Glass shrinks a little when it cools. By putting a hot glass into cold water, you are forcing it to shrink faster on the surface than inside the walls of the tumbler. Essentially the glass is cracking to relieve the stress created by that shrinkage. ... Glass expands when hot, contracts when cold.
Answers & Comments
Answer:
Glass shrinks a little when it cools. By putting a hot glass into cold water, you are forcing it to shrink faster on the surface than inside the walls of the tumbler. Essentially the glass is cracking to relieve the stress created by that shrinkage. ... Glass expands when hot, contracts when cold.