On this day, 28 years ago, on January 27, 1997 (December 19, 1996 in the lunar calendar), American scientists created an atomic laser. On January 27, 1997, physicists at the Massachusetts Institute of Technology in the United States used sodium atoms to create an atomic laser with some similar characteristics to ordinary photon lasers for the first time in the history of human science based on the theory of quantum science. This experiment was in the physics community caused a sensation. Two major academic journals, Science and Physics Review Newsletter, reported this result at the same time. The biggest similarity between the atomic lasers made by Dr. Wolfgang Kettle and his colleagues and ordinary lasers is that their particles are coherent. Ordinary lasers produce coherent photons, and atomic lasers produce coherent atoms. Atomic lasers cannot currently travel through the air like ordinary lasers, but this coherent pulsed atomic beam may be used in the future to make nanocircuits and other nanoscale structures, and to make ultra-fine measurement systems. Writing in the journal Science, Dr. Kettle and five colleagues said that in their experiments, they first used ordinary lasers and magnetic fields to cool the sodium atomic gas to a state close to absolute zero (minus 273 degrees Celsius), bringing the atomic velocity and momentum close to zero, and then created two drops of Bose-Einstein condensate each containing 1 million atoms. They then cut off the laser and used a special camera equipment to capture the coherent image that appeared when two droplets of condensate in a vacuum intersect at 3 a.m. on November 16, 1996, creating the first atomic laser in the world. Relevant experts here pointed out that when ordinary lasers were invented 37 years ago, no one would have expected it to have such a wide range of uses; in addition to being of great significance in physics, the discoveries of MIT scientists have potential for practical use. value is also great.