In physics as we understand it today, can an electron be made to move faster than the speed of light in vacuum? Whether by natural causes, or man-made means?
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No, no it can't. Electrons have mass. – Jon Custer Feb 15 '17 at 21:18
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Possible duplicate of Electrons moving faster than light and backward in time? Possibly related to Does it contradict special relativity that an electron beam in a television picture tube can move across the screen faster than the speed of light? – sammy gerbil Feb 15 '17 at 21:48
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1Yes, it can be made to move faster than the phase speed of light in a medium, see Cherenkov radiation. Can it be made to move faster than the speed of light in vacuum? No, nothing can, see speed of light. – Conifold Feb 15 '17 at 21:58
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As far as we know, any object with non-zero mass cannot be accelerated to faster than the speed of light, nor even to equal the speed of light. When we run particle accelerators at the highest energy we can manage, the speed of the particles is always just under the speed of light. We can get very close, something like 99.999999999% the speed of light. But, increasing the energy of the particle does not measurably increase its speed.
Photons, particles of light, can reach light speed because they have zero mass. In fact, because of its lack of mass, a photon can only travel at the speed of light.
Mark H
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So Mark, is there an adaquate explanation out there that tells us why massive particles cant move faster than light? Like a theory that explains why this is impossible? – Ashton Feb 16 '17 at 02:44
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Or is it just technological limitation that stops us from making particles atain such speeds? – Ashton Feb 16 '17 at 02:45
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@Ashton This is one of the fundamental conclusions of Einstein's Special Theory of Relativity. The amount of energy needed to accelerate a massive object, even a single electron, to the speed of light is infinite. – Mark H Feb 16 '17 at 02:53