Can You Bounce A Bubble Off a Laser? 

"We're all outside an aeroplane now and it's not that cold": mathsgear.co.uk/products/its-not-that-cold-t-shirt ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-C91gKuxutTU.html The sponsor is CuriosityStream: Get a whole year for just $14.99 by going to curiositystream.com/stevemould and using the promo code stevemould at checkout.

My favorite is when someone says in a video "Don't try this at home!" but it's using multi-thousand dollar pieces of equipment. :-P

Tom Scott: "Will this burn me?" Laser expert: "yes definitely" Tom Scott: *puts his hand in front of it* Good to hear Tom Scott has at least a little of the chaotic stupid instinct

The bait with the bubbles bouncing off in the beginning can’t believe y’all lied to me.

Some people: "This is my boyfried" Other: "This is my girlfriend" Steve: "This is my laser-friend"

My initial reaction was actually laser tweezers, a physics concept where you can suspend a small sphere of a particular snell ratio using a laser, the refraction causes it to impart momentum

Tricked us at the beginning with the footage...I was waiting for the sudden revelation. Great piece of experimental science to match your more theoretical stuff, I loved the video. Continues to be one of the still most underrated content creators on RU-vid.

Tom Scott: "Will this burn me?" Laser expert: "yes definitely" Tom Scott: puts his hand in front of it A true scientist

Definitely just a fishing wire tied to the pointer which is hidden by the beam.

I love the chemistry between these two. We need more videos of them together!

"We're all outside an aeroplane now and it's not that cold"

I'm imagining a laser show through a cloud of bubbles - how absolutely awesome would that be!

“I got a 30watt laser...” Styropyro “psfffttt, hold my photons!”

*Title: "Can you bounce a bubble off a laser?"* *Me: watches first 3 seconds* *"Yep, it can. No need to watch further"*

The high power laser internal reflections in the bubbles reminded me a lot of how double/triple rainbows work. Might be worth revisiting this from that direction because you can actually see the angles at which light is able to make its way back out of the bubble. That was pretty rad.

Do not try this at home. These cheap "5mW" (actually ~50mW) laser pointers from eBay can permanently blind you when they reflect off a bubble.

I'm imagining a scenario where while you were focusing on the bubbles in the laser, the laser scorched a hole into the wall.

I need a laser friend

The way his laptop is set on the floor in the first bit brings me incredible amounts of anxiety.

people at home remember to get yourself some laser protection glasses if you are going to try this 0:54

Looks like a creatively well-lit string, or string-like materials, are held taunt between two spots and then maneuvered to create an effect.

I like how they changed the subreddit name to blackmagicflippery.

9:35 look at this still frame and tell me that isn't PEAK Dad energy.

I just stumbled upon your channel yesterday, it is incredible, it is a gem, I'm out of adjectives, I just love it. Keep it up!

Gotta say the most amazing thing was hearing the guy talking about the actual death ray he is planning to use to make a light show

So if you brought a bubble blowing kit as a spy you could easily detect all the hidden lasers Edit: Ack! I didn't actually watch the full video before commenting I thought it would work! Say goodbye to my spy days, I'd die in 20 seconds

The Sun is a deadly lazer *NoT aNyMoRe, ThErE's A bLaNkET*

In this video's title "Can You Bounce A Bubble Off a Laser?" why is the first A capital, but not the second?

Here's one thing I discovered. If I shine a very bright flashlight (in my case, a Rovyvon Aurora A3) onto a piece of aluminum foil, I would hear a faint humming sound. I tried wrapping the aluminum foil around a piece of metal, then putting it over a flame to deposit a very thin layer of soot, essentially making poor man's VantaBlack. This made the humming significantly louder. The humming would only appear with the flashlight in the low or medium brightness settings, since at full brightness the LED is lit 100% of the time, but a lower brightness levels the led is illuminated using pulse width modulation

You know, I thought about how solar sails on certain spacecraft work and thought it might be doing something like that and so I sort of disappointed myself when it didn't work haha! Great video though! 👍

6:35 "Don't try this at home". Exactly my thoughts. I have persistent floaties in my vision from unprotected laser exposure in a lab at college years ago. That was a controlled environment where the laser path was protected and controlled, but my lab partner briefly fired laser while my protective glasses were off, and the black curtain that was intended to absorb the laser was down, and I caught some specula reflections off the wall. Watching these laser beams all around the room uncontrolled makes me panic a little bit.

5:30 the reflected colors on the floor are amazing

Your so great at making videos. I love all the fun topics and explanations you provide. I'm in school for the course electromechanical technician. I share your videos all the time.

Damn, you really got me there in the beginning

I wish I had a laser friend.

before the test, my theory is that the surface is being evaporated and that would be the force to lift it back up

Next vid: Steve and his laser friend on LSD testings soap bubbles. "Whoa, look at the colours!" 😮

i sometimes work with lasers professionally at my second job and the highest i've ever encountered was 10w and it's crazy seeing ones even above that. but to be honest, when i first saw the video at the beginning i really thought it could be real

My first guess was 'maybe if the laser has just the right level of power, it could be ablating the bubble and causing just a tiny bit of thrust', in the same vane that you can use lasers to shove space debris around. Kind of disappointing that even with a stupid-powerful laser, nothing happened still. I can't help but remain curious if there _is_ a sweet spot where a bubble can be gently ablated and pushed around with a laser, but not instantly burst.

I hope you two are the best of friends. I loved your discourses, really enjoyed this video

Part of the contract is always: No air quotes around "laser" ;)

And here I am with a 150w CO2 laser I bought from china just chillin' in the other room like it's nbd. It's a 7ft water cooled glass tube.

There was a colourant in the original soap bubble that is hidden by the dark background. The colourant transfers the energy into the bubble instead of allowing the light to pass thru.

I absolutely love these kind of videos.

9:09 You know you have to explain those now, Steve :p

It's Mulder ("I Want To Believe") versus Scully in Steve's brain!

Anyone else dig the gimmick of Steve in the goggles, 9:34? Like, this could be the beginning of *Steampunk Steve* and his Science Emporium of Curiosities, Scholarship and Other Odd Observations?

Gotta love the guy in the video just standing there without any eye protection as that laser scatters into a clusterf of small laserbeams in his face

my intuition was that it could work for some reasons, if the laser was strong enough: 1. The photons of the beam could transfer an impact on the bubble if absorbed or reflected 2. The light could heat the bubble up which would cause it to go up again because of bojency 3. The laser could heat the bubbles downside up, causing it to vaporize and this vaporized water might be able to push the bubble up, also. Now to calculate how strong the laser had to be to move the bubble with its impact: P=m*V=5*10^-6Kg*0.01m/s=5*10^-8Ns The impact should be transferred in 0.01seconds P=h/l=6.626*10^-34Js/500*10^-9m=1.3*10^-27Ns If one percent of the light hitting the bubble is reflected or absorbed, transferring its full impact to the bubble, then the impact of the 0.01 seconds long photostorm should have an impact of 5*10^-6Ns 5*10^-6Ns/1.3*10^-27Ns=3.8*10^21 (Photons) These Photons would have an Energy of E=N*h*c/l=3.8*10^21*6.626*10^-34Js*3*10^8m/s/500*10^-9m=1511J So the laser would have to have a power of P=E/t=1511J/0.01s=151100W This is the power, the laser would need to push a 5*10^-6 Kg bubble with a speed of 1cm/s

You had some rather serious secondary emissions going on there.

Love this one, great duo! Thanks! Love it more now I see you as the Detectorists guys 😊

in theory, it's possible to use a laser to move transparent particles. But they need to be much smaller and lighter than a bubble of water, and they need to have a high enough refractive index (which bubbles don't have, because they contain mostly air). the way the laser bounces in the particle can create a force strong enough to move it and prevent it from escaping the laser. It's calles an "optical trap" and there are scientific papers about it.

Haha, I love that the answer to the WTF diffraction pattern thing was just a disco ball! ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-tjAZbo0jb8Q.html

PLEASE do a video about the clicking sound that lasers make, I would love to see a video from you about the photoacoustic effect! It's super fascinating and I know you would do it justice. "The photoacoustic effect or optoacoustic effect is the formation of sound waves following light absorption in a material sample. In order to obtain this effect the light intensity must vary, either periodically (modulated light) or as a single flash (pulsed light)."

Just some thin transparent fishing line. One end fixed just under the output of the laser, and the other end fixed to a wall outside of the video frame. String should be always tense, hence the strange handling of the laser.

5:30 Seeing this, I'm going to need bubble machines for my rave

If I may, You should Colab with styropyro for anything related to laser or electricity in general.

You can’t just put a “WTF” in the middle of the video and then not talk about it

Laser dude: imma use dis worlds most powerful 30W laser *angry styropyro noises*

9:47 what if you would put some food colouring in the water for your bubble, and maybe absorbs a bit more light. My hypothesis is that heating one spot will cause the pressure to increase in that specific area. Whether it will bounce off the laser or even stick to it could be found out through experimenting. Crank up the amount of different colours of food colouring as you go. Hopefully this effect will be noticeable before the bubble pops. Great video man! Nice collaboration

9:08 they almost broke the Matrix

Just as a piece of logic in the intro: “If it pops it was never going to bounce”. Not necessarily true. There is an effect with molten metal where you can briefly dip finger (obvious hazards here.... if you try and it goes wrong... it’s on you). Modest temps don’t give a protective vapour layer and burn, higher temps can work. Not all effects are linear. However, in this case, my intuition matched yours, I’m just being pedantic.

The bit with you two at the end was wonderful

Heck yeah, I met Seb at Smashing Conf. Really cool fella and had a sweet live-coding talk. I love to see two creators I enjoy collaborating. Also thanks Steve for all the fizzy brain feelings you've provided 😁

"Don't try this at home!" -- Nope, just try it at Steve's house.

my first thought of that video that was sent to you was that that guy should 100% be wearing laser safety goggles. my second thought was that maaaaybe it was a high enough power to heat up the bubble and get it to rise or something to that effect...in which case wait, he should 110% be wearing laser safety goggles! or maaaaybe the composition of the bobble and the laser wavelength interacted just right?? probably faked

My first thought was "why isn't he wearing protective goggles?"

The dude who made the original video of the bubble bouncing off the laser beam really should have been wearing eye protection and the laser beam actually swiped across his face momentarily just showing how close he gotten from becoming permanently blinded.

The WTF pattern can’t be diffraction right? Because different colours show up at the same spot.

I'll be honest, the conclusion of this video made me mad at you, Steve Mould. I came in here, honestly curious at the question in the video title, but even at the end of it, I'm no closer to an answer. If this was supposed to be a riff on how 'bad science' is done, I failed to clue into it until reading the other comments. if it wasn't, then this is a cheep (in the worst meaning of the word) way to share views between your video and Seb's. Down voted for, if nothing else, a clickbait title.

Thank you for the footage, it is so pretty!

the point he makes about the guy holding the laser in a weird way points to the idea that he had a fishing line attached to the laser and off screen.

I was skeptical but i figured that if it *did* happen it would be a phenomenon like water droplets skittering on a hotplate - the laser would vaporize a tiny bit of the bottom of the bubble, which would fire off a tiny bit of steam which would propel the bubble up and away. But on further thought A) that sure seems like it would be more likely to pop the bubble than to do the cool thing we want, and B) there's no way a soap bubble (mostly transparent) would absorb enough energy fast enough from visible light to vaporize anything without *absurd* power densities. So a "no" answer makes a ton more sense.

looks like a thread anchored to a point across the room and tied to the pointer. just keep the dot next to the anchor for the string and violla. bubble appears to bounce off laser

I think you could get it to work: with colour in the bubble (maybe from coloured soap) and a laser in a color that gets absorbed by the pigments in the bubble.

One super neat detail is how the bubbles don't have any dust in them. The beam has a slight fuzzy look when going through the air outside the bubble, but the laser beam inside the bubble is perfectly coherent.

My speculation regarding the bouncing effect toward the end is that there is a very thin colorless wire (like fishing line) connected to the laser to the wall, and it's actually the line that bounce the bubble. This is because the position that they are pointing the laser at seem to be a fixed position on the wall, which is where the wire is mounted. There are some weird glaring effect when they move it around even without hitting the bubble (around 10:33), which is the effect of laser diffracting though the transparent wire (while dust can have similar effect, it just seems a bit unnatural). By the way, I haven't watch the other video yet, and this is only my speculation.

You blew my mind more than usual with this one! 😲😲😲

Первое, что приходит в голову - нитка. Мыльный пузырь даже не касается луча, да и фокусы с ниткой часто делают. 9:09 - свет попал на шар обклеенный маленькими зеркалами ("диско шар" ) Свет конечно оказывает давление, но настолько маленькое, что в экспериментах для обнаружения давления света используют сверхлёгкие крыльчатки в колбе с вакуумом. Мыльный пузырь, для этого слишком тяжёлый.

9:03 "yeah it's just doing nothing" as a light show is dancing on the floor and the walls!! haha

I love that you don't put things like this away because they seem not logic. Most thing's we still don't know, so getting into it is not to blame even if it doesn't make sense. Knowing it's fake is education too and to proove it's fake, helps against people who will say:" did you know lasers can bounce a bubble" "I saw it". Also people will remind more, that not to trust everything only because it's a popular video... ! Great impressions and wonderfull color play. Greetings from germany

It's so funny to me how strong my instinct to look away from things that would IRL be vision hazards even though I know the brightest it can get is no brighter than the white pixels around the video (get this any time I watch a video with a welding arc visible, too)

5:37I was surprised that you didn't embark on another project even though you saw the fantastic reflections on the ground. I've always been fascinated by the surface of bubbles and those reflections on the ground could have given you a good opportunity to study them.

Steve describing learning like it's the hardest drug with the longest-tailed dragon to chase.... (I kinda love it tbh)

Do you remember that laser twezers thing? Whoever made this did research a bit. Lasers can actually be used to lift and levitate microscopical diamond spheres, and they even move towards the laser source!

I really wanna know what would happen if a hollow sphere was created with a mirror surface on the inside and you trapped a laser inside. Would it infinitely luminate inside? Make a worm/white hole? A portal to the 7th dimension? Maybe create a self contained fusion reaction?

The "WTF" video pause was probably the smaller bubble at the bottom getting hit aswell and double-scattering it

those green laser pointers usually work by frequency doubling an infrared laser beam, which is supposedly filtered, but sometimes is not, so you get a 10 mW output of 1000 nm or so laser light, which is in fact quite well absorbed by water, and is quite dangerous for the human eye.

I’m a little foolish for mentioning this (because you guys were so definitive). Being MythBuster-minded, I really wanted it to work. There is a soap bubble artist/performer that uses different recipes depending on the performance or even the humidity of the environment. This wasn’t explored at all in this video. But u guys were so definitive 😆 Well, hey. If someone could just mention below how a soap bubble’s makeup wouldn’t matter neither, I guess I’d be satisfied 🙂

Lights beams and bubbles... Sounds like the perfect way to defeat some ancient aztec body builder

Let me just say one thing. There was actually a research paper recently talking about how they can slow down light, to something like millimetres per second. They do have an affect because they can actually build up in a space using high power lasers. So I'm still not sure if it would affect a physical object, but it just might. Google it, see what those scientists can tell you about the properties they are observing about them. My best guess is that it still couldn't because the higher power of a laser slowed down, just means that it has less power(kinetic power anyway). Because like solar sails used in space, it's such a minute force already. In order to use it, you really have to "catch" a lot of it.

you CAN suspend particles of diamond within a laser beam when it's properly focused.

Everybody needs a laser friend.

For context, Ive used a 30W infrared laser, it will turn a brick into glass by melting whatever the laser hits. Now that was a smaller beam diameter and wavelength but that brick wall they blocked the beam with must have gotten super hot. Also ridiculous to see them only wearing shorts and goggles and not any furthur protective equiment.

this fella would make a good bond villain. really soft spoken.. but lasers!

2:45 I would say the lazer boils the bubble edge where it passes which creates a steam jet to bounce the bubble.

remember the dual nature of light. it can behave as both a wave and a particle. perhaps as a particle in can collide with a surface or something. an inelastic collision which results in the sound/clicky sound heard

Good to know! Our future battleships will have bubble generators to distort incoming lasers. Thank you for saving us from future alien invasions. This was pretty fun. Good work.

So what I've taken from this is that if the military develops laser weapons then I need a bubble generator for protection.

This video taught me that the visual effects lasers used for concerts are terrifyingly powerful. I have a 5.5W diode laser that I use for laser cutting and engraving and it burns through 3mm plywood in less than a second when at the focal point. Seb said he's going to do a project with a 30W laser which is up into the CO2 laser power range which are used for industrial laser cutting of thick wood and plastic.