Thursday, October 05, 2006

Billions of planets and the prevalence of disease: Fermi looms

On of my favorite themes is back. The number of earthlike planets in the galaxy is a major component of the Drake Equation, and thus a contributor to the Fermi Paradox (aka, the mystery of the "great silence"). New data means astromers are starting to talk seriously about making estimates of the number of earthlike planets, and the number may be high:
New Planets Astound Astronomers in Speed and Distance - New York Times

... The results, astronomers said, confirm that planets occur across the galaxy with the same frequency that they do in the neighborhood around the Sun.

“We’ve learned now that planets are everywhere,” said Alan P. Boss, a theorist at the Carnegie Institution of Washington, who was not part of the team.

“We’re beginning to be able to calculate how many Earths there are, how many planets are habitable, if not inhabited,” Dr. Boss added...

.... Dr. Boss noted that astronomers now had found in the Milky Way all the types of planets that are in our solar system: gas giants like Jupiter, ice giants like Neptune and rocky “super-Earths” orbiting other stars. “Everything we were looking for,” he said, “just not in the arrangement we were looking for.”

As potential planets are found in increasing numbers, Dr. Boss said, the odds increase that planets and planetary systems like Earth’s would be found.

Mario Livio, an astronomer at the Space Telescope Science Institute and a member of Dr. Sahu’s team, said, “There are literally billions of planets in our galaxy.”

As these numbers mount, the hoary old Fermi Paradox will inevitably worm its way out of the whacko cult of Fermi (in which I'm fully enrolled) into the greater gestalt. The more we see, the less unique our solar system appears, with exception. We know of only one world with sentience and technology. If such things were common they'd be inescapable.

In medical terms, a disease is prevalent (common) when it either occurs frequently (colds) or lasts a long time (obesity) or both. If technological civilizations are as rare as they seem to be, they either occur extremely rarely, or they don't stay as we are for very long. The "occur rarely" number shrinks as the number of earthlike planets grow. That leaves the other one.

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