Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thedoc on 19/07/2013 02:30:01
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DON MCKENZIE asked the Naked Scientists:
We have a small hand mirror which we had for 10 years one day my wife used it and it had suddenly magnified itself like a shaving mirror so we bought another mirror. A few days later we picked up the old mirror and it was back to normal. Is there any explanation for this?
I would love to know.
Regards
Don Mckenzie, Cape Town South Africa.
What do you think?
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Extreme temperature could cause the mirror to become warped in a tight-fitting frame,
[ the mirror and the frame will have different rates of thermal expansion (https://en.wikipedia.org/wiki/Thermal_expansion) ]
then return to normal (flat) when the temperature became normal.
https://en.wikipedia.org/wiki/Curved_mirror#Concave_mirrors