In the TNG episode "The Next Phase," Geordi and Ro are "phase shifted" such that they are invisible to the entire crew, and they can walk through walls.

  • But why didn't they fall through the floor?
  • And how could they breathe or speak? Weren't their lungs and vocal chords out of phase with the air, too?
  • The out of universe answer is clearly that otherwise the second the Enterprise started to move two main characters would have started floating in space. Nov 4, 2014 at 16:37
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    @Bachrach44: As the question itself explains, the problem is much bigger than that. The instant they were phase-shifted, they would have suffocated.
    – Flimzy
    Nov 4, 2014 at 16:44

6 Answers 6


I'm sorry I don't have a link for this, since it's been a long time since I read it (and may have read it off the internet). Ron Moore, one of the writers of that episode (and, at that time, one of the co-producers) has said that they did have an explanation for this written in the script. Originally there was something about "surface tension" and how they didn't go through walls unless they pushed, so as long as they didn't push too hard on the floor, they wouldn't go through. And notice, due to gravity, that it would be easy to push against a wall, but not against the floor (without jumping on it).

The problem was production realities. In short, it was in the script, but didn't make it to the final print of the episode.

This also brings up some interesting points and issues regarding television and film production. On this site most people that ask questions about what is going on inside a science fiction or fantasy story want an in-universe explanation and sometimes people give answers like, "Because the writers are stupid," or, "The writer wanted it that way." I can understand the 2nd, but the 1st is not only a poor answer, but is invalid. Especially when it comes to TV and film.

Few know just what it takes to create even the 1st draft of a screenplay and even fewer know what it's like getting that screenplay into something that can be produced and produced on a budget. This can be a factor in film, but it is always a major factor in television. You need a new script every single week. It has to be a compelling story and you have to keep people interested for 60 minutes and through 4-5 commercial breaks that can last over 4 minutes per break. The story has to be interesting enough that people are willing to waste over 25% of the time they're watching it on being assailed by commercials.

A TV or film script goes by at about a minute per page. So a script for an hour show is 55-60 pages (or a little over that). And it has to be divided into acts, sometimes 5 (like in ST:TNG) but usually in 4 acts. You have to have a cliffhanger at the end of each act and have to watch for pacing, so you don't drag, or have slow scene right after a fast paced on. You need to be sure there is enough time in the script to allow characters to interact and if you're dealing with long story arcs, you have to make sure you include scenes to the long arcs.

An idiot cannot write a TV or film script that will be produced. It's not an easy thing to do.

But, beyond that, you have re-writes. A freelancer may turn in a script, then the story editor, the producer, and even executive producer will make changes (not "may" or "might" -- they WILL make changes). And then there's the read throughs, where it's possible they find scenes or lines that don't work. And even when the script gets in production, changes are still being made for many reasons. (Maybe they don't have time to do an extra setup in the conference room, so they have to change a scene to the ready room, and that means other changes -- or if they don't get a scene shot today, they may not have the actor tomorrow and need to write them out of a scene.)

And that carries us only until the filming is complete. FX can create issue and then, once all the footage is complete, it has to be edited. And a scene that timed out in a reading as 1:30 might run 2:05, with no way to cut it. That means 35 seconds has to be cut from somewhere else in the script and someone (rarely the writer) gets to pick what will be removed to make it work.

Throughout each step, the writer, producer, editor, director, and even other people, have to take a lot of factors into consideration. Is the pacing working? Is that scene believable? Did that line that looked good just plain suck when the actor read it aloud? Is the script running too long or too short?

If it's long, what do you cut? Do you cut a beat in the plot point so you have time to explain why Geordi doesn't fall through the floor, just so about 1% of the viewers will get that point? Or do you cut out the explanation that only 1% will care about in the first place?

Making movies and TV shows is complex. It is extremely rare that a script comes out shorter than the allotted time for the episode. (One of these very rare cases is the famous and excellent episode of The Mary Tyler Moore show, Chuckles the Clown Bites the Dust.) So things have to be cut. Some by the writer, but most by other people along the way. Each person editing the story will have a different eye and different concerns, so no one person could be blamed for an omission or error in a script. This question brings up just one example, but I'm sure, with a little thought, we can all find many others.

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    And notice, due to gravity, that it would be easy to push against a wall, but not against the floor (without jumping on it). - How do you mean? Just by standing still, your entire weight is pushing on the floor, but you have to make some effort to push against a wall with the same force.
    – Izkata
    Jun 2, 2012 at 5:13
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    @Izkata: It's also possible that the place you read it is in another answer -- this was just discussed on meta, and there's a link there to where I've brought this up before.
    – Tango
    Jun 2, 2012 at 6:32
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    "An idiot cannot write a TV or film script that will be produced. It's not an easy thing to do." -- you've obviously never seen anything from ABC. Jun 3, 2012 at 23:29
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    @MarkBeadles: That's after the network execs get their way with all their "notes."
    – Tango
    Jun 4, 2012 at 0:36
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    +1. The answer both in and out of universe is "because of Sci-Fi". The real truth is that being out of phase is more complex than Geordi's explanation, and we don't know how the ship's gravity generators (or even floors!) work. Do we really want half of every episode of a sci-fi show to be a detailed explanation of the concepts in that episode? Maybe every episode should be prefaced with a disclaimer, "Explaining the scientific principles of this episode is left as a speculative exercise for the viewer"
    – komodosp
    Jul 21, 2022 at 8:33

The phase shifted crewmembers are not completely intangible. It seems to take a small amount of effort to pass through objects. There is one point in the episode where one of them (in the background) puts on hand on a control panel. The floors, being made of tough material, may be even harder to move through (though still quite possible for sufficient force to push someone through the hull). The characters don't have a lot of leverage to move through the floor normally so it never happens. And the effect of the artificial gravity on their phase shifted bodies probably doesn't exert enough force to move through the floor.

  • 2
    You could even suppose that the artificial gravity generators are embedded in the floors and that they have some kind of repulsive antigravity effect when you get within a tiny distance of them, even if they have an attractive effect from further away. But I still can't think of an explanation for the other problem mentioned in the question: how were Geordi and Ro able to breathe and speak? Shouldn't the air molecules have just passed right through their phase-shifted cells rather than being absorbed?
    – Hypnosifl
    Jun 13, 2014 at 20:46
  • OK, a possible explanation for the breathing/talking problem that just occurred to me--maybe Geordi and Ro were equipped with something like the "life support belts" in the animated series? en.memory-alpha.org/wiki/Life_support_belt ...they were supposed to provide each person with a force field containing a personal atmosphere, and since they were still able to talk on airless planets, perhaps they had an always-active communicator system too.
    – Hypnosifl
    Jun 13, 2014 at 20:51

I asserted that the floors have a material that cannot be passed through. Perhaps a specific component of the alloy. Not any other alloy (like the duraluminum hull) seems to have it.

They did not try expressly to fall through the floor, so we are not sure if it can actually happen.

The mayor question I have is why didn't the main characters wonder more about it. Knowing that they didn't know this might explain why, the characters did not expect to fall through the floor and thus couldn't.

The aforementioned surface tension doesn't make much sense, as LaForge's experimenting made him less able to pass through things which noticeable when pushing through things. His one hand passed through as if there was no obstacle at all, the other required minor effort. It is also not consistent with gravity being introduced.

Side note: Given the affected people weren't floating freely Higgs Bosons still affected them. The affected ones did not cast shadows but could still see each other, suggesting photons and bosons were also present in that affected state. The energy leaked into affected photons and bosons must be at least 50%. This all leads to significant scientific questions about power efficiency. LaForge didn't bother with that though, strangely. Nor was the science ever used again for infiltration or similar acts.


Why would they? They're on a starship in space. There's no real mass, except for the ship, to pull them DOWN through the floor. It's well established that ships use some kind of "gravity plating" in the floors to make artificial gravity happen. So they'd only get pulled down as far as the gravity plating that is pulling them, and no farther.

On a planet it would be a different story...they should fall straight into the core. But in this case the question doesn't even apply.

  • I hope you don't mind, but I edited your question to make it less a comment, and less questioning. Jun 13, 2014 at 21:06
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    If you're in space, and a force pulls you in a certain direction (relative to a starship, say), then when the force stops acting on you that doesn't mean you will suddenly stop (relative to that same starship), instead you will keep moving at the same velocity you had when the force shut off. So if Ro takes a step and lets her foot fall back to the ground, even if there's no force acting once it moves past the gravity plating, it should just keep moving in the same direction rather than stopping (which requires a counter-force to decrease its velocity).
    – Hypnosifl
    Jun 13, 2014 at 21:24

They were not 100% phased. That's why Geordi found it hard-er, to push through objects after being exposed to the radiation. Similarly, on an episode of Eureka, when Carter was phased, he was pulled along when someone walked through him.

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    Hi, welcome to the site. Can you cite clearer evidence that they weren't 100% phased (as you put it)...? And can you explain why they passed through everything except the floor with ease...? Jul 21, 2022 at 8:32

They are contained within an envelope of phased space which extends marginally beyond their bodies. Any matter that enters the envelope also becomes phased which means they are able to breathe and interact with material immediately close to them, such as their clothes. When they walk through things those objects also become partially phased as they walk through and the matter enters the envelope. However as it does not completely enter the envelope they are not able to interact with it and it also remains visible. The molecular disruption creates a chroniton field.

The gravity plating in the floors counteract the force of their downward movements which is why they don't fall through the floor.

  • Hi, welcome to SF&F. Do you have any evidence to support this? If matter entering their phase envelope becomes phased, then they wouldn't be able to walk through anything. The moment they touched something it would enter their phase envelope, and whatever that was - or at least the portion they were touching - would be solid to them. It evidently doesn't work that way because they can walk through walls.
    – DavidW
    May 22, 2020 at 0:04
  • The evidence in the show doesn't support this. If they carried around a bubble of phased space, they would have been able to partially phase people too. Somebody like Data almost certainly would have noticed such a thing, and not have had nearly such a difficult time figuring out what was going on.
    – T.J.L.
    May 22, 2020 at 14:34

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