MAGIC and Light
The Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescope recently began operations in the Canary Islands. MAGIC found that high-energy gamma rays from a distant blazar arrived 4 minutes later than low energy photons from the same event. This may indicate that particles travel at a different speed of light. The results are being hailed as indicating a new physics.
Though gamma rays are blocked by Earth's atmosphere, upon striking the atmosphere they give off showers of Cherenkov radiation. MAGIC detects this cascade of particles and calculates origin of the incident gamma rays. The blazar is in galaxy Markarian 501, half a billion light-years away. Blazars give off powerful jets of gamma rays simultaneously with lower energy photons. Both are forms of electromagnetic radiation and supposed to travel at velocity c. UC Davis Press Release.
Not long ago talk of a changing speed of light would get a woman literally shouted down. Today in Space.com Floyd Stecker of Goddard Space Flight Center says, "There are some postulated but unproven theoretical models, inspired by the motivation to unite the quantum theory with the general theory of relativity, which violate special relativity." Notice how the "constant c" trolls remain anonymous while the GM=tc^3 advocate has a name? Who is afraid of someday looking foolish?