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URI New magnetic component discovered in the Faraday effect after nearly 2 centuries
agentifysh wrote 2 hours 12 min ago:
so what exciting applications can we see from this?
geocar wrote 1 hour 49 min ago:
We will put a box containing a little light and a magnet into every
home and people will lose their goddamned minds looking at it every
day
ghostpepper wrote 5 hours 23 min ago:
Obviously 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,
plaguna wrote 5 hours 25 min ago:
But do they understand how magnets work?
magphys wrote 6 hours 49 min 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.
gsf_emergency_6 wrote 5 hours 7 min ago:
Seems 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 [1] Here's transmission plot
(UV-IR) [2] Note there's almost no effect on transmission
Relevant?
URI [1]: https://www.photonchinaa.com/tgg-terbium-gallium-garnet/
URI [2]: https://www.samaterials.com/terbium-gallium-garnet-crystal.h...
URI [3]: https://dspace.mit.edu/handle/1721.1/51819
CamperBob2 wrote 6 hours 1 min ago:
How did no one notice that before, and what else have they (we)
missed?
gsf_emergency_6 wrote 4 hours 31 min ago:
If 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)
nrhrjrjrjtntbt wrote 6 hours 7 min ago:
Nice to see a graph of % magnetic priportion and log wavelength going
from radio to gamma.
namanyayg wrote 6 hours 52 min ago:
We 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
gethly wrote 1 hour 0 min ago:
Maybe think of it as binary(particles) vs analog(waves).
chadcmulligan wrote 2 hours 59 min ago:
I don't have the math, but doesn't quantum field theory say this?
hliyan wrote 5 hours 18 min ago:
I 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.
canjobear wrote 5 hours 21 min ago:
There'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 wrote 5 hours 6 min ago:
But thereâs no quantum explanation of gravity, right?
tsimionescu wrote 1 hour 19 min ago:
Actually, 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.
rhdunn wrote 50 min ago:
Quantum Electro-Dynamics (QED) is the application of Special
Relativity (non-accelerating frames of reference, i.e. moving
at a constant speed) to Electromagnetism. Thus, the issue is
with applying accelerating frames of reference (the General in
GR) to QM.
fnordpiglet wrote 2 hours 3 min ago:
Thereâs no explanation of gravity, quantum or no. There are
merely descriptions.
isolli wrote 49 min ago:
Isn't everything descriptions, in the end, aka models? Turtles
all the way down...
lmpdev wrote 4 hours 58 min ago:
At this point we have several
Theyâre all largely untestable though
String theory, LQG, half a dozen others
arthurcolle wrote 5 hours 5 min ago:
Classified
jagged-chisel wrote 6 hours 25 min ago:
That we're just collections of wave interference is wild.
isolli wrote 47 min ago:
We're built on so many layers of emergence, it's wild!
quantum particles => atoms => chemistry => biochemistry => cellular
life => multi-cellular life => intelligence
thaumasiotes wrote 6 hours 42 min ago:
> But actually everything is merely waves and fields.
The two-slit experiment says otherwise.
farrelle25 wrote 1 hour 40 min ago:
Another 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.
URI [1]: https://arxiv.org/abs/quant-ph/9502017
rhdunn wrote 45 min ago:
Veritasium did a video on this [1] with a surface of oil to
replicate the effect on a petri dish.
URI [1]: https://www.youtube.com/watch?v=WIyTZDHuarQ
mock-possum wrote 52 min ago:
Pilot wave is still my favorite - I donât really believe it,
but I like the image
dcl wrote 4 hours 8 min ago:
Are you getting confused with the photoelectric effect experiment?
jasonwatkinspdx wrote 4 hours 16 min ago:
It does not. It shows that individual photons self interfere, so
they cannot be idealized particles.
gucci-on-fleek wrote 6 hours 30 min ago:
Hmm? The double slit experiment definitely shows that particles are
wavesâweird quantum waves, but still waves.
thaumasiotes wrote 22 min ago:
The 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.
fragmede wrote 6 hours 18 min ago:
what happens when you only send a single photon down the line
though?
gucci-on-fleek wrote 3 hours 46 min ago:
As the other comments have already mentioned, it interferes
with itself, so you still observe the same interference
patterns [0] [1]. Which admittedly seems impossible at first,
but so does the rest of quantum physics.
[0]: [1]:
URI [1]: https://www.feynmanlectures.caltech.edu/III_01.html#Ch...
URI [2]: https://en.wikipedia.org/wiki/Wave%E2%80%93particle_du...
danparsonson wrote 4 hours 13 min ago:
It's a wave of probability, that interferes through the slits
and then collapses into a probability of one somewhere along
the wavefront at the point of detection. Whatever that means
:-)
ggm wrote 4 hours 40 min ago:
I'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.
bobbylarrybobby wrote 5 hours 28 min ago:
It 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 âparticalizeâ and pick a spot to be located at
â 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.
rolph wrote 5 hours 51 min ago:
do it once, it looks like one particle.
repeat the single photon launch many times, and you see a
wavelike distribution of photon strikes
mpyne wrote 5 hours 58 min ago:
It's worth reading about, but it's kind of wave-like even then:
[1] It would be going too far to say it's only a wave though.
It's both wave and particle.
URI [1]: https://en.wikipedia.org/wiki/Double-slit_experiment#I...
binary132 wrote 5 hours 43 min ago:
The way I read GGP was as contradicting the assertion that
everything is just waves and not at all particles.
FloorEgg wrote 6 hours 33 min ago:
The 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.
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