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Neil Marshall
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What affect does the phenomenon of "length contraction" have on the shape (e.g. spherical, rugby ball, barbell, donut) of protons accelerated to 0.999999991 c in the LHC?
Welcome to the PFNeil Marshall said:What affect does the phenomenon of "length contraction" have on the shape (e.g. spherical, rugby ball, barbell, donut) of protons accelerated to 0.999999991 c in the LHC?
No this is not a schoolwork/homework question. I'm a 72 year old nerd who loves physics.berkeman said:Welcome to the PF
Interesting question. Is this a schoolwork/homework question?
Mathman,mathman said:Flat disc?
Cryo said:In which reference frame? If not the rest frame, then how would you measure it.
Photons don't have a shape.Neil Marshall said:Mathman,
Possibility. I've heard tell that photons are 2 dimensional discs experiencing neither time or distance. Unfortunately, that implies that the proton becomes mass-less. Thanks for the feedback.
Neil
Neil Marshall said:Cryo,
Great question. It's a way of asking the question "is length contraction real or just an observation which is IRF dependent. I think the jury is still out on that question. Personally, I fall on the reality side, but let me insert a snippet from the Wikipedia article on "length contraction".
Neil
Photons don't get length contracted since, as you correctly stated, they have no shape, at least not in the usual common sense of the word. A photon is a single-particle Fock state. The common example is the generalized eigenvector of momentum and helicity ##|\vec{p},\lambda##.mfb said:Photons don't have a shape.
Protons, as everything, get length contracted as seen in the lab frame. As they don't have an actual three-dimensional structure anyway this is nothing you could see.
They would be flat in the rest system, but unchanged in their own inertial system, so they would not be mass-less. In the rest system they are quite heavy.Neil Marshall said:Mathman,
Possibility. I've heard tell that photons are 2 dimensional discs experiencing neither time or distance. Unfortunately, that implies that the proton becomes mass-less. Thanks for the feedback.
Neil
mfb said:That is complicated and above the I level.
mfb said:I said photons have no shape. Photons and protons are completely different things, despite the similar name. In the quoted part you asked about photons.
Protons are spherical, but they don't have a three-dimensional internal structure. You can't say "this quark is here and that is there".
I don't think that is a meaningful description.Neil Marshall said:If you told me that gluons mediate that space I would agree.
They don't. The binding energy does, but it is split over gluons and quarks.Neil Marshall said:Do gluons (which represent 99% of the mass of a proton)
There is not even a well-defined "number of gluons in a proton".Neil Marshall said:Do gluons increase in number and/or individual energy levels as acceleration increases?
@mfb This is interesting. The electric quadrupole moment of a nucleus plays a very important role in magnetic resonance experiments. I would think that relativistically flattening out a proton into an oblate spheroid would give it a quadrupole moment that, in principle, would be observable with the right experiment. But I'm not even sure the idea is well-posed.mfb said:Protons, as everything, get length contracted as seen in the lab frame. As they don't have an actual three-dimensional structure anyway this is nothing you could see.
Length contraction of protons in the LHC refers to the phenomenon in which the length of a proton appears to decrease when it is accelerated to high speeds in the Large Hadron Collider (LHC). This is due to the effects of special relativity.
The LHC is a particle accelerator that uses powerful magnets to accelerate protons to nearly the speed of light. As the protons reach these high speeds, they experience a phenomenon known as length contraction, where their length appears to decrease from the perspective of an outside observer.
According to Einstein's theory of special relativity, objects that travel at high speeds experience a contraction in their length in the direction of motion. This is due to the fact that the speed of light is constant and cannot be exceeded, so as an object approaches the speed of light, its length appears to decrease.
The length contraction of protons in the LHC is taken into account when designing and conducting experiments. It allows for the protons to reach higher energies and collide with greater force, producing more accurate results and allowing for the discovery of new particles and phenomena.
No, length contraction is observed in any object that travels at high speeds. However, it is most noticeable in particles like protons due to their incredibly high speeds in the LHC. It is also taken into account in other high-speed experiments, such as those conducted at the Large Electron-Positron Collider (LEP).