Did you know that April 34th is a very useful day?

That some rivers flow from bottom to top?

That the Moon moves in a straight line?

That the cover of this book might be red?

And that while you are reading these lines you are traveling at a speed of 300,000 kilometers per second?

Our perception of the world is sometimes misleading. In science, reality clashes with our prejudices and constantly challenges even our most deeply rooted beliefs. It is not always enough to be particularly intelligent to answer the big questions: above all, one must be ingenious. Sometimes a simple change of perspective is enough to illuminate the most complex phenomena.

Mathematics, in particular, offers us a powerful tool to understand the mechanisms of the universe. They teach us how to think more broadly in order to understand more deeply.

This is exactly what Mickaël Launay shows us in this book through an exciting journey that starts in the aisles of a supermarket and ends in the dizzying depths of black holes.

Along the way, the author makes sure to answer provocative questions:
- Why might Everest not be the tallest mountain in the world?
- Who is the most famous formula in science that everyone knows but few understand?
- How the theory of general relativity definitively sealed the fate of the planet Hephaestus.
- What is the Googol from which Google got its name?

Ah, yes! One last question remains to be answered: what do all these have to do with an umbrella?