Controlling Light with High Voltage and Aniseed! The Kerr Effect!

[@Iris_and_or_George]

An intro that summarises the video in under 7 seconds and straight to content. What an awesome place YT would be if all creators would do this. Got my subscription!

[@LesLaboratory]

Thanks!

[@greenaum]

You're not wrong, now you mention it.

[@BigJohn4516]

30+ years ago, I worked at the US Bureau of Mines at the Bruceton research center. They had an antique high speed camera in a bombproof's control room. This camera could take 22 photos at a shutter speed of 2Mfps. The film was stationary and held around the perimeter of a partial circle. The camera had a rotating mirrored block in the centriod of the arch, a hollow coil which, when energized with a huge current, collapsed a foil tube to stop exposure, and a Kerr cell as a high speed shutter. I had the job of troubleshooting and repairing the ancient home brew trigger and shutter driver circuitry. It was a laborious and finicky task getting everything to work correctly and produce usable images. I still run across images from that camera here and there. I don't know what they had used in the Kerr cell, but it could be modulated at 2MHz.

[@LesLaboratory]

Sweet! Without a doubt it would be Nitrobenzene, for all its toxicity it gets the jobs done, and it will easily switch at megahertz speeds. That sure sounds like a very interesting setup!

[@hygri]

"A distressingly powerful organic solvent". Can confirm, and how beautifully put!

[@Nuovoswiss]

The temperature discrepancy in freezing is how you purify it. It might indicate an impurity, but it might be slow nucleation. Some organic compounds are really finicky in crystalizing, try adding some of the solidified phase to supercooled liquid phase to act as seed crystals. As for the "stringers", anethole is not electrochemically inert (at those voltages, nothing is). If you pass current through it, you're generating biproducts. Look of electropolymerization of styrene. Anethole has that same double-bond, and that paper saw styerene polymerization at 2 volts, not 2000.

[@tissuepaper9962]

The paraffin+petroleum jelly potting is a really cool idea. Most potting compounds are non-reversible, but you could easily melt out that wax without damaging anything if you needed to repair the circuit underneath. It's even better that you can buy the two ingredients ready to use at most grocery stores or any craft store.

[@LesLaboratory]

Exactly. The original plan was to use mineral oil, but it would require a sealed container else the HV causes it to spray everywhere!

[@christopherkarr1872]

I've always been a fan of wax vacuum-potting. A whole lot less messy than tar and, as you said OP, much less troublesome to repair than a sharp point breakout in epoxy. It's also generally better for the environment than most oils or tars, as well as less toxic to the user. It serves as an early-warning if a component is over-heating and, finally, wax being a solid (as opposed to a liquid oil) allows it to prevent outside detritus from interfering with normal function.

[@mikeselectricstuff]

For high-speed switching, a simple spark gap should be a good start to create a fast edge. For ultra-short pulses, maybe some sort of transmission-line setup ? As those impurities seem to be attracted by the HV, I wonder if you could use this property to filter the solution

[@TheTemporalAnomaly]

A spark gap driving a shorted quarter wave stub, near the shorted end, with the open end across the cell would be a simple way to get damped oscillations at a frequency determined by the stub. (well into Ghz) The stub would also provide the needed voltage step up function. Also, since it is the electric field were are interested in, I don`t suppose the electrodes need to be in contact with the liquid, maybe they could be just foil on the outer walls thus avoiding potential contamination from the electrodes.

[@LesLaboratory]

There is a diagram of a spark gap arrangement in one of the papers, but I have too much sensitive stuff on the bench at the moment. That is a great idea, like a precipitator of sorts...

[@LesLaboratory]

Also very interesting. I had not considered capacitively coupling in the field!

[@christopherleubner6633]

Make yourself a spiral line pulse generator with an appropriately sized inductor on the output in parallel with the Kerr cell. It can make extremely quick HV pulses of about 4nS risetime.

[@wolpumba4099]

There seems to be an easy way to purify using water and temperatures between 0 and 30degC: *Purification of Anethole by Crystallization: Summary* 1. *Initial Preparation:* An aqueous emulsion of anethole is first prepared. The concentration of anethole can vary. 2. *Cooling for Crystallization:* The emulsion is cooled to below the crystallization point, preferably around 0°C. Subzero temperatures can be used with antifreeze like methanol. 3. *Crystal Separation:* After crystallization, the anethole crystals are separated from the aqueous emulsion. 4. *Further Purification:* The crystals are reslurried with cold water and an emulsifier (potassium or sodium soap of tall oil fatty acid) or surfactant for further purification. This step can be repeated multiple times if needed. 5. *Water Removal:* To remove residual water, the crystals are melted and water is separated at temperatures between 25-50°C. 6. *Final Product:* The resulting anethole is highly purified, with reduced sulfur contaminants and excellent odor and taste. This process aims to increase the purity of anethole, which could potentially improve its performance in Kerr effect experiments. patents.google.com/patent/US4902850A/en

[@Brandon-rc9vp]

Any day that I find a new Les' Lab or Huygens Optics video is a good one. Great topic, explanation, and demonstration!

[@3.2213]

indeed

[@suprememasteroftheuniverse]

I hope that "Les" is not the French article. Can this channel be even more sxtxuxpxixd?

[@suprememasteroftheuniverse]

Anyone making CLICKBAIT like you should be banned, fined and arrested. I'm blocking this channel. I wonder about the mental state of people liking this video or following this disrespectful channel.

[@wolpumba4099]

*Introduction and Background* - Introduces the concept of controlling light using electric fields, focusing on the Kerr effect. - Discusses the historical background of the Kerr effect, discovered by John Kerr in 1857. - Explains the traditional use of high-voltage Kerr cells and their applications in high-speed photography. - Highlights the toxicity and dangers of commonly used liquid nitrobenzene in traditional Kerr cells. *Alternative to Nitrobenzene* - Discusses the difficulty in sourcing and safely working with nitrobenzene. - Identifies Anethole, a non-toxic alternative with a high Kerr constant, as a promising substitute. - Describes the molecular structure and properties of Anethole, a component of aniseed. *Experimental Setup* - Details the construction of a Kerr cell for testing Anethole, including sourcing and assembly. - Explains the need for polarizers and a high-voltage supply for the experiment. - Notes issues with the plastic lid of the Kerr cell being affected by Anethole. *Experiment and Results* - Demonstrates the completed Kerr cell using a homemade high-voltage supply. - Observes the Kerr effect using an LED and a camera setup. - Notes the presence of impurities in the Anethole used, suggesting the need for purification. - Tests the Kerr effect using a laser, finding it to be very prominent. *Conclusion* - Concludes that Anethole is a safe and effective substitute for nitrobenzene. - Suggests future work could include purifying Anethole and testing the speed of the Kerr cell. *Positive Findings* 1. *Effective Substitute:* Anethole serves as a non-toxic and effective alternative to nitrobenzene for demonstrating the Kerr effect. 2. *Prominent Effect:* The Kerr effect was clearly observable, especially when using a laser. 3. *High Voltage Success:* The homemade high-voltage supply was capable of driving the Kerr cell effectively. 4. *Safety:* Anethole is non-toxic, making it a safer option for experiments. 5. *Affordable Setup:* The Kerr cell and other components were relatively inexpensive to source or build. *Negative Findings* 1. *Impurities:* Some impurities were observed in the Anethole, which could affect the performance. 2. *Material Compatibility:* The plastic lid of the Kerr cell was affected by Anethole, requiring a switch to a different material like Teflon. 3. *Complex Setup:* While affordable, the setup required various components and some technical know-how.

[@zhinkunakur4751]

how does one follow you on youtube or facebook 🤣 coz you just got a new fan

[@LesLaboratory]

@@zhinkunakur4751 Thanks, Sub on KZbin , I have a community Tab. I also have twitter: @LesLaboratory

[@hamjudo]

@wolpumba4099 That is an excellent summary of the video. Do you do this for other videos? Do you publish them anywhere that is easily searchable?

[@HuygensOptics]

Thanks for this video, before I only knew the Kerr effect from Simple Mind concerts. BTW: we got very spoiled the last few days with videos about polarization effects, first 2 videos by 3B1B and now this one. Great work!

[@zhinkunakur4751]

Agreed , its high time polarization gets rekt in the public pool of understanding , this is coming since I believe polarization was a very niche curiosity not covered much

[@LesLaboratory]

Thanks! I have just watched 3B1B's video, that is spectacular! I never imagined you would see anything from the side of a sugar cell!

[@mikepeterson9733]

Simple Minds, Jim Kerr -- I see what you did there! 😆

[@suprememasteroftheuniverse]

Please, you all drop the crackpipe.

[@suprememasteroftheuniverse]

Anyone making CLICKBAIT like you should be banned, fined and arrested. I'm blocking this channel. I wonder about the mental state of people liking this video or following this disrespectful channel.

[@campbellmorrison8540]

As I understand the Kerr effect is based on the field not the voltage or current directly. So I'm wondering why the electrodes are immersed in the liquid, why not place them on the outside walls of the curvet? That way there is no current flowing through the liquid, maybe that causes the ribbons etc.

[@LesLaboratory]

Yes, you are right, no current should flow in these, and building them in the glass walls might be quite convenient! The stringers I 'think' are because of impurities, however as Mike pointed out, this effect could be used to clean the solution by precipitating that junk out.

[@spanqueluv9er]

@@LesLaboratory Hey genius, that’s ^*star anise, not fuqqing (^*anise seed, not aniseed) ffs. How can you post a video with such a major and obvious mistake?🙄🤦‍♂️🤦‍♂️🤦‍♂️🤦‍♂️💩💩🤡👎

[@JoinTheTechnicians]

Every time it just keeps getting better and better. Now you even have a rotary table camera setup to add that "total pro video" look, and we love it!

[@LesLaboratory]

Thanks! I have been thinking about getting one for a while 🙂

[@JoinTheTechnicians]

@@LesLaboratory Wait, does that mean you did it by hand? Im so impressed with your videos. and THANK YOU the the ceramic pulse capacitor info. That helped us so much, and now we have a micro battery powered TEA laser

[@christopherkarr1872]

@@JoinTheTechnicians Did LesLab make a video about repotting ceramic capacitors in axial housings to improve voltage handling? Asking for a friend...the friend is me.

[@Liberty4Ever]

This is some serious homebrew science. I love stuff like this. Thanks for posting the video.

[@LesLaboratory]

Thanks! :-)

[@swabianscience]

By the way, even though it is very toxic, nitrobenzene smells absolutely great! It has an almond oil like odour, just a bit sweeter and softer than the benzaldehyde found there - probably the best smell of any chemical I've smelled so far, really unfortunate that it's so toxic

[@LesLaboratory]

Cool! I heard someone also say it smelled like boot polish. I will pass though! My workshop now smells of aniseed.

[@swabianscience]

@@LesLaboratory Well, the difference to benzaldehyde is very small, especially when dilute, so if you know that you have a very good idea of nitrobenzene. In my opinion, pure benzaldehyde has a slight stingy artificial note that nitrobenzene lacks, but it's only obvious in a direct comparison.

[@maxmustermann5353]

You make me curious. 😅

[@WoodenWeaponry]

Amazing video Les! Reminds me of Applied Science's video about the same effect. KZbin has become a big source of inspiration I must say

[@LesLaboratory]

Thanks! Yeah I saw that, it was the Faraday effect in olive oil, very cool stuff!

[@karlharvymarx2650]

The optical effect is really cool, but I'm also interested in those stringers and if the could be used to help purify the liquid by precipitating out the contaminates.

[@LesLaboratory]

For sure, there have been several comments to that effect. I reckon it's worth a shot.

[@brainretardant]

Look up isoelectric focusing. The current creates a natural gradient using natural buffers. The molecules will precip at neutral Ph point. Don't need the ribbons. You can do this easily with blood and it's proteins

[@dancollins1012]

Great video! Never would have guessed something organic in origin would have such a marvellous property. Keen to see other ways to switch light...

[@EddieTheH]

Organics generally do have the most interesting properties...

[@Drjtherrien]

Very very cool! Optical rotation of light is always interesting. Switchable effects even more so.

[@LesLaboratory]

Absolutely, wrangling light is very cool.

[@KallePihlajasaari]

@@LesLaboratory Was there a voltage that caused the light to start dimming again by rotating it too much?

[@KymDerriman]

Fantastic video as usual. Would love more on this, especially if it delves more into the physics of the Kerr effect.

[@LesLaboratory]

Thanks! I think there is more that can be done here with Anethole (and perhaps others)

[@fusion9619]

Instructions unclear. Accidentally created a lightsaber.

[@BreakingTaps]

Really neat effect, especially since it was done with a fairly pleasant-to-handle chemical! Great stuff as always!

[@LesLaboratory]

Thanks! It smells really nice (If you like aniseed!)!

[@Johny40Se7en]

Such a weird use for Star Anise / Aniseed, and I love Ouzo, so makes me want some haha 😛 Cool stuff.

[@flaviospedalieri8707]

Very nice setup and demonstration of the Principle.. Love the Ceramic HV terminals you have implemented. The concept of using an alternative less toxic liquid is such a bonus as well.

[@LesLaboratory]

Thanks! Yeah, the ceramic body has been in the parts box for years, and it was nice to be able to turn some terminals for it and put it to use!

[@MassimoCappello]

As you always say: that' absolutely fantastic!!!

[@CBMM_]

Thanks!

[@LesLaboratory]

You are welcome, and thank you for your support!

[@zilipoper]

Hello, this is your channel, absolutely fantastic) I watched all the videos FIRE

[@LesLaboratory]

Thanks! 🙂

[@jonathanlister5644]

Great stuff! When I was a lad I used to avidly read the amateur scientist column , dreaming of a pulsed nitrogen laser in my bedroom! It never came to pass but you are doing it with flair! I went on to study Natural Philosophy at the University of Glasgow where they had a museum of Kelvins apparatus I remember being fascinated by his Kerr cell.

[@LesLaboratory]

Me too! I have not been to the museum, but I will some day! It's the Hunterian right?

[@jonathanlister5644]

Yes which is in the main building, the Gilbert Scott building where they have a good deal of interest but also in the departments own building where you would be welcome to have a look round they are very happy for interested folks to visit.@@LesLaboratory

[@jonathanlister5644]

Also on Professor Square house No1 where you can see one of Kelvin's clocks it's a masterpiece but last time I checked it was needing some tender care.

[@totalrecone]

High voltage tends to emit better from pointed sources so it's my guess those "stringers" observed could be caused by surface imperfections on the electrodes. Highly polishing those electrode surfaces might reduce the stringers substantially.

[@joejane9977]

was worth my time to watch great info

[@LesLaboratory]

Thanks!

[@GeoffryGifari]

The electrodes are immersed in the anethol liquid? at that high voltage you don't see ionization and discharge?

[@LesLaboratory]

Yes, they are immersed. Anethole has relatively high dielectric strength, however if you push it too hard, breakdown can occur.

[@devrim-oguz]

We use that flower in Turkish Rakı (Alcoholic drink), which also turns white when you add water in it

[@LesLaboratory]

Nice!

[@lordofelectrons4513]

Excellent as usual. I recall seeing a Nitro Benzene Kerr cell described in a even old at the time issue of Scientific American Armature Scientist back in the late 1960. It was part of a high speed photography project. If I recall correctly the light source was an exploding wire and a high voltage switch made from a modified rat trap . Your setup is by far safer and more practical.

[@LesLaboratory]

Thanks! I read those articles as well. I think with a bit of refinement, some interesting experiments could be done on this!

[@suprememasteroftheuniverse]

Excellent CLICKBAIT.

[@suprememasteroftheuniverse]

Crackhead

[@suprememasteroftheuniverse]

Anyone making CLICKBAIT like you should be banned, fined and arrested. I'm blocking this channel. I wonder about the mental state of people liking this video or following this disrespectful channel.

[@tiagotiagot]

Do the electrodes really need to be embedded in the liquid, or would the voltage potential still have an effect even without closing the circuit?

[@dennis8196]

Interesting choice of insulation. If im not mistaken both paraffin wax and petroleum jelly are flammable under certain conditions, eg when warm they soften and vapourise at low temperatures, and have a low flashover temperature. Wouldnt a better. Choice be epoxy resin or similar?

[@GaryMcKinnonUFO]

Quite a large change in apparent magnitude too. I'm wondering if the stuff that appeared in the LED experiment is simiar to when they use lasers to grow crystals ?

[@dalenassar9152]

Thanks MUCH for the information on Anethole. Your "Verdet constant" (I think that's close to the name) seemed very impressive. I have experimented with audio modulation, and had planned on using Nitro-benzene [C6H5NO3] ! AND thanks for refreshing my memories of the horrors of C6H5NO3. Since high school, and an article in "The Amateur Scientist" in "Scientific American" I have collected, built, and put together a working Kerr cell experiment. I even have a Brewster window HeNe so I only need one polarizer. It worked good enough...BUT...I actually have two 500ml factory-sealed bottles of C6H5NO3. Since I got them several years ago, I was suddenly afraid to un-seal them. NOW, this video clinched it for me...I'm sure!! I won't even touch the glass bottles without gloves! It's just not worth the "liquid death" risk! The bottles are safely protected. I'm just looking for a safe way to dispose of them...any ideas? THANKS MUCH again. --dAle

[@LesLaboratory]

Kerr constants for these, and yep, pretty high. Ah, the Sci am articles were the best, it's a shame they don't do them any more. I think your local waste disposal can handle any nasty chemicals for you. Yhanks, you are welcome!

[@timjx3675]

Super cool, love your style !

[@usvalve]

Until today, I only knew of the Kerr Cell in connection with John Logie Baird, who used it to modulate light in television receivers. I don't know if he used the appalling nitrobenzene, but I believe he used grid electrodes to reduce the control voltage needed (and renamed it the Baird Grid Cell!) I'm surprised he didn't try a mechanical shutter to modulate light! If you can make "Phonovision" recordings on a 78, you must be able to move a diaphragm at the highest frequency needed.

[@foramagasobeselettucepurpl6911]

I'm not sure what I just watched, but it was pretty cool!😀

[@dalrob9969]

Les, try a 100 meg-ohm resistor to start, (you may need to tweek the resistance up or down to find the sweet spot ), connect it across the kerr cell electroids, It may arrest the voltage enough so that the stray impurities won't discharge after you shut it down so it turns the photons all the way off on their axis. Something I tried decade's ago that worked with N.B. I also used "Moth Balls" diluted in methanol. Be very careful. I like this chemistry your using for his project. I am: Dale Robertson.

[@sandorkonya]

Super video as always!

[@LesLaboratory]

Thanks!

[@VariacManiac]

Thanks for showing this, that's cool! This is simply what KZbin is for.

[@LesLaboratory]

Thanks!

[@jonbigman9723]

You have two effects going off there. One is a plasma effect of lensing when concentrated as you are doing between the electrodes from the very high voltage. The next effect is one of the additive you are using. It is crystalizing and then dielectrically orienting itself between the two electrodes. You can see if wiggling up and down like it is being vibrated and oriented between the electrodes (strings). This also has a lensing or focusing effect as well and shortens the path between the light source and the camera via the crystalized aniseed extract you are using, which is a sort of diffuser based on it's crystalline structure. The trick with the polarizers is an excellent way to use a light source and illuminate the targets between the plates without having to filter out the led source light for the camera. There have been many interesting experiments like this done just with seeds and high voltages. The seeds will jump up and down as they ferry charge back and forth between the electrodes. Much like the crystals are doing between your plates. This can be likened to lcd technology as well as the voltage controls the orientation of the crystals to make a shutter effect. That is what I get from this presentation. Nice presentation!

[@cambridgemart2075]

It's nothing to do with crystallising, it is a property of some liquids and solids, so the effect cannot be to do with any phase change. What is happening is that the high field strength distorts some of the bonds in the molecular structure causing it to rotate the plane of rotation of the light source.

[@Youtubuxian]

Great video! You may be interested in Mie Scattering. In particular, you can use lasers to measure the particles in both a liquid as well as air. Industrially, they use lasers to measure particle size and counts for clean-rooms. Industry typically has two topologies - diffraction, and a reflection/scattering method. You can even pick up a sensor for $30 or so from sensirion now.

[@LesLaboratory]

Cool, I will look those up! On my dream list isban external cavity He-Ne for particle counting, but the are darned expensive!

[@Youtubuxian]

@@LesLaboratory If you find yourself in need of some electronics, 3D CAD, or software help look me up. I'm working on some precision amplifiers and electronics to support some instruments so happy to help in whatever capacity if it supports your cause. Thanks again for the videos!

[@ashleyobrien4937]

yeah, I used to work with a Malvern laser particle analyzer, Mie theory, back scattering, all part of the system, I actually built a totally new dispersion unit for Dairy powders, and Malvern came out to see it. 100 k for the machine, nice toy that was...

[@cambridgemart2075]

@@LesLaboratory They can be found surprisingly cheap sometimes, I have four of them (all 25mW +) and paid less than 150 pounds for any of them, some including power supplies.

[@815TypeSirius]

So this is why Scene from Arknights has a little aniseed hair pin. Neat.

[@TheTablet314]

Very cool video! Are you interested in optimizing the performance of that device? To see what kind of transmission, modulation contrast and what speeds can be reached? Sidenote: Can't you use the exact same electrical setup for a pockels cells too? Specifically, with your KDP crystals?

[@LesLaboratory]

I think Anethole is worth seriously exploring. There is very little about it in the literature. It would be interesting to characterize it. Pockels cells are way more efficient and require much lower voltages. I already have some hardware on the way to cut and mount the KDP.

[@markiangooley]

You don’t have to use star anise. Regular anise, traditionally used in Europe, might be more practical. They aren’t related but they produce similar chemicals. Both have anethole. People nowadays seem to think that only star anise exists and other anise doesn’t. I saw a version of an ancient Roman recipe that was made with star anise even though probably Romans never used it.

[@lambda4931]

Interesting! Thank you. I thought the Kerr Effect changed the refractive index rather than the polarization.

[@nonchip]

bit of a dumb question maybe but: why is this not considered an LCD? also why does this even work if it's not an LCD and it uses 2 polarizers but the Kerr effect influences the refractive index instead of polarisation angle?

[@greenaum]

Actually turning light on and off! That's really good! (ssssh! nobody tell him, he'll be heartbroken.) Good work, now we can get some sleep, oh yes.

[@Pooua]

If anethole is non-toxic *and* has an even higher kerr constant than the liquid death now being used, why hasn't anethole replaced nitrobenzene? Either of those mentioned properties seems like sufficient reason to switch, but both are combined!

[@avenuex3731]

Lovely demo

[@TheRainHarvester]

You filter out the solids that form? Easy way to purify?

[@jmssun]

Spice can control space, time and light

[@pattheplanter]

Could the solid be from polymerisation? Anethole is similar to styrene. Add an electron and that will react fast. The impurities may be initiating the reaction. However, is the double bond on the side chain necessary for the Kerr effect? Could you hydrogenate to dihydroanethole?

[@TheTubejunky]

Love the HighVoltage power supply. Any links to the equipment. I have an old ZVS Ive made years ago by hand but wouldn't mind having a W.k multiplier.

[@QIKUGAMES-QIKU]

Have you covered the Blue laser of Hawaii at all ?

[@pauljs75]

Interesting, but it doesn't seem to offer much apparent advantage over some type of liquid crystal light shutter.

[@PJFunnyBunny-yl7co]

Awesome channel! I subbed and thank you!

[@LesLaboratory]

Thanks!

[@ParedCheese]

A use for Anusol I'd never suspected! 😮

[@1kreature]

Wonderfull research! I wonder if the used anethol can be purified by filtering since the "stringers" appear as a solid once cell has been run?

[@LesLaboratory]

Possibly. Mikes Electric stuff suggested this as well. It might be possible to just create a setup to electrically precipitate out the garbage.

[@simontillson482]

Lovely video. I do have to point out one thing though… the thumbnail shows Star Anise, not Aniseed. The former is a resinous tree seedpod, the latter is the seed of a small flowering plant. Common mistake.

[@LesLaboratory]

Thanks! Artistic licence 😉 star anise, aniseed and others all contain anethole.

[@christopherleubner6633]

Remember a kerr cell filled with mononitrobenzene at a laser lab, the stuff is extremely nasty. I prefer pockles cells made with benign lithium niobate though.

[@LesLaboratory]

For sure! It's a shame nobody is using Anethole as a substitute, but mentions of it in the literature are sparse. Pockels cells are superior in almost every respect, but I really like trying things out.

[@htomerif]

I made a Kerr cell out of nitrobenzene a few years back. I didn't know that it just plain dissolves polycarbonate. I ended up spilling quite a bit of it as it at through that cell. Its nowhere near as dangerous as people make it out to be. This is more one of those "you don't want to be chronically exposed to it" kinds of things. Thorlabs makes some long-path quartz cuvettes that I use now. Its incredibly difficult to find something that can shutter light at nanosecond timescales and sane voltages other than nitrobenzene.

[@LesLaboratory]

Yeah, benzenes are pretty good at dissolving things. Still, I wouldnt want to be exposed to the stuff, and in my house at the moment, its just too much of a liability. Anetholebis harmless. For sure. Anethole is a litte larger than nitrobenzene, but still, it would be interesting to try it out.

[@htomerif]

@@LesLaboratory It would be interesting to try recrystallizing it to get the purity up but even though its melting point is 20C, these oily aromatics are notoriously hard to crystallize. Like you said, there's probably a lot of other junk in it from anything other than an analytical source. I'm assuming most of what you can buy is just straight steam distilled and that's it. maybe heated to remove the water.

[@stevengill1736]

Very cool! I'd read about Kerr cells in laser literature, but never seen one in operation - great power supply too. When I was a kid nitrobenzene was still used comercially, and the overpowering near-almond smell was characteristic and penetrating - anethole is definitely nicer. Cheers...

[@Liberty4Ever]

I thought I recalled nitrobenzene used as an ingredient in glow plug engine fuel for R/C cars when I was a 1970s teenager. When the toxicity was mentioned in the video, I did an internet search and determined that the "nitro" that's in glow plug engine fuel is nitromethane... but was that always the case? When I was a kid, I'd roll mercury around in the palm of my hand because room temperature liquid metal is cool.

[@LesLaboratory]

Thanks! Someone said reminiscent of boot polish, but it became unobtainium here after the '80's The anethole smells strongly of Aniseed, which I quite like.

[@Liberty4Ever]

@@LesLaboratory - I need to get some star anise to make chili oil for Asian cooking. Who knew it could be used to polarize light? Gotta love science.

[@cambridgemart2075]

@@Liberty4Ever As you say, it's nitromethane and has been as far back as I can find (late 1940s when glow engines were first available).

[@tanner3801]

Interestingly enough, I recently discovered the peculiar attributes of anise extract, while making root beer. Indeed, it did not want to mix with water, and caused a bit of a light foggy appearance as it was mixed in. It also seemed to precipitate something onto the stainless spoon I used to measure it. Intriguing! Another parameter that would be interesting to test, aside from the behavior at high switching frequencies, would be the linearity and precision of the polarity change per volt, from 0-360 degrees (if you can achieve that within the breakdown voltage of the kerr cell, or before leakage significantly hampers the linearity).

[@LesLaboratory]

interesting. Yes, I want to try and properly characterize the cell, and derive the kerr constant. for that I need to properly purify the anethole.

[@zordinance]

Thank you!

[@zedmike]

Why is your homemade powersupply with 45KV measured in amperes?

[@Indie9999]

So what's inside a kerr cell shutter on a high speed camera? What's the medium? Do they just go straight for nitrobenzene?

[@LesLaboratory]

As far as I know, they just use Nitrobenzene.

[@joinedupjon]

4:42 The Ouzo effect - no doubt named after its discoverer, Joe Ouzo

[@jezmy2006]

If those "stringers" are solid impurities, could you use a small pump and circulate the fluid through a fine filter to remove it? You'd need to do it slowly to avoid air bubbles and turbulence I would think, though 🙂

[@legionjames1822]

What conclusions can we draw from this experiment? Why does it work

[@florinpetrache7834]

does it work with pure essential oil of Star Anise Illicium verum, or is the substance different?

[@LesLaboratory]

I have not tried. I first tried with Ouzo essence but no observable effect. It may be worth a try.

[@SeanDriver]

Nice share….what is the field intensity in that cell?

[@LesLaboratory]

Thanks! The applied voltage is 26kV and the gap is 4mm, so 6500v/mm or 6.5MV/M

[@andrewnelson8093]

distilling liquid death. love that

[@repairitdontreplaceit]

hi les . we use eom at work to modulate mp lasers they are fluid filled and have two xtal / glass rods inside . are they kerrs cells ?

[@LesLaboratory]

It is not likely. The Kerr effect is more or less a curiosity these days, there are more efficient materials. For Modulators and Q-switches the Pockels effect is used (Lithium Niobate), or the Acousto-Optical effect (Tellurium Dioxide or similar materials)

[@maxmustermann5353]

"Without dying" Yeah, let's keep it that way. We want to keep enjoying your content. 👍

[@LesLaboratory]

Thanks! I will try my best!

[@GIRGHGH]

If the effect is stronger and it's much less toxic, I'm very curious why it's not the more commonly used one. Is it worse in some other way?

[@LesLaboratory]

I don't think the effect is as strong as with nitrobenzene, and I lack the analytical equipment to test it. It could be for two reasons: The kerr effect is more or less a curiosity now, given there are pockels cells available that are far more practical. Secondly (related to the first), I have only found a single reference to the Kerr value of Anethole anywhere in the literature, so perhaps, as these cells fell into dis-use interest in research dwindled.

[@MrRockstar1968]

What would such a laser light be used for?

[@danielpetka446]

Very valuable, I have to try this out myself! Unlike in the Faraday effect, the rotation of light is due to birefringence, right? So you can generate circular light with this. Does it mean that, just with waveplates (fast axis, slow axis), if you rotate the laser so that it's polarisation is parallel to the electrodes, the light won't be rotated?

[@oomwat6101]

The Kerr effect was originally published by John's brother Joe ... but nobody took him seriously :D

[@alwaysyouramanda]

Typical of normies

[@BurkenProductions]

So in practicallity what is it good for?

[@Dr_Mario2007]

Interesting LCD effect with the liquid (and you could say that modern LCDs are basically efficient low voltage Kerr cells all things considered), at the same time, Kerr effects slows down in liquid (and electrodes not as closely spaced, as capacitance can affect it also), while it's massively faster in solid state Kerr cells. Planning on using it to Q-switching a laser?

[@ashleyobrien4937]

Yes, nitrobenzene is a strange beast, as a solvent for certain reactions it is unsurpassed, it also does some very weird things to plants, seeds specially treated with nitrobenzene show highly accelerated growth, of course that's not directly useful because the seedlings are TOXIC...actually, a similar effect can be seen in humans who use dinitrophenol, it has the effect of making cell membranes too leaky, ions leak out, so the cells use shitloads of ATP (energy) to pump the ions back in ! this has the effect of ultra rapid weight loss, a very dodgy way to drop tons of weight in record time. In fact, in the last century, workers at explosives factories (TNT, Picric acid etc.) were always quite thin, due to exposure to nitrobenzene...

[@testboga5991]

A wonderful video! Thank you

[@LesLaboratory]

You are very welcome!

[@mishkamcivor409]

I never thought I'd hear a solvent described as "distressingly powerful" heh

[@GaryMcKinnonUFO]

Very cool indeed !

[@LesLaboratory]

Thanks!

[@thorjohnson5237]

That's pretty cool... is the same effect (kerr) what's active in a LCD, just longer, so lower voltage, but because longer/less springy, it's slower? What's the kerr on sugar? Can I alter the twistyness with electricity or am I just gonna make an electrolysis mess?

[@cambridgemart2075]

An LCD relies on movement of the crystals in the liquid crystal, it's a mechanical process which is why LCDs are relatively slow. Sucrose, and possibly other sugars, exhibit the effect in solidus, but you'll need to grow some decent crystals to try it and somehow prevent them from hydrating.

[@dandeeteeyem2170]

... How utterly delightful 😂❤

[@LesLaboratory]

🤣

[@keghnfeem4154]

Dose the angle of diffraction change?

[@LesLaboratory]

I have not tried to experiment with that. It would be interesting if there were some easily observable change.

[@ubza1234]

Is this effect related to LCD screens?

[@LesLaboratory]

Yes, it is related, but Liquid crystals react far slower than the traditional Kerr effect.

[@theGraphicAutist]

what the pho? u can control light with your anis? amazing!

[@IamERAMOS]

So the experiement turned light on and off?... :x

[@aarashnavabi4749]

You seem to have some Raman effect occurring too.

[@ZA-mb5di]

6:04 how does the lens do that

[@LesLaboratory]

These are polarizers. Each only allows light through of a specific polarization, so if you cross the polarizers, effectively you are blocking all light, and if they are uncrossed they will let light through.

[@ZA-mb5di]

@@LesLaboratory by rotating them?

[@ericferraro2033]

It's amazing that the 19th century was rife with pioneers playing with tremendous hazards and voltages and somehow less loss of life than any given week in India

[@eeveeofalltrades4780]

We are now one step closer to creating Green Lantern Rings

[@richardlilley6274]

Not got a clue how it works But thanks for sharing

[@brianhiles8164]

A light switch utilizing anise seed liqueur? What´s next? Stopping bullets with corn starch?!?

[@LesLaboratory]

😄 has that not been done?

[@brianhiles8164]

​ @LesLaboratory Oh no, I am a complete failure as a human being insofar as my attempt to amuse has proven a utter debacle. (I would have also accepted the rejoinder, _I utilized a purified chemical (not purified enough, apparently!)_ not _a liqueur at all!_ )

[@detritic]

Seriously, is there anything better than fun scientific uses of secondary metabolites

[@LesLaboratory]

I lve this kind of stuff!

[@charliepearce8767]

6.10 this affect can be achieved by taking the lens out of real polarised sun glasses and holding them up against each other while tuning them.

[@Peter_A1466]

Is that anethol fluorescent?

[@LesLaboratory]

I did not observe any florescence, but then I have not looked too hard!