A colleague in another building emails me, inquiring why the Brookings Institution is holding Gregg Easterbrook out as an "expert" on "environmental policy; global warming; science; space policy; 'well-being' research; Christian theology..." and pointing me to Andrew Northrup:
The Poor Man: Dear God make it stop:
[Gregg Easterbrook's] Creepy Cosmic Thought: A running mystery of cosmology is gamma-ray bursts.... Astronomers assume gamma-ray bursts must be natural in origin.... [But] what if they are the muzzle flashes of horrific planet-killer weapons? Recently Louisiana State researchers... detected very strong gamma bursts coming not from deep space, but from about 3,000 light years distant.... [My] reaction: Great, maybe there is an interstellar war going on just 3,000 light years away....
[E]ven if there is never any way to exceed or circumvent the light-speed barrier, relatively nearby planets might still fight by hurling nuclear bombs at each other at 99 percent of light speed.... John Duezabou of Helena, Mont., adds this creepy postscript: “A bellicose or paranoid extra-solar civilization that could accelerate an object to 99 percent of light speed wouldn’t need to launch bombs at us. They could shoot anything with devastating results, because the kinetic energy of a moving object is half its mass multiplied by the square of its velocity, or KE = 1/2 mv2. Thus, one pound of anything — a pint of vanilla ice cream, for instance — accelerated to 99 percent of light speed has an energy of about 4.8 megatons, roughly the blast yield of the largest hydrogen bombs.”...
Now, that a man who writes a sports column likes to fantasize about space wars and disaster movie plots is not news. That a widely-published man who is employed by the influential Brookings Institution... doesn’t have any sense of what that Einstein fellow was on about might be news...
My colleague comments:
- Kinetic energy is not mv2/2--that is the low-energy Newtonian limit approximation--but rather m0c2[(1-(v/c)2)-1 - 1], which at a velocity of 0.99c is eleven times as great as the 4.8 megatons endorsed by Easterbrook.
- It is not clear what gamma ray bursts are, but it is very clear that they are NOT the muzzle flashes of gigantic cannon launching kinetic projectiles to relativistic velocities.
UPDATE: Brad Johson of the Center for American Progress is on the case