Friday, October 29, 2010
During our first 200,000 years or so, Homo sapiens ate food like plump
grubs from beneath rotting logs, and turtle eggs buried on the beach.
Although not as convenient as McDonald's fare, it was least as tasty, and
obesity was never a problem. Obesity raises concerns about heart attacks
and strokes. Earlier this month, after 13 years on the market, the FDA
forced the withdrawal of Meridia citing the risk of heart attacks and
strokes. Go figure! According to a story by Andrew Pollack on the front
page of this morning's New York Times, the FDA has now rejected Qnexa,
aother diet pill, because of concerns about birth defects and heart
problems. Just last week the FDA declined to approve a drug because it
caused tumors in rats. Use the Physics Plan: "Burn more calories than you
consume,"
http://bobpark.physics.umd.edu/WN00/wn022500.html .
Jeff Peckman, who proposed the plan, points out that the city is a mile
above sea level, so why wouldn't travelers from the distant galaxy stop
here first? A front page story by Stephanie Simon in this morning's Wall
Street Journal covers the ballot measure to set up an Extraterrestrial
Affairs Commission in Denver. Why should there be a government
commission? Folks in Denver should be free to have affairs with anybody
they want.
The first confirmed detection of an exoplanet orbiting a main-sequence star
was made in 1995, when a giant planet, 51 Pegasi b, was found in a four-day
orbit around the nearby G-type star 51 Pegasi. A wonderful article in
this morning's Washington Post by Mark Kaufman gives an estimate from
today's Science magazine by Andrew Howard and Geoffrey Marcy that tens of
billions of Earth-sized planets exist in the Milky Way galaxy alone. The
likelihood is that vast numbers of these Earth-sized planets are in the
habitable zone of their sun. This is the Goldilocks zone in which it is
neither too hot nor too cold for carbon-based life to exist -- the
temperature of liquid water. The technology so far, allows astronomers to
find exoplanets down to the size of super-Earths that are three times the
size of our planet. So the estimate is an extrapolation, but it looks
pretty good. The first exoplanets were all detected by the apparent wobble
in the position of the star as the star and its planets rotate around a
common center-of-mass. A more refined technique used by the Kepler Space
Observatory uses the transit method: Looking at the slight reduction in
light as an exoplanet passes in front of the star. Howard and Marcy
reported on 166 star systems within 80 lightyears of Earth. The abundance
of planets is not unexpected. In 1950, in an informal discussion of how
there might be many planets orbiting distant Suns, inhabited by intelligent
creatures. The great physicist Enrico Fermi asked, "Where are they."
This is referred to today as the Fermi paradox, but there is no paradox.
They are peering through their telescopes, calculating the incredible
difficulty of traveling to another star, and deciding to let others,
somewhere else, make the effort. That's what I would do.
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