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

Momentum Transfer

  1. Apr 29, 2006 #1
    Could something like this be used for a momentum Tranfer in Space Ships?:bugeye:
    If so, Then how could we improve upon it?
    If not then kindly disregard this post.
    Maximize for better reading.

    Attached Files:

    Last edited: Apr 29, 2006
  2. jcsd
  3. Apr 30, 2006 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I can't tell from the picture what the thing is supposed to do...

    But unless you dump mass, you're not going to get any momentum imparted to the spacecraft.

    [tex]\Sigma_{i=0}^n m_i*V_i=0[/tex]

    or, momentum is conserved
  4. Apr 30, 2006 #3
    It probably wouldn't work, but this was the plot.

    1. Coil #1 fires off an EM Pulse that compresses the Diamagnetic Plasma Gas towords Coil #2 which prevents the Gas from Exiting, The Field from Coil #2 acts as an EM Barrier causing the Plasma Gas to be blocked which would probably force the Momentum of the Gas to be transfered to the Field Barrier of Coil #2, Coil #1 Fires off a very Rapid Strong EM Pulse that expands rapidly then is turned off until the next firing Pulse Charge is restored, The Gas will flow back to Coil #1 via Vacuum Suction then Coil #1 is refired with as many Joules of energy possible to recompress the Gas back to Coil #2.

    I was hoping that the Compression and Decompression of the Gases Velocity difference, If any, Would cause a momentum transfer difference to make the unit travel in a linear direction in a Zero Gravity enviroment.

    I had in mind that Equal and opposite forces may cancel the Momentum transfer and be conserved but I thought I would ask about it before throwing it out the window in case it had any potential.

    Thanks for your time.
  5. May 2, 2006 #4
    Wouldn't dumping energy already near light speed be better than dumping mass (over the long run)?

    I would think that dumping huge amounts of Energy on a repulsive surface would propel a craft if the Craft was highly Diamagnetic, I Myself think that using EMPs to squeeze Diamagnetic Surfaces could have very good results if the proper amount of Energy was used The Diamagnetic surface would try to repel away from an EMP( Shaped Charged EMPs against a Diamagnetic Surface), What do you think?

    I know that if there is not alot of energy to play with then it would take a rather long time to aquire super high velocities to a mass object but even then such slowness to gain velocity may over take all the rocket engines ever put into space over time if the output is always at Light speed with Energy that can be recharged over intervals of flight, ie, High Density Capacitor Banks and some Flight recharge System collecting Electrons and or EM from Space to refill the Cap Banks for another pop.

    What could we do?
  6. May 2, 2006 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    When coil#1 pushes the gas to the right (towards coil#2), it must recoil to the left. When the momentum of the gas is absorbed by coil#2, it recoils to the right.

    You've designed an oscillator, not a propulsion drive.
  7. May 2, 2006 #6
    Another thought on momentum transfer to add littles bits of momentum over time.

    Would something like this work?

    There is an additional zoom after maximizing the page to sharpen the image, Hover mouse over the image to get the zoom button to appear.

    Attached Files:

    Last edited: May 3, 2006
  8. May 3, 2006 #7


    User Avatar
    Staff Emeritus
    Science Advisor

    The ball bearings will impart momentum to the circular tube in the opposite direction to travel, since they are accelerated - change in direction and presumably with some change in velocity.

    Think of the components of velocity and the centripetal force in the circular track.

    And, please don't get discouraged.
  9. May 4, 2006 #8


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Intuitive : your designs suffer from the fundamental flaw that momentum conservation applied to the entire system (drive + craft) prevents it from getting anywhere unless there is momentum ejection out of system. This is what enigma tried to bring to your attention.

    In other words, you are trying to power a sailboat with an onboard fan.
  10. May 4, 2006 #9
    Back to EMPs and Solar Sails I guess.
  11. May 4, 2006 #10


    User Avatar

    Staff: Mentor

    Actually, yes, in theory a laser could be used as a propulsion device. But your device doesn't dump energy linearly.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook