Schlieren Imaging in Color!

[@veritasium]

Sorry for being away for such a long time!! I've been shooting a documentary and that's involved a lot of travel - to Boston, Paris, Glasgow, Baltimore, DC, Houston, and now I'm home for a few days before heading off to Australia. I really appreciate your patience and support.

[@johnjackbogle1217]

Veritasium when will the documentary be out?

[@aboundedshark]

Veritasium you should explain bio-kinetic energies

[@FondlesHandles]

how big of a parabolic mirror could you use for schlieren imaging?

[@TheNefari]

Get the Slow Mo guys in there and play some music to see the shockwaves :D

[@PavanSharmas]

Can you show how electricity looks

[@ishbanyadav]

The amount of hardwork you put in for creating is really inspiring.

[@zes3813]

wrg

[@drashitanand]

Your comments are everywhere!!??

[@ophello]

Hard work. Two separate words.

[@ayed5349]

Sam Krochman 😂

[@ishbanyadav]

Ashit Anand Hahaha yes I like to put a positive comment on every video I like! I hope you don't mind :p

[@ArnoldsKtm]

Whoever suggested color filter - kudos to you!

[@alveolate]

what would happen if there were 4 different colours?

[@potatoonastick2239]

He should do a smooth gradient of for example a rainbow, instead of just two colours.

[@tiarkrezar]

Yeah, try printing a color wheel on a transparent plastic sheet, then focus the light through its center. Should produce some pretty interesting results, I think.

[@eruyommo]

Fly Intercourse It means hug, when you surround another person with your arms to show affect.

[@Lahim27]

Hi Derek. This might get lost in a sea of youtube comments, but nevertheless I have a suggestion for a sound-based Schlieren imaging experiment. I was wondering if it is possible to observe a 3D standing waves in air (or some other transparent medium). Standing wave will create a pressure differences, so theoretically we should be able to see with this technique the pressure gradients between nodes and antinodes. With proper set up we might see similar patterns as Chaldni patterns produced on a 2D plane. The technical realization will probably be a bit more difficult, but this was just a quick idea that crossed my mind.

[@myca.]

He'll need a much higher frame rate to capture it, hence the needed backup mentioned towards the end of the video. I don't know how high frame rates can go, but I'm willing to bet it's doable

[@wierdalien1]

@@myca. Slo-Mo guys or Destin

[@WillN2Go1]

Signal generator so you can dial in sound frequencies, or maybe just a tuning fork. Sand in a speaker will form patterns from the sound vibrations which are 340 m/s so these patterns must be standing waves. It may still be difficult to see a standing sound wave pressure differences in air, it might be easier to see the effect on the rising heated gas from a candle. With a signal generator you might be able to change frequencies and capture video of the change in standing waves in your rising gas. (You posted this a year ago. Any results?) [And I just had the probably whacky thought: What about the slit test and Schleiren? Don't ask me for results, I'm still fiddling with the basic set up.)

[@moiquiregardevideo]

Standing wave seems a good idea. You don't need high speed camera since, by definition, the wave is standing still. The wavelength (frequency) can be adjusted for the best resolution.

[@JimC]

The standing wave is an intriguing idea. If it works at all, maybe use a frequency that's very close to the frame rate of the camera. That way the strobing effect might be used to see the antinodes change in slo-mo.

[@SomeoneCommenting]

The two-colored piece is awesome, the color contrast helps to see the flow movement much better.

[@vooyas.mp4]

That is some sick vaporwave art with those filters!

[@a.yusril]

ＡＥＳＴＨＥＴＩＣ

[@santiagosepulveda8357]

ISiupick I was thinking the same thing hahaha

[@BananeDollar]

Make a collab with the Slow mo Guys. this would be cool :D

[@SuperExodian]

was gonna say the same, if you need high framerate to 'see' sound, they've probably got what you need for it. i imagine they'd also be down for a video on shlieren

[@GameCyborgCh]

i think he meant destin from smarter every day

[@Kluneberg]

Or Destin from SmarterEveryDay, he has 100000fps camera too.

[@tecrobak]

oh yes

[@tecrobak]

if you read my comment then you can also answer. please.

[@gpcaraudio]

I could watch these experiments all day. Epic

[@lingo6582]

i am actually doing this

[@user-jt6nw6wm5q]

watching a video about Schlieren in Schlieren, Switzerland.

[@pbourd]

At Roche Medical electronics we had a Schlieren through an Aquarium tank ( round pinhole light with round black dot obturator) to a video camera: we could image the ultrasonic beam patterns emanating from (3-Lens) Cloverleaf fetal monitor transducers. The cast epoxy lenses sometimes were improperly bonded to the flat PZT crystals, and the Schlieren clearly showed black streaks in the conical “flashlight beam” pattern emitted from the ultrasonic lenses. We also had a sound pressure force balance that had 90 degree corner (point-up) covered in ultrasound-absorbing rubber suspended in another tank from a microbalance. When the Ultrasonic transducer was aimed at the rubber corner, the milligram “force” created by the ultrasonic sound pressure (deflected at 45 degrees) was proportional to the milliwatts of ultrasonic energy emitted through the water. Bureau of Standards method based on the paper by my Manager (pronounced “Ya-niss”) Janis Ziedonis. In the early 1970s. Peter Bourdelle

[@Pyriphlegeton]

Please just upload 30m of uninterrupted colored Schlieren Footage. This looks mesmerizing.

[@boratsagdiev5707]

When you blew up that bubble SO close to the mirror my heart jumped because i remmemberd how mauch work it takes to clean my telescope 😭😭😭

[@SaraMakesArt]

Also, enjoy your trip, Derek.

[@philchia4764]

Internet + Veritasium = mind blown. Well done.

[@Necron3145]

"Using this razor blade to cut the light" Why does that sound so dam cool to me 😂

[@zes3813]

wrrr

[@Wawet76]

For the sound thing, maybe try a speaker with a sound frequency close to a multiple of your camera framerate.

[@robspiess]

This, or use a stroboscope LED.

[@j_ro]

that might be cool. i'd like to see a bull-whip crack. i think you need to break the sound barrier to have a powerful visual.

[@maxjost9266]

i hope im not completely false but i think when he is making sound by blowing over a waterbottle there should be a standing wave in the bottle and you don't need the shuttereffect

[@lasunncty]

For the standing wave he'd need something with a very small wavelength (to see it in the reflection), and therefore very high frequency -- at least a few thousand hertz. Maybe a piccolo?

[@yonigolombek3335]

With a balloon

[@PictureFit]

Shhhhhhhhhhlieren. That's a tough one. Getting hypno vids at 5:20 o.o

[@ristovirtaharju5030]

PictureFit hello

[@DANGJOS]

+PictureFit Hey PictureFit! So you're interested in physics as well. You and Veritasium should do a collab on the physics of different exercises

[@WatermelonBMX]

I love this channel, Always so exciting when I see it on my feed

[@nitaiflick3050]

This is by far the most clear and concise demonstration I've seen of Schlieren photography. It would be great to see the currents of an ionocraft!

[@ArunaKhudan]

This was really cool, wow, the images are stunning! I loved the colored ones, so pretty

[@nathanb611]

"I may need to call in some support..." This sounds like a job for @theslowmoguys !!!

[@DeepDarkier]

or @smartereveryday

[@426shelby426]

Hell yeah the slow mo guy

[@Ijjergom]

DeepDarkier or both! :3

[@theSato]

dont think the slowmoguys know how to visualize sound waves, they're more about just pointing a slomo cam at stuff

[@kidkangaroo5213]

+Sato Yeah, but they do have an ultra slow motion camera, which should be useful for searching for shock waves traveling at Mach​ 1.

[@supreetsahu1964]

I was waiting for a new Schleiren video for so long! Thanks Derek!

[@i.i.iiii.i.i]

Supreet Sahu "Schlieren" means "streaks". What you wrote is closer to Schleier which is German for veil/veils. :P

[@alex95sang52]

Simone?

[@PaulPaulPaulson]

Razorblade on a stick: Great science tool in the right hands, evil weapon in the wrong ones.

[@DigitalPyro]

Paul Paulson weapon? More like a tool

[@PaulPaulPaulson]

Digital Pyro Well... as wiki says: "A tool is any physical item that can be used to achieve a goal." So a weapon is just a tool used to achieve the goal of creating dead bodies.

[@projecterik1241]

Thanks for the idea

[@chowtom5174]

Paul Paulson weapon and tool may not have a difference in meaning as far as aliens communicating in coffee mug stains are concerned

[@user-yw9mw9hv8o]

even better, it's litrally used to cut light

[@caio.tavares11]

Today on How It's Made: Schlierens! First, you take a plumbus..

[@Kihidokid]

Just a regular ol' plumbus?

[@prsm3]

;D

[@ryomichael]

Second, get as drunk as Rick Sanchez!

[@rabbitpiet7182]

I only looked at the thumbnail and in already crying from its beauty and I have never liked a video so fast!!!

[@BenjaminLovelady]

It would be cool if you used a continuous spectrum filter. The only way I can think of to make it is by printing it off on a transparency sheet. Might give cooler images.

[@Seadalgo]

Love to see this revisited

[@whitemax8]

WHAT ABOUT MORE COLORS? (4 pieces of celophane, splitting the focal point into quarters; 8 splitting the point into eighths; 16 into sixteenths.... etc.)

[@piyumalperera8494]

kzbin.info/www/bejne/equ6c5uaia6AepY

[@ACECT]

guys dont click on it its not an experiment its just an ad! ^^^

[@VoidHalo]

Usually I hate added sound effects that are obviously fake, but in this case it works really well to add to the effect. Well done.

[@awestwood3955]

Why has it taken me 3 years to mind this!!! Amazing videos thanks

[@Guildrum]

I would like to see some schlieren footage of the GTAW process of welding. The shielding gas used (argon) emerges fairly cold compared to the electrical arc that does the welding, and might make for some very strange patterns. Given the sheer amount of light emitted, along with huge UV radiation, I'm not sure how well it would be photographed or video taped.

[@megalyssa]

You should do a video with the super slomo guys. Try to see if you could see the sound waves with their equipment.

[@SexyStarfleet]

Meg Alyssa Counter Proposal: use Destin’s cameras from Smarter Every Day instead.

[@unvergebeneid]

Is it possible to use not two colored halves but four different colors in quadrants to see not only light deflected vertically but also horizontally?

[@waynepage4383]

Yes, and there are methods of using a mosaic of various colors that are offset by small amounts and would provide a large number of colors in an image. These colors then can be related back to the angle the light is deflected vertically and horizontally allowing you to obtain quantitative information about the flow field.

[@eideticex]

The results wouldn't be as meaningful or nonsensical with more than two slices. Light acts as a wave so it has a very tight interaction with PI. Dividing negative and positive PI into colors results in really nice transitions between those colors, dividing it further gives unexpected and seemingly chaotic color changes. Now a smooth gradient across each hemisphere would correct the chaotic change problem and likely produce some interesting visuals.

[@originalMmusic]

Exactly my thought!

[@Oscar4u69]

Bump, exactly what I thought

[@Crosshill]

would that be super duper pretty?

[@ZRTMWA]

Ohhhhhhh that balloon popping through the two-color filter, instant thumbs-up!

[@olliehug1132]

This... looks so cool. Getting so many vaporwave vibes. There's some serious visual art potential with this, hot dayum

[@lucaileana]

The Shlieren affect sounds like what i get after 4 beers. I start shlieren my words.

[@CoDisafishy]

+aDistressedLiver I suppose your channel name is pretty fitting then.

[@rcollins0618]

aDistressedLiver lol!

[@MaMahmod]

your language has a lot of shlieren in it ......

[@maddog040400]

These videos are educational art. keep up the good work ❤️

[@sarnxero2628]

You should use a wave form generator to Make low frequency sounds and record the pressure waves in smoke in front of the camera.

[@APaleDot]

Low frequency sound waves still move at the speed of sound. They would be very hard to see. Might be a cool way to see standing waves though.

[@SoirEkim]

Love that turbulent flow!

[@IDremOI]

Those were some awesomazing ultra plus images!

[@dudeman3981]

Do an electric arc

[@AlexKnauth]

Oooh, that would be cool

[@FALprofessional]

"Do an electric arc..." off of a flame.

[@piyumalperera8494]

kzbin.info/www/bejne/equ6c5uaia6AepY

[@JK03011997]

Maybe the formation of NO2 by striking an arc though the air could be visible this way its refractive index is only ~0.3% tough

[@TheLunaLockhart]

you saying "rainbow schlieren" made me wonder how it would look to use 6 colors of triangle (sorry indigo) converging on the focal point instead of cyan and magenta. I only go with 6 because it would keep a horizontal separation between ROY and GBV, commonly considered the warm and cool colors respectively

[@zerg6205]

Who you gonna call? Slow Mo-guys!

[@random110]

Or SmarterEveryDay

[@philb8437]

This video is satisfying to an infinite level !! It is nuts. So beautiful to watch

[@MattIsAGamerCanada]

It looks like it's underwater. Seriously amazing.

[@koosnaamloos4291]

I am currently making a schlieren image of a cavitation bubble for a major school project because of your previous video

[@koosnaamloos4291]

We actually use a lens and put the camera on one side and the light source on the other because we can't afford a big parabolic mirror. Where did you get yours?

[@bel3100]

My question is how could one make one of these setups for cheap in their own? Not really in college or anything, I just wanna do this for fun. If you know any cheap materials, please let me know!

[@koosnaamloos4291]

The quality won't be as high as in this video and you can only film things the size of the magnifying glass, but for a cheap home setup it is fine. Also make sure the room is dark enough.

[@bel3100]

Koos Naamloos so what materials should I buy to set this up? I don't know where to start, but you seem to know a lot lol

[@koosnaamloos4291]

You'll probably already have most of it. For the camera I used about the same as what veritasium used, because auto focus is something you don't want. You can position the camera with some books if you have nothing else. You also probably have a razor blade or precision knife lying around, or else you can buy one. The magnifying glass has to be at least 10 cm (4 inch) in diameter, and as a point light source you can probably use a modified led (see link previous comment). You can try different objects like a candle to test if it works

[@1337w0n]

Clearly his sphere analogy is bunk, a cow approximates a donut, not a sphere.

[@Nilguiri]

true!

[@redline6802]

*could you do this with more than 2 color filters?*

[@rossmillington8700]

I dont think so no

[@SokarenT4S]

actually yes, how it would look that's a different story but you could put the light between 4 filters or 8 or any amount as long as you can get them to be roughly a circle where the light gets focused.

[@mdoerkse]

Why not a whole rainbow filter? Either linear or radial.

[@fleshwound5149]

Yes you can! A rainbow filter would work really well.

[@loljkchris]

There's a whole field of research which uses radial or linear rainbow filters for this exact purpose (Rainbow Schlieren Deflectometry). The hue of the transmitted light can then be directly linked to its deflection, and the refractive index of the transmitting medium (and its temperature by extension) can be calculated as a result. It's a really useful and powerful analytical tool. Well done on coming to this conclusion by yourself- the original publishers of this method were at NASA, I believe.

[@3dgar7eandro]

You have manage to explain "concave lens" light behavior in the most compelling way I have seeing in the all my Collage student years hahaha.

[@NicksWhipShop]

I was able to find an old Olympus iSpeed 3 high speed camera and a 12in parabolic mirror for a really good price on eBay this year. I've been having such a good time to say the least. BB's, the tip of a whip cracking, supersonic flow from an air compressor, etc. I feel like a kid in a candy shop now, and the candy shop is in my basement! 😁 Your videos were very helpful to me during the process of setting up my schlieren system. Thanks man!!

[@BlameItOnGreg]

It is debatable to what degree a shockwave can be called sound. Many definitions of sound do not include shockwaves. I think it would also be more interesting to try and see a standing wave. If you tried a clear Rubens' tube, you could possibly directly see the relationship between the standing wave in the tube, and the flames up above. If you are able to see standing waves, it would also be cool to see the difference between cylindrical and conical bore wind instruments.

[@AndrewAlcock]

I think trying to image a standing wave is an excellent idea - I came here to post it if it were not here. The advantage is that it stays in the same place, and you should see the air pressure in the non-fixed part of the wave go up and down at the frequency of the note. Tune the frequency with the fps of the camera, and you should be able to get a clear result.

[@april5054]

A sound becomes a shockwave at 190 dB if I recall correctly

[@photelegy]

6:40 Couldn't you make a repetitive clap (with a adjustable frequency) with some kind of machine which is nearly the same every time and then make the rate of clapping very slightly faster then the shutter speed of the camera? So you could achieve a "fake" higher frame rate? I hope I discribed it clearly enough 😅

[@yoongilimerence]

you're describing a speaker, lol. it could work

[@lexaf7578]

@@yoongilimerence standing wave

[@insainsin]

You could also use two light polarizers.

[@insainsin]

Put two opposite light filters in the set up to cancel out some of the unneeded coloration. One in front of the light source cutting it in half and one in the normal place.

[@hafizhoot]

The smooth flow from a fan. The flow out of a whistle. The flow out of a flute. The wing beat of a hummingbird. The waves of a housefly. The flow across a paper airplane. The whistle that comes out when you blow into a bottle in a specific way. The stationary wave produced by a tuning fork in a long cylinder. And for sound, it doesn't have to be a shock-wave. Try producing a continuous sound that would give continual waves, like that from a tuning fork.

[@tyler3201]

This is very true, I got audible and although i already like long car rides and flying, it made them even better.

[@CrucialMuzic]

Surely inhaling that in [5:50] can't be good for you ;p Amazing as always

[@ThaSPAWN]

I sprayed cough surpressants into my eye just to get a kick on a rave party.

[@kindpotato]

It doesn't produce anything unusually toxic. Burning most organic things just makes water CO2 and CO.

[@kindpotato]

If you look up the structure of the chemicals that that ball is made of, you will find that it is made of: hydrogen, carbon, oxygen, and nitrogen. Hydrogen burns in to water, Nitrogen does not burn, and carbon burns to carbon dioxide and a bit of carbon monoxide. It's much less dangerous for your health than sitting around a camp fire.

[@MM-sk8ir]

kindpotato and as we all know Carbon mono oxide is totally harmless

[@77dreimaldie0]

And what about him burning it inside a wooden cupboard?

[@AnimiHFR]

Really nice vid! Could you try something more powerful, like maybe a thermite reaction?

[@tylerprince994]

I think "more powerful" would be an understatement lol. But that would be rad to see.

[@tiagotiagot]

That would probably kill the mirror...

[@vaazig]

I was thinking something more reactive, but not to that extreme. What about magnesium?

[@Marv3Lthe1]

Or a hydrogen bomb

[@Pet_Hedgehog]

Thermite reactions are not that powerful....

[@Smart-Alec]

SlowMo Guys + Veritasium = seeing sound?

[@mike814031]

i love his videos and how he explains it in depth

[@talha8137]

is it just me or the sequel to this video is the perfect opportunity for the Slo Mo guys and him to collaborate.

[@milankarakas3005]

Make it loud. Use two wooden plates and slap it together - much louder than hands. Use ear protective gear.

[@nicholasvarner2706]

Milan Karakaš that doesn’t change the speed of sound, just the amplitude of the shockwave

[@milankarakas3005]

@@nicholasvarner2706 But, what I said? Make it loud, not fast. Okay? I am not talking about breaking sound barrier, but rather making Schlieren image of the shock wave which should be loud enough to be visible.

[@diretimes4390]

@@milankarakas3005 wot, sound travels at a constant speed through a medium, why would louder sound make it more visible, when the problem is that he cant catch the sound waves with the framerate he has.

[@MrShadowRabbit]

"anurag namdeo" mentioned using more than 2 color filters, and i must say that sounds pretty cool. Can you use other types of filters, like Polarized filters; UV Filters and Infrared filters? With the Infrared filters i think you might need something like an old DSLR camera with its infrared filter removed?

[@cavalrycome]

I think a polarizer might be interesting for this.

[@fatnose0]

fun fact, you can also read actual books while in a plane.

[@VoxelMusic]

Fun fact, not all planes have phone chargers

[@imranq9241]

Bill gates is famous for carrying a bag of books on a plane. Of course he owns the plane so there's more space to be had...

[@fatnose0]

@Mustache Merlin how many books do you hope to go through on a plane trip?

[@illsaveus]

I love literally everything you do.

[@mauzeris0]

Awesome video! I love your choice of colors.

[@louisspencer5900]

For apples next iOS update they should use this as their backgrounds

[@VikasPatel-nl8tb]

I've head that Destin has a 111,000 fps camera!

[@isramations7565]

That's cool! And also +Piyumal Perera STFU I just reported your channel for mass advertising.

[@JoshKaufmanstuff]

What camera is he using @ 2K/Sec ?

[@saityavuz76]

Both art and science.

[@deanwalker6262]

You’re an amazing human being my friend

[@jaimeduncan6167]

This is wonderful, useful and beautiful.

[@gotenbfp]

Ooo hit up Gavin Free from Rooster teeth and the slomo guys. He said on a podcast once he'd like to work with you.

[@RodrigoMarenco]

Hey everyone, now that Derek mentioned sound, how does the high speed camera's microphone work? Seems to pick up quiet sounds and then re adjust the pitch, Derek if you're reading, that would be interesting to explain

[@RodrigoMarenco]

Max Dub are you sure? Sounds really accurate!

[@BezoLS]

iirc in one of the slowmo guys vidoes one of them told that they make the sound for the slowmo part.

[@Preturbed]

Maybe imaging the effect from audio would be possible if you made some kind of standing-wave setup in front of the mirror.

[@ambercasandra6397]

Schnozzle ywjuwqqqoopwowiwiw

[@wolfgangrueckner7151]

I love the color images!

[@patricaabraham594]

Awesome imaging!

[@TeKKeNTrue_]

Do opening a cold can

[@NetAndyCz]

Pouring cold air from one glass to another or something, that is super cool! Pun intended.

[@FALprofessional]

With the boys?

[@taramas5582]

FALprofessional Finnaly I found another one meme lover!

[@moth9646]

"Slow Mo guys"?!?!!?!!?!!?

[@infernternety]

Kill Me smarter every day most likely

[@Rodlfisher]

That would be soooo awesome!

[@johnnyyoder3508]

infernternety I met him irl

[@marserolin]

Why not try this with a whip cracking? That breaks the speed of sound

[@7tonsofsalt865]

SmarterEveryDay did it

[@TheRolemodel1337]

Suggestions: - Hairdryer - Explosives - burning stuff with a Laser/shining a bright cameraflash on a dark surface - dropping things into a tank filled with SF6 - yourself talking/breathing - a Fart - a very cold pipe standing upright with both ends openso air can fall through it - a standing pressurewave - the exhaust of a small motor 4 stroke vs 2 stroke

[@kirbymarchbarcena]

One word---amazing!

[@djfreak1996]

What about a shape change? One without the cone, just HE. They have the same effect.

[@christosioannou5311]

YOU HAVE TO DO THIS , Please find a Radiometer and let's see how the air is moving inside !!!!

[@charlesshreeve319]

Don't radiometers have a vacuum inside?

[@TheOriginalFaxon]

Those pingpong balls aren't just flammable, they can be highly explosive when condensed properly. One of my friends came up with a recipe for starting solid rocket engines, which used a mix of smokeless powder, aluminium powder, potassium chlorate, and other dopants depending on his needs for the rocket at hand. When he was done making this concoction he'd coat a tiny section of unjacketed ignition wire with it while it's dissolved in acetone, then once that dried hard again, he'd coat it in several layers of ping pong ball dissolved in acetone as well. Competition ping pong balls are actually made using 100% nitrocellulose, which is the same active component of flash paper (just tissue paper dipped in nitric acid and dried), and also a significant component of smokeless powder along with nitroglycerine. He claims that if he doesn't coat it in nitrocellulose, the starter may detonate sometimes, but it's very inconsistent, so coating it in hard nitrocellulose keeps the pressure in long enough to ensure detonation 100% of the time. his rockets were pretty fantastic performance wise so I trust his knowledge. Pretty sure this is just a common thing home made rocket enthusiasts use since i've seen videos demonstrating similar techniques here on youtube with various recpies

[@ВоронМаусы]

as an optometry student, I find this madly fascinating

[@stefanuspotgieter7]

Awesome. Here is something you can try to show how heat can expand the surface of the mirror. I am currently making a parabolic mirror for my DIY telescope. I am using a similar setup to test the surface texture and profile of my mirror. The instrument I am using is a knife edge tester, where the knife cuts the light source in half, and the returning light from the mirror is also cut in half with the same knife, precisely at its focal point. Then you can see the profile and surface of the mirror. place your finger on the mirror surface for a couple of seconds and the area will expand on a nano scale, but in the camera you will see a hill forming on the surface of the mirror due to the heat expansion of the glass.

[@desmondchurch9630]

How about some sparkalers?

[@nick-pm7ub]

this is why i am still in youtube

[@florinfilip1223]

Where can i get one of those parabolic concave mirrors?

[@Rolembeek33]

My answer comes a litle bit late ... Try to find sferical mirrors : cheaper AND better results. Look for "Edmund Optics". Edit : prices seem a lot higher than a few yeas ago ... look for second hand "Newton telescope" with aperture 150-250 mm and take out the mirror ;-)

[@Avoug]

A new era of hot knife videos!

[@pixelpatter01]

Using an old fashioned newtonian telescope look at a star on a dark night, then adjust the focus to make the star fill the eyepiece. You will see all sorts of shimmering in the light. Then have someone hold their hand in front of the telescope and you will see a sharp silhouette of the hand and you can plainly see the heat coming from hand. Even someone's breath is plainly visible. This may also work with other telescopes but it I've only tried it with an old Edmund Scientific 6". Another trick to make your imitation star is to use a shiny sphere like a Christmas tree decoration or a shiny ball bearing and shine a light at it from an angle. The light will appear as a pinpoint on the sphere. A laser would also work on the sphere. Great video, thanks.

[@KingdomOfDimensions]

A cow approximates a torus, not a sphere, but still a good point about the mirror ;) edit: I'm sure someone else already commented this, sorry.

[@adityavgoyal]

#TheSloMoGuys #Veritasium .... sir you can collab with The Slo Mo Guys .... and capture that sonic boom's image..... please collab with'em

[@mr.wanted954]

Heavy audio bass maybe..

[@mr.wanted954]

Or plasma energy

[@arpadjszabo]

This just blew my mind!

[@klave8511]

To see sound you have to strobe the led at a frequency very close to that of the sound. This will “freeze” the compressed and rarified sections of air long enough to see them. You’ll only be able to get one frequency at a time.

[@oldred9122]

Half the comments on the last video wanted to see a fart... We are still waiting Derek

[@kaouiii]

Check BuzzFeed

[@ashnabwa7d]

I am disappointed that you haven't showed a schlieren fart.

[@mukitbiswas7828]

ashnabwa7d j jb

[@kaouiii]

I think BuzzFeed has a video on that.

[@hanzazazel412]

You should film a fart. For... Scientific reasons.

[@kaouiii]

I think BuzzFeed has a video on that.

[@YellowMilk14]

5:00 beautiful!! awesome work

[@anaselfellah6243]

you need to do a co-op with destin and his camera. what a beautiful video btw