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Electron Gravity Question

  1. May 8, 2014 #1
    Has anyone ever "fired" an electron down the center of an evacuated tube (horizontally) to see if the electron follows the same trajectory as a bullet fired from a gun? This might seem like a simplistic question, but I have always wanted to know what would happen.

    Mark
     
  2. jcsd
  3. May 8, 2014 #2

    ZapperZ

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    You do know that we have had many long linear accelerator, don't you? I'm fact in synchrotron light sources, the electrons stay in the storage ring for a long time.

    In all of these facility, the effect of gravity, even on protons and heavy nuclei, are negligible to indetectable.

    Zz.
     
  4. May 8, 2014 #3

    TumblingDice

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    Electrons will fall at the same rate as any other mass. But you won't measure much of a drop on Earth. Electron gun speeds are in the millions of meters per second. Typical CRT guns in monitors and TVs emit at around 1.5 to 3.5 million m/s. That's awfully fast to observe a trajectory. :bugeye:
     
  5. May 11, 2014 #4
    In other words the answer to mkristof's question is that the bullet like trajectory has not been experimentally verified. This answer could have been given in neutral manner too.
     
  6. May 11, 2014 #5

    TumblingDice

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    Why would you say that? Do you have information to support this?

    Are you suggesting that electrons may be massless, or that they might possess some new property that allows their mass to defy gravity?

    The OP wrote, "I have always wanted to know what would happen." I think ZapperZ's and my replies were offered in that direction.
     
  7. May 11, 2014 #6

    Vanadium 50

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    In addition to the other points that have been brought up, there is another issue of practicality: the force on an electron due to the earth's electric field is a trillion times larger than the force on an electron from the earth's gravitational field.

    Furthermore, if electrons did not fall, we would observe a material dependence to gravity about 40 million times larger than our present best limits. Since we don't see that, we already know the answer from other, less direct measurements.
     
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