The Light Cancelling Flashlight Experiment (Michelson Interferometer)

In this video I talk about the idea of a light cancelling flashlight. I show you how you can make a setup in which you actually gets a light that is less bright when you shine more light on it using a Michelson Interferometer setup. Learn about the idea of light cancellation using the same ideas as noise cancellation.
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DISCLAIMER: Any experiment you try is at your own risk

[@TheActionLab]

How could I not mention LIGO!

[@MammaOVlogs]

yeah what's up with that ? :)

[@WakarimasenKa]

I was just about to ask. This is the first video, Ive seen that actually has the experiment and not just a diagram.

[@onthedepth69]

Yes I also think about iy

[@ArthurEKing8472]

I was LITERALLY going to mention this... lol. You saved yourself a mildly acerbic comment, lol.

[@HeenaPatel253]

The Action Lab first

[@andreimihai3658]

My brain during exam: *information cancelling device*

[@hoteny]

I feel like this comment will go top

[@ariefdharma1458]

got a history test.... Me : Light cancellation *fursther procrastination*

[@danisahawneh5435]

Andrei Mihai lwas 6

[@kirjuschaks]

yeah man

[@100ksubscriberwithnovideos8]

😂😂😂

[@abeljohnson6]

While making this video Action lab:everybody in the house stop breathing its making the light source vibrate

[@MrPablosek]

@@HelloKittyFanMan. tf is wrong with you

[@JoseGranny]

@@HelloKittyFanMan. Laying cable

[@skillhhy8707]

@Freeway

[@serious.business]

@@HelloKittyFanMan. You're some kinda demented asshole to think women poop.

[@10Carpet]

@@serious.business i agree

[@James42_]

This is the same setup uses at LIGO that detected gravitational waves :)))

[@shlokbhakta2893]

Bach Lan oh yeah it's crazy to think we see gravity with the power of MIRROR

[@satheeshvarma.s.j.]

I was about to comment this

[@michaelblacktree]

Now I understand how LIGO can be so sensitive.

[@DanielGonzalezL]

Makes sense, since it's so sensitive to anything at all

[@Altorin]

@@f.falkwings well, it's this setup deep under ground and spread over a kilometer but yeah it's basically the same setup The trick is the bigger you make it the more sensitive it is, the one at LIGO can measure differences smaller then the width of a proton

[@nikhil8003a]

Hello Action Lab!! Whenever you post a new video, it will be around 10:00 PM in INDIA and after having dinner it gives a lot of satisfaction to watch your science experiments. Thanks a lot and LOVE FROM INDIA♥️♥️

[@SaebaRyo21]

Yeah... I just watched it around midnight... and he explains greatly also

[@josexavier5518]

Same I just finished my dinner as well😂

[@nikhil8003a]

@@AnkushKun hey I'm doing arduino water level indicator using ultrasonic signals. Can you share some resources please.

[@nikhil8003a]

Thanks for your love😆😆

[@ppskg1]

Pls subscribe to Mystic Dragon EX

[@rh001YT]

There's a type of little kiosk in stores where if you stand in/under them virtually all exterior sound vanishes. Also, sound from speakers in the kiosk did not travel outside of it.

[@pbp6741]

Fabulous demo. Surprised you didn’t mention ligo after all that work.

[@simenjorissen5357]

Read the pinned comment

[@pbp6741]

simen jorissen His pinned ligo was posted a day after I mentioned it. It simply didn’t exist at the time of my comment.

[@simenjorissen5357]

@@pbp6741 sorry my bad

[@nayankulkarni5131]

3 words for you. YOU ARE AWESOME. Thanks for giving us all of this stuff!

[@sourabhperuri1698]

This video is exactly the reason why i got to know your channel. I had this doubt for a long time and when i searched it in youtube, i got your other videos on additive mixing, subtractive mixing and those on 'if black and white are colours'. Now my doubt is finally cleared. But i can't stop following your channel as your experiments are on the next level. Thanks a lot. It is actually surprising to know that you came to this height from crushing a golf ball on hydraulic press.

[@ReesePuffSwag]

Really cool aspect to this experiment; you talked about how doing something as simple as walking on the floor can change the phase between two light sources but temperature differences actually do the same thing so if you breathed over one light source you could actually see a phase difference.

[@DanielGainesDanno115]

Love these experiments. I love learning new things that this guy teaches on science. I love that he makes it fun as well as educational.

[@panzerofthelake4460]

What I have learned: my brain don't want to.

[@ThePrufessa]

Yeah this one was hard to follow. I will have to watch it again because I'm completely lost right now.

[@defaultkid99]

N i x D a

[@FacterinoCommenterino]

Today's fact: Baked beans are actually not baked, but stewed.

[@dio66791]

@George Costarica h

[@punypete8724]

@George Costarica d

[@punypete7106]

@George Costarica p

[@familyguy2023]

@George Costarica c

[@thelockedbox2095]

WHAT?

[@Fermion.]

Could make one hell of a security system with how sensitive that setup is.

[@villentretenmerth11]

*bird sits on the roof* >>alarms blaring

[@AttilaAsztalos]

Sure, if you're trying to detect a burglary happening in your neighbor's house...

[@Fermion.]

@@AttilaAsztalos I was thinking more of a military base/nuclear plant type perimeter seismic defense system. I'm pretty sure a physicist could triangulate the exact coordinates of the slightest movements, based on variations in the interference patterns, then pass that data off to a programmer's software, which would automate the relevant security cameras to investigate, and deploy armed drones to intercept a minor threat, or send alerts human security personnel, if more lethal countermeasures are necessary to neutralize a major threat. This would be way too sensitive for normal civilian use. Every step in the home, speaker bass drop, kitchen appliance, car that passes by, etc., would set off a false positive.

[@AttilaAsztalos]

@@Fermion.Wow, this has gotta be a personal best at thread necromancy... ;) Anyway, LIGO detects gravitational waves with the same basic setup and it's just HILARIOUS to read up on what they need to go through to eliminate vibrations caused by, well, everything else...

[@Fermion.]

@@AttilaAsztalos Ahh, you're right about LIGO. I totally forgot about that. But, the thing about that is that it would be super expensive, with the miles and miles of vacuum-sealed tunnels, and several teams of world class scientists. And yeah, I made several edits after a few drinks lol.

[@y33t23]

"Everybody please don't take a shit now it disturbs my not-light."

[@AliYassinToma]

A flashlight that instead of lighting makes it dark ... Sooo it should be called unflashlight??? Or flashdark ... ??

[@bairfamilyfarm1336]

Is a "flashlight" really an "unflashdark"?

[@AliYassinToma]

@@bairfamilyfarm1336 probably.. idk

[@prism2451]

There is no good word for what we call Flash light or torch. It can be called LED

[@AliYassinToma]

@@prism2451 thats why i like arabic .. there is way more vocabulary to precisely describe almost everything :/

[@pleb6261]

We already have an unflashlight or flashdark We call that opaque object in front of light source (I guess shadow is dark light, eh)

[@alexanderpoltzer8885]

I knew about how noise cancelation works with offsetting sound waves by 180 degrees. But I wondered if light cancelation was possible. Whe I thought about it I realized how hard it would be but am very happy now to see it explained in a video. Thank you!

[@parasar1980]

Love from INDIA The Action Lab!!! ❤️❤️❤️

[@barkatrathod9301]

Subscribed your channel

[@bran1039]

i can tell by your name btw cool name

[@parasar1980]

@@bran1039 THANKS! btw that's my father's name...mine is Rishabh Raj...aka... RR

[@parasar1980]

@@barkatrathod9301 hey! Thanks!

[@bran1039]

@Dhananjay Parasar oo cooler name

[@dellhpfree]

You are an amazing teacher. Keep up the great work. Thank you 🙏.

[@vinayaka9438]

Any odd multiple of half wavelength actually.. Since moving by an even multiple will lead to constructive interference..

[@supernovactc3283]

(2n+1) * wavelength n€ Z

[@intunemediaresources5938]

I love your channel and you just seem like a genuinely cool dude! Much love and support man!

[@ryantwombly720]

Thank you soooo much. This is a wonderful visualization of concepts that come up so frequently in science and science explanation. Truly a service to education.

[@christianterrill3503]

Blowing my mind again!

[@Speeder84XL]

Really cool! Intresting that you can make a device that sensitive to vibrations, but yet so simple.

[@marcularis]

Man, you're reading my thoughts!😂 I was thinking of the exact same thing some months ago! Thank you for existing! :)

[@Bunny-zq9su]

Which would absorb more heat when left in the sun: a computer screen displaying black or a computer screen displaying white? Also, do different colors display at different temperatures on computers? (Not left in the sun, but just on its own indoors.) Does blue display any warmer than red for example?

[@AlexDicy]

@Musketeer Oliver ...............

[@TankYou90]

interesting

[@robstamm60]

Thats a really interesting question. If we use an old phone with an LCD and no way to turn down the background illumination of the screen then a black screen will definitely heat up more because the lcd crystals absorb nearly all of the sunlight+backlight. If we use a modern OLED display it gets a bit more difficult to answer this question but we can generally say that a completely black oled screen doesn't use ANY current so the device will not heat up from energy losses from the OLEDS and I can't think of any reason that an oled will absorb less sunlight if it is turned on (especially in the IR-range where the OLED doesn't emit light anyway)

[@aidanwoodward3975]

It's a close one.

[@Justin-lc8wk]

@@redtoxic8701 on lcd there is one light source with layers that make color so brightness on lcd is heat but on oleds? im not sure.

[@gamingmonkey0549]

We don't need a flash-dark in 2021, please continue your work, we don't need it, but we want it

[@Dejoblue]

The coolest thing about this was how sensitive it was. That was crazy! :)

[@NC-oy8hq]

Just watched this a second time ... the action lab is awesome. Thanks for helping me and my kid learn.

[@poopsiexpants]

Disappointed. Still waiting for the flash-shadow like on the thumbnail. 😂

[@shakilahmed6870]

yes

[@sureshkumarthottempudi8298]

I too

[@cryptfire3158]

i know heh. Like.. couldn't he just tell us he couldn't do it, rather then making us watch the whole video?

[@prism2451]

@@cryptfire3158 all of his thumbnails are like that. I still like him

[@oerlikon20mm29]

you cant do that lol, thats like making a negative sound wave... how the hell does that work. would be hella cool tho, i would love to see it happen

[@b12virus63]

ohh! now i understand that's the setup they used for gravitational wave detector ! that much of accuracy is awesome !!!

[@Sorrywerefull]

You are really funny in a geeky kind of way. I love it when you try doing things that you know won't work for us. Not talking about this video specifically.

[@fullglorywr8322]

Wow. This channel has put science into so many of my twin brother and my comic characters that we make. There’s a creature that has light cancelling eyes. Looks like it’s eye structure will have to be completely different than what I originally wanted it to look. One on the front which emits a light cancelling glow, 2 on the sides and on on the back of the head to receive light. Which goes into a bioliogical beam splitter type organ.

[@chillaxter13]

Love the idea of this! These are the experiments I watch this channel for. We do need to get you a nice, large white board though...

[@saharshbehal8766]

It always a gr8 experience on getting that free knowledge from you sir thanks for all the effort

[@swr1240]

So awesome. You think of some fascinating stuff to experiment with!

[@Krfstniper]

As always the explanation was super clear! Thanks a lot :)

[@aeroant]

So well explained! one of your best videos! I think I know how gravity waves were measured now :D

[@jaikumar848]

Hi action lab! Could you please make more videos on quantum mechanics stuffs...like entangled photons,eraser experiment etc !! Btw great video as always

[@Monoceros_323]

Wouldn’t be a flashlight then now would it, it would be a flashdark. 🤣😂😂

[@fanmaxis3004]

Nyuk nyuk nyuk

[@user-we6lw3ff8m]

One of the best things i have seen on KZbin . Keep up this good work man, congratulations.

[@obama_is_hot6]

8:30 honestly that was the most intresting and cool part. id love a whole vid on just that alone

[@xNecromancerxxx]

YES!!! another ActionLab video!! I love it! 😊

[@Waterdust2000]

This channel doesn't disappoint, I was hoping to see a total cancellation here of the light. What if you did this in a anti-vibration & sound dampening room? an maybe throw in the vanta black as necessary for light control.

[@koreboredom4302]

People on the street: "hey where are my sunglasses?" Me:

[@fanmaxis3004]

ZZ Top:

[@AwesomeTheAsim]

Oh my god! That's my idea and I have been trying to make it possible. But it looks like it is impossible unless you put a black hole inside it because black hole can suck light. I am so glad you did this video

[@waynefarrellvoiceovers]

I really enjoyed that. Beautifully explained.

[@planeteuropa]

Hi Action Lab... I wonder if there is any beam splitter " equivalent " for heat waves ? - to cancel out waves from two heat sources. Your thoughts on this?

[@cernejr]

I really enjoyed this video. Thank you!

[@stickmandaninacan]

this is basically a mini version of LIGO, they use the same mechanic to measure the tiny mirror movements to detect the gravitational waves

[@samsayshecc618]

_Those markers screech through my heart every time..._

[@edwinpj7637]

Same here. I became extremely uncomfortable. Maybe both of us have pieces of Cat DNAs.

[@filiplaskovski9993]

Same bro

[@lukenoble2539]

*Me in the lab doing this experiment* My friend: *lives* The lights: 🤯 Me: who allowed you to breathe

[@Toastmaster_5000]

Pretty cool experiment. I wonder what would happen to some of the wave patterns if you tried using a polarizing filter.

[@nikdoesstuff9338]

Me: just how sensitive are you? Soft boy: have you ever heard of a Michelson interferometer

[@itscloveryt4691]

His experiments : Light Cancelation My Experiments: Ho much lego could I put up without making it fall?

[@harish5657]

great work sir.

[@Demnus]

By the way, if you record amount of oscillation of the interference pattern, would it produce sound? Might it be the way to make supersensitive microphone?

[@davidwuhrer6704]

Yes. It is called a laser microphone, and it is used to listen in on people's conversations by the vibrations of their windows.

[@danigaming4139]

Very amazing,ilove what you were doing i learned something new bout this video Keep it up bru....👍👍👍👍👍👍👍👍👍👍👍

[@cattybound2011]

Hey this is a great video! Better than usual! You're a lot smarter than you sound! 😁😁😁😂❤️ J/k

[@GrowingAnswers]

I think the vibration sensitivity shows a good demonstration of how high power telescopes need to be vibration isolated. People who have never used a telescope wouldn’t understand that. This device shows a good representation of that. The difference though is that a telescope usually takes longer to settle out after the vibration starts.

[@24_hanif5]

I will tell my science teacher this to escape not doing homework

[@fasiuddiin]

This guy is insanely amazing

[@hannalot_]

“Hey guys, today we’re going to be...” Every time

[@JeremyMcMahan]

Amazing video! Learning is so fun.

[@aaardvaaark]

Awesome video, as always.

[@OnTheRiver66]

Another great video! Years ago I saw a picture in an encyclopedia of search lights arranged in a large circle. They were aimed at one point in the sky overhead. The beams were bright until they met at the focal point and beyond that they were not nearly as bright. The explanation was that the light beams interfered with each other. I’ve tried to duplicate that with flashlights and lasers in my house with no success. Have you seen anything like that picture in the encyclopedia?

[@mikewest3108]

That's a very cool experiment.

[@raghavendramirji9510]

I have been wondering about these since childhood 😁

[@pog4302]

Now I know where Vsauce got that thumbnail for his, 'What is the speed of dark?' video!

[@Mr.Unacceptable]

Where did you get that light table Michelson Interferometer? I'm working on making a light table from a long coffee table. That would work really well as an insert component.

[@ksp-crafter5907]

Please try the "Delayed Choice Quantum Eraser" experiment - it would be so cool because it is a kind of time travel device (for subatomic particles at least)! @The Action Lab

[@balajisriram6363]

You are an amazing teacher

[@igorgiuseppe1862]

you also build an motion detector with this experiments... or an vibration, quite cool!

[@knownbarkert6153]

Your literally the science teacher of the *world*

[@hackandtech24]

i didnt think this video would be this cool. nice

[@SuperGattan]

Excellent explanation..... so in theory can we make a NAND gate or a Boolean function from this phenomenon?

[@MaestroLives]

Great video dude

[@DXPAlien]

u explained it well sir

[@spenceranonodium711]

Loved the video, had a different idea when I read the title. Not disappointed though lol

[@franzliszt1127]

This video is more useful than school

[@PersonausdemAll]

😂All is more useful than shool

[@RomanoPRODUCTION]

09:12 TheActionLab: this is me, making baby TheActionLab #5 (I am not sponsored by Chanel perfume #5)

[@intendedviewer922]

Another , excellent , video

[@harishs7384]

Tq fr the video, action lab love❤️

[@Techvalte]

Nice video 😀✊

[@StefanReich]

Such a good channel

[@jandrei32]

I met James today at lagoon, big surprise :D

[@onbedoeldekut1515]

How about if you used a filter instead of the mirrors? I'm thinking of something like lenticular plastic or an opaque diffuser. What I think you're wanting to do is to homogenise the wavelengths of the light sources. Lenticular plastic will diffuse the light along the bars, but an opaque diffuser would cause the light to act more erratically.

[@xPulsarr1]

We lost a legend “grant Thompson” in these past few days,we are really sad about it so we don’t want to lose you, please be careful with your experiments!

[@futuregamers7341]

Im so sorry for your loss

[@Slayermunch]

I love your channel a lot!! I am liking all the videos. 😋🙂 you’re awesome 😎 please make a video on how to see photons in light. Or atoms of anything .

[@assasinatorx325]

I never understood how to cancel light but you gave me an important information i was thinking about an extremely sensitive ground vibration sensor for my snake robot and your laser fringe vibration gave an idea to make one

[@DANGJOS]

@ The Action Lab Hey man, nice video again! Just want to correct two things. At 1:35, the trough of the wave doesn't represent low electric field, it represents electric field in the opposite direction to the peak. The peak is upward electric field, and the trough is downward electric field vector. Second is at 7:39. It isn't true that there would be no interference pattern if the mirrors were exactly the same distance from each other. There would still be an interference pattern, but the fringes shift whenever a mirror is moved. The reason is that the laser is not just a single ray of light. The laser light always comes out at slightly different angles, and hence should reflect off slightly different points on the mirror. The entire path of different portions of the light is different, and that's why some places interfere constructively, and other places destructively. So regardless of the mirror distances, there will be an interference pattern. Anyway, great and interesting video! I remember when I took physics III in college, we did the Michelson interferometer, and I took one of the tuning forks in the room and struck it. The When I brought the ringing tuning fork near the interferometer, it actually blurred out the interference pattern. My physics professor and I had two completely different explanations for this. I thought it was because the pressure waves from the sound were moving the mirrors back and forth 440 times per second (I think that was the frequency), and that's why the pattern blurred. He thought the pressure waves were changing the index of refraction in the air to make the light travel at different speeds through the air, thus making it go in slightly different directions.

[@jimmy-jamesolivier-mccutch2126]

i love this channel thx

[@sonicruled]

Wouldn't your talking also affect the dark bands? Or did you just record the sound at a different time?

[@josebarria3233]

Actually even if the mirrors are equidistant from the splitter, there will be an interference pattern. The reason lies on the fact that the image projected are made of multiple "rays" and every ray travels a slightly different amount of distance (called the optical path) and arrive at the screen with different phases anyways. If your projected image is an infinitesimal dot, then there will not be any interfere.

[@karma_yogi_42]

This was a good episode

[@BariumBlue]

I don't suppose it'd be possible to have a material that reduces in albedo when it's excited by some light source? My other guess was some polarized light and filter shenanigans, though I can't figure out how that could work.

[@Snakyy1]

Can you try to have 2 “actual” light sources (2 different lasers) because light goes through and back from the same place. It may? effect it? I don’t know if it will but can you try it?

[@prabakarankarthikeyan2084]

Thanks to give some ideas bcoz long time I working on this thing... Could you try with actual flash light which have white beam... So actually i need to know....

[@ccfmfg]

Mr.Action lab,Please do a video on canceling magnetism.North,south and or both.Thank You.