Transfer of atomic mass with a photon solves the momentum paradox of light
physics.aalto.fi
physics.aalto.fi
If this proves to be true, is there a chance that our whole picture of the expanding cosmos needs a full revisiting?
It'll be interesting to see if this sparks new debate on the subject.
They didn't run any experiments. They only have some a theoretical model and simulations in the computer.
The main part of the article, that says that the momentum of the light is split in the photon and in the density wave looks good. (It almost looks obvious, but it's not my expertise area https://xkcd.com/793/ .)
The relation with the Hubble constant is totally unexpected. It is not in the abstract of the peer review article. (I can't read the full text.) So it's probably only a declaration for the press release. Take it with a grain of salt.
https://arxiv.org/abs/1603.07224
note: "on the arxiv" and not "on arxiv". The name puns on x => greek letter chi.
Edit: A clarification: I'm not an expert.
No expansion = everything falls together.
I just don't think we have any good ways to distinguish whether a high redshift is due to the object being very distant or the intergalactic medium in that direction being particularly dense, for most objects.
There's no direct way to measure the distance of very far objects. There's only red-shift and Hubble's Law.
Space is not a complete vacuum.
[1] - https://ned.ipac.caltech.edu/level5/Madau6/Madau_contents.ht...
[1] https://en.wikipedia.org/wiki/Big_Bang_nucleosynthesis
Some relatively small effects of so-called "tired-light" scenario could likely be accommodated, but it would not change the main picture.
Of course, we know that our theoretical model break down before that (since we don't have an experimetally verified theory of gravity compatible with quantum mechanics). Physicist that work in the field (and I used to be one of them) are well aware that we cannot extrapolate past the regions of validity of our theories and no one claim that there was indeed a singular point ("Big Bang") as mentioned in descriptions aimed at a non-expert audience.
http://www.hawking.org.uk/the-beginning-of-time.html
I even saw that recently Stephen Hawking started theorizing that the "Big Bang" was like a black hole. And other physicists weigh in:
http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/...
Look at this wikipedia article. Someone must be writing it?
https://en.m.wikipedia.org/wiki/Initial_singularity
In fact there are some contradictions between Quantum Mechanics and an actual big bang:
https://m.phys.org/news/2015-02-big-quantum-equation-univers...
It is pretty well accepted that light can have mass, in the sense that the authors are using the term. For example, light trapped as a standing wave between two mirrors in an etalon must have zero momentum. (By symmetry: if it has momentum, which way does the vector point?) But that light has energy, so it has mass in the sense that m must be non-zero to satisfy E² = p²c² + m²c⁴. More precisely, the momentum-energy vector of the light is timelike instead of lightlike.
This makes me suspect the whole paper, because it seems really plausible that a light wave in a medium is partly like a standing wave. In particular, there is a limit of a dense medium whose momentum is negligible. (Maybe the refractive index approaches 1 in a very dense medium, but I can't imagine why that would be so.) I'd have to spend a morning reading and thinking about it to be sure.
Also, the paper is suspiciously detailed; these questions should be resolvable at a much higher level of abstraction, and certainly without computer simulations.
Presently the Hubble’s law is explained by Doppler shift being larger from distant stars. This effectively supports the hypothesis of expanding universe. In the mass polariton theory of light this hypothesis is not needed since redshift becomes automatically proportional to the distance from the star to the observer”, explains Professor Jukka Tulkki.
It becomes a bit of a pain for animating datasets, since you need to do Blender scripting with Python which is far from intuitive. But it's doable.
Having said that, this doesn't look like Blender.
(I just checked wikipedia and it seems it's released under BSD license. Unsure if other products available which are built on top of it)
Wait a min. Can this be used to build optical logic gates?
The answer, unless I misunderstand you, is "probably not"; I don't see how this discovery would help us to implement optical transistors.
Isn't the problem with optical computers is that we don't have a way to switch light using light only. I though maybe this will enable to do something like that..because it says that light through a medium affecting a physical property, and that too at the speed of light...
https://physics.stackexchange.com/questions/3189/is-the-abra...
There is a summary statement that I found to be especially helpful in framing the question:
"To summarize... it's probably OK to "redo" the budget in such a way that a part of the momentum of the photon is attributed to the dielectric material when the photon enters it, and then it is returned back to the photon. In this way, one may justify the Abraham's form - and probably many other forms - but why should one really do it?"
In the literature, there has existed two different values for the momentum of light in the transparent medium. Typically, these values differ by a factor of ten and this discrepancy is known as the momentum paradox of light.
However, IMO none of these explanations are particularly satisfying because none of them (AFAICT) explain where these two different formulations come from. They all leave you with the impression that two physicists just pulled two different equations out of their ass and now they're arguing over which one is right as if it were some sort of theological discussion. (This is a common problem in physics pedagogy.) I would really love to hear from a physicist who understands and can explain the basis for the two different formulations.