As a result, he can read the word correctly. The word does not seem flipped left to right to him because he has not turned his head. This counter-intuitive notion arises from the fact that when we turn our head, we unconsciously rotate a word so that it reads correctly.
For instance, consider that you are standing in a long, narrow garage in between two vehicles. A car is parked on your left with its front grill facing you and a van is parked on your right, also with its front grill facing you. In order to have some fixed reference frame, let's call the wall right in front of you the main wall. You are supposed to paint the words so that someone looking directly at the front of each vehicle reads them correctly with no mirrors involved.
The main wall is the wall closest to the car's passenger side and closest to the van's driver's side. In order to make it read correctly, you put the letter "P" closest to the main wall, and the rest of the letters stretch away from the green wall.
To make it read correctly, you now paint the letter "P" farthest from the main wall, and the rest of the letters stretch towards the main wall. Do you see what is happening? In relation to a fixed reference frame the main wall , you painted the word in one direction on the car and in the opposite direction on the van in order to make them both read correctly. Why did you do this? Because when standing in between the two cars, in order to change your view from the car to the van, you have to turn your head.
But turning your head would make words that are fixed relative to the wall end up flipped backwards relative to you. So you also flip the word that you are painting to make it come out right. Turning your head flips words, so manually flipping the word restores it back to its normal appearance.
We do this all the time without realizing it. If you are looking in one direction and reading a book, then you turn your head and bring the book around to read it, you also turn the book. Photons reflected from your left hand striking the mirror near your right hand bounce away from your eye and so you don't see them.
The photons probably have changed direction a few times along the way before hitting your eye, but there never was an image until it was formed in your retina and visual cortex. But the left-right dichotomy is surely the outcome of our mental processes.
See, we can place a mirror in 3 categories of planes with respect to us. FRONT - Here the image seems to face the opposite direction that is our mental process and the left-right is reversed which is not actually happening, there is no degree rotation, because my right hand is not his right hand, mirror images are not superimposable, this is called 'chirality' for an asymmetric C-atom.
There is also basic in-out reversal, if I face East, my nose is Eastward with my ears, but the image's nose is Westward with his ears. The basic in-out reversal is doing all these. Also my nose is slightly leftward with my ears to a viewer facing the sidewise mirror, but my image's nose is slightly rightward with my image's ears to the viewer's image just like the FRONT. TOP - Now the top is reversed satisfied?
This is again the basic in-out reversal. But wait, my right hand is the image's left hand. Both I and my image face East the explanation of facing opposite direction is not working and the in-out operation is done with the top-bottom reversal Sorry Mr. Geoff Steel, the image's head is towards cardinal down, the super Scientific American article is fine but that is not the proper reason, see, in the SIDE case, when a Pormpuraaw wonder girl moves her South hand Southward her helpless image moves her North hand Northward, even in heavenly Australia.
And, well, Physics is not any cause, it is an effort to understand the 'cause'. So what is only left is really that mental process. Our brain tries to place our head downwards facing the same direction and sort out what is right-left. You don't believe? But for TOP, brain is not used to do this. Now you understand that there is a process. The process is the reason. We our brain place s our head first. Still not convinced?
Lie horizontally in front of a mirror. Your right hand is upwards say , your image's right hand is downwards. See, top-bottom with mirror is reversed, but with you it is still left-right reversal. Your brain placed your head horizontally first. Pratap K. Saha, Kolkata, India You guys are making it too complicated. The text reverses left-to-right because when you turn the paper towards the mirror, YOU'VE reversed the writing left-to-right.
Then you just see a mirror image of it. Try writing on a transparency, and hold it up so you can read it correctly. Then hold it in front of the mirror. If that's all scientists did, we wouldn't get anywhere. Adam Gulyas, Edmonton Canada Close one eye. Look at wall with two windows, but one is actually a mirror. If light bounces off everything in reverse angle, then we should experience mirror image like camera obscura.
But, only one parallax results, not total. Brain should not be able to know difference in mirror and window. It is a mirror image or what you see if you were looking from the mirror but still gazing forward.
No, wait. If you look at a mountain in a lake it is upsidedown. But not left to right. The image depends on the plane of the reflec tive surface as to what we see from where we are. It is something one could puzzle over for many hours.
Your chin is the same. Your chin is below your actual nose and your reflected chin is still below your actual nose. What flipped is the Z axis. Imagine you wearing face as a mask then flipping it inside out along the z-axis so that the face mask is now looking at you. That is the flipping that is going on People who say there is no "flipping" going on are completely wrong. There is a flip: on the z-axis. You can make a mirror flip something vertically, just put the mirror on the ground. Doxin on Oct 8, prev next [—].
A mirror doesn't mirror left-to-right, it mirrors front to back. The clue being that you're looking at a reflection of your face in a mirror, not a reflection of the back of your head. Of course since nothing but a mirror can do that in day-to-day life most people expect a mirror to do a degree rotation instead, leading to this confusion.
Mirrors reverse front and back. If you imagine your face painted on a surface, like a mask, then look at it from behind, that is essentially what the mirror is doing. I think this is the best intuition, among other things it gives the right intuition for how circularly polarized waves reflect.
A Silence "Alert" article about a 5 year old video that is a remake of a year old video. All of them fine in their own right, but Sometimes I think we're nearing the end of human advancement because we've built up so much knowledge that we're forgetting as fast as we learn. I always thought it is because our eyes are arranged horizontally and not vertically If the effect persists when you close one eye, that's not the answer.
This variable can be removed by covering one eye I'm more amazed by the ad filled lazy wrapping of a youtube video in a web page to basically remonetize the video. Fuck the internet's gotten lazy. Mirror flips front and back actually. You are facing north towards the mirror. Point south, reflection points south. Point up, reflection points up. Point north, reflection poins south.
Just link the YouTube video. The article is nothing but a summary of the video, and a very incomplete summary at that. Plenty of ads though. I mean there's a video ad playing while the Youtube ad is playing The internet is fucking lazy anymore. A mirror does flip up and down if you rotate degrees around the x axis and end up standing on your head behind the mirror.
It's just that we typically associate rotation with the y axis. MichaelZuo on Oct 7, prev next [—]. How would it be possible to construct a mirror that does flip vertically? A normal mirror already does flip things vertically just as much as it does horizontally, which is to say not at all. This about your expectations of what a person or thing facing you looks like. Normally when someone turns to face you they'll spin around while staying in a head-upward orientation.
That puts your right hand and their right hand on opposite sides because they've spun around, while your reflection's right hand stays on the same side as your own because the mirror doesn't flip anything.
If you instead expect the other person to turn to face you by doing a hand stand, then you can say "Why is my reflection's head on top?! It should be on the bottom!
The mirror has flipped it vertically! Now flip it so a mirror in front of you can see it. The text is right to left, isn't it? Now notice that, in order to "show it to the mirror", you applied an horizontal rotation to the paper. Try placing the piece of paper as it was at the beginning, so it's readable to you again, and then "show it" again to the mirror, but this time flipping it with a vertical flip.
There you go, the text is left to right but upside down. Vertical flip! You're probably thinking "yeah but the original is upside down too" to which I would reply, yes, and in the first case the original was also right to left from your position - you just coudn't see it because the paper is opaque.
Yetanfou on Oct 7, parent prev next [—]. The image you see in that corner will be flipped vertically. The same trick can be used to create a horizontal-flipping mirror, simply by positioning the mirrors so that the edge is oriented vertically.
You can make one of these by sticking two pieces of mirror in an inside corner in a room somewhere. Lie on your side in front of one. Stand on a mirror. Your reflection will be flipped vertically along the y-axis. Your reflection will be upside down relative to you.
The flip happens perpendicular to the surface of the mirror. They think that a flip happens parallel to the mirror, but the flip happens into the mirror. Like flipping a glove inside out. I suppose a concave mirror would. Two mirrors at 90 degrees to each other should do it. Do you mean for it to flip both horizontally and vertically though? That would be more difficult. I'm not sure but maybe a type of prism. My way of thinking of it is like this: imagine your eyes were located above and below your belly button on a vertical axis.
What would be 'flipped' when you look in the mirror? Vanit on Oct 8, prev next [—]. I don't understand why there is any confusion about this or needs any explanation at all that's not related to photons. JoeAltmaier on Oct 7, prev next [—]. Stand facing a mirror. Hold an open book up so you can read it. Now turn it to face the mirror.
The text is backward! How did you turn the book? Well, that's why its 'backward'. Try it again, but this time flip the book vertically to face the mirror. Now the test is not flipped right-to-left, but top-to-bottom. It's nothing to do with 'physics'. Its just perception. This is probably why a cat doesn't recognize itself, even as another animal, in a mirror.
Look in a mirror. There is no reversal, it's a myth. If they raise their left hand, you see it on the right. Because THEY are reversed. They are facing the opposite direction.
Ever tried to read text in a mirror? Now turn the paper around so the word faces away from you. Hold it up to a light and you can see that the word is now flipped horizontally. Now face a mirror: the image is projected onto the mirror with no change, so you see the exact same thing you saw when it held it up the light. IOW the mirror is inessential. We can ask the same question about just a transparent piece of paper. That's because you flipped the paper horizontally not vertically.
If you flipped it vertically it would be flipped verically. But you didn't flip the ambulance. The text isnt reversed, you're seeing it from the back. The leading A and the trailing E are in the same right to left position that they are in the real sign. There is no reversal. That would also be true if the text was flipped vertically. So why is it flipped around horizontally and not vertically? Um, because it's not flipped around. Seriously, look at any text in the mirror.
The rightmost feature of the text will be the rightmost feature in the mirror, and the leftmost will be leftmost. You would need to flip it horizontally to make it look "normal". Yes, it's mirrored horizontally. Why not vertically? Did you watch the video? We are trained on rotated mirrors in the vertical axis Y , seldom we see them rotated on the horizontal axis X. If you go to an hotel with mirrors on the ceiling or on the floor, the reflections are all flipped vertically.
Did we really have a discussion about this? Justsignedup on Oct 7, prev next [—]. Or as Shafer the dark lord puts it: Because mirrors are lazy.
And why don't the show vampires? This is so dependent on the system of coordinates that it is not even wrong. GrumpyNl on Oct 7, prev next [—]. Nothing is flipped, its a mirror. Mirrors flip things front-to-back. Physics Girl explains this in the video. Yep, ours too. Hhhmm, no. Mirrors don't 'flip' things. Also, z axis is generally used as the height.
In computer graphics z is generally used as the depth. See OpenGL's z-buffer. I always felt like the explanations people give are way too complicated. It flips front to back. YOU flip left to right when you turn things to the mirror. You're in a room with your friend. You look at a sign on his forehead saying "AOM". There's a mirror on the wall. You can see your friend in the mirror, the sign on his forehead is now saying "MOA".
Nobody turned anything to the mirror, the whole scene is stationary. Their conclusion is inaccurate and may be disproven simply by leaning oneself over to a 90 degree angle, or greater, while leaving the mirror and the text source stationary. The conclusion is wrong? The conclusion is that mirrors "flip" for lack of a better term front-to-back.
This is terrible physics! It's just reflecting things in a straight line. This is easily demonstrated by holding a sign with a transparent background in front of the mirror.
The image you see on the back of the sign aligns with the one you see on the mirror. A person in front of the sign is able to read the words properly because, relative to you and the sign they are flipped. Their right eye is in front of your left eye and vice-versa. The mirror gives the impression of a flipped image precisely because it's not flipping anything!
Edit: It's already been pointed out twice to me that Z for height is not in any way a convention. I never thought it was, which is why I used the phrase "commonly used" instead. Turns out that doesn't seem to be the case either, regardless of my personal experience so this is an acknowledgement of that mistake. GuB on Oct 7, parent next [—]. The way X,Y,Z axis are portrayed in the way that is most common in computer graphics.
X is left-right, Y is up-down, Z is front-back. That's convenient because X,Y are your screen coordinates for 2D work, if required, Z is stored in a separate buffer, aptly called the Z-buffer.
Orientation of the base vectors can vary between tools, engines and APIs but the Z axis is almost always perpendicular to the screen, and having the Z axis perpendicular to the mirror follows this convention. And a mirror certainly flips things. In a mirror image, parity is reversed, right hands become left hands, screws turn the other way. A person in front of you doesn't see you flipped, he sees you rotated degrees around the up-down axis. You can achieve the same effect with two vertical mirrors at a right angle from each other.
Because there are two mirrors, the image is flipped twice, and because of the way parity works, it is the same as not flipping. One thing we can say is that flat mirrors both flip and rotate. The flip is always the same, there are only 2 parities and the only thing you can do is go from even to odd and odd to even. The rotation depends on the position and orientation of the mirror. If the mirror is vertical, the axis of rotation is vertical and therefore, it will flip left-right.
If the mirror is horizontal the axis of rotation will be horizontal and it will flip up-down. Funhouse-style distorted mirrors also flip, like all mirrors, but will apply a complex, non-linear transformation instead of a simple rotation. I think it's pretty reasonable to say the image is flipped, but it's flipped along the 3rd axis: Front-to-back. The image in a mirror is physically symmetrical to the direct image from objects in the real world, with the mirror itself as the plane of symmetry.
I find the front-to-back explanation to give a better intuition than the typical "but left and right are relative to your body" , which only serves to explain the paradox of "left-right are reversed but up-down ar not" , but not the fact that everything looks flipped. AnimalMuppet on Oct 7, root parent next [—]. Well, it flips front-to-back. But this side of the mirror, we can't physically do that, so it's not in our brain's list of expected possibilities. We can, however, rotate ourselves degrees.
And because we're bilaterally symmetrical, our brain finds it easy to interpret the front-to-back flip as a degree rotation. But that leaves left-to-right weird, because what happened wasn't actually a degree rotation. Don't beat yourself up about Z. The Z axis is both a convention and commonly used for height in many fields, such as civil engineering, vehicles, and geology. All areas where the horizontal ground is important. It's computer graphics with its vertical screens that mainly has Z for depth.
There does seem to be an underlying commonality to these conventions which might be that Z is normal to some important reference plane, the direction without homogeneity, or the most unique direction.
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