Physics of the Speed of Light

A Short Proof of Why Nothing Can Be Faster Than Light

by John Michael Williams


I found this old paper on relativity while I was reorganizing some of my records.

Readers with a formal logic or theoretical bent will enjoy this simple piece.

The proof was inspired by an assignment given in a physics course given by Professor Leonard Susskind at Stanford University in 2001.
The abstracted part here is entirely the author's own work and has been rewritten slightly and converted to HTML for posting.

Latencies in the visual system represent depolarization propagation speeds on the order of 0 to a few hundred meters/second. The Space Shuttle can achieve a speed of at most 10 km/s, below the required escape speed from the Earth's gravity. But light propagates in air or vacuum at about 300,000 km/s. We try to show what this means here.

The speed of a photon absolutely is a constant, c. However, in nonvacuum medium, photons may be destroyed and created rapidly. The creation delay causes the "speed of light" in material media, therefore, to average below c.

For example, if photons are created and destroyed in a lossless (or loss-regenerating) environment, with momentum always on exactly the same vector or its opposite, light can be "stored" dynamically. Bandwidth then is proportional to momentum dispersion. For references on stored light, see "Dynamic Photonic Crystals", by Fan, et al, in Optics and Photonics News, 2007, 18(3), pp. 41 - 45 (March 2007 issue).

  1. Introduction

  2. The Proof

  3. Postscript


Email Comments.

Back to Pulfrich Effect Home. University Privacy Policy

The Pulfrich Effect, SIU-C. Last updated 2007-04-05