Time = a big snowglobe

From "Being Human," s1x02:

Mitchell:

Things move and shift and settle again. It's like those -- what are those snowstorm things called?

Annie:

Snowstorms.

Mitchell:

Yeah, 'bout so big, glass?

Annie:

No, they're called snowstorms.

Mitchell:

Right. Well, them. You shake them and it's all mad and then it settles again. That's what time is like.