Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Realism in space technology

  1. Jan 2, 2007 #1


    User Avatar

    I didn't know where to post this. It seems a bit week on science for the forums.

    I had this idea in for a role playing group I am in on myspace. Anyways the story is that I am in charge of the martian space navy and this is supposedly our newest weapon to use against the "space Nazis." It is an unmanned spacecraft that can be driven into other spacecraft at very high speeds.

    I want to know what you all think about the feasibility of this thing. We always try for realism and I think that is especially important whenever we step up the technology of our universe.

    This is what I wrote
    OK the 100's of gees I just made up and I have no idea what this thing might be capable of. I don't know what equations to use but I imagine they involve the efficiency of the lasers and the mass of the craft.

    The last paragraph is pretty much pure science fiction.
  2. jcsd
  3. Jan 3, 2007 #2


    User Avatar
    Gold Member

    Well, let's be real; the whole thing is pretty much science fiction.

    What kind of answer are you looking for? Is it plausible in an RPG? That's up to you and the established tech level of the campaign. Do you want science that backs it up? Nope.

    Question: you're going to build fleets of these things with all this fabulously advanced technology, and then you're going to sacrifice them on the windshields of your enemies?

    Whatever happened to KISS? What about simply showering the enemy fleet with a cloud of pellets moving at relativistic velocities?
  4. Jan 3, 2007 #3


    User Avatar

    I am looking for the science to back it up. Weather or not this might be a better option than good old fashoned kinetic kill can be debated till the cows come home.

    I did read once that relaivistic projectiles are completely ludicrous in terms of short term technology. This is because massive amounts of energy (in fact all the destructive energy of the weapon) needs to be packed into the projectile at the time of launch, (I mean talk about kickback).

    Rather what I have is a super smart relativistic misile. It has no kickback and is much harder to dodge. The economics are overcome with the magic of nanotechnology. Nanotechnology is an assumption we have about our universe. What I am interested in is the physics.

    I guess to answer your question well yes that is the general idea, although some times they can serve other purposes as well.
  5. Jan 3, 2007 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Well, here are some of the potential scientific problems that I see.

    I'm under the impression that if your black hole is too small, it will radiate high energy photons and miscellaneous subatomic particles. I don't know how big it has to be in order to radiate heat.

    That wastes energy: the recoil from the laser counteracts the momentum delivered to the sail, generating waste heat. You'd get better performance if you shone the laser away from the sail.

    The laser-pushing-sail system is meant for a planetbound laser to push a spacebound sail -- in that situation, the recoil from the laser pushes against the planet, rather than slowing the spaceship.

    This is just off the cuff, if your laser carries enough energy to cause your missile to accelerate at 100 g's, I find it very hard to believe it would be an ineffective weapon. It will certainly deliver enough energy to punch a tiny hole through any object it's aimed at. I would expect it to be able to cut through the enemy ship like a knife! (I don't know how quickly you'd be able to cut before it loses its potency, though)

    Just remember that the laser gets accelerated in the opposite direction when doing so.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook