Why Does This Happen?

Question 1

Why do glasses fog up when you walk indoors from the cold?

Question 2

Why does your phone screen look rainbow-colored under polarized sunglasses?

Question 3

Why do your ears pop in elevators and planes?

Question 4

Why does a metal spoon feel colder than a wooden one at the same room temperature?

Question 5

Why does the sky look red or orange at sunrise and sunset?