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Sci-Fi Gravity

  1. Jun 13, 2005 #1
    How come on whatever Sci-fi show/movie e.g. Startrek, Star Wars, Stargate SG-1, star.*, etc. you never see people struggling to pick up their feet or bouncing around freely on whatever random planet they visit, as though whatever planet happens to have exactly the same as Earth's mass, isn't that one big coincidence?
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  3. Jun 14, 2005 #2
    because it is a movie. it is not real life. they are not really on another planet.
  4. Jun 14, 2005 #3


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    Planets with a much different gravity than Earth may not be that hospitable to human life. A planet where you could bounce around freely probably can't hold a substantial atmosphere, therefore you could only visit in a space suit. Planets where you struggled to pick up your feet are probably gas giants. Even if they're rocky with 2g of gravity like the exosolar planet recently discovered, they might have such a thick atmosphere that humans would never be able to visit them without a spacesuit.
  5. Jun 14, 2005 #4


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    The most accurate answer is: "because it doesn't enhance the story".

    Where it is relevant to the story, you will find the SFX demonstrating varying gravity (a *very* badly damaged ship in Star Trek VI, the rock cutting scene in Armageddon).

    But demonstrating high or low gravity just to be scientifically accurate merely causes a distraction. Because ultimately it's a story, not a documentary.
  6. Jun 14, 2005 #5


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    Have you ever noticed in the Star Gate series that whereever they go through their "worm hole gate", the natives, however alien, speak English?
  7. Jun 14, 2005 #6


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    I suppose Star Trek writes it off by a focus on their exploring only "M Class" (Earth-like) planets.
  8. Jun 14, 2005 #7


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    Very special M-class planets.
    If Kirk doesn't take a love interest (cute female crew member) on the away team, he almost invariably finds a scantily-clad very attractive humanoid female, complete with all the physical attributes we associate with B-movie starlets. OK, you might have to overlook blue skin!
    There is an interesting rule involved in visiting these planets, too. Any "new" male crew member on the away team (an actor not previously seen in a Star Trek episode) has an almost 100% chance of getting killed right after the team beams down.
  9. Jun 14, 2005 #8
    COST, moolah, production budgets, that's why.
    Faking micro-gee on film is ALWAYS, always and without any exceptions whatsoever, MUCH more expensive than adding "artificial gravity" to the list of new toys people have to play with in the future.

    The cheapest way to do it, and (if you like "coincidences" how 'bout this one), also the most common way it's done, is through the use of wires that suspend the actors in mid air to either make them look like they're flying, or weightless.
    It's such a common method (the use of wires), that it even has a name, "wire work".
    "Wire work" is always dangerous. People have been very badly hurt by accidents that occur during a "wire work shot".
    The most common injury is to a leg. The actor suspended bends his knee for just a second. Bending his knee makes the wire to the lower part of his leg go slack. The slack wire gets looped around the shin. When the actor panics, and tries to straighten his leg, the wire that's now looped around his shin goes tight, and pivots him head over heels. The momentum built up during the spin YANKS the wire looped around his shin tight and can come very close to severing the lower half of the actor's leg, often cutting clear down to the bone.
    This is why insurance companies absolutely HATE actors doing their own wire work, and often simply refuse to insure them. Which means filming comes to a dead stop, because - by law - that actor has to be insured while working on the set.
    Wire work generally requires special (and very VERY expensive insurance) to be procured before the start of principal.
    There are union laws that apply to wire work that restrict the amount of time anyone can spend in the wires, the presence of a stunt coordinator and stunt crew that have been rated for wire work is required, along with the presence of an ambulance and paramedics before the cameras are allowed to roll.
    Forget putting kids in a wire harness. Not only is it a stupid thing to do, there are so many restrictions on doing it that no one in their right mind would.

    All of which boils down to money.
    It costs a LOT of money to fake zero-gee on film, it's dangerous, and THAT'S the "real" reason that everything from "Buck Rodgers" sparkling space ships to the "Nostromo" to "Darth Vader's Star Destroyer" all have "artificial gravity".

    It's not that it never occurred to anyone in Hollywood that "gravity" on another world might be something other than 1.0 gee. It's just that it's too expensive to show that on film. Thus all space ships in the future have artificial gravity, and on all planets visited in the future people weigh the same as they do on Earth.

    (And before you ask, at the moment, doing it with pure CGI is still more expensive than using wires, which is why wire work is more common than pure CGI for this kind of thing).
  10. Jun 14, 2005 #9
    They just need a little tug from one wire really, just to give them a little more hop when they're walking, that's all. They don't have to be flying all over the place like Peter Pan on this planet. And how hard is it to fake higher gravity? Look, I'm doing that right now, on no budget and I don't need insurance. "Oh this apple, it's so heavy! I guess I'll just lower my head down since I can't lift the apple. Chomp, chomp. Oh no, now I can't pick my head up off the table! Why did I come to this planet?!?!?" When things fall to the ground maybe have a louder klunk, and pick the natives to be more built-up instead of anorexic and it should convince the viewers.
  11. Jun 14, 2005 #10

    And they always have some kind of fancy shrine around the gate and call it "circle of the Gods" or the "God Ring" or the "Holy Circle" and the female natives shave their pits just like on Earth and even wear makeup. I think I saw one of the Gou'ald warriors wearing Nikes once.
  12. Jun 14, 2005 #11
  13. Jun 14, 2005 #12
    Good answer. I didn't see those two you mentioned but the only other time I'd seen it done was on Stargate SG-1 when the black hole invaded the base and time was slowed it was cool. I'm wierd because I think lack of accuracy is the distraction. Like in Star wars when the Tie Fighters and X-Wings are going at it and I hear all their lasers firing back and forth and I'm distracted thinking "how is this sound traveling?" wishing I could watch the scene in silence. I guess I'm just nutz so the answer makes sense because everyone else doesn't care about these otherwise pointless trivialities.
  14. Jun 14, 2005 #13


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    Star Wars is not Science Fiction. Never has been, wasn't intended to be, and never will be. It is Space Fantasy.
  15. Jun 14, 2005 #14


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    A little story: You know how in the original Star Trek series opening credits the Enterprise makes this woosh sound as it flies by? They originally did it without the sound to be accurate, and found it lacked oomph. It seems that we are so used to sound, the scenes lose their emotional punch with out it.

    You might want to check out a movie called "Moontrap" made in the 80's. It stars Walter Koenig (Chekov from star trek). It has a lot of action that happens on the moon which is all shown in complete silence.
  16. Jun 14, 2005 #15


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    Not all sound in space scenes is completely unrealistic. A spaceship whooshing by, complete with dopler effect obviously is fake. But inside the spacecraft sound does exist. So the firing of engines, guns, etc could be considered real.

    Movies are often filled with unrealistic sounds for effect. Canned laughter is not realistic. It's just a sound effect to add to the atmosphere of the scene.

    Same when some corny love song is playing in the background as the girl dumps the guy. In real life, there's not some musical soundtrack following you around waiting for the emotional moments of your day. But we never pick on that as unrealistic.

    So I look at the spaceship whooshes as just a sound effect to compliment the visual, rather than something that's supposed to be an accurate representation of what a person positioned at the camera (also unrealistic) would hear.
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