On the Today programme this morning they had a science Q&A. They did the Qs just before I left for work, so unfortunately I missed the As
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If you define left and right so that both I and the image have their own, or in terms of chirality like a chemist, then if I move my right hand, the image moves its left hand. A right hand glove in real life looks like a left hand glove in the mirror.
If you define left and right as my right and left, as the position of an object and not an integral property of the object, then if I move my right hand, the image moves the hand that is also on my right. It is my right but its left.
Yes, my left hand will be reflected as my reflection's right hand. However, it's still not left and right that has been switched. They've stayed constant while the direction I/my reflection is facing has been flipped.
But if you count left and right as a local co-ordinate system with its origin in the middle of the person or image-person that it's local to, then it looks flipped. Also, for things like gloves, leftness and rightness are a topologically non-changeable property, and the image has the opposite leftness/rightness to the object.
I think that's the point I was trying to make wasn't it?
That the reflection will have it's left/right labelled the opposite way round to the image (assuming you don't flip the local coordinates system with the object), because it has been flipped forwards/backwards and is now facing the other direction. This makes it look as if left/right have been flipped when they actually haven't.
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If you define left and right so that both I and the image have their own, or in terms of chirality like a chemist, then if I move my right hand, the image moves its left hand. A right hand glove in real life looks like a left hand glove in the mirror.
If you define left and right as my right and left, as the position of an object and not an integral property of the object, then if I move my right hand, the image moves the hand that is also on my right. It is my right but its left.
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That the reflection will have it's left/right labelled the opposite way round to the image (assuming you don't flip the local coordinates system with the object), because it has been flipped forwards/backwards and is now facing the other direction. This makes it look as if left/right have been flipped when they actually haven't.
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