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|u/Cyanopicacooki - 1 day
|
|>That should rule out light, since photons are massless...creating
|quasiparticles called polaritons.The team admits that technically it's
|these polaritons, which do have mass, that are casting the shadow. But
|on the other hand, polaritons are still half-photons, So, photons are
|massless, but their half-particles. polaritons, do have mass... It's
|not yet half past 9 on a Saturday morning and already I've realised how
|little my brain is in comparison to the wealth of the universe. I
|wonder how many other facts I'll learn today that I know I'll never
|understand.
|u/patricksaurus - 1 day
|
|It’s a very interesting phenomenon, but not as crazy as I think you
|are envisioning. In the article, it mentions that this effect takes
|place when a green laser is shined through a ruby, right? Polariton
|is just the name given to a specific interaction between the photons
|and the atoms of the ruby. So the mass comes from plain old atoms,
|albeit in a specific chemical environment, just interacting with a
|specific kind of plain old light.
|u/telmesumpm - 20 hours
|
|Does that mean we could make a spaceship with ruby sails and push it
|across space with a green laser? Just kidding
|u/redopz - 20 hours
|
|I'm not entirely sure how necessary the ruby and green are, but
|you are thinking like Stephen Hawking. As part of a team he helped
|propose the [Breakthrough Starshot
|project](https://en.m.wikipedia.org/wiki/Breakthrough_Starshot)
|which would use powerful lasers to propel very small, unmanned
|spacecraft to distance star systems. The hypothetical probes would
|be fast enough to reach the closest star, Alpha Centauri, and
|send back signals within a single human life-span.
|u/AtomicPotatoLord - 17 hours
|
|Not necessarily thinking like Stephen Hawking, considering this
|technological concept has been considered in the past by other
|people.
|https://www.niac.usra.edu/files/studies/final_report/4Landis.pdf
|And definitely earlier.
|u/chudthirtyseven - 1 hour
|
|they are also thinking like me, because I am thinking this
|now.
|u/AtomicPotatoLord - 16 minutes
|
|I am now thinking like you, but you like me.
|u/Logicalist - 15 hours
|
|Lightsails or Solar Sails are a thing.
|u/gramathy - 8 hours
|
|We can do that with any reflective surface already, it’s just very
|low power. Even without mass, light has momentum (the energy is
|sapped in the form of redshifting the light reflected slightly,
|something I actually looked up about a month ago because I
|recalled the phenomenon and wondered about that exact consequence)
|The Sith ship in the prequel trilogy had a solar sail
|u/sceadwian - 19 hours
|
|Laser propulsion doesn't need anything like that.
|u/idkmoiname - 10 hours
|
|>So the mass comes from plain old atoms, albeit in a specific
|chemical environment, just interacting with a specific kind of plain
|old light. So... just like any shadow is a result of photons
|interacting in a specific kind with atoms?
|u/patricksaurus - 9 hours
|
|No, it’s because if it was, the ruby would be blocking the whole
|beam, not just the portion interacting with the first laser.
|u/FireMaster1294 - 15 hours
|
|You found polaritons having mass weird? Well, the *really* fucky stuff
|is when you get into the fact that polaritons can have *negative* mass
|https://www.nature.com/articles/s41467-023-36618-6
|u/WATTHEBALL - 21 hours
|
|Dude your brain is equally as impressive and complex as the entire
|universe.
|u/InformalPenguinz - 19 hours
|
|Possibly more so. As far as we can tell, the universe isn't
|sentient. We humans give ourselves very little credit on how complex
|we are.
|u/gooyouknit - 15 hours
|
|You are a part of the universe and you are sentient, no? I am not
|saying that the only thing that exists is consciousness like some
|mystics would but I do think you have an unnecessary divide
|between us and the universe in your head
|u/healthierlurker - 14 hours
|
|Agreed. This is the basis for r/pantheism.
|u/VayneFTWayne - 10 hours
|
|More like non dualism
|u/healthierlurker - 10 hours
|
|Most pantheists believe in non dualism but obviously
|attribute divinity to it.
|u/VayneFTWayne - 10 hours
|
|Okay, but many types of thought believe in non dualism, so
|pantheism isn't special in that sense.
|u/healthierlurker - 14 hours
|
|Only if you view life and consciousness as separate from the
|universe. We are clearly all part of one thing and thus the
|universe absolutely is conscious.
|u/sceadwian - 19 hours
|
|Not even vaguely close ;) The human brain isn't even as complicated
|as the interactions going on in a cubic meter of the sun's volume.
|u/TheMurrayBookchin - 18 hours
|
|Neurons, neural pathways, hormonal regulation, the Krebs cycle
|influencing brain energy regulation, the consolidation of visual,
|sound, and touch information as storage (memories), etcetcetc. I
|dunno. There’s lots going on. They’re incomparable, but saying
|it’s “not even vaguely close” is pretty wrong in itself. Helium-4
|production through nuclear fusion is awesome, positrons and
|neutrinos included, but you’re downplaying the complexity of the
|human brain and the interconnected systems regulating it.
|u/sceadwian - 17 hours
|
|You don't understand how complex plasma systems are. That's
|really all you're saying.
|u/TheMurrayBookchin - 17 hours
|
|You don’t understand how complex biological organisms are.
|That’s all you’re really saying.
|u/sceadwian - 17 hours
|
|The statement your brain is as complex as the universe is
|ludicrous. If you don't like the complexity of plasma
|physics then how about we go into quantum mechanics? The
|human mind can not even cast a shadow on the complexity of
|the universe. That's the anthropocentric ego there, not a
|rational argument.
|u/Ravarix - 17 hours
|
|What a weird statement when our brains are part of the
|universe.
|u/sceadwian - 17 hours
|
|Why is that weird? If our brains are part of the
|universe they can't be more complex or even as complex
|as it. That would be a logically incoherent statement.
|That is weird!
|u/TheMurrayBookchin - 17 hours
|
|My statement? I didn’t say that. I’m not even the person
|you originally directed your smarmy “;)” comment to. “The
|human brain isn’t even as complicated as the interactions
|going on in a cubic meter of the sun’s volume.” is what I
|commented on, which is, frankly, a stupid argument you’re
|making. Yikes. I teach chem and physics, but yes,
|continue pretending you’re smarter than everyone you meet
|in life and on the internet. It’s a good look. Meh. The
|bulk of my education is in bio, so I get it, you don’t
|know much about biological processes in (not just human)
|organisms. It’s ok to be wrong sometimes, and to not know
|everything. I forgive you, we all do. I’d suggest you
|diversify your education rather than be leagues out of
|depth in general science discussions.
|u/sceadwian - 17 hours
|
|Right. But that's what I was commenting on. Please
|actually read my last post which fully addressed that.
|You seem to not have actually read it. My argument is
|not stupid, your interpretation of it is wrong and
|you're starting to turn this into an emotional argument
|with that stupid comment. Check your ego somewhere
|else please.
|u/gfat-67 - 11 hours
|
|An analogy in jest I like to use is that humans understanding the
|universe is about as likely as successfully explaining a ride sharing
|app to an ant.
|u/Frites_Sauce_Fromage - 1 hour
|
|So... What else did you learn yesterday?
|u/TolMera - 10 hours
|
|`E=mc2` strikes again
|u/Successful-Sand686 - 20 hours
|
|You know great science words. I thought particles and energy were the
|same in different temps. Like light will be a wave at certain temps
|and closer to a particle at different temps ?
|u/DarkStar0129 - 15 hours
|
|No, it's more like light will be a wave until observed, after which
|it collapses into a particle.
|u/Successful-Sand686 - 12 hours
|
|How do we observe the light without effecting the outcome?
|u/DarkStar0129 - 11 hours
|
|We don't. Any time a wave function is observed, aka, the wave
|interacts with another particle or wave, the wave function
|(which is the probability distribution for finding that particle
|in a small region of space) collapses into a single point in
|space. Normally, a quantum object (electron, photon, atom,
|quarks, etc) has a probability density associated with it, this
|is basically the distribution in % over a small in region in
|space of the probability of finding a particle. Probabilities
|are necessary to describe quantum objects, because as per
|hiseberg's uncertainty principle, it is impossible to
|simultaneously know both the position and the momentum of a
|particle. Therefore, the popular solar system model of the atom
|is inaccurate since it is impossible to exactly define the
|orbits and velocities of the electrons around the nucleus of an
|atom.
|u/RiddlingVenus0 - 11 hours
|
|We don’t. In the double slit experiment, light that isn’t
|observed creates a pattern that a wave would make. Light that
|*is* observed, whether that be before or after it travels
|through the slits, will create a pattern that a particle would
|make. The fact that light doesn’t seem to respect time means
|that no matter what, observing it will always affect the
|outcome.
|u/Majik_Sheff - 13 hours
|
|I always envisioned photons as continuous string across spacetime
|between their point of creation and absorption. When we see wave-
|like behavior we are actually observing how those strings interact
|with each other. This is my own interpretation derived from my
|admittedly limited education on the the subject. I'm sure I'll be
|politely corrected in short order.
|u/patricksaurus - 1 day
|
|I expected this to be a flavor of interference, but the actual effect is
|much cooler. Now I can daydream about possible applications.
|u/DroidLord - 16 hours
|
|Am I missing something? Isn't the interaction between the two light
|sources casting a shadow that's just a thin black line?
|u/patricksaurus - 16 hours
|
|That’s not quite what is happening. The first laser interacts with
|the atoms in the ruby in such a way as to change how they allow
|light to pass though. In this case, the change is that the excited
|ruby atoms transmit less blue light. Since this effect requires the
|first laser’s photons to hit the atoms, and since a laser only
|shines in a narrow column, the effect is a laser-shaped barrier of
|ruby atoms that blocks blue light.
|u/Gstamsharp - 19 hours
|
|"Light pushes mass. That mass casts shadow."
|u/alangcarter - 1 day
|
|This seems to be a simpler use of a nonlinear optical medium than [phase
|conjugate mirrors](https://en.wikipedia.org/wiki/Nonlinear_optics#Optica
|l_phase_conjugation). If they don't reawaken the sense of wonder geeky
|kids get out of physics nothing will! (They are also the reason
|retaliation will outperform attack when using laser weapons.)
|u/Xe6s2 - 19 hours
|
|TIL about optical phase conjugation, thanks stranger
|u/hammylite - 20 hours
|
|Wouldn't this mean it can be used as an optical transistor?
|u/florinandrei - 16 hours
|
|Bullshit title. One light beam passes through a material (ruby). It
|modifies the material. The modified material casts a shadow when
|illuminated with a second light beam. Boring.
|u/incognino123 - 16 hours
|
|Misleading headline, green light is manipulating the ruby to absorb more
|blue light, the ruby is casting the shadow as the term is used
|u/ZadfrackGlutz - 20 hours
|
|Basically light can move mass....in the form of those quasi photons,
|from the ruby.
|u/hpmd50s - 21 hours
|
|Maybe a thermal lensing effect where the laser heats up the ruby,
|changing its local refractive index and creating a little lens that
|deflects the other laser?
|u/Infinitely--Finite - 17 hours
|
|No, it's using 4 specific atomic energy levels in the ruby. One laser
|controls the ability of the ruby to absorb photons from the other
|laser.
|u/monkeysareright - 18 hours
|
|Pretty cool, it's basically an optical transistor without directly using
|electrons
|u/I_love-tacos - 16 hours
|
|Question, wouldn't you be able to build a transistor out of this? It
|would be infinitely faster and I assume no heat
|u/bjornbamse - 3 hours
|
|What makes you think that it would be faster? It is light interacting
|with matter.
|u/robertomeyers - 22 hours
|
|Maybe stupid question. Can anyone confirm this was done in a vacuum? I
|assume they wanted to rule out excited air molecules as the mass.
|u/wandering-monster - 20 hours
|
|It was done in a block of ruby. > "Where the green laser hits the
|ruby, it increases the amount of blue light the crystal absorbs."
|Which like... I'm sorry but I don't exactly see how this is different
|from any other photo-reactive material.
|u/Poly_and_RA - 12 hours
|
|It really isn't. It's in principle no different than having a
|material that is transparent when cold, and then claim that a laser-
|beam that heats a slice of that material is casting a shadow. It's
|clearly not. It's just changing the physical proerties of a material
|so that \*that\* material casts a shadow. Not the same thing at all.
|u/hibernial - 10 hours
|
|OMG does this mean I can actually become a shadow scientist and study
|shadows? This is soo metal
|u/QuantumCrutches - 9 hours
|
|I wonder if you could use this in lithography to make extremely detailed
|designs
|u/Youngringer - 9 hours
|
|can someone explain this like I'm stoned
|u/Polar_Vortx - 9 hours
|
|tbf “eh kinda sorta not really but more than you’d think” seems to be
|the usual when it comes to light
|u/moschles - 1 hour
|
|High powered lasers that emit UV light can ionize the air. You can
|construct such a laser in your own home if you know what you're doing.
|u/ABob71 - 21 hours
|
|I wonder how this can be applied to astronomy- can light shadows from
|things like quasars reveal anything?
|u/exitomega - 18 hours
|
|The sun itself casts a shadow (it blocks other light sources). All of
|the light we see from the sun's core is millions of years old as the
|light-blocking the sun does is actually very effective
|u/creepythingseeker - 15 hours
|
|When light isnt being observed in a lab setting, it can often not be
|seeing smoking as well.
|u/frosted1030 - 21 hours
|
|No citations yet.. given the newness I expect the reproduction of this
|effect first and plenty of review before anything can be confirmed.
|