The experiment was sponsored by NASA and conducted by a research team led by Dr. Lene Hau, a professor of physics at Harvard University. It was observed that the light slowed down or even stopped moving for a few thousandths of a second. Scientists such as Dr. Lene Hau began to study atomic cooling in the mid-199s. They found that when an atom is cooled to ultra-low temperature, it turns into a so-called Bose-Einstein condensate. In this state, the behavior of the atom is completely different from that of normal, and it does not conform to the traditional laws of physics. Dr. Lene Hau's team broke the record of the lowest light speed for the first time in March, 1998. In the summer of that year, it reached a low speed of only 6 kilometers per hour, about 17m/s, which was 2 million times lower than the normal light speed and even lower than the speed limit of the expressway. After improving the instrument, Hau finally stopped the light completely in the summer of 2. The speed of light is about 3, kilometers per second, which can slow down the light to a certain extent in some media such as water and diamonds, but if you want to slow down the light further, you need breakthrough technology. Dr. Lene Hau's team used a laser to cool a cigar-shaped sodium atom cloud to one billionth of the absolute temperature of today's scientific and technological limit in an ultra-high vacuum environment. When the light passed through this sodium atom cloud, it magically slowed down and even stopped moving! Then the scientist shoots another laser to restore the light to its original speed.
According to Agence France-Presse, Paris, April 7, 27, the above experimental results of scientists from Harvard University in the United States were published in the British journal Nature.