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

Time dilation of fast moving object that are not relative?

  1. Jul 5, 2015 #1
    I meant to say fast moving "objects" in the title, my bad... my title kind of sucks

    https://en.wikipedia.org/wiki/Relativistic_electromagnetism#The_field_of_a_moving_point_charge

    That section is basically what my questions are about. I want to know generally about the overall forces. Two protons in the LHC moving the same direction will not experience much repulsion difference relative to their own perspective, but from our perspective outside the LHC their repulsion should weaken? The repulsion of two protons without electrons I mean.

    But two protons colliding in the LHC going opposite directions. Because their speeds are not relative, they would have increased repulsion? I can't understand the wikipedia article that well. I think it's saying the increased repulsion would be from the sides as they pass each other (assuming they didn't collide)?

    ok, one more question about, voltage and current, that i guess kind of has to do with time dilation. If you took a beam of fast moving electrons, could that create a voltage for a wire or something near by right? I mean of course a wire with current would create a voltage, but would it also work for a beam of electrons in a vacuum? How come electrons are supposed to repulse other electrons, but a voltage creates a current? thanks
     
    Last edited: Jul 5, 2015
  2. jcsd
  3. Jul 5, 2015 #2

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    Two protons in the LHC moving together feel an electrostatic repulsive force in their frames. When you transform this force to the Lab frame, it is weaker, because of time dilation.

    In the Lab frame, these protons still have their electrostatic repulsion, but they also create a current, which is attractive, and substantially reduces the attraction. You get exactly the same force in this frame through this analysis as you did in the preceding paragraph.
     
  4. Jul 5, 2015 #3

    ok, what about colliding protons?
     
  5. Jul 5, 2015 #4

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    What about them?
     
  6. Jul 7, 2015 #5
    by lab frame, you mean for an outside observer i assume

    nothing should change relatively so i don't see why there would be an attraction force, when we don't see an attraction force at low speeds

    the link i gave suggested that moving charges which are not relative have different forces acting upon them, just read my middle paragraph for the thread topic, or read anything past the first paragraph instead of asking me "what about them?"
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Time dilation of fast moving object that are not relative?
Loading...