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Feasible way to go the speed of light?

  1. Jun 11, 2014 #1
    Hey guys, I was recently thinking about theoretical ways to accelerate objects (spacecraft) and I had the idea that seems feasible and could potentially reach the speed of light in a reasonable time period.

    In order for this to work, we would need to develop an artificial gravity generator that could produce gravity in one constant direction. If we had that on the front of a ship, no matter the weight, the acceleration would be constant. So lets say that the gravitational acceleration from the generator was tuned at Earth's 9.81m/s^2. I figured that a ship with that constant force would reach the speed of light in just under a year. Now, lets say we tuned up the generator to 5 times the normal gravity here on earth. It is still well within the survivable limits of humans and it would cut the time to the speed of light from just under a year to just over 2 months, (~71 days).

    The main problem with accelerating to or near the speed of light, is that your mass gets infinitely larger. With conventional acceleration methods such as rockets or other expulsion based engines you would need an equally infinite amount of particles being accelerated out the nozzle to continue accelerating. This equates to an infinite amount of energy and thus is impossible. However, unless the gravity generator requires more power to effect more mass, the weight of the ship would be irrelevant to the acceleration.

    Anyway, I am no expert on this material but it seems like this would work if we had an artificial gravity generator. I know this seems somewhat far fetched, but let me know what you guys think!
  2. jcsd
  3. Jun 11, 2014 #2


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    Science Advisor
    Gold Member

    1) You can never reach the speed of light. This is forbidden by special relativity. So I will assume that you mean "approach close to the speed of light" in your post (say 99% of the speed of light).

    2) If you could provide a constant acceleration of 1g, then indeed you will approach the speed of light within a reasonable amount of time. The problem is how to provide this constant 1g of acceleration.

    3) We have no idea how to create an "artificial gravity generator". As far as the laws of physics goes, mass and energy generate gravity. And you need a lot of mass to generate a little gravity (say, all the mass of the Earth to generate the gravity of 1g at its surface). There's no way around this with any current theories of physics.
  4. Jun 12, 2014 #3
    What you are proposing suggests that we could all go into space just by pulling on our bootstraps.
  5. Jun 12, 2014 #4


    Staff: Mentor

    Until we get such a device anything that we can possibly say about it is speculative. If you have some professional scientific papers about possible gravity generators that you would like to discuss then please PM me and I can re-open the thread.
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