[deuterium17]

When I was in p-chem a few years ago, my professor said that it is highly improbable, though not impossible, to walk through a wall (according to quantum mechanics). I'm just curious, what is the probability of walking through a wall (just a ballpark figure), and how would a person go about calculating that? I've had some statistics and a couple years of calculus. This question is just to satisfy my curiosity, not for class. Thank you.

[Borek]

Look for tunneling.

[Donaldson Tan]

quantum tunnelling

[Dude]

I've heard these silly analogies before also.  I believe that these comments are taken completely out of context to incite imagination in first year college students.  The correct answer is 0 for most walls.  You would be far closer to truth by calculating your probability of walking through a wall using classical Newtonian physics along with fracture mechanics for the material that the wall is constructed of.  Quantum mechanics doesn't apply to objects as large as a person and I look forward to the first report of teleportation in Science or Nature (although it was reported to have occurred for a ship going from Philadelphia, PA to Newport News, VA in the 1940's without documentation "The Philadelphia Experiment").

Just going off the top of my head, the odds of "walking through a wall" are staggeringly low.  First, there is the temporal aspect that this must occur for the duration of time corresponding to the object velocity and wall thickness.  Second, ALL of the person's molecules must be in the low probability region simultaneously (have you ever computed how many molecules are in the human body?).  Third, what does "walking through a wall" mean?  It really becomes a permeability problem, not a quantum mechanics problem.  Do your molecules shift to fill in the vacant pore space in the wall?  Is the "wall" really necessary?  Perhaps it's really a time warp and the "wall" is just an unnecessary physical construct to represent the "real" world.