All she needed say was that mirrors show exactly what they see. Go to a mirror and try it; the mirror will show exactly what it sees.

A mirror shows a reflection, simple. She just over complicated it

A mirror copies all the light that hits it and sends it back where it came. It's not flipping anything. It's like a rubber stamp on paper, but with light.

LOL ITS JUST ONE ASSUMPTION :P HOWEVER NICE FOR DA CLEARUP. N DAT GALZ R STILL HOT AS FUG. IM JUST HONEST N YEAH A DUDE. ++ (COULDNT JUST FOCUS N WHAT SHES TALKING)

me too

Did you just...

Perfect pun doesn’t exi...

You're gonna be a great dad

You must be PUNished :)

I mirror your move

I think this part makes it all make the most sense. That it’s a z-axis flip.

I'm glad that you came away enlightened. From the comments, I think most of us did not.

It is not a z-axis flip. The mirror is simply reflecting light. I can not understand why so many people have troubles undertanding that.

@@musknoer89 the mirror reflects light VIA the z-axis, which is why it is correct to call it a z-axis flip AND the mirror simply reflecting light.

@@prehensiledale1215 that doesn't make sense and is simply wrong which is why I pointed that out. Try standing slightly on an angle the left or right of a mirror and point a laser at it. If it is a flip in the z-axis, the laser should reflect towards you. Do you really think the laser will be reflected directly back at you? The angle of incidence equals the angle of reflection. Calling it a flip in an axis is nonsensical when talking about a mirror.

...ereht morf gnipyt dna rorrim eht ni deppart ma I woN ,raelcnu snoitcurtsnI

S

That's a horror movie plot in the making.

Say "hi" to Mirror Julie.

You've been watching too much of the flash mate 😂

get yourself a De lorean

+Madscientist with a doc brown.. and a idiot sycopath

HAHAHHAH

119 llɒɔ

;) ...gniniart fo sraey sekat kcutsnu gnitteg yletanutrofnU .taht tuoba yrros ma I

Can you provide me with a link of a product in real life? I want to know the keyword so I can get one.

you can do this today with an LED or TV screen with a cam that you configure to flip he image horizontally - Voila

And then we would all be more confused than ever. If I hold a mirror above my head, I dissappear. Only my bald head is up there and, since I can't see it, I have disappeared. So there !!!

She was a "why?" child rather than a wild child ... 😏

Yea but she's so darned cute what parent could get mad at her?

@@garymartin9777 i think she is right.

I can’t stop smiling at how brilliant she is.

absolutely.. I think to she drove her parents insane with questions. I know that's why she is so smart, ask questions to find out the answers.. She ROCK's..

cant you just lie down? that mirror is pretty heavy🥂🥂🥂

The is the "BEST" explanation and should be locked at the top of the comments. Thanks.

@Amethyst not sure what you mean by "normal line" but a convex mirror reverses in the plane of the mirror just like a flat mirror. For a concave mirror things are complicated by the fact that the light is focused and then spreads out again. The appearance of the reflected image depends on where your eye is relative to the focal point. Past the focal point the image is rotated as well as flipped. Your image will be upside down.

I have a better idea Don't worry about what the mirror does to your image just worry about the person in the mirror 🍦

Your point complements her explanation nicely. That image you see from below is also flipped in the z direction, the component perpendicular to the mirror plane, towards you. Just like the others she demonstrates.

this is literally the greatest comment in the history of comments

😂😂😂 Genius comment

Lmaooooo

LOOL😂

Well at least its not a particular body part stuck in a mirror.

Jesse Stewart - As Captain Jean-Luc Picard would say: Well, they say if you travel far enough, you will eventually meet yourself.

* vsauce soudtrack stars playing *

The mirror lies, and it toys with your mind.

That is when it all made sense to me!

The earth is flat.

In fact, we have spent many years visually compensating for our asymmetries as apparent in a mirror. When we see a photo (or correcting mirror, or live camera display), the asymmetries are exaggerated because they go in the opposite direction.

@@RaineStudio spot on

Oh boy… I just commented almost exactly the same experience before I saw yours

If this is the case, why nobody gots confused about selfies vs "normal photos"? If your theory is correct, other people should feel (or don't like) your selfies, because a selfie is a mirrored image, i.e., the same as when you look into the mirror. I never heard anyone saying, "oh man, in this group photo, you look nice, but the selfies you showed me, something seems odd". Do you disagree?

@@StefanHoffmann84 because after you take a selfie the device flips it horizontally so the saved image is now normal like how people view you irl.

"..... damn it!" Physics Girl, probably

😟🤯

Big Brain

I think it's because the Mirror is a Translational symmetry rather than Rotational symmetry of the image

This is exactly what I was going to post. Glad your post is at the top. :)

mirror mean it just reflection not flip.... got nothing to do with what direction....

Honestly, she caused some of the confusion intentionally, if she just wrote something in the mirror which was written on a transparent paper it would have made it clear

I was frustrated, then I broke the mirror, and it was an entire room mirrored in my direction and the mirror was just a glass window.

Try watching PBS spacetime for a few days. You think you understand, and then you get lost, but then find your way again and by the end of the video it leaves you with more questions than answers.

Bruhh..this is easy...my father also taught me this

personally, it went from wtf to "ah"/"duh" once she said it's flipped in the z-axis

make sure you have clothes on of course.

Thanks man to tell that to a girl, as I wanted to. This video is a joke.

That's just changing the coordinate system. It's still flipping in the Z direction.

Thank you.

no mirrors don't flip anything mirrors actually reflects light where it hits it

People have to understand that there are unintelligent people in this world, there always has been and there always will be (relative to the average IQ at any given period). Just because something seems obvious to you, doesn't mean there aren't many people who struggle intellectually who would benefit from this knowledge. I don't understand how you can't get this.

bdalem Because its mirrors. They are intuitive to everyone without a serious mental disability. And besides, how does explaining it wrong benefit anyone? And to top it of, this is a pretty confusing video thats hard to follow.

w0mbatina It honestly baffles me that someone might not understand how a mirror works and after reading some comments on facebook and on here... it's truly sad some people struggle with a concept as simple as a mirror. She didn't even explain it properly.

I completely agree with you. Just raising the question of "why do mirrors flip things?" adds more confusion to the topic since, like you said, a mirror doesn't flip anything, it just reflects.

Not everyone has good geometric / spatial awareness dude. At some point it became obvious to you. Just like there are things which are complex to you and obvious to these people.

This is what I have always visualized. This video only confused me lol.

It’s a very counterintuitive explanation

It's the same I've always understood, and most surely what is really true. What she says never maked sense.

😂😂😂@NotParticularlyAmused I think she understands but somehow for content

​@NotParticularlyAmused that's strange speculation given that you can easily look up her resume... Not a physicist, you say? She has a physics degree from MIT, and was even a research fellow at the Harvard & Smithsonian Center For Astrophysics, researching low-metallicity stars... What's your physics background? 🤷🏻‍♂️

+The Technoclast hats off

Damn, The opposite happened to me!

+Taran Singh I'm a multitasker 😏

+The Technoclast you've made my day :D

+The Technoclast My faith in humanity is restored....now to scroll down and read some more comments to obliterate it again.

Or stand on it

Instructions unclear Mirror pieces stuck in the face

Or stand *over* it

I just had a mini mind explosion!

ooh

🤣🤣

😂😂😂 Same bro

+Simon Clarkstone Actually if you have a sticker in the back window of your car intended to be read from the outside, it looks right in the mirror.

Yep.

+Simon Clarkstone - Good idea - I was thinking along these lines, but didn't quite graduate to clear plastic (I was thinking thin paper with dark ink and light shining from your side.).

+Robert Billing Also, very interesting!

+Robert Billing does it also look right to our eyes?

:))

@BluesyBor I don't suppose you've watched the film "Mirrors" (2008) then. It's an effective way to develop a phobia of mirrors, I'll say that much.

Mine does it all the time... We cant really talk with each other because of this.

so creepy ~

PLEASE BE CAREFUL.

It will flip you on.

You just made my day!

you get seven years of good luck..

But what if i flipped the mirror off ? 7 Days bad luck !

You're a king under all physicians. With joyful laughter, I solute you.

lol lol

😂

What if you turn the mirror inside out ?

Lol, um sorry loL

I hadn't until someone asked me!

cuz they're not flipped. theyr'e just mirrored

I JUST asked the same question LOL!

It's because you simply kant.

kant Because it's the simplest physics.

then add to it [in our perspective]

More precisely, it laterally inverts.

THANK YOU!

exactly it reflects light where it hits it

Same thing. If you teach children, the word flip is synonymous with reflect or mirror. She is making something non-intuitive simple to the average kid or adult.

That's no plot twist, it's the foundation of a horror story.

Plot twist: thats not a joke 2:31

@Sune Wallentin Goettler i need a science fiction with these beings in it please

If you get it could you possibly explain whatshe meant with the glove at 2:19 ?

@@mangolassi_0613 The main idea is that when you turn a glove inside out, the reversal is happening through the circular hole through which you put your hand. In order to see this in a mirror, you have to orient the circle (the part where your wrist is) towards the mirror. If *you* point the fingers of the glove upwards, the circle through which you invert the glove gets oriented along the Y-axis, and in the mirror, the hole essentially looks like a line instead of circle. And when you invert the glove along the Y-axis, meaning take off the glove by moving it along the Y-axis, the fingers flip and point downwards because you have oriented the circle of the glove along the Y-axis. Hope that helps.

@@jtherrington77 i do get some part of what you said, but i don’t get how the glove is being inverted thro the y axis. I mean isn’t the circle still orienting towards the z axis through which it is inverting frontally and then kind of reversing it’s direction?

@@mangolassi_0613 I don’t know how to explain it any better without using a visual aid like she did.

@@jtherrington77 ahh ok thanks tho for trying💜

You never tried Google?

@@davecarsley8773 People sometimes get busy with life and don't get around to getting all the little questions they have answered as soon as possible.

but i still dont know why i get 7 years of bad luck if i break one...

I have what's known as a "true" mirror: two mirrors that seamless intersect at 45-degrees. It corrects the z-axis inversion. I'm surprised she didn't use one in the lesson. When you look at it it shows you exactly how you look to other people. You stand in front of your objective self. It's like seeing yourself in a photo or video, but in perfect, life-size, natural 3-d. And as up-close as you dare to get -- which is VERY freaky. You wanna know what you look like when someone moves in for a kiss? Yikes!). I like to surprise my students with it at the beginning of the year. Being early teens, they cannot get enough of the effect. A couple of them in every class come in early enough to adjust their hair. Why not see it as it really looks?

@@carlodave9 The correction done by the 45 degree mirror can be quite confusing to some people though. If you ever want to see a woman get angry with a mirror, ask her to apply her makeup using a 45-degree corrected mirror... unless she is the really adventurous sort, she will never want to try that again. LOL There's also the coordination issue... like when one tries to fly a remote control model aircraft, and loses their orientation once it's turned around to come back towards them... as such, this is where trainers tend to crash a lot. A simpler example would be when you indicate to a friend that he or she has a piece of icing on their left cheek, you will generally point to your right cheek indicate it. And even though you may actually say "left cheek" , they will almost always still check their right cheek because you pointed to your left one, unless you're compensating for this response by pointing to your right, which most people innately do... due mostly to our conditioning from normal single-plane mirrors, but also because that is how we relate, as this young lady in the video describes our left/right biased mental symmetry.

You had me until this: "If while facing a mirror, you simply turn to the right, suddenly the image of your right hand is not only on your left, but to the left of the image of your left hand."... If I turn right my right hand would be behind me, not to my left. Did you mean if you turn 180 degrees?

No I mean if you turn 90 degrees to the right, resulting in the mirror being on your left. That's what I mean.

Ah I see.

Yeah I kinda tossed that example in at the end, it wasn't very important so I didn't explain it very clearly.

the mirror reverses the front and the back but my question is does it affect our physical image in other words is that others see us the same way when we see ourselves

😂

my mirror can flip an 8 ball to a kilo ok, hand me my beer back.

Thank you for the nice comment! Glad the video cleared things up.

Physics Girl I think that was sarcasm....no wonder you do science about mirrors...

***** You are entirely wrong, *and* you suck at detecting sarcasm.

***** Because random, unknown KZfaq commenters are totally trustworthy, of course.

It's not science. Trust me, I'm a soon-to-be engineer, she just gave you 1% of the real explanation.

PKBeast +1

Same exact thought. Word for word

I like the girl.

this is from old Royal Institution Christmas Lecture. i think it was 80s or 90s

My first video too. I think I broke my brain.

More or less what I was thinking. When she showed that she had in fact flipped the paper to show the writing to the mirror I was hoping she'd then point the camera through the back of the paper to show that the writing bleedin through the paper matched the reflection she could see in the mirror.

exactly! the same with writing food on a piece glass. if you look at it on the other side of the glass, it will be the mirrored word.

yeh but it only correctly reflects the back when you turn the paper horizontally, not vertically. ;/ Other wise the reflection would still be upsidedown. You're just demonstrating that it DOES flip the image on a single axis, not why... ;/

The point is that the mirror does no flipping on any axis, the light being reflected back in the exact same orientation it was presented to the mirror (assuming a flawless flat mirror), you just had to flip the paper (horizontally) for the mirror to reflect it back to you, so you turned it back to front from your own point of view (as the ink through the back of the page would demonstrate), if you flipped it verticallly instead then by definition you have got it into the same position as if you had turned it upside down and turned it horizontally to face the mirror, so the writing facing the mirror is now upside down and back to front, as is the writing in the reflection, and so too would be the writing seen through the back of the paper. So demonstrating both of those things with sufficiently see-through paper, or sufficiently bleed-through-able ink, would clearly show that the reason why it appears to flip the image, is because you have flipped yourself or whatever you present to the mirror, so you are now viewing the thing as if you are looking through it.

Yeh but you could have just said "because when you face a mirror, your orientation is yaw-rotated 180 degrees from the mirror's which is where the difference comes from. If you turn your back to the mirror, you're seeing what it sees which is not flipped."

+Ed C23 Remember, just because it's a mirror it doesn't mean you should do everything it says. Also try telling it to do some things for you too, in exchange.

+circ1ebreaker Right? Reflections are such freeloaders if you let them. Tell it to kill ITS whole family for a change.

Sometimes it tells me to burn things... :(

may I suggest that you...GET THE HELL OUT OF YOUR HOUSE!!!

My mirror is named, daniel, he says damn in excitement whenever i bury the bodies :) my mom says i'm "special".

always wondered why that happens, why does the mirror choose that image and not the other way around, if things are equal whats the difference.

hogarth heathan, each time an image reflects it flops. With 1 mirror, the image flops once, and must rotate it the full 180°. With 2 mirrors the image is reflected twice, and each mirror only rotates the flopped image 90°. So 180 degrees of image rotation, but with two flops instead of one. This effect is exaggerated in the extreme when you bring the mirrors to a parallel orientation with the reflections facing in, then look into either mirror, at the reflection of the other mirror. As you bring the mirrors close to parallel it seems that there are endless reflections, and every other one is flopped.

That's not correct. With 1 mirror, the Z-axis is flipped. With 2 mirrors arranged as you described, the z-axis is still only flipped once, but now you are ALSO flipping the image horizontally - making you appear as you would to someone else, but your image is still wrong - flipped in 2 ways.

iPhr0stByt3 what the heck are you trying to say that I didn't already say? When looking into a mirror you are on this side not that side. We all get that, but the effect of your z(in front of or behind the mirror) axis is effectively cancelled by the two mirror arrangement. What you see is what a person opposite the mirrors from you would see if the mirrors were removed, your true image, not the incorrect reversed image a single mirror suggests.

So you could read stuff thru a Periscope, which has 2 mirrors, but the angles are vertical, not horizontal.

Physicists: enjoying complications since the 1600s

🤣😂🤣😂

Physics is theoretical but the fun is real😂😂😂😂

It's the same physics that developed tech nd made it possible to write this comment

@@spacebarbarian._ Of course!!!! *physics is more than just important*☆

Glad you liked it. This was the best explanation I could find before making my video kzfaq.info/get/bejne/i9GGa5qJqJeZdIU.html, but I still had a few questions.

Exactly what I was thinking. I could instantly relate as soon as she mentioned flipping through herself in Z. :)

That's true. The reason why we think letters Get horizontally flipped in the mirror, is because we think the 'original' image is what other people see, whose point of view is horizontally flipped from ours.

Does your dog or cat lose sleep over it?

Wtf did i just learn? Still Mind blown lol

This video hints at, but poorly explains the phenomena. The proper explanation requires we think in terms of dimensions. To turn a letter in the 2 dimensional plane into it’s mirror image I need to rotate the letter out of the plane i.e. “flip” it over. To turn your left hand into into your right hand you can’t just “flip” it over. You need to do a double flip in 3D space or one “flip” in 4D space. Good luck! This is because your right hand is NOT the mirror image of your left hand. Your hands exist in 3D space not on a 2D plane. Alternatively, to the double flip to turn your left hand into your right, you can do an “eversion” of the hand, meaning turn it inside out. It helps to study topology to appreciate this significance of all this. The confusion occurs when we treat a 2D image of ourselves as if it were our real 3D body.

Z-axis explanation is wrong though. Just turn sideways to the mirror, you still get a mirrored image, and the you on the mirror is still raising the opposite hand.

+William Barnes Actually they don't "flip" at all.. It's like the old mind game joke "What goes up and down but never moves?" to wit the answer is : A road... The mirror is stationary and its the light wave which hits and bounces back in an exact opposite direction. Therefore, the only thing which actually changes is our own individual "perception."

Chris Banzet No, they absorb photons and emit different ones with reversed chirality. They actually flip them front to back.

+William Barnes No, they do NOT recreate new photons. Its the same photons being ricocheted back at the observer. And again, they don't actually reverse, there's many scientific documents available that you can read about the subject matter. "chirality" is not the exchange of molecules produced by a mirrored reflection, they merely use the mirror image to create an impression of it being "identical". Chirality is merely the state of equal identity to another molecule - see this definition "Chirality is a property of individual molecules. If a molecule is chiral then we know that the molecule has two enantiomeric forms (which are almost identical but are actually different molecules)."

Chris Banzet I'm going to give you a moment to read those "many scientific documents available" yourself.

+William Barnes I've already spent about 35 plus years reading them, I don't NEED to read them again.. I know what the internet says, and I know what science says.. They're contrasting, and definitely there is a truth, and yours wreaks of Google searching..

Of course there's a z axis. If you take the plane of the mirror as having an x (horizontal) and Y (vertical) axis, then the z axis is the depth between the observer and the mirror. (Include apparent depth in the mirror image of you wish.) Stating that there is no z axis is similar to saying that there is no distance between the observer and the mirror and the observer is 2D object. Clearly this is not the case.

@@paraicmcdonagh6062 Did you notice the part where you said "plane of the mirror"? A plane is a 2 dimensional object, period, full stop. IRL nothing is really 2 dimensional because that would require the (missing) 3rd dimension to be zero, but as a practical matter the reflection in a mirror all happens on that 2 dimensional flat plane. What you perceive as depth or distance in the reflected image is just a result of angles because angles are a large part of what or brains use to perceive depth/distance (and also speed). If the image you were looking at was created by replacing the mirror with a camera would you think the resulting picture had a z axis or would you recognize it as a flat 2 dimensional representation?

@@stevepseudonym445 No I didn't miss that part. What you are saying it's incorrect. Clearly there is depth between the observer and the mirror. Whether or not you accept that there is depth within the mirror reflection is irrelevant. Clearly you can draw a straight line at right angles to the mirror surface. This is a line along the z axis, not the x or y axis of the mirror plane.

@@paraicmcdonagh6062 I don't know what's so difficult, but you're confusing the real world outside of the mirror with the *reflection*. The real world obviously has a z axis. The flat reflection at the back of the mirror doesn't. Maybe it would help if you watched the video again. When she talks about the arrow pointing back at you what's actually happening is that the arrow is pointing up or down, and it's apparent length changes as a result of it's angle to the mirror. What you see in the reflection is width and (apparent) length. That's two dimensions.

@@stevepseudonym445 What's actually happening, is photons leave the surface of the observer (and the arrow they are holding), travel in the z axis (and also x and y) to the surface of the mirror and back to the retina of the observer's eye. The mirror isn't the only consideration. It's just one of the objects in a 3D environment. I don't know why it's so difficult for you to understand. LOL!

I lol'd.

Did you check the mirror?

Don't worry we all lose thousands of brain cells every day

It flips perpendicular to the plane of the mirror.

+carultch The light coming from the mirror, what I consider the reflection, doesn't flip at all. That's exactly why it looks backwards.

Jim Doe Oh, but it does. The mirror reverses the perpendicular component of the incident light's momentum, and preserves the parallel component.

+carultch All you're saying is that the mirror reflects light. Whoopdiedo. We know that already.

are you fucking dumb?

+1

👍👍

Well said ;)

yeah man i'm sure you are the 1 one to came up with that.

She probably doesn't give a damn about physics. Rather, she is just some media company's business venture. Chill yourself.

This comment needs to be higher up.

The Z axis can go only one way, normal to both the x and y axes. The question of which is the positive Z axis is answered by the right-hand rule. By convention. In engineering terms it is orthogonal to both the X & Y axes. By the way. I'm quite sure that someone "got it right" long before this. Thank you for playing.

@@touristguy87 I think many lay people got it wrong but its not there fault. It depends on how you present it. Its not incorrect to say the mirrored image will appear horizontally flipped compared to a photograph. It will, it does not say who is doing the flipping or why. Most people experience life looking at others and knowing that the hand on the right is really that persons left hand. (well some people are just terrible with left and right period) but you get the point. Some where along the line people started saying the mirror does the flipping. One can make a case that the mirror is responsible for this illusion and most people can get by in life just fine remembering that that a mirror image means its flipped on the horizontal axis and bi-convex lens creates a real but inverted image (Flipped on both axis) Again its "Appears" to be z axis flipped but its not actually doing that either (that is part of the illusion) Do you really think the mirror is pulling your eyes to the back of your head and then re-bending your arms to bend the opposite way? That is not what is happening in reality, but it sure looks that way as the video demonstrated.

^This

What do you mean by reflect? This video describes what a reflection actually is. A reflection is an image reversed in the direction perpendicular to the mirror surface. Saying “mirror’s reflect” is really just saying they flip in the z-direction. Asserting that mirrors don’t flip is incorrect.

@@andrewthenoble a mirror reflects the exact image that's in front of it. Mirrors dont flip. The end.

Raul J You’re completely missing the point. How would you describe a reflection without using the word “reflect?” This video is describing what it means for something to be reflected. Your comment is the equivalent of saying the definition of a reflection is “a reflection.” That doesn’t explain what is physically happening.

@@andrewthenoble what? Lol. I said "reflects the exact image". The content is about reflection, so therefore there is no reason for me to be more specific about a mirror. Also, i'm not going to waste my time with someone who spells "your" the wrong way. Enjoy your day.