new statistical method to describe photons. Albert Einstein extended Bose's work to atoms, predicting that at sufficiently low temperatures, bosons (a class of particles) would fall into the lowest possible quantum state, their wave functions overlapping until they became indistinguishable. For seven decades, this remained a theoretical concept. No one had the technology to reach the required temperatures and densities until the work at JILA. The achievement earned Cornell and Wieman, along with Wolfgang Ketterle of MIT who created a condensate a few months later, the 2001 Nobel Prize in Physics.