Slowing light speed as “Researchers at UC Berkeley, along with scientists from the University of Oregon and the University of Illinois, say they can slow the speed of light in a way that could help speed the delivery of movies to your PC” claims an article from CNET News.com 28 Sep 2004 entitled Slowing the speed of light to improve networking. Scientists at University of California, Berkeley have slowed light using a technique called coherent population oscillation, which uses two lasers of different frequencies creating an interference pattern, to slow down a beam of light passing through a semi-conductor to 6 miles (about 10km) per second. This is 31,000 times slower than the speed of light through a vacuum, which is 186,000 miles or 300,000km per second. Engineers and computer scientists are hoping to use slow light pulses for more effective control of communication between computers.
Editorial Comment: These experiments remind us that the speed of light is not always the same – it varies according to the medium light is travelling through. This is why objects appear distorted or displaced when light from them passes through two different substances, e.g. from air to water. Creationist Barry Setterfield contends (controversially) that when light travels through the vacuum of space it is not travelling through absolutely nothing. The vacuum is actually filled with energy called zero point energy, or ZPE. He further argues that there is evidence this energy (ZPE) has increased over time and the speed of light has decreased correspondingly. A detailed explanation of this is available on a two part DVD lecture by Barry Setterfield entitled The Decreasing Speed of Light, available from Creation Research. (Ref. light, speed, semiconductor)