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It's what the standard model teaches.

Is light actually a massless traveling particle? Experiments show contradicting possibilities.

Concerning the double slit experiment: The quantum fields must be responsible because electrons sent through two negatively ionized slits in a vacuum one at a time every 60 seconds for a month accumulate as a sum into the exact same interference pattern on the screen which means it cannot be interacting waves of particles forming the pattern.

I have been told things that make no sense concerning electromagnetism.

If light is a massless particle, then it is the only particle that we know of that has zero mass. Somehow a massless light particle can still retain momentum even though momentum is dependent on mass because mass has inertia which propagates momentum. P=mv. I don't know what your definition of momentum is, but to me if an object has momentum, it must have mass with inertia otherwise it wouldn't retain a given movement. Or if light is actually an electromagnetic wave, then it wouldn't have mass with inertia or momentum but rather would be a wave that attenuates through an EM field. If light is an electromagnetic wave moving through an electromagnetic field, then it wouldn't have mass and it wouldn't have momentum either because the field is already there and the wave is only changing the field flux where it already is.

If you dare, read this entire physics article about what you were never taught. You may attempt to write me a better explanation. I've never heard of one.

Science is about asking questions over phenomena in order to understand them which doesn’t begin without speculation. There is a type of speculation that is ordered and structured into a network of comparisons that predicts unknowns with the known. The theory must come first in order to find the variables. An accurate mathematical function cannot be written without knowing and understanding the relationship between the variables in the system that you are trying to describe.

Infinity Loop
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The full relativistic energy-momentum relation is given by $$E^2=p^2c^2+m^2c^4$$ Light is massless meaning $m=0$ and therefore light has energy and momentum given by $$E=pc$$

That the speed of light is a constant independent of the motion of the source and observer is one of the postulates of special relativity and all experiments to date show this to be true. Why this is the case is a philosophical question and not of physics.

joseph h
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  • Yes, I have read this explanation before, but to me it seems doctored with nonsense to make the equation work. Doctor an equation to get a desired result. Or backtrack on all the variables to figure out whether it even makes sense to begin with. Experiments show something else. Anomalies in the standard model. – Infinity Loop Dec 24 '21 at 05:12
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    It's not "doctored" at all. You may believe this since it seems your understanding of these topics is very limited. I suggest you read an introductory text on relativity, assuming you have the mathematical background. Good luck. Cheers. – joseph h Dec 24 '21 at 05:15
  • When defining light having energy and momentum given by the equation E=pc, where do we get the value p? Is it just pulled out of Schrodinger's box? – Infinity Loop Dec 24 '21 at 05:20
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    If you are also finding it hard to use and manipulate a simple expression of the form $E=p\times c$ then I certainly cannot help you. You have a lot of study ahead of you if you want to understand relativity. Good luck. Cheers. – joseph h Dec 24 '21 at 05:24
  • Yes I can manipulate the equation to bring "P" to one side, but wouldn't we be going in circles? If we want to find the "E" we have to know "P" and if we want to find "P" we have to know "E". That's what my original questions were. How do we find "P" or "E" of light? How sure are you? You never wondered why there are anomalies that cannot be explained with light? Something is off. – Infinity Loop Dec 24 '21 at 05:35
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    You can calculate the energy of light by measuring its frequency, then you can get its momentum. You can also directly calculate its momentum from its wavelength. Make sense? Cheers. – joseph h Dec 24 '21 at 05:41
  • I get it. There are people that spend 1000's going to school for many years or spend 1000's researching with costly experiments funded by special interests with much on the line making all these science ideas very serious. Education is a life-long pursuit and from what I have studied so far about electromagnetism/light, there appears to be some anomalies that cannot be properly explained. So why are you surprised that I do not understand? You fully understand it? Ok then... – Infinity Loop Dec 24 '21 at 05:57
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    @InfinityLoop You keep mentioning anomalies and inconsistency with experiment. Perhaps there's a specific inconstancy of theory and experiment that you perceive and it might bring you clarity if it's addressed (starting a new question would be appropriate). – electronpusher Dec 24 '21 at 05:59
  • I agree that you can measure the energy of an electromagnetic wave by its frequency, but frequency is nowhere in that equation and it assumes light is a particle that has momentum to begin with rather than a wave that attenuates through an EM field. – Infinity Loop Dec 24 '21 at 06:04
  • @electronpusher The mechanics behind the double slit experiment have been argued over since it was first conceived. There is one. – Infinity Loop Dec 24 '21 at 06:05
  • @electronpusher Bells Theorem: https://en.wikipedia.org/wiki/Bell%27s_theorem – Infinity Loop Dec 24 '21 at 07:16
  • @Infinity The equation $$E^2=p^2c^2+m^2c^4$$, like most of the equations in SR, is a consequence of applying Pythagoras theorem to the geometry of flat Minkowski (flat) spacetime. The Newtonian equations are adequate at low relative speeds, but they need to be modified to account for how space & time are related in spacetime. – PM 2Ring Dec 24 '21 at 07:46
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    @InfinityLoop said “there appears to be some anomalies that cannot be properly explained”. Nonsense. There is, to date, no observed electromagnetic phenomenon that is not explained by our current theories of EM. The double slit is not a counter example, it is well understood by scientists even if new students find it difficult – Dale Dec 24 '21 at 14:07
  • @Dale I guess you never heard of Bells Theorem: https://en.wikipedia.org/wiki/Bell%27s_theorem I just want to point out, this thread is not about me. Its about checking and double checking what we believe is the truth concerning electromagnetic mechanics. Its so easy to be certain? Answer the question: Is light a wave or a particle? I understand it as a wave and am looking for explanations as to why others say it must be a particle with momentum because the predicted mechanics are anomalous if it is. – Infinity Loop Dec 24 '21 at 22:55
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    @InfinityLoop I have heard of Bell’s theorem. It certainly is not a counterexample. There is currently no such anomaly as you suggest. As I said above, there is no observed EM phenomenon that is contrary to our modern theory of EM. Note that even as a wave (Maxwell’s equations) light has momentum, so your “I understand it as a wave” and your “others say it must be a particle with momentum” seem self contradictory. If you think it doesn’t have momentum as a wave then you don’t understand it as a wave either – Dale Dec 25 '21 at 01:40
  • @Dale I think you have a lot to learn about electro-magnetic waves as well. If light is not a massless particle and is rather a wave flux of the field, then it doesn’t need to retain “P” momentum where P=mv. No doctored equations are needed to make it work. Anyone who has studied waves understands that they need a medium in order to propagate. The speed at which the medium (in our case EM field) updates to a change in energy (wave) is what we measure as the speed of light which doesn’t have momentum since waves moving ± through a medium have a net zero velocity due to their ± cycle. – Infinity Loop Dec 25 '21 at 17:17
  • @InfinityLoop said "light which doesn’t have momentum" see section 8 here: http://www.phys.lsu.edu/~jarrell/COURSES/ELECTRODYNAMICS/Chap6/chap6.pdf no photons, just Maxwell's equations and the resulting waves. The light momentum is experimentally measurable, so if you have a private theory without light wave momentum then it is already falsified. Also, I don't find your "doctored" claims objectionable. Regardless of any doctoring the only important thing is if it matches experiment or not. The standard "doctored" equations match experiment. – Dale Dec 25 '21 at 21:08
  • @Dale Experiments can have errors which is why they need to be checked and double checked. Even when there is a conclusion made, there can be new variables that are made known that we were unaware of when we did the experiment. Example: https://www.nature.com/articles/nature.2012.10249 If neutrinos could travel faster than light you could make a communication trading device that is faster than all communications in and out of the world trade center and make billions on the stock market. Either "the gods" don't want this known, or they actually accounted all variables & measured it correctly. – Infinity Loop Dec 28 '21 at 01:24