Jan 28, 2015 01:07 AM
http://www.livescience.com/49555-speed-o...phole.html
EXCERPT: A universal rule of thumb may need to be rewritten: Light moving freely through empty space does not necessarily travel at the speed of light. As physicists have come to know, light particles traveling through empty space should zip along at exactly 186,282 miles per second (299,792 kilometers per second). This velocity is what's usually referred to as "the speed of light". Light naturally travels more slowly when it passes through a medium like water or glass, or artificial structures called waveguides. But once the light exits through the other side of the medium, it should immediately ramp back up to its maximum clip. But now, new research suggests there is an exception to this rule: Light will not travel at top speed in empty space if the "structure" of the light is first changed....
EXCERPT: A universal rule of thumb may need to be rewritten: Light moving freely through empty space does not necessarily travel at the speed of light. As physicists have come to know, light particles traveling through empty space should zip along at exactly 186,282 miles per second (299,792 kilometers per second). This velocity is what's usually referred to as "the speed of light". Light naturally travels more slowly when it passes through a medium like water or glass, or artificial structures called waveguides. But once the light exits through the other side of the medium, it should immediately ramp back up to its maximum clip. But now, new research suggests there is an exception to this rule: Light will not travel at top speed in empty space if the "structure" of the light is first changed....