In a mirror, a 'b' looks like a 'd', but that is only the flip of the right-left ankle. If you would flip the up-down ankle, it would be a 'q'. Why doesn't it flip the up-down ankle? What is the difference between up-down and left-right?
Wait until he discovers spoons
Mirrors don't flip images. They simply reflect light rays such that incident and reflected ray make the same angle from the surface and the intersection of those rays produces the image.
Concave mirrors, like spoons, would produce upside-down images.
Concave mirrors, like spoons, would produce upside-down images.
@mR-HAl-9000 said in #1:
> In a mirror, a 'b' looks like a 'd', but that is only the flip of the right-left ankle. If you would flip the up-down ankle, it would be a 'q'. Why doesn't it flip the up-down ankle? What is the difference between up-down and left-right?
I've thought about this years ago and have figured out the answer and can explain it easily. In order for the mirror to reflect a letter written on a piece of paper you must first turn the paper to face the mirror. If the paper faced away from the mirror you wouldn't be able to see the letter's reflection right?
So, how do you flip the paper to face the mirror? Usually people flip it left to right, hence why the letter gets flipped that way. But if you had flipped the paper from top to bottom the letter would also be flipped that way! And it wouldn't be flipped left to right at all. It's that simple. The mirror doesn't flip it, you do.
To further prove this point try an experiment. Face a mirror and raise one of your hands. If you raised your left hand do you think the image of the hand that gets raised in the mirror will be in front of your left hand also? Or would the image of the hand raised be in front of the right side of your physical body? It will be the first one.
> In a mirror, a 'b' looks like a 'd', but that is only the flip of the right-left ankle. If you would flip the up-down ankle, it would be a 'q'. Why doesn't it flip the up-down ankle? What is the difference between up-down and left-right?
I've thought about this years ago and have figured out the answer and can explain it easily. In order for the mirror to reflect a letter written on a piece of paper you must first turn the paper to face the mirror. If the paper faced away from the mirror you wouldn't be able to see the letter's reflection right?
So, how do you flip the paper to face the mirror? Usually people flip it left to right, hence why the letter gets flipped that way. But if you had flipped the paper from top to bottom the letter would also be flipped that way! And it wouldn't be flipped left to right at all. It's that simple. The mirror doesn't flip it, you do.
To further prove this point try an experiment. Face a mirror and raise one of your hands. If you raised your left hand do you think the image of the hand that gets raised in the mirror will be in front of your left hand also? Or would the image of the hand raised be in front of the right side of your physical body? It will be the first one.
@mR-HAl-9000 said in #1:
> In a mirror, a 'b' looks like a 'd', but that is only the flip of the right-left ankle. If you would flip the up-down ankle, it would be a 'q'. Why doesn't it flip the up-down ankle? What is the difference between up-down and left-right?
As Buttercup22 has already pointed out a mirror neither flips things left-right nor up-down. It flips things in-out. The reason why a "d" looks like a "b" in a mirror is that YOU flipped it left to right without noticing. Had you flipped it upside-down, the mirror would show the "d" upside-down, i.e. as a "q". Here's a video showing and explaining the effect in more detail (while Buttercup22 explained it well, the visuals really helped me understand it):
www.youtube.com/watch?v=1t4dOPxKgrY
> In a mirror, a 'b' looks like a 'd', but that is only the flip of the right-left ankle. If you would flip the up-down ankle, it would be a 'q'. Why doesn't it flip the up-down ankle? What is the difference between up-down and left-right?
As Buttercup22 has already pointed out a mirror neither flips things left-right nor up-down. It flips things in-out. The reason why a "d" looks like a "b" in a mirror is that YOU flipped it left to right without noticing. Had you flipped it upside-down, the mirror would show the "d" upside-down, i.e. as a "q". Here's a video showing and explaining the effect in more detail (while Buttercup22 explained it well, the visuals really helped me understand it):
www.youtube.com/watch?v=1t4dOPxKgrY
What if the rest of the world is flipped, and mirrors show us things for what they really are?
Actually, we do see everything inverted due to optics of the eye. The brain adapts to this during the first few months after birth.
Mirrors do "specular reflections" and the view is affected by the "focal point".
@Toscani said in #8:
> Mirrors do "specular reflections" and the view is affected by the "focal point".
That would be the physics of it. I think the op was talking in more abstract terms. but that might be your point.
Related. i remember in some Discovery type documentatry a long time ago about few weeks long 24h goggle inversion experiement, where we were told that the person in that environment could make the transformation at the time scale of a week, and view again the world as it was and locomote through it..
I assume the inverse transition must have happened after (I hope for the subject person). Anyone can corroborate that? maybe a traceable hint about it. That was before the internet... but have have had some reproduced versions.
The point was about plasticity. more than we think, at least at that sensory-motor level.
But still the op was asking a mathematical question about geometric operations, reflection with various centers or axes...
the focal thing would be about center.. in the op case, i think it was around horizontal versus vertical axis..
noticing we have a possible bias in our visual field. we do believe vertical is different from horizontal, otherwise we might have evolved our alphabet in an "isotropic" fashion. or maybe not. i get lost usually in my own reasonings at that point....
> Mirrors do "specular reflections" and the view is affected by the "focal point".
That would be the physics of it. I think the op was talking in more abstract terms. but that might be your point.
Related. i remember in some Discovery type documentatry a long time ago about few weeks long 24h goggle inversion experiement, where we were told that the person in that environment could make the transformation at the time scale of a week, and view again the world as it was and locomote through it..
I assume the inverse transition must have happened after (I hope for the subject person). Anyone can corroborate that? maybe a traceable hint about it. That was before the internet... but have have had some reproduced versions.
The point was about plasticity. more than we think, at least at that sensory-motor level.
But still the op was asking a mathematical question about geometric operations, reflection with various centers or axes...
the focal thing would be about center.. in the op case, i think it was around horizontal versus vertical axis..
noticing we have a possible bias in our visual field. we do believe vertical is different from horizontal, otherwise we might have evolved our alphabet in an "isotropic" fashion. or maybe not. i get lost usually in my own reasonings at that point....
gravity makes for strong biases.
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