I was posed an interesting problem which relates to upsizing quantum physics, that boils down to a math problem. I was trying to calculate the probability that a 1000 tonne bridge would be found 1m from its resting position, if you model it as having the ground energy of a harmonic oscillator.

Eventually the problem boils down to calculating 1 - Erf(7.79x10[itex]^{19}[/itex])

which is the same as calculating Erfc of 7.79x10[itex]^{19}[/itex]

as you might be able to figure out the number is unbelievably small.

i was womdering if anyone might have a good approximation to it, or an interesting way to calculate it on mathematica/matlab?

ive given a few approximations a try already, but have been rather disappointed with the results.