why are the images of objects reversed in a mirror?

Answer 1

On a flat mirror, light bouncing from an object and reflected in a mirror is basically traveling in straight lines. So when you look into a mirror, light waves bouncing from the right side of your face travel in a straight line to mirror, and are reflected back to you showing the right side of your face in the right hand side of the mirror (your right hand side).

What this means is that the image you see in a mirror is the opposite of what people see when they are looking at you. Try taking a digital camera picture of your self and comparing that to what you see in the mirror. The camera picture is what other people see, the image you see is the one that is "flipped".

Curved mirrors reflect light at angles relative to your eyes, so a curved mirror can invert and flip images. Try looking at your reflection in both sides of a highly polished spoon.

In astronomy, curved mirrors are used to gather and focus light, but result in an inverted image. Many telescopes come with a lens that corrects the image to appear "right side up".

Answer 2

To expand on Ronin's answer: the mirror (if flat) reflects light back toward it's source. Since the mirror "sees" objects as if it were a camera or an eye, the reflection from it has to be reversed.

Telescope mirrors actually invert images (Newtonians do, anyway) so that both north and south AND east and west are reversed. Cassegrains invert east and west but not north and south. Astronomers get used to that fact and account for it.

Answer 3

They only appear to be. It's an illusion.

When you look in a mirror, your left side is reflected back towards your left side, right side to right, so it looks like your body is reversed.

Answer 4

Tell you what I'm gonna do. Why don't you look in a mirror, and I will ask you the same question. And then ask you the same question that you asked us . And I guess the answer will be what you will tell me.

Answer 5

They're not reversed: left, right, up and down are all in their proper positions. It's only front and back which are reversed!

Answer 6

I won "Best Answer" for answering this kind of question about a month ago. Below [quite a bit below] is a slightly modified part of that answer.

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BUT FIRST, let's get rid of that old canard that people bring up, propagating error unthinkingly. Astronomical telescopes DO NOT "INVERT" IMAGES, THEY ROTATE THEM !

Just think about it for a minute. Is there ANY way that a rotationally symmetric lens would know in which way gravity was pointing, or where "up" and "down" were ? (You should answer a resounding "OBVIOUSLY NOT !" to that question.)

They do, however, know where the axis of the lens system is. What happens is that EVERY POINT in the original source appears in the image on the OPPOSITE side of that central axis. That means that EVERY angle theta measured with respect to some fiducial line of theta = 0 has 180 degrees added to its angular measure. But
theta ---> theta + 180 degrees is also simply a ROTATION through 180 degrees.

So, BINGO : in their overall effects, astronomical telescopes ROTATE images by 180 degrees !

I hope that the scales are now dropping from some responders' eyes. Now to the FAR MORE SUBTLE effects associated with a FLAT mirror.
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I confronted myself in my bathroom mirror; as a result, I offer the following analysis.

Looking in the mirror with my recognizable bathroom and bedroom beyond "in its depths," I imagined myself being the person in the mirror examining how all things were treated as they appeared in or were "transformed" in the "mirror world." Walls, floor, ceiling all continued into the mirror world, but the things furthest behind me in my world were now the furthest in, in mirror world.

It's like holding out an infinitely thin sweater by the sleeves, front upwards, and then turning it iside out, away from you. The right sleeve becomes the "left" one and vice-versa --- try it! And yet the front of the sweater, held flat, upwards, remains upwards during this process. So, the left-rightness of this "mirror inversion" appears to "switch left and right," but doesn't affect "up" and "down," in this EXPLICIT, practical example.

I think this is the nub of the answer, but there are further implications found by examining mirror world a bit more carefully.

If you now start looking around in mirror world, you notice a remarkable thing: the left-right interchange is not just for your own mirror image, it's true for EVERYTHING. Looking straight into the mirror, this is hardly surprising: the edge of a picture I could just see through the door, behind my real world left hand, was now behind the "right-hand" of mirror man (MM).

I then turned, to look to the side, parallel to the mirror. In the real world, there was my toilet, just beyond and below the far edge of the mirror. (You may not wish to know that.) A corner shelf was to my right.

Mirror man disagreed, and pointed out in rather strong and critical language that I had it all wrong. He asked me to look at the situation from his point of view. I had to reluctantly agree. His toilet was to the right; his corner shelf was to the left!

This meant that no matter in what direction mirror man looked, while standing on the projection of my floor, EVERYTHING had a left-right switch, no matter in which direction he turned.

I confess that I found this remarkable. It meant that the "sweater-like inside-outness" applied to everything, to depth in the mirror, sideways, in fact turning around and looking in any direction. It's an INTRINSIC property of mirror world, without altering the way gravity operates --- that still pulled mirror man to the floor.

I decided to take what mirror man had told me lying down, on my right side, parallel to the mirror. Gravity pulled me to my "right"; but it pulled mirror man to HIS left, though physically it was still downwards.

What did all this mean, mathematically?

It meant that if a set of coordinate axes (O, x, y, z) in my world had their origin O in the silver reflecting surface of the glass mirror, with Ox horizontal to the left, Oy straight out at me, and Oz vertical, then in mirror man's world those same axes, for him, would be Ox', - Oy', and Oz'. The - Oy' is the mathematical consequence of the "sweater inside out effect" perpendicularly to the mirror surface. It's the ONLY one that's changed.

In my world, my axes form a "right-hand screw set (RHSS)." It's responsible for advanced physics students screwing up their hands and faces as they try to imagine which way a vector cross-product points, the direction of the Coriolis effect, in which direction a tipped-over gyroscope will precess, or which way a moving particle will be deviated in a magnetic field.

But mirror man lives in a world governed by a "left-hand screw rule." When I stand, doing my physics student thing in front of the mirror, my right-hand screw rule demonstration becomes mirror man's left-hand screw rule demo. I do it with my right-hand; he does it with his "left-hand."

So: ALL of the strange effects described come about from just one simple transformation, the "flipping" of all the coordinates normal to the mirror so that y ---> - y'. This DOESN'T change the direction of the x- and z- axes, but it does imply a change from an RHSS world into an LHSS world, or an "everything horizontally inside-out" world.

And THAT'S finally WHY: When you look in the mirror ... left becomes right and right becomes left ... but the top and bottom aren't reversed as well.

It's also why ambulances write "Ambulance" backwards rather than upside-down.

Live long and prosper.

Answer 7

I would say reflections.