I’ve been thinking about superheroes a lot lately, and how my favorite characters are almost always the ones with “utility” powers. They don’t have the pew-pew offensive abilities, but they do a lot of nifty things, like teleport or turn invisible or walk through walls. This last one is relevant to a story I’m writing, which involves a character who can “phase” through solid objects.
Phasing is most associated with Marvel’s Shadowcat a.k.a Kate Pryde, whose entire powerset revolves around being able to make herself intangible. She’s able to do a lot of really cool things with it, and even though she can’t control the weather or have adamantium claws, she’s used it pretty effectively on battles and missions.
In the comic books, this ability comes from her being a mutant, and though I don’t normally require any more explanation than that, the project I’m working on is a bit more grounded (and set in a world that does not have mutants as generally understood). So I looked into whether and how this could potentially work in real life.
In The Physics of Superheroes, physicist James Kakalios explains how DC’s Flash has also been able to pass through solid walls by controlling the vibration of every atom of his body and matching it to the vibrational frequency of the atoms in a wall. Of course, I didn’t read The Flash (this was also a really old story), and I found that absolutely fascinating.
Going down this rabbit hole, I had assumed such an ability would require rendering a body less dense or intangible in some way. After all that’s how it’s usually described in books and media, like ghosts or Kate Pryde or Vision. As it turns out, passing through barriers is not a matter of tangibility at all but vibration and probability.
The book also explains the phenomenon called “quantum tunneling”. As it turns out, there is a non-zero probability that an electron can move from one point in space to another through a barrier. The probability of going through is very , very small, but not impossible. The process by which the particle moves through the barrier is called tunneling (though that’s a misnomer because no tunnel is actually created).
How would this work in a larger body, like a human for example? Because the probability is already so small from electron particles, it is much smaller on the scale of a Kate Pryde. Again, small but not impossible. To follow quantum tunneling principles, a human body would have to run against a wall 1) really, really fast and 2) millions of times per second. Chances are, one of those tries will allow the body to phase through. Infinitely small chances, but still.
Viewed from the quantum physics lens, Kate Pryde’s superpower is thus not “intangibility”, strictly speaking. It also doesn’t involve altering one’s density, or reconstituting into mist or ether or anything like that. Rather, Dr. Kakalios describes her ability as “maximizing her tunneling probability”. Which makes her more like Domino (And raises the interesting possibility that Domino too can phase through solids)!
