I love that every Sci fi show eventually does the "out of phase" episode, and I love seeing the fun twists and flavorings they use to make it "their" version.
Like Stargate sg1 and their crystal skull radiation and advanced dimension-shifting technology episodes.
And my personal favorite lampshading for this is actually from Stargate. in the in-universe parody show "Wormhole X-treme" one of the main character parodies asks "if I'm out of phase, why don't I fall through the floor?" and the response from the writer/director/producer/whatever he was, was something along the lines of "I'll have to get back to you on that"
My favorite part is all the inside jokes they pack in as well. You don't really get all of them as a viewer, but I've watched every episode with commentary, and a lot of interviews with a lot of the directors, producers, prop/costume/sfx people.
Nothing beats the "special effects coordinator" guy screaming BIGGER at everyone after they show him progressively larger explosive effects.
In Batman Beyond, the out of phase person is a bad guy. He's using a machine to control his phase. Eventually he loses control of it and he really does fall through the floor. He's stuck in the center of the earth for the rest of the show.
EXTREME WARNING if you have something important to do today. The above link is to TV Tropes. It's too late for me, but you still have a chance to be productive today!
I believe there was originally a line of dialogue about there being resistance when they pushed through objects, which was supposed to explain why they don't just fall. That line was cut, but IIRC it is still referenced indirectly when Geordi's hand gets zapped and he says that there was more resistance to pushing through stuff afterwards.
That wouldn't explain why there is enough resistance in the floor to stand and walk, but not enough resistance in walls to prevent them from easily passing through. Presumably their mass and the pull of gravity are unchanged, so the resistance would have to be enough to counteract their weight. And even if they did weigh less, they still propel themselves forward through walls by pushing off the floor, so either the floor needs to be more solid, or they should be nearly weightless and move by paddling their feet through the floor until they build up momentum enough to smash through a wall. Also, if they are applying pressure to objects they pass through, shouldn't people they touch feel it?
Personally, I'd probably explain the floors specifically being impassable by blaming it on the way the artificial gravity is generated.
I don't have a good explanation for how they can breathe, how they see without interacting with light, how they can hear clearly when matter isn't really touching them and therefore can't conduct sound, etc.
I don't have a good explanation for how they can breathe, how they see without interacting with light, how they can hear clearly when matter isn't really touching them and therefore can't conduct sound, etc.
That is obviously due to a phase shift in the quantum fields, which is correlated to the mass of the interacting matter (through the Higgs field). This leaves you interacting with light stuff like air and light, but prevents you from interacting with solid stuff like walls (and potentially force fields, if that would fit the episode).
Of course, artificial gravity affects the mentioned phase shift by bending spacetime.
And now I must go, before my handwaving creates enough energy to form a black hole.