Hello all. First time posting here. I have a basic understanding of special relativity and I have few questions about what the Large Hadron Collider (LHC) looks like to a proton going around inside it. As I thought more and more about it the few questions turned into a bunch of questions. I know that special relativity might not apply everywhere since the proton is accelerated by traveling in a circle. I am not sure where special relativity can be used and where general relativity would be used. What shape does the LHC have to a proton traveling the 27km circumference with a Lorentz factor of 7500 (in about 89 ns)? I am guessing it would look like a very flat oval with a diameter contracted by 7500 in the direction the proton is moving and the diameter perpendicular to that (about 8.6km) would not be contracted. Is that correct? At least, that is what it would look like to a proton traveling straight and tangent to the LHC with the same speed. Does traveling in an arc make a difference? By the way, assuming it's an oval, is the oval an ellipse or some other shape? (When I say "looks like" I mean according only to whatever relativistic transformations would apply, not what it looks like to a camera, but that would be another interesting question.) Also, would a proton see clocks on the circumference of the LHC running slower or faster? The moment a proton passes by a clock on the circumference it seems that special relativity would say it would be running slower. Is that correct? But it also seems that when a proton makes its 12ns (89us/7500 I'm assuming) cycle according to the proton's clock, an LHC clock on the circumference would have to show 89us having passed when a proton passes by a second time making the clock appear to run faster. How is this resolved? How would a clock at the center of the LHC or on the opposite side of the LHC appear to run to a proton? What about a proton's clock on the opposite side? How long is the 27km LHC circumference as seen by the proton? It seems it could be 12 light nanoseconds (3.6m) considering the proton sees itself traveling in the LHC at near the speed of light for 12ns to make a cycle, or it could be about 2 x 8.6km = 17.2km looking at the very flat oval with the circumference being about two non-contracted diameters, or it could be 27km since it seems the proton is always at the most outer point of the oval from its point of view. I'm not sure if this is a meaningful question but, if a proton were to slowly feed out a string, with 1 meter markings, behind itself as it went around, how much string would be fed out, by the markings, when the string gets all the way around? I am guessing that it could be 27km x 7500 = 20,2500km, calculating from the LHC point of view if the string is contracted. If the proton looks across the LHC to the other side, what marking does it see on the string. It seems it would be the halfway mark, or could it be something else? Are the 1 meter string markings on the opposite side contracted even more than 7500 since the string is traveling in the "oncoming" direction? If so, how much? From the four different numbers the circumference, are some more correct or meaningful than the others? Also, what radius of curvature and centrifugal force (how many g's) does the proton experiences as it goes around? And finally, what would everything look like to a proton's video camera?