Wikipedia: History of Faster-than-light

Difference (from prior major revision) (minor diff, author diff)

Changed: 3c3

However, according to physics as currently understood, the speed of light, 299,792,458 meters per second, is in reality an absolute barrier. Anything with mass must travel below this speed. Massless objects (such as photons) must always travel at this speed. Certain theories postulate that there could be a class of particles (known as tachyons?) which travel faster than the speed of light, but these could not slow down to below this speed, or interact with particles below the limit. These particles would have an imaginary mass.

However, according to physics as currently understood, the speed of light, 299,792,458 meters per second, is in reality an absolute barrier. Anything with mass must travel below this speed. Massless objects (such as photons) must always travel at this speed in a vacuum, as must electromagnetic radiation. Certain theories postulate that there could be a class of particles (known as tachyons) which travel faster than the speed of light, but these could not slow down to below this speed, or interact with particles below the limit. These particles would have an imaginary mass.

	Revision 9 . . (edit) December 14, 2001 9:33 am by (logged).12.93.xxx
	Revision 8 . . November 2, 2001 9:50 am by Vicki Rosenzweig [clarified that light travels at c <em>in a vacuum</em>]
	Revision 7 . . November 2, 2001 4:29 am by DrBob [expanded a little]