With all the stars in the universe, why isn't the sky saturated with light?
Logic1: If the universe is infinite AND static, the sky will be saturated with light. 

Note "AND."

Logic2: If the sky is not saturated with light, the universe is not infinite or not static.

Note "OR."

Logic1 = Logic2

Observation: the sky is not saturated with light.
Therefore: the universe is not infinite or not static.

We know that the universe is dynamic, at least.