-----Forwarded Message-----from Akira Kawasaki
>From: What's New <[EMAIL PROTECTED]> >Sent: Apr 27, 2007 2:27 PM To: [EMAIL PROTECTED] Subject: [BOBPARKS-WHATSNEW] What's New Friday April 27, 2007 WHAT’S NEW Robert L. Park Friday, 27 Apr 07 Washington, DC 1. THE HABITABLE ZONE: THE GOOD NEWS IS THEY’RE NOT COMING HERE. Humans, 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. 2. WARHEADS: THE GOOD NEWS IS THAT NUCLEAR STOCKPILES ARE AGING. It was just five years ago that the Nuclear Posture Review, was leaked http://bobpark.physics.umd.edu/WN02/wn031502.html . 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. 3. MISSION ACCOMPLISHED: IRAQ NO LONGER POSES A NUCLEAR THREAT. We 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. THE UNIVERSITY OF MARYLAND. Opinions are the author's and not necessarily shared by the University of Maryland, but they should be. --- Archives of What's New can be found at http://www.bobpark.org What's New is moving to a different listserver and our subscription process has changed. To change your subscription status please visit this link: http://listserv.umd.edu/cgi-bin/wa?SUBED1=bobparks-whatsnew&A=1
