Friday, April 27, 2007
fragile self-replicating chemical factories, are trapped on a tiny planet
for a few dozen orbits about an undistinguished star among countless other
stars in one of billions of galaxies. And yet, these insignificant specks
have the audacity to imagine they can figure it all out - and maybe they
can. The most compelling scientific quest is to find life to which
Earthlings are not related. The first great discovery of this Century was
to confirm that other stars have planets - lots of them. This week
European astronomers found a planet in the habitable zone of Gliese 581, a
red dwarf in the constellation Libra. The public was thrilled. We can
learn a lot from here, and it's going to be exciting. Each year I ask my
class of freshman physics majors if they think humans will visit another
star someday. Most say yes, so we take a few minutes of each class to
plan the mission. What's the closest star? How long are you prepared to
travel? How big will the spaceship have to be? How will you pass the
time? Anyway, we'll be able to travel much faster some day, so maybe 50
years. There's always one that insists there's gotta be a basketball
court. Near the end of the semester they calculate the kinetic energy of
the spacecraft to make the trip in 50 years. Hmmm, the velocity is
squared. Maybe, they conclude, we could just find a way to exchange e-
mails.
just five years ago that the Nuclear Posture Review, was leaked
(WN 15 Mar 02) . It was a Pentagon
report calling for development of a new class of small nuclear weapons to
blur the distinction between nuclear and conventional weapons. Public
exposure killed the plan. But Dr. Strangelove never gives up. The Bush
administration is again pushing for a new generation of nuclear weapons;
this time it's the Reliable Replacement Warhead, an idea that's been
around for 30 years. In fact, having spent billions on a Science-Based
Stockpile Stewardship Program, there's no need for the RRW. U.S. warheads
will retain their capability for another century.
invaded Iraq because of their weapons of mass destruction. It worked
perfectly. Iraq hasn't had a nuclear weapon since. But now we learn that
there's a nuclear threat brewing across the border in Iran.
Unfortunately, our troops are sort of tied up. We need more missile
defense sites like the ones we built in Alaska and California to deal with
the missile threat from North Korea. Of course that missile defense is
still being tested and we don't actually turn it on, but we think we
could. It worked anyway. North Korea still doesn't have a missile, or a
warhead. To take care of the Iran threat we want to install missile
defenses in Eastern Europe like the one that doesn't work in Alaska.
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