The Boston Globe, Sep 3rd, 2002
Earth's travels linked to ice ages
Ice ages may be linked to the Earth's travels through the spiral arms of the Milky Way, according to Nir Shaviv of the University of Toronto and Jerusalem's Hebrew University. His hypothesis is based on correlations he's found between changes in cosmic radiation reaching the Earth and geological evidence for ice ages in the past billion years. The cosmic ray intensity the Earth experiences varies with its passage through the arms, and Shaviv suggests that increases in cosmic radiation might promote global cooling. Currently, the Earth is in the minor Orion spiral arm, giving us about half the cosmic radiation we would receive in a major spiral arm. If Shaviv is right, that means we're coming out of a major ice age, which is consistent with the global warming we're experiencing now.
ref: Physical Review Letters, July 29 back to homepage