# Cover: Icarus + Daedalus vs Minotaur

#### The Story

If you want you can choose as your companions through your studies, the young Icarus and his father Daedalus, a skilled craftsman and artisan from Athens (later to become the patron saint of engineering).

Daedalus had constructed the Labyrinth of Knossos in Crete on the request of King Minos to house the Minotaur, half man half bull, which was the result of an extra-marital affair between Pasiphae, the wife of King Minos, and a bull given to King Minos by Poseidon to be used as sacrifice. When King Minos instead kept the bull for himself, Poseidon got angry and with the help of Aphrodite gave Pasiphae lust to the bull and the bull did not say no.

Daedalus&Son were imprisoned in a tower by King Minos because Daedalus had shown Minos’ daughter Ariadne, in charge of the Labyrinth,  how to find the way out of the Labyrinth by stretching a clew of string, ball of yarn, when entering into the Labyrinth. Ariadne taught this trick to Theseus, an enemy of Minos from Athens, which allowed Theseus find and kill the Minotaur in the Labyrinth and then escape.

Similarly, you can view yourself imprisoned in a Tower of Ignorance, with the challenge to get out to liberate your potential. To do so you need to solve a certain riddle presented in the following dialog between Icarus and Daedalus.

#### The Riddle

Daedalus: We are in real trouble. I fear we will have to stay imprisoned for ever. I see no way out.

Icarus: Yes, it seems hopeless. But this morning something surprising happened: A bird flew in to the Labyrinth and dropped a piece of paper in front of me. Let me show it to you:

• $\dot \rho +\nabla\cdot (\rho u )= 0$
• $\dot m +\nabla\cdot (mu +p)= f$
• $\dot\epsilon +\nabla\cdot (\epsilon u +pu)= 0$

Daedalus: Let me see. Strange. Is it some kind rebus to be resolved?

Icarus: Can it be a message telling us how to get out? A message from a bird telling us how to fly like a bird? I have some friends out there who may help us to understand.

Daedalus: Can you get the bird to bring the paper to your friends to dechiffer the message?

Icarus: I’ll try. Here the bird comes again…I expect to get some feedback…

Daedalus: That is our only hope…

#### A couple of days later:

Icarus: See, there is the same bird again, dropping a message. I have it, let see what it says:

• The rebus is a set of mathematical equations describing the flow of air. The equations are called the Navier-Stokes equations. The solution hides the secret of flight, which the birds have discovered but keep for themselves. The trouble is that it seems impossible to find a formula for the solution. People have tried for centuries all possible formulas but no-one works. Some say that it is because the solution is turbulent and there is no formula for turbulence. The rich merchant Cassius Clay has offered one million Drachmas together with his beautiful daugther Madonna to the person who can find the formula, but it has not helped. But there are some rumours that it is possible to find a solution using a computer, and we are now pursuing this upshot. We will inform you about any progress. Don’t give up your hopes. Since birds can fly, it should be possible also for humans…

Daedalus: Can it really be possible for us to fly? I know that mathematicians have proved long ago that it is impossible, but since birds anyway fly there must be something wrong with the mathematics, if I rely on my engineering intuition.