Realistic Physics in SciFi Movies and Shows

Discussion in 'Community' started by Mr. Anderson, Oct 24, 2002.

  1. Mr. Anderson Moderator emeritus

    Mr. Anderson

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    #1
    I'm not talking about the future tech posibilities, phasers, FTL drives, time travel, etc. Although they probably could be discussed here. What started this what the SW vs. ST thread and the fact that weapons fire misses more often than not, even the computer controlled guns - all for Capital D - Drama.

    One other thing the gets me is when a ship has its drives taken out, it usually slows down and stops - maybe some smoke, yeah, right, and lists a little. This is one of the most blatant cases of bad physics. Why don't they show it stop accelerating and continue in a straight line? Most likely because the producers/directors/writers think the audience wouldn't understand....

    Anyone else got any thoughts on this?

    D
     
  2. sturm375 macrumors 6502

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    #2
    Check out Babylon5. The fighters (I forget what they called them) used real physics. (spinning on a hit, coasting when drives out, Not using more engines when up to speed, turning around, and still traveling in the direction that the momentem was.
     
  3. mischief macrumors 68030

    mischief

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    #3
    it seems to be a US thing.....

    The Japanese and British seem to do better physics. Derelicts actually drift..... for the most part dammaged ships "mist" out rather than the cheesy fireball bit seen in SW and ST.

    Plus theres issues with how the models relate to the description..... For example: the rated size of the Enterprise in STNG, when related to the exterior shots makes the windows close to 15 feet tall!

    Not to even get into ship design, which most Sci-Fi has fared very poorly on. If the back-story dictates a war-torn reality don't you think that a small cross section and compact sillouette would be quite common? Then theres the whole artificial gravity and "enertial dampers" thing.... once you've stretched things that far there's nothing to prevent rapid, sudden changes in vector, orientation and acceleration.


    Then of course: the most commonly bogus issue: Bad weapons design. A Phaser is a SOUND BASED WEAPON, look it up. Weapons for spacecraft need a whole different approach.... percussion does nothing so you have to literally cut into the hull to do any dammage.

    Once you get into shielding there's the possibility of making the shield system itself an effective weapon in a variety of ways and ditch the entire weapons system concept as a separate issue. If there's no energy-based shielding automated Rail-Gun turrets, Particle weapon turrets, pulse-LASER turrets and Missile racks loaded with Flechette impregnated shape charges or better yet small Nukes designed for high-yield EMP fitted to high intelligence missiles would be the bulk of weapons used.
     
  4. Spike Spiegel macrumors regular

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    #4
    a couple quick points and questions:
    in shows and movies in which missiles are fired in space from both moving and stationary vessels, could missiles gain enough speed from frictionless space to be of any use?(the same question for conventional propulsion, does it work disregarding atmosphere?ive seen video of those extra-vehicular astronaut chairs that can fire mini-jets to change trajectory, does that only work because they are in earth's orbit still, and effected by its atmoshere?)
    -In Cowboy Bebop, all the ships are based on prototypes that the creators designed beforehand. theres actually an amazing amount of detail that doesnt get explained in the episodes, but one could find out online given enough time.
    -Would weapons like vulcan cannons be effective against the type of hull you'd find on a space-worthy vessel?
     
  5. Mr. Anderson thread starter Moderator emeritus

    Mr. Anderson

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    #5
    Rockets work wonderfully well in space, not because of the atmosphere.

    What basically happens is one of Newton's laws in effect here, the third law of motion - for every action there is an equal and opposite reaction. The propellant shoots out the back and pushes the rocket away because of the propellant's mass and velocity against the missle create a very powerful force. The higher the velocity of the propellant/exhaust gas the more force. So even though the propellant being used up might not weigh all that much, its speed does.

    You could be in space and floating helpless 30' from the space station and a can of spray cheese would be enough to get you going in the right direction. (as demonstrated in the Journeyman Project)

    D
     
  6. mischief macrumors 68030

    mischief

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    #6
    more than a couple of quickies really....

    Chemical propulsion doesn't work by displacement, it works on neutonian physics: a mass of hot exhaust goes one way, you go the other. It's the pressure of the gas against the inside of the combustion chamber and any nozzle fitted to the back coupled with the basic force/velocity/mass equation that states that any given mass, provided with acceleration will have an exponential force to deliver on contact ( Force = Mass • Velocity^2 ). So the net effect is: the gas presses in all directions while ignited except for the exit path to the outside.... so a vector of Force is created diametrically opposite the exit point of the combustion chamber.

    This type of propulsion actually works better in open Space and the Vector is simply "bent" by gravity to create an arcin trajectory.

    In a situation without Energy Shields Rotary Cannons work very well with 1 common drawback for all projectile Weapons: The Force created by the continuous streaming of small massive objects creates thrust propotionate to the relative mass fired. Any ship's projectile-based weapons will be directly related to the size of the craft and at the smallest size would likely need directional thrusters mounted in opposing clusters to any gun mount or turret to "zero" the resulting thrust from the Gun.
     
  7. Durandal7 macrumors 68040

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    #7
    One thing that has always bothered me on a lot of sci-fi is that no matter how damaged a ship is, some of it's systems always continue to work. Look at how rarely it is ever zero-gravity in most shows, it only hapened once or twice on Star Trek and never on most programs.

    The cheese can was an interesting approach in BIT though.
     
  8. Mr. Anderson thread starter Moderator emeritus

    Mr. Anderson

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    #8
    Re: more than a couple of quickies really....

    And that's not easy if you have a turret system, or multiple turrets. Recoiless guns might work, but a recoilless railgun? That would mean the rail would have to move in the opposite direction of the projectile....but it might work, if you limit your shots and not to a continuous stream. It also depends on the length of the gun.

    The weapon systems we develop in space for ship to ship warfare are going to be mostly missles and lasers, would be my guess. Most likely lasers for defense (destroy the incoming missles) and missles for both defense and offense. A scattering/shrapnel explosion in space from a missle warhead would do tons of damage, especially if the relative velocities of the missle and target are high. The US gov't has already proposed satellite killers that basically go into the same orbit as the target and explode close by, pretty much shredding the satellite. Considering the amount of debris already causing concerns in orbit - a war in space around the planet would make space travel and satellite deployment hazardous for decades.

    D
     
  9. mischief macrumors 68030

    mischief

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    #9
    It evolves very quickly to high-mass Vessels.

    Once the to-orbit cost is removed from the equation a thick-skin becomes a neccessity. The higher the mass of the craft, the heavier the guns you can rack on. If the inert mass of the craft is 20 Tons or more the small trust created by firing small-bore glass flechettes (best cutting surface EVER) would be insignificant and easilly countered. Having symetrically opposed turrets would work if the urrets had guns on one side and thrusters on the other but it would mean that the turrets would have to be computer-synced.

    I don't think Rail Guns (Gauss Rifle or Magnetic Induction Cannon) would produce any real thrust if the projectile had a very small ferrous core and was accelerated slowly at first along a very long barrel. a LASER assisted Rail Gun could get very ugly for firing high speed-low mass projectiles. With no atmosphere to worry about projectiles need not be streamlined. A plastic slug loaded with a sticky tip, shape charge and beaucoup small steel balls shaped roughly like a pie pan... say the sticky is around the rim.... would be very effective.
     
  10. Mr. Anderson thread starter Moderator emeritus

    Mr. Anderson

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    #10
    One of the things that will happen even with cheap to-orbit transportation is capturing and mining of Near Earth Objects. A c-type asteroid has 1000s of tons of metals, values in the trillions of dollars (if on Earth, not even adding the cost of getting to orbit) and water/ice for fuel.

    But the major advantage of these objects is that the delta-V, or required energy to get to them and back is a small percentage of the the delta-V needed to get from Earth to orbit. Several companies are working now to send survey robots to a couple choice ones, and I see it as being a huge business in a few decades.
     
  11. mischief macrumors 68030

    mischief

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    #11
    They also make very economical weapons. All you'd nee is a catalytic thruster system and basic guidance. Screw the cannons and LASERS: throw rocks!:D :eek:
     
  12. Mr. Anderson thread starter Moderator emeritus

    Mr. Anderson

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    #12
    Its all potential energy! Wasn't that something that was done in Starship Troopers - to get the thread back on topic? The bugs would throw comets or asteroids at the Earth? But they some how managed to do it across planetary space, bypassing the laws of physics.

    Well, the enemies planet is that-a-way, 50 lightyears distant. If we launch one of the new Astro-bombs now, it should reach them in 100,000 years.......

    And if you ever get something up to relativistic speeds, the ablation of material would be amazing and you'd burn up and disintegrate, just from hitting the randomly and sparcely found hydrogen atoms in deep space. That's one of the main reasons for deflector shielding.

    D
     
  13. elensil macrumors regular

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    #13
    Proton Torpedoes???

    If any of you knows StarTech, please explain why did they stop at proton torpedoes as a prime weapon.

    How about Anti-Matter projectiles of some sort. To use against shields they could contain both matter and anti-matter isolated by a force field, they would detonate upon impact.

    Rail Guns would be a very efficient choise given a limited manuevarability of early space craft.
     
  14. mischief macrumors 68030

    mischief

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    #14
    Re: Proton Torpedoes???

    I like the idea of using the shields systems to create a "wave" of destruction.:D
     
  15. elensil macrumors regular

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    #15
    Don't even start with StarShip Troopers

    Star Ship Troopers was so full of **** from a simple logical point of view that any discussion has no meaning...
     
  16. sturm375 macrumors 6502

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    #16
    Re: Proton Torpedoes???

    Proton Torpedoes is a StarWars tech. I am not sure what it is composed of however, Star Trek uses Photon Torpedos which do use a Matter-AntiMatter detonation to create destruction. These torpedoes (in ST) also have the ability to achieve warp, thus are able to "catch-up" to vessels at warp. Of cource this is all fiction. I also remember in the origional series, Kirk uses a Photon Granade launcher (looked like a Morter), with the Granades that looked like Raquette Balls:D
     
  17. elensil macrumors regular

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    #17
    Thanks for your reply Sturm.

    Mischief, when would there be more information about CrystalSphears. The concept fits escapist mode of mentality and would probably be embraced by many a fantasy fan.
     
  18. mischief macrumors 68030

    mischief

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    #18
    Well.... being that the design team is all folks with full time lives and all.... it may be a while I'm afraid. If you or anyone you know has Game Design experience with either Marathon or the Aleph engine please let us know. Also: Anyone who has experience in Cocoa, Object C, etc.;)
     
  19. Durandal7 macrumors 68040

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    #19
    Good to see that the word about CS is getting out. Maybe you should solicit recruits again...
     
  20. Mr. Anderson thread starter Moderator emeritus

    Mr. Anderson

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    #20
    We need to keep focused on the current project, CS needs to wait for a bit I think. But this discussion should probably go in the gone3d thread.

    Anyone here ever see the Forbidden Planet ? Probably the best pre StarWars SciFi movie ever made. And its from 1956! I highly recommend it. I don't know what made me think of it, but I'm going to have to go and rent it soon.

    Monsters from the Id!!!!

    D
     
  21. Mr. Anderson thread starter Moderator emeritus

    Mr. Anderson

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    #21
    Forgot the pic - Robby the Robot, flying saucers, B&W and an amazing good story. The physics in this are very cool, harnessing the power of the planet, such a great concept.

    Mischief, if you haven't seen this you really need to.

    D
     

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  22. mischief macrumors 68030

    mischief

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    #22
    Yes actually I have seen it.

    It was good sci-fi and a decent film with some cool optical FX for the time period. My only issues with it were basically period-camp anyway.

    I was thinking recently (dangerous as D and Eye probably already know;) ):

    Would anyone be into developping a sci-fi genre with good ET's, really unique cultures and good physics? It seems that there is a whole lot of writing talent here going to waste kvetching about existing bad sci-fi..... anybody wanna do it right?:D :cool:
     
  23. Mr. Anderson thread starter Moderator emeritus

    Mr. Anderson

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    #23
    Re: Yes actually I have seen it.

    Developing it for what? Would you like to help create the Floss Gordon Universe? I'd be more than willing to collaborate on that, seeing as I'm swamped. And campy is good once in a while - humor has a way of making things more appealing sometimes.

    D
     
  24. mischief macrumors 68030

    mischief

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    #24
    Re: Re: Yes actually I have seen it.

    I'm as bound by practicallity as you are but i have a gut-level inspiration about this one that an experimental "opensource" Sci-Fi universe could be quite entertaining and useful. It could be developped as a "limited source" RPG system if you like. Honestly I don't care what the output becomes I just think that the discussion itself could be very cool and the resulting Universe and Races could be good for many things.

    Here's a recruitment thread for it....:

    http://forums.macrumors.com/showthread.php?s=&threadid=13584
     
  25. Mr. Anderson thread starter Moderator emeritus

    Mr. Anderson

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    #25
    Sounds interesting, but again, what would all that be used for? What this makes me think about is how do all the sci-fi shows come up with they're ideas that make absolutely no sense (realistically)? Do they find themselves backed into a corner and the only way out is to invent or provide a convenient loop hole?

    I'm trying to think of a good example of this, it seems to me its been done, but I'm failing in coming up with anything.
     

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