Question

explain air bubbles trapped in a glass paper weight appears silvery.

Answer 1

The first ans gives an interesting view to the question. Here is what I think. It is because of total internal reflection of light from glass-air interface, a very well known law.

The light strikes the paperweight from all directions and then goes inside to strike on the glass-air interface (bubble). Definitely some of the light incidents on this interface at angles greater than “criticle angle” required for total internal reflection and instead of going into the air (medium inside the bubble) it reflects back into the glass and out. This is the light we see that makes the bubble surface appears silvery.