From sands@netcom.com Sun May 5 01:40:54 1996 Date: Sat, 4 May 1996 23:34:32 -0700 From: sands@netcom.com (Sue and Sean) To: gurpsnet-files@io.com Subject: [malloy00@io.com: RE: GURPS- Name] Return-Path: Date: Sat, 4 May 1996 10:28:13 -0500 (CDT) From: MA Lloyd To: Harold Carmer Subject: RE: GURPS- Name On Sat, 4 May 1996, Harold Carmer wrote: > Point the second: How much anti-matter would it take to destroy a > planet? Using photon torpedo pods, holding a moderate amount of > anti-matter, they shouldn't have all that much of a problem succeeding in > destroying a planet... Depends on how completely you want to destroy it. If you want to totally blow it apart, its the gravitational binding energy of the total mass Eb = (9/15)GM^2/R. For the Earth, that is 2.25 x10^32 J, requiring 1.25 x10^12 tons of antimatter, a chunk about 7 kilometer across. Yes that does mean to generate the beam the Death Star used it had to totally convert about 1000 cubic kilometers of mass to energy to power the beam. Conversion losses better be small, 1% losses are enough to boil a chunk of solid iron about the size of the moon. Rule 1 of Space Opera, NEVER check the math. You'll spoil the great plot idea. If you want to reduce the planet to fine particles, but can tolerate it if they recombine in a few years, you only need 71% as much. If you just want to strip off the crust, you need about 5 x 10^29 J, or 3 x10^9 tons of antimatter. If you will settle for just melting the entire crust, you only need about 10^28 J, or about 3 million tons of antimatter, to boil off the atmosphere and the oceans you need about 20% of that, to just start to boil the oceans about 3%. -- MA Lloyd (malloy00@io.com)