- #1

- 376

- 0

there is about a 50% chance that at least one atom remains. What assumptions are you making?

answer:

so P (at least one survives past t) = P (no one does) = .5

now, I'm making the assumption that Prob of survival is so small and since n is huge, this follows a poisson disn.

thus .5 = P(k=0) = e

^{-μ}

then μ = ln 5

now μ = np = 10

^{20}* e

^{-ln 2 t}. ln 2 is my parameter since half time is 1 century.

thus t = ln(10

^{20}/ln 5) * (ln 2)

^{-1}≈ 65 years