[ExI] SETI signals

[BillK]

New Scientist comments on a paper about detecting alien civilizations:

<http://www.newscientist.com/article/dn25807-pollution-on-other-worlds-may-show-advanced-alien-life.html>

Quote:
Henry Lin at Harvard University thinks we could find more advanced
civilisations if we look instead for industrial pollution. His team
calculates that James Webb Space Telescope (JWST) should be able to
spot two kinds of chlorofluorocarbons (CFCs), complex carbon-based
gases used in solvents and aerosols.

JWST would only be able to filter out signs of CFCs from highly
polluted atmospheres, the team found, but still within levels that
humans could tolerate. In addition, the telescope could in principle
detect the remnants of civilisations that annihilated themselves,
since some CFC molecules survive for up to 100,000 years and could
outlast their sources, says Loeb.
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Quite a thought that aliens may detect CFCs on earth long after humans
have died out.


BillK