Why Do Mirrors Flip Left & Right (but not up & down)?

[@MinutePhysics]

I know lots of people have made videos about this before, but I felt I still had something to add, so, well, here you go! Also, I'm working on a video about CP violation (aka mirror symmetry violation) in particle physics, so I've been thinking more about mirrors recently. That video should be out soon!

[@jamenneel342]

Physics Girl made a pretty good video on this.

[@rapidaceful]

Can you also explain why when you're short-sighted, you look far away is blur, when you look at the mirror, the reflection was blur too for far distance, but your eyes muscle are being strained at short distance instead of long. This bugged me.

[@samuelplyr99p]

Im pretty sure CP violations are just felonies, not too complicated

[@korbynspooner3166]

It’s brilliant. The examples made it way easier! Thanks for forever turning complex into simplex

[@FrankLeeMadeere]

I've seen some other videos too, but I do think you explain it better than the others I've seen. The writing on transparency was a great way to dispel the flipping notion.

[@iveharzing]

That transparant card you used really made it click for me!

[@norsktorsk8982]

Me too

[@GamesFromSpace]

If you somehow don't have one, you can still reproduce the result by looking at the inside of a cheap tshirt with printed text on the front.

[@AaronHamm]

Yeah, that was something that I hadn't seen before that I'll definitely be using when I explain it to people.

[@RomeoYouMust]

I aaaaaalmost got it when he said depth is flipped, but it really only clicked with the transparent card for me, too

[@matthewpepperl]

me three :)

[@aidanbalac]

I’ve seen a lot of videos attempting to explain the mirrors flipping images, and this is the best explanation I’ve ever seen

[@KalikiDoom]

Definitely!

[@karlkastor]

Using the transparent foil with writing on it was genius.

[@batfan1939]

Science Asylum is a close second.

[@captainobvious3174]

aidan balac same

[@gammergames3322]

The explanation was more simple than I thought, when he showed the visual experiment of how this worked I was like oh duh that makes sense

[@lassievision]

You took something really simple that I took for granted, and made me realise that actually, I know nothing at all. Well done. Flipping brilliant!

[@lassievision]

Of course. But it's a common enough phrase here in the UK to mean what it says, too.

[@coryellis1877]

I think the main problem is that our brain has such a strong focus on the distinction between Left/Right. I had a philosophy professor who talked about this, in the context of "how would you explain left/right to an alien who had no concept of left/right", I guess a similar issue to explaining color to someone who was born blind. Some cultures (Idk some island natives somewhere) don't use relative direction (left/right) but instead they use only absolute direction (North, East, South, West). To someone who sees their hand as not a "right hand" but a "north hand" if they're facing west, would observe no horizontal flipping in an object's reflection (provided the text or image being reflected is parallel to the mirror). I just think that's super interesting, and I wish I could better understand that way of thinking. But left/right is so deeply ingrained in most of our brains and in our society, we use them every day and in almost everything we do. Isn't it weird that one of your hands does many things much better than the other?

[@ericzhang8170]

@@coryellis1877 You should check out "Death and the Right Hand, by Robert Hertz! Its kind of a dense text but it analyzes exactly what you are talking about and presents some interesting theories on it.

[@ishworshrestha3559]

Yyu

[@grashoprsmith]

I feel the same way. Nice pun

[@Totone56]

I love it when things are so "trivial" that you don't even think about them, but are very interesting the second you start to study them.

[@lowlize]

Nothing is really trivial

[@Totone56]

@@lowlize That's ... Actually very true indeed

[@TheArchsage74]

Yeah like your mom lol sorry

[@thebeatingcow595]

lowlize Exactly.

[@MrNicePotato]

You see things move and you study them... Boom we have physics

[@TheRealGuywithoutaMustache]

Mirrors are really fascinating. I really needed some time reflecting on this topic.

[@joelmoore7081]

M

[@blauesserpiroyal2887]

You are really everywhere

[@x_Xith_x]

And here you are again

[@Kram1032]

True and punny. You have polished your skills to a specular sheen

[@xyz8206]

Found ya

[@ricardoalves9605]

I feel like an idiot for not understanding how words are reflected earlier

[@Siyan4x]

Saaaame 😩😂

[@gammergames3322]

The explanation was more simple than I thought, when he showed the visual experiment of how this worked I was like oh duh that makes sense

[@tabaks]

I love the addition of transparencies! I knew that the "flipping" mirrors do is in "z" axis, but imagining it mentally is 10 times easier with your transparency idea. Excellent!

[@rsm8995]

Producing mirrors must be super fascinating and exciting I could really see myself doing that

[@ltericdavis2237]

One technic to make sure that glass for windows and mirrors is flat and smooth is to float the glass on molten metal. While your joke was great, it actually is super exciting.

[@NJ-wb1cz]

If I'm getting overly excited while looking at myself it starts to feel weird

[@Jimmeh_B]

@@ltericdavis2237 what's a technic?

[@michaelsommers2356]

@@Jimmeh_B Technique

[@TheOneWhoMightBe]

That was awful. Five stars.

[@oLuii]

When I read the title I was like "well this is pretty obvious" in my mind. And then I saw the part about the word in plastic film and was like "well thats obvious too, why tf didn't I think of that?!" The more we think we know all about a subject, the less we get to learn about different ways of looking at it. Great video!

[@brianpso]

Wow, using a transparent card was such a simple but mindblowingly powerful idea! I can't imagine the feeling of happiness that came when the person who thought of that had the idea. This was by far the best explanation about mirrors I've seen, short, simple and clear (pun not intended).

[@yawer2608]

Feynman talks about this magic. Actually all that Feynman talks about is magic. Beautiful work, once again @minutephysics

[@JankieHands]

1:11 hide the pain Henry Reich

[@cybervoid8442]

Lmao

[@gammergames3322]

I would like this comment but it has 111 likes for 1:11

[@JamesOKeefe-US]

The transparency was absolutely brilliant. Thought about this for years and now it makes sense. Thank you, one of my favorite KZbin channels!!

[@dougmcguire2187]

When you did the word on the clear glass I was like “oh wow” and then when you explained that we flip it, I was like “son of a bitch” I literally said that. In a very sincere way. I hope you know this is a huge compliment

[@Plant_Parenthood]

I'm in!

[@Michaelonyoutub]

I have thought about this a lot before and have come up with reasons why in order to explain it but I have never seen such an intuitive way to understand it until you held up the transparent word

[@manik1477]

The way he says mirrors in the end sounds like Hermione Granger saying its leviosa not leviosar

[@benYaakov]

Yeah

[@bencushwa8902]

I'm a physicist and a photographer, and this is by far the simplest explanation of this phenomenon that I've ever heard. Bravo!

[@Master_Therion]

Whoa! This is a deep concept. I need some time to... reflect.

[@mazajee]

Go to your room

[@amritas2400]

Ahaha

[@styledarc19]

stop

[@feynstein1004]

Hello Therion-sama. It's been a while lol

[@Master_Therion]

@@feynstein1004 Hey! ^_^

[@GeertDelmulle]

The very best video on the subject out there, bar none! That transparency / rotation demo really proved it in the best and simplest way possible. Fantastic!

[@tbnrthebestneverrest5834]

me on a date: hey nice to meet you. how are you? oh im great! did you know that mirrors...

[@benc8386]

Great video and explanation. As for the _psychological_ reason why we arbitrarily tend to think of mirrors flipping left right rather than up down I think it's because when you look into that window onto another world you naturally imagine your Doppelganger got there by walking around behind the mirror (which is a left/right flip) not by diving over the top like a sort of porpoise (because we tend not to move around like that).

[@AdityakrishnaMr]

This video makes me feel I've circled the youtube once, because years ago the first video i watched of Physics Girl was mirror flipping as well.

[@Kram1032]

I may have known and understood all of this before. But this is probably the cleanest and best explanation I've ever seen of this effect! Well done! - Using transparent slips was a great idea

[@georgplaz]

This is so simple, I can't believe I have never figured it out myself. I feel very humbled 😂

[@fluchterschoen]

*This finally makes sense. The only question unanswered is, who is the person in the mirror when I look at one? How many copies of 'me' are there in these alternate universes you described?*

[@patrickhector]

This video title jumped out from under my chair and battered my brain with a sandwich toaster.

[@alwayscommenting56]

I've somewhat learned about this before, but this is the first time someone explained the concept to me so succinctly. Thank you for this video and everything you do.

[@rrm9055]

I want all physics textbooks to remove the stupid "lateral Inversion"

[@mithil1711]

Omg!

[@chairwood]

Omg!

[@DarkJMKnight]

0mg cholesterol!

[@colerobbins124]

@@DarkJMKnight nice

[@yahiaaymankamaly3518]

@@DarkJMKnight rip vines

[@DraRed73]

Wow. So much insight packed into so little time. Well done

[@MirceaKitsune]

I'm not sure how to feel right now: I wondered the mirror thing for ages and couldn't figure it out my whole life... until today, at the age of 30, a KZbin video just pointed it out and suddenly it makes sense.

[@NixLeGaulois]

It always seemed impossible to explain because it was so natural and "obvious", yet you gave a perfect explanation. Great job 👍

[@andyortlieb3768]

Beautifully explained, as always!

[@tim40gabby25]

A third mirror, above those 2 at right angles, but closer to the observer and angled so that the rightangled mirrors can be seen via it, with a screen preventing direct observation of those 2 mirrors, allows for all combinations of left-right, up-down reflection, reversal or double reversal.. try it. I constructed this setup for an A level biology project in '76, here in the UK, showing how folks slowed in completing a reflected maze, depending on the combinations used.. :)

[@CrucialMuzic]

[2:23] When you come home and find food in your fridge

[@ultimasurge]

Lmao

[@scottmuck]

I’ve seen another KZbin video try to explain this and fail. With one simple piece of transparency you clarified everything (pun not intended, but welcomed)

[@teavea10]

Mirrors "sort of" do flip left and right. Left and right have to be defined in relation to front and back. When a mirror flips front and back which is taken for granted, that gives the appearance that left and right are flipped.

[@alexf0101]

Exactly! This is why when you raise your right hand, the person in the mirror raises their left hand -- because front and back are switched, even if "absolute" left and right are not, so relative to the reflected person's front it did flip left and right.

[@caribbeanman3379]

I've seen the explanation for this on another channel, but I didn't understand it. The way you presented here with the transparent card makes it perfectly understandable.

[@alexlandherr]

Made me reflect a lot... I’ll see myself out.

[@the8flo1]

I can't tell if the second sentence is part of the joke...

[@mikeymike1145]

Only if you use a mirror while you do it.

[@Twobarpsi]

Don't let the door, hit ya, where the good Lord, split ya!

[@gammergames3322]

@@the8flo1 I think it is

[@kenhaley4]

I've frequently told people that mirrors don't flip left & right, they flip in and out. But this video illustrates it perfectly! Nicely done.

[@zynx1828]

When talking about 1 mirror me: Okay cool Talks about multiple mirrors Me: *Thousands of ideas manifesting simultaneously*

[@anindyaambuj]

This is one of the best explanations of mirrors, in about 3 mins. Very nicely done.

[@dr3yk]

please, put your * comments a bit heigher in the frame - when I pause to read the KZbin controls are getting in the way

[@zippersocks]

Seeing you happily making a video in the video really made me happy. Thanks again for the great work!

[@contravariant_functor]

1:46 Redrum

[@ydna]

great explanation - there are soooo many other videos trying to explain the construct but they instead ramble about physics for 10 minutes without SHOWING the solution

[@AlexPBenton]

I came thinking “well, duh” but I actually learned something new!

[@DarkJMKnight]

This is one of those rare videos I think deserves a _super_ upvote... I wish I could upvote it more than once, or more powerfully than just an upvote. It is the _most_ concise and clear and comprehensible explanation of this phenomenon that I have ever seen. The transparent word portion was genius, and the multiple mirrors portion made it only all the better. _ALL_ the upvotes!

[@DarkJMKnight]

#SuperUpvote

[@Ouvii]

Mathologer already told us why Something something LIVE EVIL

[@giacomostojacco383]

The best and simplest explanation for that phenomenon, nothing more than needed to fully show what is really going on.

[@feeltoofree]

lol, didn’t know I needed to know this. Always though I somehow knew the answer

[@sd19389]

Concise. Precise. And very very clear. One of the best videos on this subject.

[@Helvetica09]

This always confused me as a kid because everyone around me was like "The MiRrOr FliPs ThIngS" and I was like... no it doesn't... it just reflects it... and people called me stupid because I didn't understand what they meant..

[@MrCallofkill]

You do look stupid, and they probably meant flips the images "horizontally" but they didn't know the word or something.

[@likebot69]

@@MrCallofkill uhh

[@Just_J7]

@@MrCallofkill Did you not watched damn video.

[@RamadhanTriyantoPrabowo]

Aw you’re not stupid just because you have different thinking with other people

[@tonydai782]

@@MrCallofkill uhh...Maybe watch the video before commenting?

[@MeDjezze]

Best video I've ever seen about this topic. I never understood why people describe the image in a mirror as a flip of left and right of the real world.

[@m.s.b.8929]

THANK YOU THIS HAS BEEN MY SECRET SHAME QUESTION FOR YEARS AND YEARS!!!!

[@robertmurdock2072]

THANK YOU!!! I'VE WATCHED SO MANY BAD EXPLANATIONS OF THIS ON KZbin AND IT MADE ME FEEL LIKE THE WHOLE WORLD WAS INSANE

[@FHBStudio]

"Just like a parallel world but with in and out reversed" So planets have their cores on the outside and the atmosphere at their core? Arthropods and non-arthropods are also reversed? Are my bowels dangling on the outside?

[@andymcl92]

And this comment is thinking inside the box?

[@fragon8188]

I felt like heard the cause of Big Bang when he said " mirrors and flip, we flip! " Awesome video 🔥🔥🔥🔥🔥 Awesomely explained ! I am your new subscriber! 👍👍👍

[@Kyrelel]

Why Do Mirrors Flip Left & Right (but not up & down)? Short answer: They don't Also, WTF is a mirrrrr :/

[@3ATIVE]

Another good reference is The Science Asylum's video: "Why aren't Mirrors White? Why isn't EVERYTHING a Mirror?" - kzbin.info/www/bejne/Z5_CoKd_qJutbKc

[@aidant3718]

Somebody's been watching old Richard Feynman videos

[@Prawny]

Or Physics Girl videos.

[@djambrosia]

His quantum explanation to mirrors is amazing!

[@VicJang]

Oh god. Thank you so much! I watched PhysicsGirl’s video on this a couple of times but still didn’t understand. I just watched yours and with your explanation and demonstration, it’s now perfectly clear how it works!! Thank you!

[@shikharpriyadarshi3537]

MKBHD: So guys, I've had this new mirror tech for a few weeks now, turns out they can flip up and down

[@trth1]

I agree with consensus here, you explain it better than most. And you highlight people's misconception of what they expect see when they look in a mirror. People expect to see themselves as if they were in front of the mirror looking at themselves instead of the a mirror flipping of themselves. You also, in much great detail, describe how I initially came to understand mirror images. My initial understanding came by imagining I had a glove on a hand and as you take off the glove you turn it inside out, resulting in the mirror image of my hand. But I like explanation better.Also i thing people describe the flipping as left to right or right to left only because they lack a better conceptual model to describe the flipping.

[@sparkythesnowman9243]

Physics girl already made a video on this. But still a great video.

[@radaroreilly9502]

palmomki I don’t know, it kinda seemed flipped inside out to me...

[@EricssonB]

Dude I woke up this morning and was really upset that mirrors be flipping stuff left-right but not up-down. It’s like I knew why, but not first thing this morning. Needed this. Back on earth now. Thanks.

[@simonduran515]

This video makes me feel mentally handicapped because I don't get anything.

[@finn9756]

life seems so simple in your videos. man you understand everything in these videos

[@asherang7]

What’s a solid 10/10 beard

[@sphakamisozondi]

*The Science Asylum* channel helped me understand wat u explained abt mirrors "flipping words around" as well. Great job sir.

[@RJRJ]

Serial killer smile 🤪

[@sarah12232]

Nothing like what I've seen lol

[@kinsan89]

I have never thought of it flipping depth, geez. I'm glad I found this channel

[@JohnDoe-ew2hr]

"They turn walls into portals to another world" jojo reference?! Man in the mirror thinks the same

[@UtsukShah9]

I am watching this channel after a while now. I often found your previous videos too fast to explain something very complicated. Maybe im just dumb. But its just too fast. So I unconsciously skipped your videos. Today I saw a simple question and I knew this was not something too hard to understand, and I did! :

[@radaroreilly9502]

Didn’t physics girl talk about this forever ago?

[@Draconis_Eltanin]

kzbin.info/www/bejne/rHPTqZucd9GJgrc yeah

[@-phantasm-]

What is the point of asking this? Many science channels have similar content between each other. Or if it was just a question, it literally took less than 10 seconds to find an answer. Yes, 4 years ago.

[@Onihikage]

It's funny, before watching the video, I thought about the question in the title for a few seconds, and I came to the same conclusion. I even imagined writing words on a transparent sheet. I think watching this channel for so long has actually made me smarter.

[@amritas2400]

The explanation with the transparent card is so helpful. Thanks for the video.

[@endymionas]

The only clear and thorough explanation on the whole internet. Thank you

[@MichaelKathke]

Most precise video on the topic I have seen so far. Thanks!

[@BariumCobaltNitrog3n]

You can make your own right-reading mirror with a sheet of flexible silver mylar. Reflective window tinting works well attached to a sheet of thin plexi. Just make a simple curved sheet, curving away from you, flat top to bottom, but curved left to right. Or search for right reading mirror. It's very strange and cool.

[@chrisg3030]

0:35 "What does get flipped is the direction into or out of the mirror. The things closet to us end up farthest away". But surely the things closest to the mirror end up ... closest to the mirror, and the things farthest end up farthest from the mirror. Or to be more precise, the black square is closest to the mirror and so is closest to the mirror image of the black square. So no flip there either.

[@subinmdr]

This is really brilliant explanation. Even though I knew that mirrors don't actually flip the letters, I always found it difficult to explain to others. Now, I'll just direct them to this video.

[@thisguyispeculiar]

That was a very good way of explaining the concept! The channel name is definitely justified 👍

[@Sarahhannahtx]

Idkw but I never realized this before. Your simple explanation + the transparent paper really made it click.

[@vijayjain843]

I have watched quite a few videos trying to understand this and I FINALLY do!! Thank you so much

[@michaelsheffield6852]

Best explanation I have ever seen of this bit of physics.

[@harshsawant4936]

This by far the most clearer explanation than any other videos I saw. The use of transparent object was useful for understanding!

[@hillrp1]

Thank you for the bit with the transparent card. I've tried to understand this or have people explain it to me multiple times and never got it

[@nicholassolly4703]

This was one of the questions I had at my Oxford Uni interview for undergrad Physics. Thanks for bringing it back to mind all these years later. :-)

[@steve42lawson]

Beautifully explained! In fact I'd go so far as to say: *_The Best Video, Yet, On This Subject!!_*

[@stevevernon1978]

DAMN you, Henry! I saw your title and had a rant ALL PREPARED that mirrors DON'T flip left and right, and and explanation of HOW they CAN'T flip left and right and was going to film a video that would SHOW how they don't flip left for right. but you already did that. now i can't. {sadface}

[@frankharr9466]

Every time I see something on this, I learn a little bit more. Thanks!

[@ethanbrandt8617]

I vaguely understood this before but this still makes it vastly easier to understand

[@TheJoaovascorodrigue]

Simple yet MARVELOUS video. Thanks

[@ricardoabh3242]

One of the best simple explanation to date!

[@coryman125]

This is a problem I've seen lots of people talk about, but this has to be the most simple and straightforward explanation I've seen. Just enough detail that it's interesting, but not so much that the answer to the question is lost

[@Shadow81989]

I already knew that, but the transparency example is the most awesome and easiest visual explanation! :-)

[@iwanabana]

I couldnt stop laughing when YOU turned the word!! Fantastic. I felt my brain scramble for a second.

[@ShadabGhafar]

Best explanation ever, especially the small objects.

[@GelidGanef]

This is the best explanation of this phenomenon i've seen, I love this channel