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

Artificial gravity

  1. Apr 30, 2008 #1
    E=mc2 says that mass and energy are interchangeable.

    to make interstellar space flight possible artificial gravity must be generated. assuming that energy generation is not a factor, according to the equation given sufficient energy a gravity field could be generated.

    most everything that i've read regarding artificial gravity says that a superdense core of some sort is needed. since mass and energy are essentially the same thing, again assuming energy generation is not a factor, wouldnt it be possible to focus energy on a single point sufficient enough to generate 1g aboard the vessel?

    there are many variables that i did not discuss and everything i said is theoretical, i just want some feedback on the idea.
  2. jcsd
  3. Apr 30, 2008 #2
    Rotation to create a simulation of gravity using a centrifuge?
  4. Apr 30, 2008 #3
    not really. same concept, energy into gravity, but no moving parts in my question. just a supremely massive amount of energy concentrated in a single place to generate gravity.
  5. Apr 30, 2008 #4


    User Avatar
    Science Advisor
    Gold Member

    I think what he meant was: There is no need for "artificial gravity", it is much easier to simply use a centrifuge.
  6. May 1, 2008 #5
    I'm not sure I understand you properly, do you mean like a donkey chasing a carrot?


    Remember Newton's 3rd law. There will be an equal and opposite force on the source of the mass, tending to push it towards your spaceship. If you wish to maintain the distance between yourself and the mass you will need to provide some sort of repulsion force of equal magnitude, which in turn means you move nowhere.
  7. May 1, 2008 #6
    I have to defer to someone with a better understanding of GR to refute that, but since it would essentially be a free energy device I'm quite certain it wouldn't work that simply.
  8. May 1, 2008 #7
    Yeah, I think I misunderstood what you were saying, but I'll still defer to someone with a better knowledge of GR to say whether or not this would work.
  9. May 1, 2008 #8


    User Avatar
    Science Advisor

    Yes, that propulsion system has occured to me as well, every time I see a scifi show where they have artificial gravity and are only using it to keep their feet stuck to the floor! It would be a novel form of propulsion.

    Yes, in hteory enough energy generated in a concentrated area would create a gravitational field. However, I think that much energy condensed into a very small space would essentially be...matter! One image used to teach GR holds that matter and energy are simply the two forms of mass. Enrgy is the "spread out" form, and matter is the "packed tight" form. It's not a perfect image, but accurate enough for the current conversation. If you carm enough energy into a small space to generate a 1g grav field, you will end up creating matter, like they do in partical accelerators.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Artificial gravity
  1. Artificial Gravity (Replies: 2)