Fatman weighed 5 tons and used 2.65 tons of explosives
2.65 tons of tnt can move 120000 tons 1 foot in the air
that's 240000000 psi
plutonium core had a surface area of 40 inches
the explosive device itself had a surface area of 11308 inches
that's 21000 psi on the plutonium core
thats the weight of a single semitruck balanced on a quarter
you can find this pressure just 2 miles into the earth
the marinas trench has a pressure 16000psi
the density of seawater down there is *1.03 normal density
thats a .03% increase at around 75% of the pressure fat mans core felt
water is 16 times lighter than plutonium (not included)
the lowest yield nuclear bomb is said to achieve a 23% increase in density
fatman was said to have achieved double density
Fat man would have only caused a .04% increase in density
tnt is strong but its not beyond the things we see in nature and nature does not show anything remotely resembling double density
225000*2000=450000000psi
240000000/11308=21000psi
16000/21000=.76