Exergen DT 1001-LN - Manual (Page 19)

17
Alice’s Quest for Emissivity
Is it possible to see a mirror?
When the mirror is looked at, all other objects in the
room are seen.
Is it invisible?
No, if it were, the wall would show behind it.
So how can it be seen?
If crayon spots are painted on the mirror, then the
mirror can be seen.
Of course, it can only be seen where there are spots.
Everywhere else still reflects.
Thus, light is emitted from the spots
and reflected from the non-spots.
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