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Thread: matter traveling at half the speed of light

  1. #1
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    matter traveling at half the speed of light

    If there was some process that caused matter particles to travel at one half the speed of light, how far would that matter particle go before it was slowed down? Could it go billions of light years without being interfered with? Do supernovas or anything eject matter at super high velocities?
    The moment an instant lasted forever, we were destined for the leading edge of eternity.

  2. #2
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    Depends on the "matter particles", and the route they follow. There will be an interaction with the interstellar/intergalactic medium, which will depend on the medium, its density, and the interaction cross section of the specific particles. If the particles are charged, there will also be interactions with magnetic fields encountered along the way.
    The typical energies of cosmic rays correspond to proton velocities between ~50% and >99% of the speed of light, so something is certainly producing these things.

    Grant Hutchison

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    The GZK limit is more or less the maximum energy a proton could keep after travelling a long distance through intergalactic space. Note that it corresponds to a velocity very close to the speed of light. We see cosmic ray particles at that energy, and occasional particles well above the limit, with a number of possible explanations for the latter. So there are definitely particles produced at those energies, and they can travel hundreds of millions of light years and still be moving at close to the speed of light.
    Conserve energy. Commute with the Hamiltonian.

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    Quote Originally Posted by Grey View Post
    The GZK limit is more or less the maximum energy a proton could keep after travelling a long distance through intergalactic space. Note that it corresponds to a velocity very close to the speed of light. We see cosmic ray particles at that energy, and occasional particles well above the limit, with a number of possible explanations for the latter. So there are definitely particles produced at those energies, and they can travel hundreds of millions of light years and still be moving at close to the speed of light.
    Is there any estimate to how much of this stuff there is. Like percentage of the mass of the universe.
    The moment an instant lasted forever, we were destined for the leading edge of eternity.

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    Quote Originally Posted by Copernicus View Post
    Is there any estimate to how much of this stuff there is. Like percentage of the mass of the universe.
    Small. See Item 9 in Table 1 of the Cosmic Energy Inventory.

    Grant Hutchison

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    Quote Originally Posted by grant hutchison View Post
    Small. See Item 9 in Table 1 of the Cosmic Energy Inventory.
    Nice!
    Conserve energy. Commute with the Hamiltonian.

  7. #7
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    Quote Originally Posted by grant hutchison View Post
    Small. See Item 9 in Table 1 of the Cosmic Energy Inventory.

    Grant Hutchison
    Very nice!
    The moment an instant lasted forever, we were destined for the leading edge of eternity.

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