Would Star Trek holodecks physically affect you once you exit the Holodeck?

Meaning, if someone programmed a holodeck to dump a bucket of water over you head, would you have wet hair (outside later on)?

  • 1
    One would assume that the hair would be wet in the holodeck. But afterwards . . . ?
    – Martha F.
    Commented Jan 8, 2012 at 20:57
  • I meant afterwards OUTSIDE the holodeck. Edited.
    – TR14
    Commented Jan 8, 2012 at 21:02
  • 1
    Well, with the safety off, it could kill you (or convert you to energy, as happened in on ST:V episode); I'd say that physically affects you.
    – Kevin
    Commented Jan 8, 2012 at 21:10
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    And of course what happens if you eat and digest holomaterial? Would the tissues that are built up by it simply vanish into nothingness when you leave the holodeck? That is something that has always vaguely freaked me out.
    – fluffy
    Commented Jan 8, 2012 at 22:58

2 Answers 2


I believe the answer depends somewhat on how the holodeck is programmed.

BUT there is a classical example of the water being "real", so it's certanly one of the feasible outcomes with right programming:

In "Encounter at Farpoint", Wesley Crusher falls some water (a river IIRC) while in holodeck, and exits holodeck later on while still being wet.

I even found a screenshot (Yay Google image search)

Riker (left) and Data (right) stand behind a soaking wet Wesley Crusher who is speaking to Picard (seen from behind, over his left shoulder).  The open door of the holodeck, showing a forest environment, is in the background.  The picture has captions:  Wesley "I'll get something to clean up this mess." Picard "See that you do."

A second frequently cited example is a piece of paper held by Data in "Elementary, Dear Data":

Data, right with his back to the viewer, is dressed in a Holmesian grey deerstalker cap and cape and holding a piece of paper between his hands, showing it to LaForge, facing him on the left, dressed in a brown suit with a long jacket over a waistcoat and a brown bowler hat.  Several other crew can be seen walking in the background of the Enterprise corridor.

Interestingly enough, this seems to be a BUG rather than a feature (e.g. contrary to canonical understanding of holodeck technology). Wiki Holodeck article has this to say:

Matter created on the holodeck ("holomatter") requires the holoemitters to remain stable and will quickly disintegrate if it is removed from the holodeck without a mobile emitter to sustain it, although this principle has been overlooked in some episodes.

Writer Phil Farrand has often pointed out how in many episodes matter from the holodeck that gets on a real person still exists when the real person exits the holodeck. In "Encounter at Farpoint", Wesley Crusher falls into a holodeck stream, but is still wet after exiting the holodeck. In "The Big Goodbye", Picard has lipstick on his cheek after encountering a holodeck simulation of a 20th-century woman. In "Elementary, Dear Data", Data and Geordi La Forge exit the holodeck with a piece of paper that originated in the holodeck.

This could be explained using replicated rather than holographic matter.

However, that last statement is unreferenced and I'm not sure that there's any canon references to holodecks incorporating replicator technology.

  • 1
    There is, somewhere. I remember a reference that overly simple objects (like water) are replicated instead, because the one-time replication uses less energy than continually sustaining them as holographic matter. (Though it may perhaps have come from a novel, so the canon could be questionable)
    – Izkata
    Commented Jan 9, 2012 at 0:02
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    The paper in the second image always puzzled me for a different reason: When Geordi takes it, he flips it over vertically to show Data a drawing of the Enterprise. Which means Data was showing it to Geordi upside-down, suggesting that... well, just that the two of them see the world in weird ways, I suppose. Commented Jan 9, 2012 at 17:36
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    In some episode (can't remember which, could be TNG or VOY) it is stated that beam-technology, replicators and the holodeck are highly related technologies. Also, it does make a lot of sense to replicate the water because even with the advanced processing power in ST I would imagine that it's still hard to realistically simulate (large quantities) water.
    – bitmask
    Commented Jan 9, 2012 at 18:18
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    It's probably a safety feature; imagine drinking a cup of water on the holodeck, and then walking out. All of a sudden, there's gaps in your bloodstream where the holo-water used to be, creating a bunch of small vacuums in your veins. That's got to have the potential to cause medical problems. Really, anything that has the potential to be ingested would have to be replicated.
    – Tacroy
    Commented Jan 9, 2012 at 19:38
  • 2
    I'm fairly certain the TNG tech manual doesn't make any reference to "holomatter". Instead, it says that objects that the user is meant to interact with - to pick up or move - are replicated. Objects they can just see but not touch are simply manipulated as projections. More complicated things that require active motion (people) are a combination of projections and shaped force fields.
    – T.J.L.
    Commented May 25, 2016 at 18:11

Yes. In the episode Angel One, Picard got wet from a snowball (even though he was in the corridor outside!)

Picard gets hit by a snowball from the holodeck

GIF from this site.

And Dr. Crusher was pushed into water by Data.

Dr. Crusher and Worf, in period attire, fall from the deck of a 18th century warship in a simulated sea environment.


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