SCIENCE: Circumventing the Solid

Have you ever thought to yourself: Man, opening doors is such a pain, I wish I could just walk through things. Well, you may not have noticed it but there’s been something of a renaissance of phasing characters. J’onn J’onzz is running around in the Brightest Day, the new Vision is doing his thing over in the Children’s Crusade and Shadowcat is back from biting the bullet. One thing these characters have in common is they can phase through solid objects by either altering their density or rearranging their atomic structure. This has always been one of those powers that intrigued me because it’s not as obviously offensive which means creative solutions for making those characters formidable opponents (if you ignore all their other options). But how does it really work?

What were the odds of finding this image so easily?According to Martian Manhunter and Vision they alter their density to the point where they can pass through other objects. Density is the amount of stuff in a given space, or to throw out some math its density = mass / volume. The first problem is that when J’onn or Vision decrease in density they should change size, because mass cannot be destroyed they’ll have to spread their personal mass across a larger volume to decrease density. Humans are mostly solid and liquid, Martian Manhunter is an alien but I’ll assume he’s something similar and Vision is an android so I imagine he has slightly more solid than liquid. The solid of a given material is generally denser than the liquid form which is in turn denser than the gaseous form. So a mostly solid humanoid might need to get pretty big to be as light as a gas, which is a useful state to be in to avoid getting punched. This size changing trick is one that I’ve never seen utilized in the comics before but could be a cool trick to intimidate the hell out of an opponent. The corollary to this is that when these characters get denser they should get smaller, but probably less dramatically than the alternative since they’re already mostly solid. I’m cool with the notion that you’d be tough to punch if you were mostly a gas but would that allow you to phase completely through solid objects? Well probably not, if gases could just pass through objects balloons wouldn’t work all that well. So just because you can’t fight the wind doesn’t mean you don’t still need to breathe, i.e. you hand goes through air but you can still hold it in your lungs. Martian Manhunter, a guy nearly as strong as Superman, could walk through your screen door. That’s about it.

Shadowcat is a more interesting case because they have attempted to give her powers a plausible explanation. She can alter the vibratory rates of her atoms so they’re able to pass through the empty space of the atoms of the object she’s phasing through. This may sound absurd to anyone who’s ever had a really bad day and ended up punching an oak dresser. It certainly doesn’t feel like there is a whole lot of empty space but it turns out there is. In an atom you have a nucleus and electrons orbiting it. Even though the distances we’re talking about are really frickin’ small, there is a large amount of relative empty space between the nucleus and its electrons, basically if the nucleus of an atom was the size of a marble the entire atom would be the size of a football stadium. The electrons move around in orbitals that keep them at a specific distance from the nucleus. The reason solid objects still feel solid is the electrostatic force between the negatively charged electrons and the positively charged nucleus. Theoretically, Shadowcat’s powers could work if she really was able to make it so that all her atoms “missed” the atoms of the object she was passing through, which I think is what they were driving at with the whole “vibratory rates” thing.

The matter gets complicated by Quantum Theory because according to Quantum Theory the electrons don’t move around those orbitals like a planet around a star, rather they move around the orbitals in probabilistic fields creating what’s called an electron cloud. This means we can’t really ever know where a specific electron is at any given moment, making it that much trickier to avoid hitting it while phasing. Like Nightcrawler’s teleportation, this seems to just be one of the issues her powers already compensate for in some way, but when discussing the science behind it all it’s worth noting. I remember a physics class where this very concept was being discussed and someone asked if this meant that there was a chance, albeit however small, that your atoms could spontaneously line up and allow you to pass through a wall. The professor answered that indeed yes, it was in fact a possibility, but in order to give yourself decent odds of phasing occurring you’d have to walk into a wall repeatedly for longer than the age of the universe. No big deal, right?

The final issue with her powers is one of gravity. Presumably gravity still works on Kitty while she’s phased because her atoms still have mass. But if she’s not interacting with solid matter what’s preventing her from being pulled towards the center of the earth? Think about it, you’re sitting on a chair; if that chair suddenly disappeared you’d fall on the floor. If the floor suddenly disappeared you’d fall even further. That’s kind of how I imagine things happening with Shadowcat. If you’re suddenly intangible but susceptible to gravity you’d keep falling until you either un-phased or reached the center of the earth. In her Wikipedia article there’s something in there about her using the air around objects blah blah blah. I honestly cannot make sense of it, and I doubt it actually does make sense, so we might as well say Kitty has some sort of localized gravimetric field while phasing to prevent this from happening. There are plenty of other characters that can fly, lets toss the girl a bone so she doesn’t die somewhere around the mantle.

So those are your options for walking through stuff. You can because gaseous, gigantic and pass through the permeable or you can defy the probability of the quantum. They each have their benefits and their downsides, at the end of the day I'd say it'd just be easier to get used to opening the door.


Some days Ryan Haupt feels like he's just phasing through life.


  1. These are just great, just damn great

  2. There have been a number of Kitty stories wherein she’s continuously fallen through objects. The "air walking" thing is based around the idea that Kitty can selectively unphase a very small amount of surface area to balance on an molecule of air. I think Mark Waid also explained the Flashes (all of whom could at times vibrate through things like Kitty does) escaped falling through the planet because of how fast they were going vs. how thin the object was they were passing through. Waid also had an era where Wally could phase through objects, but that he wold pass off so much kinetic energy the object he passed through would explode.

  3. @Prax YES! that was my favorite power that wally had and when he first got it he used it quite a bit. that and the thing where he could drag other moving objects along in his wake

  4. @PraxJarvin – While writing this I had completely forgotten that the Flashes could also phase. D’oh! I like the explanation for getting through things due to relative thickness and extreme speed, but remember: A bullet dropped from your hand and another bullet fired horizontally from a gun will hit the ground at the same time! Gravity’s a bitch.

  5. @haupt agreed, gravity is indeed a bitch

  6. This whole story is a little transparent…. I can see right through it!

  7. The funny thing about pushing against a wall to eventually pass through it is that it’s also possible that you will just pass halfway through.

  8. Believe it or not, JULIE POWER used the "get larger by getting less dense" trick in Power Pack (when she was Molecula, Mistress of Density).  Oh wow, now it’s all flooding back to me.  It was an issue that was a crossover with Sunspot and Warlock when they were slumming in the "Fallen Angels" mini.

  9. Besides the gravity thing for Kitty, I think breathing would be important too. But again, that’s a nuance I think we can do without.

    Nice article, Ryan!

  10. @powerdad I thought about getting into the breathing thing, I think the long and short of it is if her lunges are intangible than they couldn’t hold air, if her hemoglobin still functioned while intangible perhaps it could just diffuse O2 and CO2 for whatever she was passing through? Like her entire body is a fish’s gills. Really only works if what she’s passing through has enough O2 and even then it requires her hemoglobin to function differently than the rest of her body. Interesting problems to consider. Thanks for the love!

  11. @Haupt, that’s a really cool idea about "fish-gill-phased-bodies".

    Storyline-wise Astonishing X-Men confused this whole matter even more so. In one of the issues Kitty has phased herself and Emma inside of a concrete buttress for an extended period of time, thus there is no air around them to possible breathe/filter (only concrete).

    Okay, I’ve got it!  Kitty is able to tap into a dimension which is composed of only oxygen and nitrogen…   😉

  12. @powerdad – NOOOOO not dimension tapping again. Damn you, Quantum Physics!!

  13. If you are going to start messing with the vibrational states of all the atoms in your body such that they do not act like normal atoms and will "phase" between normal atoms, it is entirely possible you might find a way to be immune to gravity. General Relativity makes no allowance for this — you will slide down the curvature of space phased or not — but it has long been theorized that there may be a more particle way of describing gravity. That gravitons might exist that would carry the force of gravity. This of course is where Quantum Mechanics meets relativity and is often none as the Grand Unified Field Theory, or Theory of Everything and is the present Holy Grail of physics. This is where string theory comes in as well, which is literally a universe made up of tiny vibrating strings   (vibrating in something like 11 dimensions). All those particles, photons, and maybe gravitons are just vibrations on those strings.

    Bottom lining it: If you can effect your vibrations on that level, yeah you could avoid gravity. Maybe even adjust yourself to feel enough gravity so you didn’t fly off the face of the earth instead. 

    Now the breathing thing… Previously I would have said she just held her breath or phased nearby oxygen. Now the only explanation that makes sense is that when she phases she disconnects herself from the normal energy production and transmission processes of biology. She must tap into some other power to keep herself alive and moving. 

  14. @JimBilly4, mind you I’m just having fun here, but you also need to make sure whatever "breathing" thing we come up with here needs to work for any and all other people she’s phasing at that moment (such as Emma Frost in my above example).

    There is a very fun episode of Star Trek: The Next Generation from the 5th season titled "The Next Phase" (see the episode at which has the same sort of problem occur when Ro and La Forge are "phased" out of "normal" space (making them invisible and intangible) and for a short while Ro believes she is a ghost who needs to make peace with the world before moving on to the next life (or whatever).  The episode is a whole big bunch of fun, but if you think about it too much you realize we end up with all of the same sort of Kitty Pride issues mentioned here.

    So sorry, Ryan, it just looks like we need that hyper-atmosphere-dimension! One for inhaling, and another for exhaling, maybe? Perhaps we can double up with the one where Colossus’ switches his metal and flesh body (that was the original explanation of Colossus’ as he changed forms, as I recall).