When I asked him for his planet causing the boom calcs he sent me this. I make no claims to the actual science in the thingy, nor did I fake this or change this in anyway from the E-mail sent to me.
Volumme of a sphere of "heavy" metals 5Km O.D. The smallest size postulated
that I could find. The size varries between 5 and 80Km. in the search that I
made. 2500M^3 x Pie x 4/3 = 6.5^10 M^3
Density? Since the pressure at the center of the Earth's core should be many
times the pressure of a nuclear bomb's implosion and that routeenly results
in compression factors of more than 40. I have used 20 as a density
Explosive pressure.= <31,000Kg./Cm^2! After inertial multiplier
Mass of Earth above every square centimeter of the "heavy" core =
R.=250,000Cm.^2 x 3.14159 = 1.963Cm.^2 = surface aria of 5Km sphere.
Mass of planet. = 5.974^24Kg. / 1.963^11 Cm^2 = >3.0^13Kg./Cm^2
The above makes a compression factor of 20 seem reasonable to me. That makes
every cubic meter of core mass 379 metric tons.
Volume of 5Km. sphere. = 2,500M.^3 x 3.14159 x 4 / 3 = 6.5^10M.^3 x 18.95 x
20 = 2.464^13 metric tons, or 2.464^16 Kg.
At 50% efficiancy, a number easily acheaved by modern weapons that are not
tamped by the inertia of 6^24 tones of planet and a many kilometer thick
secondary fisile shell for a increased yeald, both things that increase
yealds dramaticaly. That makes 1.09^30 Joules, more than enough to acount
for the effects as seen on film.
(2.464^16 x 8.9^13 J/Kg.)/2 = 1.09^30
If any of these very conservitave assumptions are too low, then the number
gets very much bigger very quickly. if the fissile core is ~8Km. instead of
five, or the efficiancy goes up because of the tamping, or because of the
high nutron flux to start, for instance. The first nuclear explosion was
started by only 3-8 nutrons, average guess <5, according to some sources.
The U-238 decay series is U-238, 4,500,000,000 YEARS, TO, Th-234, 24 days
toPa-234,2.1 min, to u-234, 250,000 years, to Th-230,80,000 years, toRa-226,
1,600 years to, Rn-222, 3.82 days, to Po-218, 3.05 min, to Pb-214, 26.8 min,
to Bi-214, 19.7 min, to Po-214, 16 mS, toPb-210 22 years, toBi-210, 5 days,
toPo-210, 138 days to Lead, Pb-206 all of which are less dense than U-238
and Pu-239 and would surround the pit as it decays. Every single element on
that list will fission when struck by a fast nutron and act to boost the
yeald when struck by that ever elusive "fast" nutron that is a minor, 17%,
byproduct of the fission reaction. If any of those elements were more
effective that the initial statements above, the total yeald could easily go
to 1^31J to 2^32J.
The energy required to supply the origional nutron flux, sufficiant to
fission the entire core, could be miniscuel in compairison, say 2^18J to
4.5^19J. ( A 20-1 ratio of nutron energy depending on whos book you read.One
metric ton of nutrons accellerated to fast nutron energies instead of the
socalled slow "thermal" nutrons used for conventional nuclear explosives.
Remember that almost anything will fission when struck by fast nutrons.
Given that the chain reactions will not be self sustaining, a very large
imput will be required to ensure that enough of the pile is fissioned so
that the 17% of fast nutrons liberated will eventialy fission the entire pit
as the reaction dies down. About three generations to fission an additional
21% beyond the origionaly targeted core.