For the first time, physicists have created a one-dimensional gas made out of pure light, and they want to use it to study how photons, or particles of light, behave on a quantum level.
Scientists created the new state of matter, called a photon gas, by firing a laser into a reflective container filled with dye, causing photons in the beam to cool and eventually condense. The researchers published their findings Sept. 6 in the journal Nature Physics.
