# How's gravity supposed to work on a sci-fi spaceship **URL:** \ **Category:** Cafe Society\ **Created:** [September 18, 2009, 6:27pm UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626 "2009-09-18T18:27:15Z")\ **Posts on this page:** 15\ **Page:** 2
**Author:** ![boytyperanma](https://avatars.discourse-cdn.com/v4/letter/b/4491bb/32.png) [@boytyperanma](https://boards.straightdope.com/u/boytyperanma)\ **Post date:** [September 19, 2009, 2:17am UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/21 "2009-09-19T02:17:21Z")
In Star Wars they have grav-plates that make up the floors of the ships. They never attempt to explain the science behind them. In the novels the only reference I can recall was in ‘The Dark Fleet Crisis’ they were exploring long abandoned ships and malfunctioning grav-plates were a concern because when walking down a hallway stepping and stepping onto a grav-plate that had too high or too gravity could result in injury or death. For the most part people aren’t looking for realism in their Sci-Fi, so authors don’t need to explain the gravity and it’s easier for people to conceptualize spaceships that have a top and a bottom and are more like giant aircraft people can walk around on. As people mentioned in Star Trek outside forces cause them to get thrown about all the time. When was the last time you saw a shot of to ships nearing each other that were not oriented so their tops had the same direction. If they have their own gravity systems why would they do this? Is their some sort of space etiquette that even enemies follow that you can’t appear to be upside down to other vessels? ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [September 19, 2009, 5:24am UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/22 "2009-09-19T05:24:13Z")
It’s like this: The shows that don’t bother to at least mention the technology simply “suck.” My apologies. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [September 19, 2009, 5:28am UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/23 "2009-09-19T05:28:49Z")
ISTR hearing of ‘graviton plates’ in one movie or another. ---
**Author:** ![kitemaker\_chuck](https://avatars.discourse-cdn.com/v4/letter/k/a88e4f/32.png) [@kitemaker\_chuck](https://boards.straightdope.com/u/kitemaker_chuck)\ **Post date:** [September 19, 2009, 5:31am UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/24 "2009-09-19T05:31:41Z")
I hope this isn’t too off-topic, but how did they simulate zero-g in movies like Apollo 13? ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [September 19, 2009, 5:33am UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/25 "2009-09-19T05:33:16Z")
> [@kitemaker\_chuck](#): > > I hope this isn’t too off-topic, but how did they simulate zero-g in movies like Apollo 13? Many of the scenes in _Apollo 13_ were actually shot in zero-g. EDIT: [Cite](http://en.wikipedia.org/wiki/Apollo_13_(film)#Cast_training_and_filming). > [@](#): > > The actors then traveled to Johnson Space Center in Houston where they flew in NASA’s KC-135 Reduced gravity aircraft to simulate weightlessness in outer-space. While in the KC-135, filming took place in burst of 25 seconds, the length of each weightless period that the plane performed. The filmmakers would eventually fly 612 parabolas which added up to a total of 3 hours and 54 minutes of weightlessness. Parts of the command module, lunar module and the tunnel piece that connected them were built by production designer Michael Corenblith, art directors David J. Bomba and Bruce Alan Miller and their crew to actually fit inside the KC-135 airplane. Filming in such an environment, while never done before for a movie, was a tremendous time saver. In the KC-135, the actors moved wherever they wanted, surrounded by floating props; the camera and cameraman were weightless so filming could take place on any axis from which a shot could be set up. . ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [September 19, 2009, 5:37am UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/26 "2009-09-19T05:37:43Z")
> [@kitemaker\_chuck](#): > > I hope this isn’t too off-topic, but how did they simulate zero-g in movies like Apollo 13? They shot a lot of those scenes on a [“vomit comet.”](http://en.wikipedia.org/wiki/Vomit_Comet) ---
**Author:** ![Turek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/turek/32/18782_2.png) [@Turek](https://boards.straightdope.com/u/Turek)\ **Post date:** [September 19, 2009, 12:52pm UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/27 "2009-09-19T12:52:47Z")
> [@boytyperanma](#): > > For the most part people aren’t looking for realism in their Sci-Fi I think this is one of the defining characteristics between sci-fi and “hard” science fiction. ---
**Author:** ![Lynn\_Bodoni](https://avatars.discourse-cdn.com/v4/letter/l/e47c2d/32.png) [@Lynn\_Bodoni](https://boards.straightdope.com/u/Lynn_Bodoni)\ **Post date:** [September 19, 2009, 6:17pm UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/28 "2009-09-19T18:17:57Z")
> [@Turek](#): > > I think this is one of the defining characteristics between sci-fi and “hard” science fiction. I think it’s the defining characteristic between sci-fi and science fiction, even squishy science fiction. I’ll accept a new technology. I won’t, however, accept things that are scientifically impossible (sound in space, for instance). ---
**Author:** ![appleciders](https://avatars.discourse-cdn.com/v4/letter/a/85f322/32.png) [@appleciders](https://boards.straightdope.com/u/appleciders)\ **Post date:** [September 19, 2009, 6:32pm UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/29 "2009-09-19T18:32:28Z")
> [@Lynn\_Bodoni](#): > > I think it’s the defining characteristic between sci-fi and science fiction, even squishy science fiction. > > I’ll accept a new technology. I won’t, however, accept things that are scientifically impossible (sound in space, for instance). I remember a hard science fiction author (don’t remember who, sorry) noting that readers will typically accept one example of “things we don’t know how to do but we don’t actually know to be impossible” per universe. After that one freebie, readers get twitchier and twitchier until they actually start objecting. ---
**Author:** ![randwill](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@randwill](https://boards.straightdope.com/u/randwill)\ **Post date:** [September 19, 2009, 8:13pm UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/30 "2009-09-19T20:13:18Z")
> [@kitemaker\_chuck](#): > > I hope this isn’t too off-topic, but how did they simulate zero-g in movies like Apollo 13? In other sci-fi movies like **2001** wires and cameras attached to moving sets effectively simulated zero gravity. In older films sometimes they just had the actors stand on a elevated platform and moved him up or down with the actors feet below the frame. Also green screen super-imposed figures on separate backgrounds is widely used. ---
**Author:** ![Lynn\_Bodoni](https://avatars.discourse-cdn.com/v4/letter/l/e47c2d/32.png) [@Lynn\_Bodoni](https://boards.straightdope.com/u/Lynn_Bodoni)\ **Post date:** [September 19, 2009, 8:34pm UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/31 "2009-09-19T20:34:30Z")
> [@appleciders](#): > > I remember a hard science fiction author (don’t remember who, sorry) noting that readers will typically accept one example of “things we don’t know how to do but we don’t actually know to be impossible” per universe. After that one freebie, readers get twitchier and twitchier until they actually start objecting. I remember reading what was probably the same author and article. I’ll usually accept one advanced technology for an average story. Two or three if the story is great, and the technologies make sense, and especially if they’re logical extensions of current technology. Anything more than that, and the story has to be extraordinary. ---
**Author:** ![Apollyon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/apollyon/32/4238_2.png) [@Apollyon](https://boards.straightdope.com/u/Apollyon)\ **Post date:** [September 19, 2009, 9:46pm UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/32 "2009-09-19T21:46:24Z")
> [@randwill](#): > > In other sci-fi movies like **2001** wires and cameras attached to moving sets effectively simulated zero gravity. And sometimes even small effects can be used to “sell” zero-g. In _2001_ when the stewardess walks down the aisle and picks Dr. Floyd’s floating pen out of the air the actress was simply pretending no gravity and the pen was secured with a tiny piece of tape to a wheel of glass that was invisible to the viewer and being turned slowly by hand (out of frame). ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [September 19, 2009, 10:12pm UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/33 "2009-09-19T22:12:28Z")
> [@Lynn\_Bodoni](#): > > > [@appleciders](#): > > > > I remember a hard science fiction author (don’t remember who, sorry) noting that readers will typically accept one example of “things we don’t know how to do but we don’t actually know to be impossible” per universe. After that one freebie, readers get twitchier and twitchier until they actually start objecting. > > I remember reading what was probably the same author and article. I’ll usually accept one advanced technology for an average story. Two or three if the story is great, and the technologies make sense, and especially if they’re logical extensions of current technology. Anything more than that, and the story has to be extraordinary. Maybe for a single story or novel that seems about right. But when you get to Universes of stories (I’m looking at you especially, **Larry Niven** ), they build up even if there’s only a new technology every couple of stories. I don’t remember getting twitchy reading all the Known Space stories. ---
**Author:** ![Superhal](https://avatars.discourse-cdn.com/v4/letter/s/b4bc9f/32.png) [@Superhal](https://boards.straightdope.com/u/Superhal)\ **Post date:** [September 19, 2009, 11:19pm UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/34 "2009-09-19T23:19:50Z")
> [@Lynn\_Bodoni](#): > > I remember reading what was probably the same author and article. I’ll usually accept one advanced technology for an average story. Two or three if the story is great, and the technologies make sense, and especially if they’re logical extensions of current technology. Anything more than that, and the story has to be extraordinary. Imho, I believe this ties into the idea of “[suspension of disbelief.](http://en.wikipedia.org/wiki/Suspension_of_disbelief)” I think that scientific explanations are unnecessary _until_ the fictional situation interferes with the audience’s ability to suspend their disbelief. Caveats: 1. Some audience members have higher or lower tolerances of “interference.” For example, a physics major would get bothered by more than a medical major, while a completely different set of things would bother the latter but not the former. 2. “Critical” errors in the science: imho, the error has to be pretty major to knock the average non-scientist audience member out of suspension of disbelief. For example, the use of the macbook to create a computer virus for the alien ship was not as jarring during the film as after the film in Independence Day. 3. As people get more educated in science through science fiction, their tolerance decreases. A person who hardly reads scifi may not even register bad science, while someone who has read hundreds of sci fi novels may require more “hard” science to be satisfied. Therefore, the more science fiction you read causes less enjoyment with future science fiction because of the need to “check” the science facts as they are presented. I never really enjoyed “hard” science fiction. I felt the explanations, however correct or not (there’s no way I could tell, being a Lit major) got in the way of the story. ---
**Author:** ![alphaboi867](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alphaboi867/32/3898_2.png) [@alphaboi867](https://boards.straightdope.com/u/alphaboi867)\ **Post date:** [September 19, 2009, 11:23pm UTC](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626/35 "2009-09-19T23:23:11Z")
> [@Mr.Excellent](#): > > Actually, might that be the explanation for gravity on the Galactica? I mean, she does appear to be under thrust in every scene … No, and she’s not layed out correctly to acceleration to simulate gravity. Like nearly every other fictional starship (not counting ones using centrifugal force) the Galactica’s decks are arranged horizontailly\*, to use acceleration to simulate gravity they’d need to be layed out vertically\*\*. In the former occupants would consider the ship to be moving forward, in the latter it would always be moving up. \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\* * * * * * * \_\_\_\_\_\*\* * * * * * * * * * * * * * * * * * * * * * * * * [Previous page](https://boards.straightdope.com/t/hows-gravity-supposed-to-work-on-a-sci-fi-spaceship/510626.md?page=1)