Dad takes Christopher’s hands in his and suggests him to jump together, beginning at three the first time. Dad and Christopher, squatting, count aloud. Christopher waits with excitement for the signal to jump up. Did you hear the figure three ? Here they are in the air, full of joy.

Now, Christopher knows the three magic words which lead him to the air. Dad suggests him to prolong the adventure by jumping at five : that must be funny ! Christopher tries to feel what that makes, to count until five. At three, the temptation is so big that Christopher sometimes succumbs to it. The reward comes to whom knows how to show patience and concentration.

Little by little, dad lets Christopher count alone, when he takes self-assurance.

To count until ten is a tricky road. Christopher sometimes stumbles on six or eight. But the pleasure to jump always triumphs and Christopher will soon know how to count until ten.

The bottom of the pool is removable. At the beginning, the children can stand and Christopher takes self-assurance.

But suddenly, the floor is set moving : the serious things begin. When the water arrives at his mouth, Christopher realizes that he is not within his depth anymore, and roars : “Dad, I want to go out of the bathtub !”. Poor Christopher, dad bursts out laughing instead of coming to help him.

Some sessions later, Christopher swims like a fish in water, a fish with armbands.

She prepared several objects of various densities : a buddha in metal, a Playmobil knight and a small plastic duck.

The duck seems to be so afraid of this water that Christopher thinks it is going to sink. Bizarrely, it rises and stays to the surface, still keeping a frightened look.

The knight seems more daring and Christopher, who knows him well, is sure that his taste for adventure will lead him to visit the ocean deeps. What a disappointment ! As soon as he plunges into water, he rises to the surface at top speed : he needs to breathe.

Buddha is so heavy that he slides from Christopher ‘s hands and directly sinks at the bath bottom. Christopher is not surprised to see him staying under water, immovable, imperturbable.

Mum shows Christopher that objects are made of various materials, more or less dense, that is to say more or less heavy for the same volume. Objects which are made with materials denser than water are those that sink.

Mum lifts him, takes him in her arms and makes him turn in the music tempo, now fast and worrying, now peaceful and relaxing.

Christopher’s heart beats at top speed : he imagines himself aboard a boat, bounding in rapids or discovering unknown lands.

After a few minutes, mum wants to rest one moment. Christopher does not agree : he would like to continue to discover classical music !

Christopher is attracted by the Galileo thermometer : the lively colors of liquid in glass bulbs, suspended inside the glass cylinder, draw his attention. Mum takes the opportunity to show his young scientist that the more there are bulbs down, the more it is warm in the house.

Mum also prolongs the experiment by setting up a graph to visualize the evolution of the outside temperature : every morning with Christopher, she reads the outside temperature at the weather station ; she records its reading on a graph which has time on abscissa and temperature on ordinate.

The more it is cold, the more the point drawn on the graph is down.

Dad draws the various forms of the moon on a paper, which he reuses at each observation. Christopher notices that the moon does not always have the same shape : sometimes it is fully round, sometimes only a crescent is visible.

Christopher is in bed and dad shows him, in a book, big photos of the moon. Dad prepared his boy a surprise. He switches off the light, switches on an electric torch, then lights a globe in the bedroom by changing the pencil of rays orientation. From his bed, Christopher alternately sees a completely lightened disk or only a crescent.

In December 2011, on the 10th, a total lunar eclipse took place. It was partially visible in the Eastern Europe.

From afar, Christopher actually sees a cabbage, but when he approaches and looks more closely, a multitude of cabbages of various sizes appear : one cabbage, two cabbages, three cabbages, hundreds of cabbages ! Even mum could not count them.

Mum shows Christopher the vegetable’s fractal structure : spirals leaving the cabbage summits expand into geometrical arabesques, which parts have a shape similar to that of the whole set. Christopher is interested in its details and caresses its irregular surface. The ramifications of fractals allow to see the infinite.

At lunch time, Christopher will eat fractals heartily !

He asks him to begin the ascent while he takes some photos.

Along the staircase, openings, allowing inward views, allow Christopher to see dad on the other side, at the same height. The ascent continues : dad and Christopher take the same staircase, without ever crossing themselves ! When they arrive at the top, they finally join together at the roofs.

At Chambord, the main staircase is a double spiral one : two staircases, turning one in the other one, allow to climb without crossing each other.

Dad shows Christopher how to brandish this sword to impress the opponent, by calling upon the power of perpendicular rights. Which enemy can resist this incantation ?

Dad makes Christopher‘s finger slide on the sword blade then, perpendicularly, on its guard. Christopher draws the shape of a cross.

To see if two rights are perpendicular, it is enough to put the sword at their junction. At home, Christopher found many perpendicular rights : bathroom wall tiles, table corners and even the outline of piano keys.

To become a great knight and bring down his enemies, it is necessary to begin by acquiring the wisdom of the ancients. These are the bases of the art of war apprenticeship.

This posture gives mum an idea : she suggests her young Y miming the alphabet letters.

A is a sharp mountain : legs are with feet apart whereas the arms, stretched out, join together above the head. B is acrobatic : mum keeps her balance on one foot, the other leg forming the first buckle and a bent arm drawing the second one.

C is more restful : it is enough to place the arms perpendicularly to the chest.

Sometimes up, sometimes lying, Christopher tries his skill at this new game with amusement, by imitating her mum who is forming the alphabet letters.

Will Christopher and mum be supple enough to mime all the alphabet letters ?