Ask yourself: How does The Vision phase through a wall? Canonically, he does so by changing his density. What about The Flash? I think most people would say that he vibrates really fast. Wrong and wrong. Science fiction has been lying to you for a long time. And in my latest Because Science, I’m looking at the most famous phasing superheroes to figure out how they really do it.

Vibration or density or mutation won’t let you outrun the Juggernaut (“…female dog!”), but one phenomenon will let all three pass through barriers: quantum tunneling. With physics as we experience it, you can’t avoid a wall without using some energy to go around, over, or through it. Quantum mechanics, the physics of the universe’s smallest scales, works differently.

Even if a particle doesn’t have the energy to get over or through some barrier, you still might see it pop over to the other side. In quantum mechanics, particles are more like probabilities than solid objects. There is a chance to find them in one location or another when you look. So, if a particle’s probability wave encounters a barrier, there is a small chance (if the barrier is not too big) that it will be on the other side. It sounds weird because it is.

Complete control over one’s quantum state may be fiction, but we understand quantum tunneling enough to make microscopes harnessing the phenomenon. It’s complete fact.

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