7 ms·
New magnetic component discovered in the Faraday effect
- namanyayg 1y agoWe intuitively think in particles and see a world of billiard balls colliding with one another. But actually everything is merely waves and fields. There's going to be a time where humans finally reconcile the quantum with the newtonian -- and I can't wait for that day
- thaumasiotes 1y ago> But actually everything is merely waves and fields. The two-slit experiment says otherwise.
- FloorEgg 1y agoThe way I've always thought of this is there are potentials for interactions and interactions. Interactions act like point particles and potentials for interactions act like waves. Arguing over the distinction is a bit like debating whether people are the things they do, or the thing that does things. There is some philosophical discussion to be had, but for the most part it doesn't really matter.
- gucci-on-fleek 1y agoHmm? The double slit experiment definitely shows that particles are waves—weird quantum waves, but still waves.
- fragmede 1y agowhat happens when you only send a single photon down the line though?
- mpyne 1y agoIt's worth reading about, but it's kind of wave-like even then: https://en.wikipedia.org/wiki/Double-slit_experiment#Interference_from_individual_particles https://en.wikipedia.org/wiki/Double-slit_experiment#Interfe... It would be going too far to say it's only a wave though. It's both wave and particle.
- binary132 1y agoThe way I read GGP was as contradicting the assertion that everything is just waves and not at all particles.
- rolph 1y agodo it once, it looks like one particle. repeat the single photon launch many times, and you see a wavelike distribution of photon strikes
- bobbylarrybobby 1y agoIt still interferes with itself, and that interference affects the pattern of detections. It's as if the photon were a wave right up until the moment of detection, at which points it's forced to “particalize” and pick a spot to be located at — but it's the amplitude of the wave it was just before detection that determines where on the detection screen the photon is likely to show up. If you send many photons through one at a time, the detections (each just a point on the screen) will fill out the expected double slit pattern.
- ggm 1y agoI've always wondered what degree of confidence exists amongst the cogniscenti that a single photon event happened. I tend to think the criteria of measurement here would suggest the most likely outcome was a shitload more than 1 photon, and that all the "but we measured we can see one only" measurements are themselvs hedged by a bunch of belief. That said, I do like the single photon experiment, when it's more than a thought experiment.
- uberduper 1y ago
- thaumasiotes 1y agoThe two-slit experiment shows that photons behave like waves if you aren't looking at them, and that they fail to behave like waves if you are.
- deleted 1y ago[deleted]
- layer8 1y agoEverett reconciled that. They only appear to fail to behave like waves because the observer is waves as well.
- jasonwatkinspdx 1y agoIt does not. It shows that individual photons self interfere, so they cannot be idealized particles.
- dcl 1y agoAre you getting confused with the photoelectric effect experiment?
- farrelle25 1y agoAnother interpretation of the double-slit posits a guiding 'Pilot Wave' separate from physical particles... aka DeBroglie-Bohm Theory or Bohmian Mechanics. Apparently it's not popular among professional physicsts though John Bell investigated it a bit. Einstein had some unpublished notes in the 1920s about a "Gespensterfeld" (ghost field) that guided particles. Born was influenced by this 'Ghost field' idea when he published his famous interpretation of the 'Wave Function' |Ψ|^2 as a probability rather than a physical field. More info: Nonlocal and local ghost fields in quantum correlations. https://arxiv.org/abs/quant-ph/9502017 https://arxiv.org/abs/quant-ph/9502017
- mock-possum 1y agoPilot wave is still my favorite - I don’t really believe it, but I like the image
- deleted 1y ago[deleted]
- naasking 1y agoIt is indeed a great way to translate classical intuitions to the quantum domain.
- rhdunn 1y agoVeritasium did a video on this [1] with a surface of oil to replicate the effect on a petri dish. [1] https://www.youtube.com/watch?v=WIyTZDHuarQ https://www.youtube.com/watch?v=WIyTZDHuarQ
- jagged-chisel 1y agoThat we're just collections of wave interference is wild.
- isolli 1y agoWe're built on so many layers of emergence, it's wild! quantum particles => atoms => chemistry => biochemistry => cellular life => multi-cellular life => intelligence
- piva00 1y agoIt can keep going! Intelligence -> societies -> technology -> ? One has to wonder how far can emergence stretch given enough time, some kind of entropic limit probably exists but I'm just a layman, hopefully someone more knowledgeable can share if we already know a physical hard limit for emergence.
- jacquesm 1y agoI like your progression. It makes me wonder if intelligence could lead to technology absent societies.
- boyanlevchev 1y agoIf we take a simple definition of technology - such as “tool” or some external inanimate thing we use as an extension of ourselves - then I think all animals on Earth that we have deemed intelligent to some degree use “technology”. Crows using sticks to pick things out holes, chimps crafting spears for hunting, dolphins wearing “hats”, octopuses building stone fortresses, etc. So I guess it’s important to define the limit of the definition of technology.
- vixen99 1y agoAfter a brilliant start (atoms etc.,) it starts to be problematic once one hits societies. After all, the earlier progressions are undeniably astounding stable successes in their various incarnations. A pessimist might say 'Stable' societies so far have tended eventually towards being self-destructive tyrannies.
- canjobear 1y agoThere's no problem reconciling the quantum with the Newtonian. Quantum mechanics recovers Newtonian mechanics in the appropriate limit. The problem is reconciling the quantum and the Einsteinian.
- sosodev 1y agoBut there’s no quantum explanation of gravity, right?
- arthurcolle 1y agoClassified
- lmpdev 1y agoAt this point we have several They’re all largely untestable though String theory, LQG, half a dozen others
- fnordpiglet 1y agoThere’s no explanation of gravity, quantum or no. There are merely descriptions.
- isolli 1y agoIsn't everything descriptions, in the end, aka models? Turtles all the way down...
- B1FF_PSUVM 1y ago"Two masses attract each other with a force F = m1 m2 G/r^2" "OK, but why don't they repel each other?" "That would make life really hard, and we wouldn't be here discussing it ..."
- tsimionescu 1y agoActually, Newtonian gravity can be added to QM and work perfectly well. It's GR gravity that doesn't work with QM, especially if you try to model very high curvature like you'd get near a black hole.
- hliyan 1y agoI think neither analogy is correct. We're using macro metaphors (real world things at human time and spatial scales) to explain microscopic phenomena that may not correspond to anything that we find familiar.
- setopt 1y agoI agree with this. As a physicist, I believe the most accurate resolution is to say that «quantum fields» and «quantum particles» describe neither waves (in the sense of e.g. water or acoustic waves) nor particles (in the sense of marbles and billiard balls), but a third thing that simply has some things in common with both classical waves and classical particles. The analogies are useful for understanding that third thing, but if you believe the analogies too literally, then you’ll make mistakes.
- IAmBroom 1y agoThank you! That's a paradigm that I had in the back of my head, but not explicitly phrased. Photons aren't like particles nor waves. Particles and waves are like photons. And, as with all similes, they fail when you inspect too closely.
- chadcmulligan 1y agoI don't have the math, but doesn't quantum field theory say this?
- gethly 1y agoMaybe think of it as binary(particles) vs analog(waves).
- baq 1y agoJust listen to Feynmann trying to explain why he can't explain magnetism in macro terms (e.g. https://www.youtube.com/watch?v=MO0r930Sn_8 https://www.youtube.com/watch?v=MO0r930Sn_8)
- zyxzevn 1y ago3Blue1Brown has a very good explanation of how light works as a wave And the barber pole effect shows how matter (sugar) rotates light https://www.youtube.com/watch?v=QCX62YJCmGk https://www.youtube.com/watch?v=QCX62YJCmGk There is also evidence that "photons" are just thresholds in the material that is used to detect light. The atoms vibrate with the EM-wave and at a certain threshold they switch to a higher vibration state that can release an electron. If the starting state is random, the release of an electron will often coincide with the light that is transmitted from just one atom. This threshold means that one "photon" can cause zero or multiple detections. This was tested by Eric Reiter in many experiments and he saw that this variation indeed happens. Especially when the experiment is tuned to reveal this. By using high frequency light for example. It happens also in experiments done by others, but they disregarded the zero or multiple detections as noise. I think the double detection effect was discovered when he worked in the laboratory with ultraviolet light. Here is a paper about Eric Reiter's work: https://progress-in-physics.com/2014/PP-37-06.PDF https://progress-in-physics.com/2014/PP-37-06.PDF And here is his book. https://drive.google.com/file/d/1BlY5IeTNdu1X6pRA5dnJvRq3ip6cRKTg/view https://drive.google.com/file/d/1BlY5IeTNdu1X6pRA5dnJvRq3ip6...
- ta988 1y agoThere are so many artifacts that could cause those observations that I emit serious doubts that's what is happening in those experiments.
- uberduper 1y agoWhat a timely article and comment. I've been watching a lecture series over the last few days about quantum mechanics and the many worlds interpretation. And I have questions. I may have missed it or didn't understand it when I heard it explained. What underpins the notion that when a particle transitions from a superposed to defined state, the other basis states continue to exist? If they have to continue to exist, then okay many worlds, but why do we think (or know?) they must continue to exist?
- moi2388 1y agoBecause quantum mechanics describes the universe with a wave function, which evolves according to the schroedinger equation. In it, there is no notion of collapse. The only thing that makes sense is saying the observer becomes entangled with the measurement. So if you only look at the Schrödinger equation, this is the only conclusion. Wave function collapse is something which is simply added ad-hoc to describe our observation, not something which is actually defined in QM
- uberduper 1y agoThat's an unsatisfying answer. I have some work to do if I want to understand it.
- sevensor 1y agoI disagree. Our notion of waves is no less an analogy to macroscopic phenomena than billiard balls. There’s no avoiding the dual nature, and there’s no problem with saying that the wave analogy works in some places, but the particle analogy works in others. The only real truth here is “neither.” A photon is a photon, and there is no macroscopic analogy it reduces to perfectly.
- szundi 1y ago[dead]
- user3939382 1y agoSoon!
- magphys 1y ago> To quantify this influence, the team applied their model to Terbium Gallium Garnet (TGG), a crystal widely used to measure the Faraday effect. They found that the magnetic field of light accounts for about 17% of the observed rotation at visible wavelengths and up to 70% in the infrared range. Nearly 20% seems already significant, but 70%?! that's massive.
- nrhrjrjrjtntbt 1y agoNice to see a graph of % magnetic priportion and log wavelength going from radio to gamma.
- CamperBob2 1y agoHow did no one notice that before, and what else have they (we) missed?
- gsf_emergency_6 1y agoIf I'd to guess: all that exp. characterization to-date has revealed no anomaly (See my other comment) This team might have looked at bandstructure. or not (they didn't say, & I'd guess not)
- gsf_emergency_6 1y agoSeems to be a minor typo . Paper: >17.5% of the measured value for Terbium-Gallium-Garnet (TGG) at 800 nm, and up to 75% at 1.3 µm. Here's what the crystal looks like https://www.photonchinaa.com/tgg-terbium-gallium-garnet/ https://www.photonchinaa.com/tgg-terbium-gallium-garnet/ Here's transmission plot (UV-IR) https://www.samaterials.com/terbium-gallium-garnet-crystal.html#:~:text=Terbium%20Gallium%20Garnet%20Crystal%20Transmission%20Curve https://www.samaterials.com/terbium-gallium-garnet-crystal.h... Note there's almost no effect on transmission Relevant? https://dspace.mit.edu/handle/1721.1/51819 https://dspace.mit.edu/handle/1721.1/51819
- sehansen 1y agoYes, the paper and magphys talks about rotation, not transmission.
- dmead 1y ago[flagged]
- idiotsecant 1y agoPeople in countries you don't like can still do valid science.
- dmead 1y agoI don't care. I hope they enjoyed themselves while their countryman were running the meat grinder a short drive away
- plaguna 1y agoBut do they understand how magnets work?
- ghostpepper 1y agoObviously hindsight is 20/20 but this sentiment just reeks with comical levels of hubris > However, the new research demonstrates that the magnetic field of light, long thought irrelevant,
- agentifysh 1y agoso what exciting applications can we see from this?
- discoutdynamite 1y agoThis isnt exactly new. This is a obvious and predicted effect of ECE Theor. I'm surprised that neither the article nor any other commentor mentioned it yet. tl;dr on ECE Theory: Gravity is a curvature of spacetime, electromagnetism is a torsion.
- prmph 1y agoFrom Wikipedia: Einstein–Cartan–Evans theory or ECE theory was an attempted unified theory of physics proposed by the Welsh chemist and physicist Myron Wyn Evans ..., which claimed to unify general relativity, quantum mechanics and electromagnetism. The hypothesis was largely published ... between 2003 and 2005. Several of Evans's central claims were later shown to be mathematically incorrect and, in 2008, the new editor of Foundations of Physics, Nobel laureate Gerard't Hooft, published an editorial note effectively retracting the journal's support for the hypothesis.
- deleted 1y ago[deleted]
- Noaidi 1y agoI’m sorry if I offended anyone’s consciousness by bringing this up, but this can affect how we view the health effects of radio frequency electromagnetic fields. Since the magnetic fields of these EMF’s can pass deeper into the body than the electric field, that would mean that the magnetic field can affect many of the voltage gated ion channels in the body. That’s including the brain.
- wasabi991011 1y ago> Since the magnetic fields of these EMF’s can pass deeper into the body than the electric field, Can they actually though? I'm not an expert, but to my knowledge the penetration depth of an electromagnetic wave depends only on its frequency. I can't find anywhere online that makes a distinction between electric waves and magnetic waves.
- Noaidi 1y agoWhen the electromagnetic wave hits a substance, it splits into separate electric and magnetic waves. The electric wave does not penetrate deeply, but magnetic waves can go through anything. Magnetic waves can only be diverted, not blocked.