Why you'll never see a right angle on a stealth aircraft - corner cube reflectors

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My collaboration with Geoff is here:
• Cube Reflectors on the...
Retroreflectors send light back in the direction it came from. They are useful in lots of way. But accidental retro reflectors need to be avoided sometimes.
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[@JackLe1127]

Normal Scientist: Meticulously proves the geometry of the phenomenon. Steve: "Just look at it"

[@NoobLord98]

To be fair, the amount of times a proof in my lectures comes down to "well, obviously that's true, just look at it" is astoundingly high.

[@lindenbasket]

My favourite bit is when there's a hazy leap-of-faith step in some proof and the lecturer fixes everything by writing "clearly, ..."

[@lindenbasket]

@@TheRybka30 hahaha stop it. I never once did those "trivial" cases that were left for exercises, not bragging though: I barely passed.

[@InXLsisDeo]

To be fair there is nothing more to it than the law of reflexion that he recalled at 0:45. You just apply it in 3D along the two axes of the plane of reflexion instead of in 2D like in the drawing.

[@spacewombat4569]

^"Just look at it?" Flat Earthers: "Am I a joke to you?

[@geronimo5537]

lure me in with fancy stealth topics and talk about cube corners the whole time. cheeky...

[@scunthorpe5513]

*sneek 100*

[@americanpanzer4163]

I feel clickbaited but not disappointed

[@jujuyee2534]

i was clickbaited and i'm not happy

[@Dacronhai]

JuJu Yee Technically it isn't clickbait.

[@squirrelwholikeshentaiiam6798]

He said the truth... "you'll never see ..."

[@ElectroBOOM]

Smooth... I like how smoothly you feed science... I'M YOUR NUMBER ONE FAN!

[@SteveMould]

Too kind!

[@BluedoesMusic]

oh hey its electroboom.

[@IdontKnow-nm8bz]

Oh hey it's that guy who explodes every two seconds

[@harshvithlani9399]

Yooo, Electroboom

[@muslimcrusader3085]

It's surprising such a big KZbinr has so little likes

[@belathor1578]

Steve: “Is the moon sneaking up on us?” Moon: *slowly backs up at 4cm per year*

[@ZNotFound]

It's making us lower our guard. We think it slowly backs up but in fact it's waiting for the right opportunity to get the jump on us.

[@fatherofdragons5477]

@@ZNotFound it uses a decoy to make us think we are safe.

[@sauliusltcool6902]

where did you copy this? there is already this comment in this comment section? coincidence? I think not.

[@tihspidtherekciltilc5469]

Cool, that means we're getting longer breaks between PMS.

[@Z3R0F1V3]

@@sauliusltcool6902 who cares

[@Gamesaucer]

Ah, "Proof By Look There You Go It's Doing It" is definitely one of my favourites. The only thing that can beat it is "Proof By Pouring Things Out Of Beakers".

[@tolep]

The best proof begins like "As you can see..."

[@Moses_VII]

Mathematical proof is my favourite

[@okuno54]

Steve: Is the moon sneaking up on us? Moon: *backs away slowly*

[@nova_vista]

He hasn't been the same ever since the isolation room ... hold up

[@tatotiteta]

the moon is cheese created by italians to win WW2

[@MostlyPennyCat]

@@perfumedmanatee6235 Trying. AND FAILING! Apollo landed that RFID tag up there.

[@rileycoyote4924]

He missed a great opportunity for a Majora's mask reference

[@TremixNeo]

1 inch a year....1 inch a year

[@tryAGAIN87]

"A proof by 'Look! There ya go!'" That is the best quote I've heard from you yet Steve :D

[@darengauthier522]

I found one that I appreciate, from a different video of his.. But this one maybe comes second or third.. for me

[@darengauthier522]

I find similar humor but more of it, from the you suck at cooking channel

[@macronencer]

I can actually remember when I first noticed the 90-degree mirror effect. When I was a young child, I was in an ice cream shop, and they had a corner mirror by our table. I ended up shuffling from side to side, fascinated that I couldn't stop the corner going right down the middle of my reflected face. I worked out what was happening in the end, but it took me a while :)

[@circuit10]

That happened to me a few weeks ago

[@barnabydixon]

This was really informative Steve! Just by chance, I've been playing around with the anti-paparazzi fabric to use in my puppetry. Cool way of making the puppet really visible while I remain in the shadows :D

[@SteveMould]

Oh nice! Look forward to seeing it.

[@thepip3599]

Oh my gosh I’m a huge fan!

[@Preposter]

I didn't expect you here. I shouldn't be surprised though

[@tybronx2446]

Ohmygod it's Barnaby!

[@Moses_VII]

@@tybronx2446 The puppets on his channel look so disgusting

[@martinperry1843]

"90 degrees or 1/4 tau radians" perfection

[@csheadtrip]

Trying to make Tau happen. Is it going to happen?

[@halimceria]

@@reedh3950 bah

[@benjaminwilkin2960]

I think pi is just as good

[@bedjentlewithme]

Bothers me way more than it should π/2 is superior to quarter Tau

[@RichardDuncan]

Yep, 1/4 tau is always the right angle to take. Unless you're of the pi-suasion.

[@GasMaskManifesto]

I’m a land surveyor, we use reflectors like this for most of our work in order to take measurements within 1/1000th of a foot/sub millimeter accuracy over very long distances. You can look into the prism and the pupil of your dominant eye will always be at the center of it.

[@ThePoxun]

Fun Fact. In classic Doctor Who they sometimes used reflection to do alien glow effects without needing any post production. One of the best examples of them doing this is in the Silvester McCoy episode Silver Nemesis. Some shiny fabric and a guy with a bright light behind the camera is really cheap ;) PS: I love it when all my favourite content creators collaborate unexpectedly :)

[@lifeunderthemic]

Same propaganda machine you know-nothing loser in life. derp

[@dbadilotti]

1/4 Tau Radians I'm surprised Matt Parker didn't appear just to frown at Steve in disappointment. Go Steve!

[@howardbaxter2514]

Long live Pi!

[@Peter_1986]

A quarter-Tau radians. That's the spirit, Steve!

[@entropy3956]

01:00 Pi is much superior.

[@NonFatMead]

Nope. Nope nope nope. Disgusting language. Wash your mouth out, Steve!

[@vwertix1662]

@@Peter_1986 i prefer cake

[@matthewstuckenbruck5834]

Can't we just stick to Pau? Pau = 1.5Pi = 0.75Tau

[@itsevilbert]

@@matthewstuckenbruck5834 It would have been better if you had added a reference to what Pau actually is xkcd.com/1292/ - "A compromise solution to the Pi/Tau Dispute." - exactly half way between the Pi and Tau is Pau.

[@bryanandhallie]

A proof by "Look, there you go... it's doing it" Best proof ever

[@howardbaxter2514]

So much better than all the convoluted proofs professors give.

[@admiralmudkip9836]

As my geometry teacher would always say, "What if it's not drawn to scale?"

[@Stagprince1000]

Treeko beats mudkip

[@unamuseddeathgod5128]

@@Stagprince1000 you may be correct based on type advantage, but you are wrong on almost every other level

[@alphax1049]

SAT: Am I a joke to you?

[@AdrianOkay]

My crowbar beats treeko

[@sploog]

@@AdrianOkay my nuclear missile is sufficient for beating all the treekos

[@firewingsworld146]

Title: whh you dont see eny right angles on a stealth bomber. Video: *BIKE REFLECTORS!*

[@braden1edwards]

Perfect companion video to Destin’s Smarter Every Day video on the topic! You all should have a collaboration

[@tsg_frank5829]

This is actually a rather curious topic that I haven't often thought about. Also, appreciate that you show directly what you're talking about when explaining it lol

[@MrSteeleFPV]

Solid video Steve. Just found your Channel. Can’t wait to dig deeper into you videos. Cheers !

[@SteveMould]

Hey thanks! Love your drone work. Watching your video feels like flying!

[@arjunsadananda9012]

Woah! This is so cool! :P

[@mjames7674]

*lololol* Creeping moon. I love this channel. I had just barely found it a few days ago and subbed immediately.

[@HebaruSan]

Are you known as Steve Mold in the USA?

[@ewthmatth]

Nice humour mate. I mean, nice humor bro.

[@alexander1055]

@@ewthmatth You meant _Houmour_ I'm certain.

[@Hjjja]

NICE

[@estoylaroca]

The combination of 1:25, almost clickbait video, and easy to understand explanation, is an easy subscribe for me. You are KZbin Genius.

[@SilverSergeant]

Having been a missile maintenance technician on the ADM20C Quail, I thank you for using that outstanding example of reflective surfaces!!!!!

[@kellerdeantonio352]

Absolute madlad, 9 minutes and 13 seconds. so close to 10.

[@bigboijuice6523]

Keller DeAntonio *9:14

[@juniyahh]

Keller DeAntonio sponsored ?

[@MashiroShiina]

ya but it's sponsored by NordVPN so all good

[@me.unpredictable280]

@@MashiroShiina lol what are you doing here?

[@michalnemecek3575]

1:23 Proof by "Look, there you go!" -Steve Mould, 2019

[@gyrocompa]

That is what I have tried to explain to my students for ages. Not only is your video very clear and illustrative but it is also quite exhaustive. Thank you for the good work !!

[@Mikeztarp]

Fantastic video! You pack so much into just a few minutes, but it's super clear.

[@jennitro]

I was just wondering about how that reflective fabric worked the other day. Thanks!

[@dimaryk11]

Amazing and easy to understand content. Keep it up, thank you

[@MedlifeCrisis]

This was awesome. I learn more per minute from your videos than any other channel. I mean, it's knowledge I'll never need. But I like it.

[@marcellocalabresi6018]

Thanks for this video! I had never thought about the mirror properties of the cube. I will make my personal experiments about it! thanks for the explanation too, you are very clear and you have a nice voice.

[@indyjons321]

Yes... it is in fact 2am.... and yes, I do plan on watching "just one more video"

[@MikheilGhvinianidze]

I want to cover my car with those tiny bids. That would show to those pesky speed cams, and high beamers.

[@calvinnyala9580]

You may accidentally ward off bird with that bids. Birds don't fancy bright light

[@jjc5475]

love the practical effects in this video. just subbed from a list on a website, glad yt recommended it.

[@royzevisionneur2045]

I have always been wondering why that kind of shape was fitted stealth aircrafts but too lazy to search the info... Thank you for that really interesting and well explained video, I have never learnt so many things in 9 minutes, that's some quality work right here!

[@SchutzmarkeGMBH]

I think Steve might be a werewolf. His boggart is the moon.

[@lycanrocvevo147]

Ha

[@crazytosh1]

Veritasium, Steve Mould and Smarter Every Day all mentioned Total Internal Reflection within a week!

[@wynterblackburn9102]

Once is normal, twice is a coincidence, and three times is a pattern.

[@jaypaans3471]

I smell a conspiracy theory..

[@MrEDMeaner]

3, triangle, illuminati confirmed?

[@magonus195]

Probably something that came up on Google metrics, so they (each independently) decided to make a video for the searches results.

[@lifeunderthemic]

Same propaganda machine.

[@mirek4357]

What a lovely chap, great commentary and I am happy youtube recommended me your video, congrats on the sponsor as well have a great day

[@u8myshorts]

This video answered a large amount of questions I've had since the pandemic started. I looked at those street signs ... Awesome content!

[@agdtkry]

You should've used the moon from Majora's Mask for 3:18

[@The.Talent]

The third KZbinr in the space of a week that has mentioned “total internal reflection”. First Smarter Every Day, then Veritasium, now Steve. I wonder if there is some sort of collaboration coming up.

[@AndRewUK24]

Thank you Geoff Marshall for alerting me to this interesting KZbin channel. I love reading about science and this channel fits the bill perfectly. Thanks!

[@aDifferentJT]

I saw the two notifications next to each other and got very excited, not a team up I’d have expected but I love it, you should do more about the cool physics and engineering stuff on the rail network (both Network Rail and TFL)

[@typha]

3:14 ♫ Mister Mould, you did it right ♫ ♫ But soon comes mister night ♫ ♫ creepin' over ♫ ♫ Now his hand is on your shoulder ♫ Never mind

[@bluetoothenjoyer]

I remember you this, I remember you this way

[@KokoroKatsura]

a n i m e n i m e

[@althaz]

"...quarter tau radians" - well you've got my thumbs up :).

[@nopnop6274]

This was Excellent!! Very well explained, intuitive and Relatable. Thank you. The Best explanation video about this so far.

[@MegaNardman]

Whoa, I just watched an old SmarterEveryDay video on this subject yesterday...it was 3 years old, so I strongly doubt it had anything to do with this video, but I'm now a little worried that the KZbin algorithm is some sort of logical corner-cube reflector. :(

[@itskdog]

I have this theory that KZbin might recommend older videos on a topic when a new video is being uploaded as private by someone you subscribe to, as it likely indicates the video is going public soon.

[@SangheiliSpecOp]

KZbin is creeping up on you...... It's like RIGHT behind you bro

[@danielbrandstetter8713]

Did you and Destin plan to both talk about reflection on the same day?

[@dpatts]

And Derek from Veritasium! kzbin.info/www/bejne/fZTHc2iYe9ycpZY He coats his skin in a hydrophobic surface and it shimmers in water due to total internal reflection

[@smoove_]

Holy shit 6 minutes in and he finally mentions an aircraft

[@ifalone]

during those 6 minutes he was explaining why the aircraft have no right angles and exampling how it works

[@jasoncrobar724]

I suspect that the corner cube refection of sound mentioned around 5:50 is the same reason why home theatre systems recommend putting the subwoofer in the corner of the room nearest the screen & front speakers. The bass is directed toward the floor or wall, and reflected out into the room. The imperfect geometry is in effect here as well, so it spreads. Any corner cube reflection path you can draw from your ear to that corner & back, will likely intersect the subwoofer driver, so any sound the driver produces will follow both of those paths to your ear.

[@ZSchrink]

Fantastic explanation. I love your delivery of information!

[@josephjackson1956]

1:21 how I wish I can show proofs in math class

[@herenow6953]

Came here from Geoff Marshalls - very interesting and subscribed 👍

[@bazza945]

In this illuminating video, you covered the subject from all angles. I will reflected on what I have learned, thank you.

[@LeonardoBPG]

It feels like I'm watching "Toby" from "The Office". Can't unsee it! I love your channel, excellent videos!

[@sumdumbmick]

proof by doing it is my favorite. it's also arguably the only proof that actually is proof, and thus the entire reason that experiment is important to science.

[@y.z.6517]

It's verification, not proof. Verification should only be done for simple, fundamental phenomenons, or to *check* your prooves. It's possible that it's true for 1 million different angles, but false for a special angle that is practically impossible to get in experiment. It's also possible that small inaccuracy makes it appear true. Once the setting changes slightly, small inaccuracy becomes unacceptable error.

[@y.z.6517]

The rationale is that it's better to verify 1 phenomenon for 1 million times, than 1 million phenomenons for once each.

[@y.z.6517]

This is not that fundamental. The reason a proof is not shown in video is that it's not as fun or intuitive. That doesn't substitute scientic/engineering work.

[@kikivoorburg]

Science and Railway KZbin meeting up?! Win-win!!

[@mcantisnake]

Thanks for explaining al those subjects, keep up the good work !

[@kjrunia]

Lovely video as always! I'm always amazed at the effort you put into your video's. Big fan. Also, quite hilarious that in my preparations for writing an article on the upcoming 50th anniversary of the Apollo 11 mission, I have been reading up on corner cube reflectors (as one of the experiments of that mission). Imagine my delighted surprise :)

[@thomaskaldahl196]

1:00 "Quarter Tau Radians" just earned my subscription

[@taka4059]

The only reason I decided to watch the video right away after seeing the comments.

[@WhatColourIsYourBugatti_]

Steve: quarter tau radians *pi left the group chat*

[@ewthmatth]

Should be top comment

[@WhatColourIsYourBugatti_]

Matthew H thank you

[@cjthomp2005]

Pi is overrated anyways

[@djrbaker1]

3:10 I love how he can instantly switch to that deranged look

[@thomashughes4859]

Another banner video, Steve! Thanks for doing what you do. I learn a lot. Question, can you do a video on how the metronome, viz, double-weighted pendulums work, and why?

[@TommyCallaway]

I was scared for your camera sensor during this video.

[@signalworks]

Laser pointers legal in America and most of the world have a maximum output of less than 5 miliwatts, as in not enough to cause damage to human eyes. They are not powerful enough to damage the vast majority of CMOS sensors used in cameras.

[@dreggory82]

@@signalworks yes, that is the law. But I purchased a 2 watt laser that was advertised as less that 5mW. Not everyone has an optical power meter either.

[@signalworks]

Yup, Styropyro did a bunch of videos with them. However do you really think that's what he's using? A laser that sets things on fire and blinds faster than one can blink?

[@tylergarza8695]

@@signalworks right, i mean just WATCH the first part where he has it pointed at his hand for almost a minute straight.

[@jakegarrett8109]

If you can see the beam even with some fog, it’s probably over 5mW... I have a handheld laser, it’s well over 1w, probably about 1200-1700mW (you can set a T-shirt on fire in a couple seconds, or burn through plastic quickly etc. I mostly use it for killing spiders from a safe distance, those things creep me out!) Those green lasers he used are probably on the scale of 200mW, that was one intense 5mW if I’ve ever seen one! You can have or sell any laser you want (how else are you going to cut sheet metal or engrave wood? normal CNC? Boring!), you just can’t call it a “pointer”, because it really wouldn’t be that safe to point with...

[@lancelot_dev]

The real question is why i got this in my recommend

[@gru4079]

Why not?

[@swugger]

STFU

[@gagangill5512]

I had my Nord VPN on when i got this recommendation

[@lifeunderthemic]

Paid for propaganda as usual from this channel.

[@lifeunderthemic]

@i_gRape_Babies x lol not much to say ya fanboy, know-nothing, jerkoff loser in life✊✊

[@nonothebot]

@05:32 : OKAYYYYY ! ! ! Finally I understand those strange things on boats ! Thank you ! ! !

[@johnburnett4035]

Terrific video, awesome content structure and great segway :) Cheers m8

[@3_pancakes767]

4:33 How to make something real look photoshopped.

[@joshc6699]

Odd.. Smarter Every Day just did a video on total internal reflection as well

[@JakeBiddlecome]

I hadn't seen that one yet. Glad Steve shared some knowledge on this as well!

[@moooseman3]

And now Veritasium also pointed out an example of total internal reflection in today's video!

[@poutineausyropderable7108]

This isn't total internal reflection but ok.

[@bara9880]

@@poutineausyropderable7108 it is I've taken an exam yesterday about it

[@edwardabel3716]

I love your digressions Please keep them in your videos

[@alexander-kirk]

I love your style Mr. Mould. Proof by look it's doing it!!

[@youngpistol6117]

"Why you'll never see a right angle on a stealth fighter" *showing rectangular panels on thumbnail*

[@ArmchairChemist]

You're looking at it from an angle, they're look more shaped like diamonds

[@luckyblockyoshi]

@@ArmchairChemist it’s... literally a corner cube reflector

[@PhilBoswell]

¼τ radians…I see what you did there ;-)

[@AJD...]

Mould, you did it again you brilliant bastard. Another terrific video

[@6shadowflame]

Please, sir, digress at your leisure. I really love the way you link the concept to many other real world situations.

[@lochadyloo1294]

"a quarter Tau radians" much appreciated

[@xtahc2207]

Title: “Why you’ll never see a right angle on a stealth aircraft” Me: *looks at thumbnail and sees a right angle on the window*

[@ArmchairChemist]

That's not a window, plus you're looking at it from a skewed angle, its more like a diamond

[@noapoleon_]

*A brilliant answer to a question I didn't have! Love it :)*

[@p1ll]

My new favourite channel. Tell me I'm not correct! Thank you steve

[@royrogers3133]

“Eughnnnnmmmnn, look there you go, it’s doing it”

[@Z4G.]

Teacher: Alright, explain your answer. Me: 1:25

[@strxwberry4766]

Very educational video mate Keep up the good work

[@azharbobat2818]

Love the always simple explanations 👍

[@ChikaNeca]

This aircraft got shot down by crazy Serbs in 1999.

[@kosovoimetohijasrbija1483]

We shot down B2 too, only Americans hide their shame and failure!

[@machy8515]

SRBENDA Srpska so ur fam did it

[@jacksoncude9824]

SRBENDA Srpska congrats u learned to fire a Sam missile that costs the same as a 117, it was shot down due to a predicable flight path, not a radar lock, the missile was prefired. the B-2 is an ok aircraft but has no maneuverability, that’s why once a middle is shot, it’s a 99% chance the middle will hit, plus countermeasures don’t do much against radar guided. Now that we have advanced to beasts like the f-22 and the f-35, ur outdated 1980s pew pew shooters can’t do shit. Or we just launch a drone, or surface missile from a ship or a cruise missile. You get the point

[@trev972]

Crazy mf’s

[@getsideways7257]

@@jacksoncude9824 An SA-3 missile costing the same as an F-117 at the time? Are you feeling alright? As for B-2s not having any maneuverability... it was made stealthy so that it could defeat radars and in turn would have little need for maneuverability. It's a freaking *strategic bomber*, for crying out loud. If it still gets shot down, though, there's very little reason for its existence in the first place. Countermeasues don't do much against radar guided? Oh, really? Lucky Israelis in the Battle of Latakia didn't know that. I suggest you do a little research first before posting anything...

[@alyssadannah5366]

F117's: We are stealth! Serbia: Hold my AK

[@jonnyreverb]

Really great videos. The movie Real Genius has a corner cube reflector on the target house hit by the "Crossbow" laser weapon. They just put it on the house, and never explained. A little musical montage of them making the reflector would have made the scene make so much more sense.

[@daudidaudi]

Always with thought provoking content...thanks.

[@KensleyInnocent]

(4:39)That why the pictures taken by a paparazzi will be dark Manual Mode+ RAW: hold my shutter!

[@AdrasHoriaGaming]

advantage of going manual

[@sleepydog9968]

3:18 majora's mask, much? :3

[@AntonioClaudioMichael]

Very cool explanation

[@TheExplosiveGuy]

I work with these daily at work, we have two 1.5" diameter steel ball bearings with a perfect corner cube cut into one side, the corner of the cube is within .0005" of the center of the sphere, and each surface has been polished down to microns. Each sphere costs $2,500, and are used for our laser tracker ($150k+) which is for spacial measurement of machined parts. The unit we have is accurate to within .001" while 150 feet away, aka it measures parts too large to be inspected with CMMs or Romer/Faro arms. We can build a 3D model or align to a 3D model and measure any feature the laser unit can see, and with some extra magic, parts it cannot (the laser tracker is moved but the first alignment is kept, allowing the first set of measurements to be combined with the next set of measurements taken from a new station). The laser tracker works by measuring the angle, elevation and time of flight of the laser beam to the reflector and back through use of interferometry combined with computer 3D modeling. It's an odd sensation holding a ball bearing in your hand and watching what is essentially a laser turret track your hand's every movement lol. I should tape my 5 Watt 470nm laser to the thing and make a real laser turret hah.

[@sammy3212321]

Thought there was gonna be a Majora's Mask reference

[@Jesse__H]

You're my favorite stony-eyed educator on KZbin. Admittedly it's a modestly sized category ... but I'm confident you'd still be my favorite if a bunch of knowledgeable stoners suddenly flocked to KZbin to jack your steez. 💙💙

[@tusharjamwal]

I was gonna comment about the sphere reflection idea and why it's my favourite because of the size and flexibility as a replacement for corner reflectors and then he just showed it in the video.

[@a.sanaie2460]

Never paid attention to this. Good job Steve, as always thanks for sharing and making great videos 🤙

[@wwebadgerse]

"proof by eh look there you go" first coined by fermat in the tiny margin of a book

[@SimonLanghof]

The spray paint did just the opposite of making it clearer 😉

[@jonathancook4022]

yeah, it made it translucent or worse.....

[@GloveSlapnz]

Thanks for introducing me to another great channel Geoff!