What if?

“What if?” is a very fun book. It is about stuff like “What would happen if we all pointed a laser at the moon?” or “What would happen if you got such a high dose of neutrinos that you died?”. Its author is Randall Munroe. He also wrote “How to” and “Thing Explainer”. Additionally, he created the “xkcd” website. I recommend you to start reading it at the age of 7.