Letters from the April 15, 2006, issue of Science News

Light shift

Regarding “Blasts from the Past: Astronomers begin to go the distance with gamma-ray bursts” (SN: 2/11/06, p. 88), why is it that visible light is shifted to lower frequencies but gamma rays aren’t? Shouldn’t they have become X rays after all that distance?

Stephen Wood
Orlando, Fla.