So the laser is making the ruby cast a shadow by making the ruby absorb different wavelengths than usual? I don't understand why we would say the laser is casting a shadow but I'm probably misunderstanding it.
Thats exactly it. The laser is not a physical object, but its energy can alter physical objects, which then become opaque instead of their usual transparent. Lots of interesting material science and applications but the shadow of a laser it is not.
I'm scratching my head about this too -- because if the ruby's atoms are absorbing certain wavelengths of the light, how is that any different from any other object blocking a light's path? Both involve the light being absorbed, the only difference I see is the EXTENT of absorption.
Yes. This is so dumb. It's not a discovery it's something I've had to take into account when designing lasers that operate near saturation. Thinking this is a discovery is a symptom of hypersspecialization in academia.
@robmorgan1214 I think it's a bit presumptive to call Anton an _acedemic._ He's just a civilian youtube science communicator. That said, clickbait titles and calling old things new discoveries is still highly disappointing from Anton.
[Edit: I have now read the paper. It does state that the excited ruby atoms are what actually casts the shadow. They emphasize the shadow effect because unlike most commonly used mechanisms for switching light with light, it is independent of the illumination angle and not strongly dependent on the wavelength of the light being switched. So, they have characterized a nonlinear optical interaction that isn't particularly useful for switching laser beams, but does make interesting shadow effects.] Original comment: The green laser pumps some electrons on ruby atoms to a state where those electrons can absorb blue light. The experimenters managed to tune the process so it could absorb up to 22% of the blue light. As optically modulated optical switching processes go, 22% doesn't sound very impressive. Perhaps the authors were describing this as "casting a shadow" because it is a relatively weak effect. However, it seemed like the shadow terminology was clickbait. If they can find some pairs of laser wavelength combinations that lead to fluorescence, then they can make a true 3d display. I will read more of the paper and see if it sheds light on their motivation.
The possibilities of developing a 3D display occurred to me as well. But I wonder what the latency is. The paper does not mention how long it took to get the atoms to the absorbing state or how long the effects lasted. That info would be critical too, if you want to use it as an optical switch.
Until it can be accomplished in a vacuum (without material to cause the effect), it is NOT a true "light shadow" but merely the result of manipulation of material properties (like electrochromic glass)!
Yep. The nearest we've got is focusing a few lasers on a point in thin atmosphere to create a plasma ball that reflects and absorbs other light. Used to project 'E-CHAFF' and DUMMY WARHEADS to confuse radar and heat seekers. Old Western tech even the Chinese are using now.
What is a shadow but deflected or absorbed light... scientists use photons to deflect light every day. Maybe there's something important in this paper, but it's not definitely not that there's a shadow.
Not necessarily. Let's face it, the question that's getting answered is, can coherent electromagnetic radiation interfere with non-coherent electromagnetic radiation and obviously, the answer is yes. In a vacuum one can confirm that and one would still observe the effect and likely even be able to measure constructive and destructive interference in a fairly random distribution. Remember, non-coherent sources are in a wider phase and polarization mode, whereas the laser is coherent in phase and polarization, so interference to a degree is inevitable. Just nobody thought to confirm a known phenomena that might prove useful in technology for switching.
Technically, normal shadows do not happen in complete vacuums. They require something to block the light. This does not seem too different from putting a rock or planet or person in front of a light source. Only difference here is that the thing blocking the light is normally transparent unless it's hit by a laser.
This is a fundamental principle that could allow photonic transistors. Meaning, we could actually doing computation with light instead of having to transform it back into electricity for switching. This is important because light has much higher bandwidth.
@@ValorantNexus This concrete interaction might be too slow, to enable the type of frequencies that would be usable, but the principle itself, with some tweaking, might turn out to be everything we ever wished for from computers. in terms of pure material and energy cost savings Light base computers would be a major game changer.
@@stianweiseth5784 I'm not sure how switching energy states for matter will be faster than current silicon chips :/ I only trust light to light interactions for that
I thought this might be an experiment where an extremely powerful laser beam might be able to block some light that otherwise would pass through it. I'm a little disappointed that this wasn't what this video was about, but I'm moving on with my life. With regard to what the video was about, this result didn't surprise this non physicist. A material needs to have shell energy levels that won't absorb the energy of photons passing through it. If you zap the material so that it does have energy levels that allow it to block a beam, it seems like a nice technical accomplishment but it also sounds like it isn't completely unexpected that something like that is possible.
Don't think it's absorbing anything, more like destructive interference. Even money, with white light, other non-laser bands would be observed, with some degree of interference of a lower, but predictable degree. They're using coherent in phase and polarization light interfering with an oblique "beam" of non-coherent multi-wavelength light. No interference would be unexpected, interference should be anticipated. It's light, not magic!
Yep. We know darn well that folks are going to read that title and not pay attention to the explanation, then claim that light casts shadows. Otherwise, I suppose, in theory, air could potentially act in the same way if the laser could excite air (gas) molecules to absorb another wavelength to create a shadow.
@@RiiDii some gases, not air by itself without a laser tuned to employ similar effects. It all comes down to excitation of the appropriate shell that's capable of being excited. Hence, a different gas and set of wavelengths. But, destructive interference can generate a similar effect on randomly polarized white light, in the bandwidth of the laser and that should also be measurable.
I'm not sure why this is considered unusual or unexpected. Optical non-linear absorption has been known about and studied for decades. The excited volume of the ruby should be considered as being a non-transparent object, so it'd be odd if a shadow didn't formed. Also, while the green laser (or any light source of close enough wavelength) is necessary to create the excited volume of ruby, those excited states have a lifetime and they exist after the exciting beam is switched off, meaning the shadow can be cast for some time without the green light. That lifetime is probably puny (likely nanoseconds) and constantly decaying, but it still exists and will cast a shadow for a short time, showing the ruby is casting the shadow and not the green laser. Also, if you could excite the crystal by other means, such as electrically, you'd see the same result and is also an area of research that has been studied for decades.
Definitely not unexpected for me either. I'm surprised this kind of experiment hasn't been done before (or maybe it has?), but it's certainly a mechanism that might be useful in optical systems.
Anton, you might the greatest science communicator in the world. What a masterclass on communication and science. I'm in your patreon. Really big fan here from Rio, Brasil.
So the laser light is changing the atomic structure of the ruby which changes how other light interacts with the ruby? You still need atoms to cast shadows though. The laser is not causing the shadow, the ruby still is, it is just induced by the laser, but so would any other change to the atomic structure of the ruby by any other means. This doesn’t sound like a breakthrough. Light actually casting shadows would be.
Not structure, but electron energy state. It bumps an electron into an orbital from which the blue light can bump it higher. Normally the electrons are in their ground states, and the blue light doesn't match any of the available jumps. Also, I don't believe that light can cast shadows in vacuum. Photons moving orthogonally to each other don't interact I believe. I'm curious if you could get an interference pattern with two beams passing each other at an angle, though.
@@Zeuskabob1 sorry, I use different orbitals as structure because in my mind it is a different structure, one we can’t fully understand yet, but a different structure. Which follows the rule I’ve found the universe exists in. Structure determines function.
That’s how I’d interpret this as well, you need a laser to bring the crystal is an excited / specific condition, after which it is the crystal that casts the shadow. You use a laser to trigger the state, not to cast the shadow.
You are correct. Saying ANYTHING more remotely close to "light casts a shadow!" is straight up incorrect and literally clickbait. Usually Anton provides a hint against clickbait, but this time the title is straight up spreading the misinformation... I'm genuinely disappointed both in the research paper and in Anton. I would include the other outlets that are straight up saying the same thing, but let's be real: Anton usually has better standards.
If its instantanuous, thats pretty much an optical logical transistor. The absolute best scenario would be to find a material that do that with a single laser wavelength that come from 2 directions or have different phases.. Could allow a light logic circuit to work with a single source light and produce the whole calculation at the speed of light istead of the speed of transition of a material
Actually a simpler version of a light shadow in terms of just photons casting shadows is the classic two slit experiment where the wave property of light shows the classic pattern of light adding and cancelling. This involves no atoms and does work in a vacuum. That said, I can think of a lot of interesting follow experiments from these electron effects to further confirm what we think we know in the Standard Model and perhaps get more observable precision in what we think we know. That said, Anton, you did a great job! Thanks! Electron Mass as resistance to a force provided by the Higgs field affecting photon-electron interactions seems to be illustrated here as well with lots of interesting experiments to speak to the time taken to move the electrons to the needed energy levels to block photonic absorption with photonic absorption. Really cool.
Thanks Anton. Ive read thru a lot of comments ( Sort of regretably ) and, well, It seems this one has created quite a bit of a controversy. The good news is that we still really don't know. I watcg every day and appreciate you providing sources and ways for me to get involved. Going to school for science this spring and will be taking astronomy for my bachelors. Your videos have inspired me to go for it, the mysteries are seemingly limitless and I am hoping that I am intelligent enough to one day become an astrophysicist.
Photons _do_ have mass; they just don't have _rest_ mass, so a photon has mass m = E/c^2 = |p|/c, where E is energy (the 0 component of the four-momentum), p is the three-momentum and c is the speed of light. Discussing absorption in terms of mass or "physical objects" is an irrelevant distraction. Glass leaves a very slight shadow. because it does not scatter (at the relevant frequencies) and can't absorb. So you can have shadows or not with mass. The reason that light doesn't cast a shadow in the vacuum is that photons have too slight an interaction. But real photons do interact -- they form virtual particle-antiparticle pairs of charged particles. The interaction of one photon's virtual particles with the fields of another photon, or the Coulomb scattering of different photons' charged virtual particles, do cause photons to interact. These effects are calculable and very, very small, but they would be "light casting a shadow." The research you describe here is polaritons casting a shadow. Interesting, but not surprising.
In other news: Lasers have negative mass! They fired a high power laser at a sheet of metal and created a hole so the sheet of metal had less mass after. Amazing!
@@ashkebora7262 Meh those who don't pay attention will always be misinformed. Believe me you can't beat common sense into someone with a shovel i've tried. But you can fertilise your plants so even the inattentive and stupid have a job in life
You can see a shadow from a CO2 laser on Fluorescent material if you illuminate it with a UV light while pointing the laser at the surface. The Infrared light from the CO2 laser Suppresses the Fluorescence and creates a shadow. It's used to find the CO2 beam and check its profile, since it's invisible normally.
Anton, you blow me away everyday with something interesting, fascinating or head scratching. I wish we can share a beer one afternoon. You seem to be a fascinating person and would love to know more about you. Anyway, never stop, your fans really appreciate what you do.
Technically laser A makes originally kinda transparent parts of the ruby cube capable of absorbing a certain other laser B, and the result is the visual effect that laser B(big laser here) is partially "blocked(absorbed actually, like other physical objects absorbing light and seen as blocking them)" when shined through the cube, so a shadow of the shape made by laser A can be seen as a result.
This is huge because of capacitance. Capacitance is the chokepoint in why motherboards can't run at higher speeds. When the frequencies get to high, the traces on the board start interacting with each other like they were capacitors. A motherboard of light and shadow wouldn't do that no matter what frequency the optical trace was flickering at.
There is VERY MUCH still hysteresis in excited electrons, which is what this relies on. It is NOT limited to light, but to the material's reaction speed, which could easily be MUCH slower than ghz.
The laser is not actually casting a shadow, it's creating a matrix of polaritons in the ruby which in turn can partially absorb specific wavelengths. Nonetheless, it is an interesting discovery that could have practical applications. I'm having a hard time, though, thinking of any that couldn't already be accomplished in some other way. Likely a slow and only partial process for photonic switching, but it could have applications for modulation of light especially where ultra-high reliability is required since there is essentially nothing that can break, at least within the ruby.
From a qFT/standard model perspective, light can interact with light. A photon can become a pair of electron positron, which can then interact with other photons. So it's not exactly surprising in the theoretical sense, but it is surprising that someone found a way to make it. I'm sure the interaction inside the crystal is orders of magnitude more complex than that though.
The laser shadow provides the base the quantum computer AI uses to design the fusion reactors that supply power to the laser to create the shadow. It's really very simple once you marry entangled atoms together. This is why we can't have nice things.
Id have to argue with this. In order for light to cast the shadow it would have to do it in a vacuum and use only light. The ruby is casting the shadow not the light, the ruby is the one that changes and its electrons go into the higher state only where the green laser is at. In order for this to actually be true no ruby would be involved at all, only light.
You are correct. The title is pure clickbait and the researchers themselves merely SPECULATE that it might magically work without a Ruby, solely because they do not understand quantum effects appropriately. This effect REQUIRES electrons loosely tied to nuclei, which ... is matter! This effect _cannot_ happen with only light vs light.
I instantly thought, here is a breakthrough the quantum computers were just waiting for. Mosfet to a laser pointer, and boom here is your QUANTUM MACHINE.
I think you can do this trick with the material they make photo-gray eyeglasses out of. Darken a stripe with a blue light and throw a shadow of red light, at right angles to it. It just isn't as instantaneous.
in 1980 I carried out an experiment of this type with a helium plasma induced in a helium atmosphere by a high-power CO2 laser, . And then observe it by shadowgraphy with a short-pulsed dye laser that can be absorbed by helium excited states.
Even though photons are bosons, they do affect the total energy in a volume. This will probably affect the vacuum energy of that volume which should impact the density of certain virtual particles in the space. At some very minute level the effect of a very intense laser beam probably does cause a true shadow in vacuum for light waves of some extremely high energies whose wavelengths are on the order of the virtual particle pairs. Maybe?
From the study: "Strictly speaking, it is not massless light that is creating the shadow, but it is the material counterpart of the polariton, which has mass, that is casting the shadow." Polariton is a superposition of a propagating photon and atom excitation. Since photon is considered to be massless, it is assumed that atom excitation is causing the shadow. One should thus stop claiming then that it is the light that is creating the shadow. In other words, not a groundbreaking effect, but potentially could have groundbreaking applications (although I don't see anything surprising here, there's nothing theoretically new here). On the other hand, one should not claim that photons are massless either - this has NOT been proven! I believe that photons do have mass, so they could be contributing to the shadow effect directly, but that contribution, if it does exist, is negligible - unless photons themselves are localized to significant mass, which is probably not the case (typical localization mass of photons is on the order of 10^-54 kg).
@@amenoum7623 Yes, it has been proven. You can have all the theories you want, but if they're not congruent with observations, they are worse than useless.
@@amenoum7623 Go watch all of PBS Spacetime. They'll clear it up and then some for you. Or if you think you know better than them, go ahead and propose something that might disprove general relativity on normal scales...
Light (typically UV) in a solid causes it to absorb different colors of light? Hasn't that aspect been known for a few decades? Maybe there is something to this, but it sounds a fair bit about things that don't need lasers...
1:1, laser-like precision of an experiment. Now let's see if this leads to the second part of the prediction of light, with implications to quantified phenomenon we can use for compute workflows. Thank you for this wonderful insight of the proven experiment.
I'm not a specialist in the field (I got a Grade D in my Physics 'O' level) but it seems to me it is the alteration in the opacity of the Ruby cube that causes the shadow and not the laser itself which is casting the shadow. Let me put it simply - you have just washed your car, there is a lovely clear windscreen through which the sun shines brightly. A bird craps on your windscreen, there is now a shadow because the bird crap blocks the light. The shadow is a result of the blocked light. What causes the blocked light is essentially irrelevant, bird crap, parking fine notice, smeared insect ... the crap itself does not have the inherent property of 'shadow' ! If I'm way off the mark please correct me ... but keep it simple; I've only got a 'D' in physics 🤨
If it'd be more defined and at a smaller scale, this could be used make photon based transistors and computers This might still be provide very interesting possibilities for analog quantum computers
Personally I don't know if I would say that this is a shadow of the laser. As you describe it, it's the shadow of the ruby cube, which wouldn't normally be visible in the blue light, becoming visible thanks to the interaction between the green and blue light. So it's not really the laser's shadow, it's the ruby's shadow being made visible under specific conditions that allow it to absorb the blue light that it normally wouldn't be able to.
The laser causes the crystal to mimic the properties of a physical object, but I wouldn't say that the laser 'created' a physical object. It temporarily creates a zone of optical interference. Still... Interesting. Thx.
Anton it’s okay to take a break from being strong every day. I know. I lost mine too back in 2019. Won’t go into detail , know that your community has your best interest in mind. -Ron.
Shadows come in pairs; the objective and projective. The objective shadow, is on the object, causes moon phases, so it should follow that there is an objective shadow on the projecting end of the laser and ruby. Is this observed?
i did this 7-8 years ago in my bedroom with red, green, blue, and 405nm 5mw lasers and crystal filters and films, i found that the lower frequency leaves a shadow.
I wonder if this discovery can be useful in "photolitography" in the semiconductor industry to make better computer chips somehow? I assume it's useful some way, but probably still unknown how :)
I suppose photons do not pass through each other but transfer energy from one to the other in precisely equal amounts then continue as if nothing has transpired . These shadows are a result of unequal exchanges of energy due to the effect of the medium .
7m 35s . Neither laser blocks light like a physical object, the Green laser energises the blue laser to higher frequencies that happen to be opaque in a ruby.
Ps if you could read the Sine wave of the green laser before it interacts with the blue one and then again after it has passed through you would finde that it has changed its colour to one of a lower energy as it has in turn lost energy in the exchange.
Ah, it's about manipulating atoms, and not something like photon-photon interactions or interactions between photons and temporary electrons/positrons that photons very rarely turn into, or gravitational distortions caused by concentrated photons etc...
wow, you change the opitical characteristics of a "real" object so THIS objects kind of "impede" light which produces a shadow. who would have thought this was possible.
what this really leads to, is the possible mode to create a laser diode or laser transistor, at least from an on/off form. which could lead to a true optical computing device baseline.
Sounds like where this will end up going is into real Star Wars style lightsabers, where we pass a Lazer through a crystal to make it a physical object 😂
Sounds like a logical NAND gate any traditional computer can be thought to be made of. The question is how fast the crystal reacts on the laser beam that behaves like an object in order to decide whether fast photonic applications are conceivable.
Eh... It's still an opaque object casting the shadow, this object is neither the green laser nor the ruby cube as a whole, but a line of opaque excited atoms inside the cube.
I think the key end Point of interest here; the ability to study the atomic states of the rubies, and how they THEN affect incoming light to produce the shadow; which they've already done, yes, but if they were to try scaling that same conceptual frame of cause and effect, into the non-physical realm; plasma, gasses, magnetic fields, etc. All sorts of non-physical structuring and ordering systems could be used to emulate and refine this effect. I imagine it's already a highly researched and guarded topic amongst the worlds leading technology manufacturers. Solving this, would allow for true 3d Holography; solid and with shadow, even tone. Cloaking technology First. Then entertainment. If it's decided that such mind bending tech should even be revealed. I don't think it should be.
Quantum range finding \ location : different wavelengths of light refract at different angles so the position of the shadow will be affected by the optical media. Especially if it has different refractory indices on different axis
So the laser is making the ruby cast a shadow by making the ruby absorb different wavelengths than usual? I don't understand why we would say the laser is casting a shadow but I'm probably misunderstanding it.
Thats exactly it. The laser is not a physical object, but its energy can alter physical objects, which then become opaque instead of their usual transparent. Lots of interesting material science and applications but the shadow of a laser it is not.
My exact thoughts, and from the comments people are not understanding what was actually talked about.
I'm scratching my head about this too -- because if the ruby's atoms are absorbing certain wavelengths of the light, how is that any different from any other object blocking a light's path? Both involve the light being absorbed, the only difference I see is the EXTENT of absorption.
The lazer is changing the atomic structure of the ruby crystal challenging the definition of a shadow.
@@olic7266 except it doesn’t. The ruby is still absorbing the light. If anything it reminds me more of light spectroscopy.
TL;DW One laser changes physical properties of a ruby such that the light of another laser is partially absorbed
Not really what someone would imagine happening after reading the title
Yes. This is so dumb. It's not a discovery it's something I've had to take into account when designing lasers that operate near saturation. Thinking this is a discovery is a symptom of hypersspecialization in academia.
@robmorgan1214 I think it's a bit presumptive to call Anton an _acedemic._ He's just a civilian youtube science communicator.
That said, clickbait titles and calling old things new discoveries is still highly disappointing from Anton.
This is basically click-bait. It is NOT light casting a shadow. Sabina has a good word for this kind of "research".
I mean, the study material refers to it as a shadow. It appears to be a shadow even though that`s just an optical effect of what`s really happening.
[Edit: I have now read the paper. It does state that the excited ruby atoms are what actually casts the shadow. They emphasize the shadow effect because unlike most commonly used mechanisms for switching light with light, it is independent of the illumination angle and not strongly dependent on the wavelength of the light being switched.
So, they have characterized a nonlinear optical interaction that isn't particularly useful for switching laser beams, but does make interesting shadow effects.]
Original comment: The green laser pumps some electrons on ruby atoms to a state where those electrons can absorb blue light. The experimenters managed to tune the process so it could absorb up to 22% of the blue light.
As optically modulated optical switching processes go, 22% doesn't sound very impressive. Perhaps the authors were describing this as "casting a shadow" because it is a relatively weak effect. However, it seemed like the shadow terminology was clickbait.
If they can find some pairs of laser wavelength combinations that lead to fluorescence, then they can make a true 3d display.
I will read more of the paper and see if it sheds light on their motivation.
Thank for your thoroughness.
The possibilities of developing a 3D display occurred to me as well.
But I wonder what the latency is.
The paper does not mention how long it took to get the atoms to the absorbing state or how long the effects lasted.
That info would be critical too, if you want to use it as an optical switch.
great clarification, thanks
So maybe a new way of looking into the darkness?
Thought so. Perhaps Anton should change the title of the video then.
Until it can be accomplished in a vacuum (without material to cause the effect), it is NOT a true "light shadow" but merely the result of manipulation of material properties (like electrochromic glass)!
Yep. The nearest we've got is focusing a few lasers on a point in thin atmosphere to create a plasma ball that reflects and absorbs other light. Used to project 'E-CHAFF' and DUMMY WARHEADS to confuse radar and heat seekers. Old Western tech even the Chinese are using now.
This is what I'm thinking. It was the excited atoms of the ruby that blocked the blue light, not the green photons.
What is a shadow but deflected or absorbed light... scientists use photons to deflect light every day. Maybe there's something important in this paper, but it's not definitely not that there's a shadow.
Not necessarily. Let's face it, the question that's getting answered is, can coherent electromagnetic radiation interfere with non-coherent electromagnetic radiation and obviously, the answer is yes. In a vacuum one can confirm that and one would still observe the effect and likely even be able to measure constructive and destructive interference in a fairly random distribution.
Remember, non-coherent sources are in a wider phase and polarization mode, whereas the laser is coherent in phase and polarization, so interference to a degree is inevitable. Just nobody thought to confirm a known phenomena that might prove useful in technology for switching.
Technically, normal shadows do not happen in complete vacuums. They require something to block the light. This does not seem too different from putting a rock or planet or person in front of a light source. Only difference here is that the thing blocking the light is normally transparent unless it's hit by a laser.
This is a fundamental principle that could allow photonic transistors. Meaning, we could actually doing computation with light instead of having to transform it back into electricity for switching. This is important because light has much higher bandwidth.
too slow
it's not light affecting light
it's light affecting the structure of a material affecting light
@@ValorantNexus This concrete interaction might be too slow, to enable the type of frequencies that would be usable, but the principle itself, with some tweaking, might turn out to be everything we ever wished for from computers. in terms of pure material and energy cost savings Light base computers would be a major game changer.
@@stianweiseth5784 I'm not sure how switching energy states for matter will be faster than current silicon chips :/
I only trust light to light interactions for that
@@ValorantNexus Even if it was pretty slow, photons are quantum mechanical, so you might well be able to make a very high q-bit quantum computer.
Yeah it is surely posible to make Xor gates and with it all the boolean logic.
I thought this might be an experiment where an extremely powerful laser beam might be able to block some light that otherwise would pass through it. I'm a little disappointed that this wasn't what this video was about, but I'm moving on with my life.
With regard to what the video was about, this result didn't surprise this non physicist. A material needs to have shell energy levels that won't absorb the energy of photons passing through it. If you zap the material so that it does have energy levels that allow it to block a beam, it seems like a nice technical accomplishment but it also sounds like it isn't completely unexpected that something like that is possible.
Well put.
Don't think it's absorbing anything, more like destructive interference. Even money, with white light, other non-laser bands would be observed, with some degree of interference of a lower, but predictable degree. They're using coherent in phase and polarization light interfering with an oblique "beam" of non-coherent multi-wavelength light. No interference would be unexpected, interference should be anticipated.
It's light, not magic!
Yep. We know darn well that folks are going to read that title and not pay attention to the explanation, then claim that light casts shadows.
Otherwise, I suppose, in theory, air could potentially act in the same way if the laser could excite air (gas) molecules to absorb another wavelength to create a shadow.
I was disappointed too. But something like this may be used in photonics, which are electronics that use light instead of electricity.
@@RiiDii some gases, not air by itself without a laser tuned to employ similar effects. It all comes down to excitation of the appropriate shell that's capable of being excited. Hence, a different gas and set of wavelengths.
But, destructive interference can generate a similar effect on randomly polarized white light, in the bandwidth of the laser and that should also be measurable.
I'm not sure why this is considered unusual or unexpected. Optical non-linear absorption has been known about and studied for decades. The excited volume of the ruby should be considered as being a non-transparent object, so it'd be odd if a shadow didn't formed.
Also, while the green laser (or any light source of close enough wavelength) is necessary to create the excited volume of ruby, those excited states have a lifetime and they exist after the exciting beam is switched off, meaning the shadow can be cast for some time without the green light. That lifetime is probably puny (likely nanoseconds) and constantly decaying, but it still exists and will cast a shadow for a short time, showing the ruby is casting the shadow and not the green laser.
Also, if you could excite the crystal by other means, such as electrically, you'd see the same result and is also an area of research that has been studied for decades.
Definitely not unexpected for me either. I'm surprised this kind of experiment hasn't been done before (or maybe it has?), but it's certainly a mechanism that might be useful in optical systems.
Anton, you might the greatest science communicator in the world. What a masterclass on communication and science. I'm in your patreon. Really big fan here from Rio, Brasil.
So the laser light is changing the atomic structure of the ruby which changes how other light interacts with the ruby? You still need atoms to cast shadows though. The laser is not causing the shadow, the ruby still is, it is just induced by the laser, but so would any other change to the atomic structure of the ruby by any other means. This doesn’t sound like a breakthrough. Light actually casting shadows would be.
My exact thought
Not structure, but electron energy state. It bumps an electron into an orbital from which the blue light can bump it higher. Normally the electrons are in their ground states, and the blue light doesn't match any of the available jumps.
Also, I don't believe that light can cast shadows in vacuum. Photons moving orthogonally to each other don't interact I believe. I'm curious if you could get an interference pattern with two beams passing each other at an angle, though.
@@Zeuskabob1 sorry, I use different orbitals as structure because in my mind it is a different structure, one we can’t fully understand yet, but a different structure. Which follows the rule I’ve found the universe exists in. Structure determines function.
I would say it's "ruby in a specific state" casting the shadow
That’s how I’d interpret this as well, you need a laser to bring the crystal is an excited / specific condition, after which it is the crystal that casts the shadow. You use a laser to trigger the state, not to cast the shadow.
You are correct. Saying ANYTHING more remotely close to "light casts a shadow!" is straight up incorrect and literally clickbait. Usually Anton provides a hint against clickbait, but this time the title is straight up spreading the misinformation... I'm genuinely disappointed both in the research paper and in Anton. I would include the other outlets that are straight up saying the same thing, but let's be real: Anton usually has better standards.
If its instantanuous, thats pretty much an optical logical transistor. The absolute best scenario would be to find a material that do that with a single laser wavelength that come from 2 directions or have different phases.. Could allow a light logic circuit to work with a single source light and produce the whole calculation at the speed of light istead of the speed of transition of a material
Actually a simpler version of a light shadow in terms of just photons casting shadows is the classic two slit experiment where the wave property of light shows the classic pattern of light adding and cancelling. This involves no atoms and does work in a vacuum. That said, I can think of a lot of interesting follow experiments from these electron effects to further confirm what we think we know in the Standard Model and perhaps get more observable precision in what we think we know. That said, Anton, you did a great job! Thanks! Electron Mass as resistance to a force provided by the Higgs field affecting photon-electron interactions seems to be illustrated here as well with lots of interesting experiments to speak to the time taken to move the electrons to the needed energy levels to block photonic absorption with photonic absorption. Really cool.
Technically, it's still accurate to say that to create a shadow a physical object is required.
So... an optical transistor? Interesting, not sure groundbreaking but certainly interesting.
I was thinking the same thing.
@@K9Megahertzlikewise
> “an object may not be required for shadows”
> looks inside
> ruby
Thanks Anton. Ive read thru a lot of comments ( Sort of regretably ) and, well, It seems this one has created quite a bit of a controversy. The good news is that we still really don't know. I watcg every day and appreciate you providing sources and ways for me to get involved. Going to school for science this spring and will be taking astronomy for my bachelors. Your videos have inspired me to go for it, the mysteries are seemingly limitless and I am hoping that I am intelligent enough to one day become an astrophysicist.
Considering the sheer number of places lasers are used, something like this can be a real changer for many fields
Photons _do_ have mass; they just don't have _rest_ mass, so a photon has mass m = E/c^2 = |p|/c, where E is energy (the 0 component of the four-momentum), p is the three-momentum and c is the speed of light.
Discussing absorption in terms of mass or "physical objects" is an irrelevant distraction. Glass leaves a very slight shadow. because it does not scatter (at the relevant frequencies) and can't absorb. So you can have shadows or not with mass. The reason that light doesn't cast a shadow in the vacuum is that photons have too slight an interaction.
But real photons do interact -- they form virtual particle-antiparticle pairs of charged particles. The interaction of one photon's virtual particles with the fields of another photon, or the Coulomb scattering of different photons' charged virtual particles, do cause photons to interact. These effects are calculable and very, very small, but they would be "light casting a shadow." The research you describe here is polaritons casting a shadow. Interesting, but not surprising.
So the laser isn't casting a shadow, the ruby is.
In other news: Lasers have negative mass! They fired a high power laser at a sheet of metal and created a hole so the sheet of metal had less mass after. Amazing!
Ha! Perfect. That is the level of clickbait this drivel is... To the point of misinforming those not paying close attention.
@@ashkebora7262 Meh those who don't pay attention will always be misinformed. Believe me you can't beat common sense into someone with a shovel i've tried. But you can fertilise your plants so even the inattentive and stupid have a job in life
You can see a shadow from a CO2 laser on Fluorescent material if you illuminate it with a UV light while pointing the laser at the surface. The Infrared light from the CO2 laser Suppresses the Fluorescence and creates a shadow. It's used to find the CO2 beam and check its profile, since it's invisible normally.
Anton, you blow me away everyday with something interesting, fascinating or head scratching. I wish we can share a beer one afternoon. You seem to be a fascinating person and would love to know more about you. Anyway, never stop, your fans really appreciate what you do.
Technically laser A makes originally kinda transparent parts of the ruby cube capable of absorbing a certain other laser B, and the result is the visual effect that laser B(big laser here) is partially "blocked(absorbed actually, like other physical objects absorbing light and seen as blocking them)" when shined through the cube, so a shadow of the shape made by laser A can be seen as a result.
This is huge because of capacitance. Capacitance is the chokepoint in why motherboards can't run at higher speeds. When the frequencies get to high, the traces on the board start interacting with each other like they were capacitors. A motherboard of light and shadow wouldn't do that no matter what frequency the optical trace was flickering at.
There is VERY MUCH still hysteresis in excited electrons, which is what this relies on. It is NOT limited to light, but to the material's reaction speed, which could easily be MUCH slower than ghz.
I hope I get to see an optical computer using tech like this in my lifetime. That would be really cool
Grandios! Thank you very much for this video Anton!
The laser is not actually casting a shadow, it's creating a matrix of polaritons in the ruby which in turn can partially absorb specific wavelengths. Nonetheless, it is an interesting discovery that could have practical applications. I'm having a hard time, though, thinking of any that couldn't already be accomplished in some other way. Likely a slow and only partial process for photonic switching, but it could have applications for modulation of light especially where ultra-high reliability is required since there is essentially nothing that can break, at least within the ruby.
From a qFT/standard model perspective, light can interact with light. A photon can become a pair of electron positron, which can then interact with other photons. So it's not exactly surprising in the theoretical sense, but it is surprising that someone found a way to make it. I'm sure the interaction inside the crystal is orders of magnitude more complex than that though.
The laser shadow provides the base the quantum computer AI uses to design the fusion reactors that supply power to the laser to create the shadow. It's really very simple once you marry entangled atoms together.
This is why we can't have nice things.
Only realize, that there is no fotons
Id have to argue with this. In order for light to cast the shadow it would have to do it in a vacuum and use only light.
The ruby is casting the shadow not the light, the ruby is the one that changes and its electrons go into the higher state only where the green laser is at. In order for this to actually be true no ruby would be involved at all, only light.
You are correct. The title is pure clickbait and the researchers themselves merely SPECULATE that it might magically work without a Ruby, solely because they do not understand quantum effects appropriately. This effect REQUIRES electrons loosely tied to nuclei, which ... is matter! This effect _cannot_ happen with only light vs light.
"Enter the Shadow Realm!" ^.^
Cool find anton!
I instantly thought, here is a breakthrough the quantum computers were just waiting for. Mosfet to a laser pointer, and boom here is your QUANTUM MACHINE.
You had me at “laser based quantum computers”
I think you can do this trick with the material they make photo-gray eyeglasses out of. Darken a stripe with a blue light and throw a shadow of red light, at right angles to it. It just isn't as instantaneous.
in 1980 I carried out an experiment of this type with a helium plasma induced in a helium atmosphere by a high-power CO2 laser, . And then observe it by shadowgraphy with a short-pulsed dye laser that can be absorbed by helium excited states.
Even though photons are bosons, they do affect the total energy in a volume. This will probably affect the vacuum energy of that volume which should impact the density of certain virtual particles in the space. At some very minute level the effect of a very intense laser beam probably does cause a true shadow in vacuum for light waves of some extremely high energies whose wavelengths are on the order of the virtual particle pairs. Maybe?
From the study: "Strictly speaking, it is not massless light that is creating the shadow, but it is the material counterpart of the polariton, which has mass, that is casting the shadow." Polariton is a superposition of a propagating photon and atom excitation. Since photon is considered to be massless, it is assumed that atom excitation is causing the shadow. One should thus stop claiming then that it is the light that is creating the shadow. In other words, not a groundbreaking effect, but potentially could have groundbreaking applications (although I don't see anything surprising here, there's nothing theoretically new here). On the other hand, one should not claim that photons are massless either - this has NOT been proven! I believe that photons do have mass, so they could be contributing to the shadow effect directly, but that contribution, if it does exist, is negligible - unless photons themselves are localized to significant mass, which is probably not the case (typical localization mass of photons is on the order of 10^-54 kg).
Photons do NOT have mass. They carry enertia.
@@ashkebora7262 Again, that is the established theory. It has NOT been proven. I claim that they do have mass. I have my own theories.
@@amenoum7623 Yes, it has been proven. You can have all the theories you want, but if they're not congruent with observations, they are worse than useless.
@@ashkebora7262Show me the proof.
@@amenoum7623 Go watch all of PBS Spacetime. They'll clear it up and then some for you.
Or if you think you know better than them, go ahead and propose something that might disprove general relativity on normal scales...
Light (typically UV) in a solid causes it to absorb different colors of light? Hasn't that aspect been known for a few decades? Maybe there is something to this, but it sounds a fair bit about things that don't need lasers...
1:1, laser-like precision of an experiment. Now let's see if this leads to the second part of the prediction of light, with implications to quantified phenomenon we can use for compute workflows. Thank you for this wonderful insight of the proven experiment.
I'm not a specialist in the field (I got a Grade D in my Physics 'O' level) but it seems to me it is the alteration in the opacity of the Ruby cube that causes the shadow and not the laser itself which is casting the shadow.
Let me put it simply - you have just washed your car, there is a lovely clear windscreen through which the sun shines brightly. A bird craps on your windscreen, there is now a shadow because the bird crap blocks the light. The shadow is a result of the blocked light. What causes the blocked light is essentially irrelevant, bird crap, parking fine notice, smeared insect ... the crap itself does not have the inherent property of 'shadow' !
If I'm way off the mark please correct me ... but keep it simple; I've only got a 'D' in physics 🤨
You are correct and this is clickbait drivel.
I was expecting a very powerful laser heating the air and the heated gas behaves like a lens which leaves a shadow. But this is pretty neat!
This makes me think of a question I've had since college: can enough photons be concentrated into creating a black hole?
If it'd be more defined and at a smaller scale, this could be used make photon based transistors and computers
This might still be provide very interesting possibilities for analog quantum computers
Personally I don't know if I would say that this is a shadow of the laser. As you describe it, it's the shadow of the ruby cube, which wouldn't normally be visible in the blue light, becoming visible thanks to the interaction between the green and blue light. So it's not really the laser's shadow, it's the ruby's shadow being made visible under specific conditions that allow it to absorb the blue light that it normally wouldn't be able to.
It is absolutely not the shadow of the laser itself, ever, period. This is a sensationalist headline at best and clickbait at worst.
So, it's not the light that cast the shadow but a portion of the Ruby excited by a particular color of light into being less translucent.
The laser causes the crystal to mimic the properties of a physical object, but I wouldn't say that the laser 'created' a physical object. It temporarily creates a zone of optical interference. Still... Interesting. Thx.
Anton it’s okay to take a break from being strong every day. I know. I lost mine too back in 2019.
Won’t go into detail , know that your community has your best interest in mind.
-Ron.
OK, so nothing new, but you make it sound amazing. What is the point? Clickbait? What does one learn?
2:55 "The most generic gaming slop you can possibly imagine"
Thank you for this info, very interesting!
Regular shadows are 2D not 3D. They have width and height, but no depth needed for a 3D object.
I don’t know about quantum computing, but for optical computing This discovery seems like a big breakthrough
It is not the breakthrough the title leads people to believe.
This is so simple I’m surprised no one did it before
Interesting but the ruby is casting the shadow, not the green laser beam itself
So... Yeah, that simulation theory is feeling real good right now.
So it's more like the laser's *wake* casting the shadow, not the laser itself. Still really neat!
Phased, "discrete" light is as much a barrier to interference as a solid object.
I see laser-based "gates" in a light-based "computer".
This video is perfect! As I'm sitting in my apartment after having 74mph winds last night with no power, I'm seeing lots of shadows! Lol
on the west coast perhaps? Im on vancouiver island, pretty good storm the other night
The controversy around this paper in the comments is interesting.what say you, Anton. Does the ruby cast the shadow, or does the laser?
Thanks!
Shadows come in pairs; the objective and projective. The objective shadow, is on the object,
causes moon phases, so it should follow that there is an objective shadow on the projecting end of the laser and ruby. Is this observed?
i did this 7-8 years ago in my bedroom with red, green, blue, and 405nm 5mw lasers and crystal filters and films, i found that the lower frequency leaves a shadow.
Guess you invalidated their pending patents. 👍
@@interstellarsurfer😂😂😂 nice.
'Who knows what evil lurks in the hearts of men?
The Shadow knows!"
From "The Shadow" radio show.
Laser beam have always looked solid. Now we know our eyes did not deceive us.
To me this is one of the baby steps to achieve full 3d holographic imaging. It is one heck of a step though.
I wonder if this discovery can be useful in "photolitography" in the semiconductor industry to make better computer chips somehow?
I assume it's useful some way, but probably still unknown how :)
I thought we could already do this with those 'light transistors'
I suppose photons do not pass through each other but transfer energy from one to the other in precisely equal amounts then continue as if nothing has transpired . These shadows are a result of unequal exchanges of energy due to the effect of the medium .
It looks like Anton has a group of human centipedes behind him in the intro.
There are actually lasers which do not produce shadows because you can't block the light these lasers produce by anything.
They call it "light saber".
Maybe findings of this project will help explain the laser anomalies captured on high speed cameras at Skinwalker Ranch 🤔
You dont know how hard it is to explain to a normie how figuring out light casts a shadow is a NEW thing without a MAJOR explanation first.
Lasers as a physical object. Rejoice….We are one step closer to actual lightsabers.
I always thought light sabers were made of plasma not layers but that's just me
I was thinking forcefields myself. The ability to cancel out specific frequencies of light would help defend against future laser based weapons. :)
That is specifically not what this video is about.
7m 35s . Neither laser blocks light like a physical object, the Green laser energises the blue laser to higher frequencies that happen to be opaque in a ruby.
Ps if you could read the Sine wave of the green laser before it interacts with the blue one and then again after it has passed through you would finde that it has changed its colour to one of a lower energy as it has in turn lost energy in the exchange.
This explains why the lightsabers cast shadows on the floor of the Emperor's throne room on the second Death Star at the end of Return of the Jedi
Theoretically, energy is mass, so with enough powerful laser, one should be able to bend another...
Ah, it's about manipulating atoms, and not something like photon-photon interactions or interactions between photons and temporary electrons/positrons that photons very rarely turn into, or gravitational distortions caused by concentrated photons etc...
Making shadowpuppets will never be the same again
In other words, optical computers are coming, and precious metals investors only have about a decade to make a plan.
wow, you change the opitical characteristics of a "real" object so THIS objects kind of "impede" light which produces a shadow. who would have thought this was possible.
what this really leads to, is the possible mode to create a laser diode or laser transistor, at least from an on/off form. which could lead to a true optical computing device baseline.
infrared light suppresses fluorescence from UV light making a "shadow".
This experiment will pave the way to the development of hard-light technology!
Sounds like where this will end up going is into real Star Wars style lightsabers, where we pass a Lazer through a crystal to make it a physical object 😂
It's strange that the light just disappears as if it was being stored up somewhere, though. I wonder...
Brilliant use of nonlinear optics.
Sounds like a logical NAND gate any traditional computer can be thought to be made of. The question is how fast the crystal reacts on the laser beam that behaves like an object in order to decide whether fast photonic applications are conceivable.
Thanks Anton! Love your vids!
I always thought that the red color of ruby is caused by iron, which gives blood its red color. Chromium causes blue color like in blue sapphires.
One step closer to runners hardlight drive
Once more Richard Feynman demonstrates that he was one of the smartest physicists of last century. RIP.
Eh... It's still an opaque object casting the shadow, this object is neither the green laser nor the ruby cube as a whole, but a line of opaque excited atoms inside the cube.
Doesn't that make it the shadow is cast by diffraction due to the changed atomic structure. so not really a shadow then.
I think the key end Point of interest here; the ability to study the atomic states of the rubies, and how they THEN affect incoming light to produce the shadow; which they've already done, yes, but if they were to try scaling that same conceptual frame of cause and effect, into the non-physical realm; plasma, gasses, magnetic fields, etc. All sorts of non-physical structuring and ordering systems could be used to emulate and refine this effect.
I imagine it's already a highly researched and guarded topic amongst the worlds leading technology manufacturers. Solving this, would allow for true 3d Holography; solid and with shadow, even tone. Cloaking technology First. Then entertainment. If it's decided that such mind bending tech should even be revealed. I don't think it should be.
Blocks laser, casts shadow, refuses to elaborate.
Just a matter of time before we imprint a QR code onto the Lasers Shadow.
Quantum range finding \ location : different wavelengths of light refract at different angles so the position of the shadow will be affected by the optical media.
Especially if it has different refractory indices on different axis
The system is breaking down.
"THANK "GOD" IF DONE PROPERLY"
Time for a reboot
Ahh this is some serious Necrontier tech we are stumbling on I think. lol