Thinking about intangibility while revising. I’m pretty sure I already made this post now, but whatever. Superhero stories tend to go for a handful of explanations for “character can phase through solid objects” and I’m gonna look at them scientifically
Density shifting. No. If you’re shifting your density down, the only way you’re gonna go through that wall is if it’s porous and your molecules are sufficiently small. If you’re shifting your density up, you might go through that wall but the wall’s not going to come out of that looking good. The only way this could work is if you’re shifting your density enough that your individual atoms/subatomic particles can tunnel through the barrier, but then either your volume has massively increased or you’ve lost a lot of mass. Where does it go? Where does it come from?
The Flash had Barry go through a wall by vibrating at the natural frequency of air. This is stupid, and I only mentioned it to state how mind-numbingly stupid it is, if you’re going to make something remotely sci-fi adjectent at least do enough research to not sound like an idiot pretending to be a scientist
Quantum tunnelling. Now this is interesting. What quantum tunnelling essentially comes down to is that the Schrodinger equation - which links the potential a particle moves in to the wavefunction, a description of how likely you are to find a particle in a given place and time - predicts that, for a finite potential, there’s a chance that the particle will pass through a barrier even if the potential in the barrier is larger than the particle’s energy (i.e. classically, it should not be able to pass through)
Now, we don’t actually know at what scale quantum weirdness stops, or even if it does stop, but since quantum tunnelling depends on probability, and it’s the one explanation for phasing through objects that kind of holds up, I’m just gonna suggest something here:
Phasing, as a superpower that uses quantum physics, is a specialized form of probability manipulation
Being able to link superpowers like this is one of my favourite things
And - worth noting - if this is the case, then depending on how flexible this power is, you can do other things. For example, since you’re essentially manipulating the wavefunction of you, you can use this same power to teleport
And if we extend “you” to objects you’re in contact with (like the clothes you’re wearing, or in this case, something you’re holding), well, alpha decay depends on quantum tunnelling. You could manipulate the wavefunctions of particles in something you’re holding and make it emit alpha radiation, which will 1/ alter its chemical composition, 2/ ionise nearby surfaces, and 3/ cause serious health issues for anyone who eats it (alpha radiation isn’t very penetrating - it can be stopped by paper - so you’re safe as long as you don’t eat it)
