swansont Posted December 15, 2021 Posted December 15, 2021 10 hours ago, pzkpfw said: What observer will agree with this? Different observers will measure different shapes for anything that’s not a point particle. Nuclei in accelerators (such as the RHIC) will be more “pancake” than spherical, and this affects the charge distribution when modeling the interaction in the frame where the nucleus is moving. The claim is not wrong, but it doesn’t demonstrate the point they are claiming. 6 hours ago, MigL said: I thought you said you understood relativity ... Something cannot be relative to itself. The particle has different positions ( and times ) relative to different observers. Each observer, in a different frame, sees the particle in a different position ( and at a diferent time ). That is why frames of reference are so important. I would go a step further and say that we can transform between frames, so the notion that it’s a “different location” is likely another manifestation of the fundamental misunderstanding of relativity. Transforming from (x,t) to (x’, t’) is an acknowledgment that it’s the same location, but each observer has their own coordinate system. The particle is not in two places at once. One person can say a location is 123 Main St while another describes it in terms of latitude and longitude. One location, two ways of describing it.
34student Posted December 15, 2021 Author Posted December 15, 2021 14 hours ago, swansont said: True of any relative property. Shape is not relative. It is inherent to the structure of the universe. Equating kinetic energy to length contraction as being the same kind of relative property to the universe does not work either. We know this because the change in the structure of the universe from length contraction actually causes the muon to interact with the Earth's surface earlier than it should. But if there were no contraction, it would not interact with the Earth's surface. Whereas a train having kinetic energy does not cause something different to happen than the train not having kinetic energy as seen by the passengers. 11 hours ago, MigL said: I thought you said you understood relativity ... Something cannot be relative to itself. The particle has different positions ( and times ) relative to different observers. Each observer, in a different frame, sees the particle in a different position ( and at a diferent time ). That is why frames of reference are so important. So if each observer sees the same particle in a different position, how is that not a superposition of position?
Bufofrog Posted December 15, 2021 Posted December 15, 2021 14 minutes ago, 34student said: Shape is not relative. It is inherent to the structure of the universe. Incorrect.
swansont Posted December 15, 2021 Posted December 15, 2021 1 hour ago, 34student said: Shape is not relative. It is inherent to the structure of the universe. Not according to relativity, which is what we’re discussing. 1 hour ago, 34student said: Equating kinetic energy to length contraction as being the same kind of relative property to the universe does not work either. Why not? 1 hour ago, 34student said: We know this because the change in the structure of the universe from length contraction actually causes the muon to interact with the Earth's surface earlier than it should. But if there were no contraction, it would not interact with the Earth's surface. The contraction of the length doesn’t affect the “structure of the universe” As you have acknowledged, length is not a physical object. It’s merely the distance between tow points, which is shorter when there is relative motion. 1 hour ago, 34student said: Whereas a train having kinetic energy does not cause something different to happen than the train not having kinetic energy as seen by the passengers. Tell that to an object in its path. 1 hour ago, 34student said: So if each observer sees the same particle in a different position, how is that not a superposition of position? As I explained, it’s not in a different position, and also please review the explanations about superposition. Ignoring everyone and repeating your misconceptions is not a path forward here. You don’t understand relativity and you don’t appear interested in fixing that.
34student Posted December 15, 2021 Author Posted December 15, 2021 6 minutes ago, swansont said: Why not? I tried to explain in the following sentences. 11 minutes ago, swansont said: The contraction of the length doesn’t affect the “structure of the universe” As you have acknowledged, length is not a physical object. It’s merely the distance between tow points, which is shorter when there is relative motion. But the different shape from length contraction causes the muon to interact with the universe in a different way than if there were no length contraction. Of course the structure of the universe has changed because of length contraction. 15 minutes ago, swansont said: Tell that to an object in its path. You are not paying attention to what I am saying. Your argument about the relativity of kinetic energy of the train is not the same as the relativity of the difference in shape from a length contraction (keep reading because I am about to explain why.). The length contraction from muon's frame of reference actually causes something different to happen, such as impacting the Earth's surface when it should have decayed before making it to the surface. The change in shape actually causes something different to happen than if there were no length contraction from the muon's frame of reference. But with the kinetic energy of the train versus no kinetic energy from the passengers' point of view, nothing different will happen. An object in the train's path is still going to get struck, etc.
MigL Posted December 15, 2021 Posted December 15, 2021 2 hours ago, 34student said: So if each observer sees the same particle in a different position, how is that not a superposition of position? If you place your finger about a foot away from your face, and you look at it with one eye closed, you see it in a certain position relative to the background. If you then close the open eye, and open the other one, you see your finger in a different position relative to the background. Do you think your finger moved ??? Is it in two places at once ??? Is that a superposition of ststes ??? Or is it simply your viewpoint that has changed ? 1
Ghideon Posted December 15, 2021 Posted December 15, 2021 41 minutes ago, 34student said: length contraction Why do you speak of only length contraction and never mentioning time dilation in this context? 42 minutes ago, 34student said: Of course the structure of the universe has changed because of length contraction. Can you support that claim with a reference to relativity? 45 minutes ago, 34student said: An object in the train's path is still going to get struck, etc From the point of view of the passengers on the train they, and the train, are not moving. And from the same point of view (the passengers on the train) an object in the trains path will appear to be moving towards the train and strike the train.
34student Posted December 15, 2021 Author Posted December 15, 2021 33 minutes ago, MigL said: If you place your finger about a foot away from your face, and you look at it with one eye closed, you see it in a certain position relative to the background. If you then close the open eye, and open the other one, you see your finger in a different position relative to the background. Do you think your finger moved ??? Is it in two places at once ??? Is that a superposition of ststes ??? Or is it simply your viewpoint that has changed ? But aren't we assuming that length contraction is not just an illusion? In that case, when you and I say "see it in a different position" doesn't this really mean, "is in a different position"? 26 minutes ago, Ghideon said: Why do you speak of only length contraction and never mentioning time dilation in this context? I do not know what context you are referring to because you cut out only "length contraction". 27 minutes ago, Ghideon said: Can you support that claim with a reference to relativity? Relativity says that length contraction is not just an illusion. So when a sufficiently fast particle turns Earth into a pancake, then I have to figure that this changes the structure of the universe from what it would have been if there were no such frame of reference from the particle. 33 minutes ago, Ghideon said: From the point of view of the passengers on the train they, and the train, are not moving. And from the same point of view (the passengers on the train) an object in the trains path will appear to be moving towards the train and strike the train. Yes, but the outcomes are the same. The outcomes are not the same in the muon evidence of length contraction. Something different happens because of the length contraction than if there were no length contraction, specifically the impact on the Earth's surface vs not impacting it without length contraction.
swansont Posted December 15, 2021 Posted December 15, 2021 1 hour ago, 34student said: I tried to explain in the following sentences. But the different shape from length contraction causes the muon to interact with the universe in a different way than if there were no length contraction. Of course the structure of the universe has changed because of length contraction. The length is different, but nothing has changed. 1 hour ago, 34student said: You are not paying attention to what I am saying. Your argument about the relativity of kinetic energy of the train is not the same as the relativity of the difference in shape from a length contraction (keep reading because I am about to explain why.). The length contraction from muon's frame of reference actually causes something different to happen, such as impacting the Earth's surface when it should have decayed before making it to the surface. Should have? There’s no situation where they should have decayed, because that’s not in accordance with the laws of physics. You can’t make the comparison to what happens if the laws of physics are different. That’s ridiculous. 1 hour ago, 34student said: The change in shape actually causes something different to happen than if there were no length contraction from the muon's frame of reference. It’s not a change in the shape. The shape depends on the frame of reference. 1 hour ago, 34student said: But with the kinetic energy of the train versus no kinetic energy from the passengers' point of view, nothing different will happen. An object in the train's path is still going to get struck, etc. But you’re arguing based on one set of physics laws and some other set of laws. Surely I get to fabricate the same thing.
beecee Posted December 15, 2021 Posted December 15, 2021 20 hours ago, 34student said: I told you in my last post to you that I agreed that distance is not physical, not spacetime. Spacetime is clearly physical. Clearly space, time, spacetime are not physical entities. That does not mean they are not real, and validated as real by the effects they have on light, mass, energy, orbits etc. Just as clearly, distance are spacial dimensions that exist in space, and time obviously the 4th dimension. Your distances whatever they are can only occur in space....no space, no distance, no time, no nothing.
MigL Posted December 15, 2021 Posted December 15, 2021 (edited) 1 hour ago, 34student said: 1 hour ago, MigL said: If you place your finger about a foot away from your face, and you look at it with one eye closed, you see it in a certain position relative to the background. If you then close the open eye, and open the other one, you see your finger in a different position relative to the background. Do you think your finger moved ??? Is it in two places at once ??? Is that a superposition of ststes ??? Or is it simply your viewpoint that has changed ? Expand But aren't we assuming that length contraction is not just an illusion? In that case, when you and I say "see it in a different position" doesn't this really mean, "is in a different position"? Whether the contraction is real or not, does not really matter. For an observer in the object's rest frame, there is no contraction. For observers in any other frame there could be contraction. What makes contraction 'real' to those other observers is the fact that Relativity deals with the speed of light, which is also the speed of information. Any information you observe from a relativistic contracted object supports that contraction. That means any forces/interactions, or other effects will also manifest as if the object is contracted. IOW, for that observer, who sees relativistic contraction ( or time dilation ) the object is effectively contracted. Again, this is why frames matter. Until you wrap your head around the fact that different frames give differing observations, and all are equally valid ( no preferred frame ), you don't understand Relativity. From now on, when you mention an observational effect ( like your Muon example ), I expect you to specify which frame this effect is being observed from. Edited December 15, 2021 by MigL
studiot Posted December 15, 2021 Posted December 15, 2021 31 minutes ago, MigL said: Again, this is why frames matter. Most people do not understand the origin of the term 'frames' and what makes them special and different from just coordinate systems. I am sure the OP is not listening to anything I say so I can't tell him. +1 for your previous post about the finger and eye experiment. Do you know about the second part of that experiment - the flying double thumb ? I think I am going to win that bet with myself that this thread will reach 5 pages of silly argument before the Moderators get fed up and close it.
Ghideon Posted December 15, 2021 Posted December 15, 2021 1 hour ago, 34student said: Relativity says that length contraction is not just an illusion. So when a sufficiently fast particle turns Earth into a pancake, then I have to figure that this changes the structure of the universe from what it would have been if there were no such frame of reference from the particle. I was hoping for some reference to a scientific paper or text book. That could help finding where any misconceptions or misinterpretations come from. 1 hour ago, 34student said: I do not know what context you are referring to because you cut out only "length contraction". The context = your topic, the whole thread. You only mention length contraction. 1 hour ago, 34student said: Yes, but the outcomes are the same. The outcomes are not the same in the muon evidence of length contraction. Something different happens because of the length contraction than if there were no length contraction, specifically the impact on the Earth's surface vs not impacting it without length contraction. At high relative velocities, where length contraction is not negligible, relativistic effects has to be taken into account also when calculating kinetic energy (or momentum). If you have a setting where length contraction large enough to have an impact then you should not use newtonian physics for kinetic energy and momentum, it will result in wrong predictions.
swansont Posted December 15, 2021 Posted December 15, 2021 2 hours ago, 34student said: Relativity says that length contraction is not just an illusion. So when a sufficiently fast particle turns Earth into a pancake, then I have to figure that this changes the structure of the universe from what it would have been if there were no such frame of reference from the particle. But relativity does not “turn the earth into a pancake” because that implies something is happening to the earth. The earth is a pancake in certain frames of reference. That’s always the case.
studiot Posted December 15, 2021 Posted December 15, 2021 3 minutes ago, swansont said: But relativity does not “turn the earth into a pancake” because that implies something is happening to the earth. The earth is a pancake in certain frames of reference. That’s always the case. A point worth making is that even a pancake has thickness.
Phi for All Posted December 15, 2021 Posted December 15, 2021 2 hours ago, 34student said: Relativity says that length contraction is not just an illusion. So when a sufficiently fast particle turns Earth into a pancake, then I have to figure that this changes the structure of the universe from what it would have been if there were no such frame of reference from the particle. ! Moderator Note OK, that's enough of that! It's pretty clear you're ignoring the replies you're getting because you don't understand them, so I'd go back to the basics and study some more. Perhaps start with some maths so trying to understand Relativity isn't such a chore. If you want to learn how to act, you shouldn't dive right into Shakespeare, right? Thread closed, don't bring this up again for at least a year.
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