CLEver Friction

A day with Frédéric Restagno

The students of the European section of the Lycée Expérimental of Hérouville-Saint-Clair, have the lucky on Friday, January 10, to welcome the physicist Frédéric Restagno (Doctor of Physics and Director of the Paris-Saclay University). In fact he have support us during three activities. A Masterclass in the morning, where we studied the different beers foam. The afternoon was cut in half, at the beginning we participated in a round table to debate on the different job related to research. Then at the end of the day during one hour and a half, we have assist to a conference on friction named « Sciences Friction ».
(Agathe & Maël)

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Friday the 10 january 2020 on the morning we had the honnor to receive Mr. Frédéric Restagno for a master class on the subject of foams (more speficly of beers). In fact during the first half of this class we had measure de height of the foams depending on the beers, of the Guinness and the Heineken at room temperature but also cold (refrigerated). After having poured beer in a burette, each 30 seconds and during 10 minutes we measured the height of the foam, then with our data we had build a graph representing the evolution of the height of the foam depending on the time.

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After having finished this TP, during the second part of this class, Frédéric Restagno did us a class about the formation of the foams and their composition depending on the gases inside of them, for example CO2 diffuses a lot so it creates a big foam wich reducts fast while N2 diffuses less so it creates a more concentrated foam but smaller
• The drainage which consists in that the liquid slides between the bubbles
• The coalescence which explains the explosion of the foam bubbles
• The coarsening which demonstrates the fusion between 2 bubbles depending on their pressure

(Nayle & Hugo)

For the table ronde at our school Friday the 10. January, it was announced as an open event in advance. The subject was scientific study courses. Other colleges in Caen was informed that anyone interested in hearing people talk about their education and studies could come and listen. We had the pleasure of hosting :

  • Jean Charles Thomas, searcher of GANIL, Grand Accelerateur National d’Ions Lourds
  • Wilfrid Preltier, director the CRISMAT, ENSICAEN
  • Laurianne Fau, former pupil of CLE, now student of acoustics engineering in Le Mans
  • Frédéric Restagno, the great physicist , searcher of the University of Paris-Saclay
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From left to right : Jean Charles Thomas, Wilfrid Preltier, Laurianne Fau, Frédéric Restagno

All of the scientist had a different background of education, but one could see that they were all alike when it comes to their love for science. Each one talked about how they caught interest in their study subject. For example :
Laurianne, who is much younger than the other speakers, talked from the view of a college student since she was not that far into her study course. Uncertainty, stress and fear in relation to work future is something many in the audience could relate to.
Frédéric Restagno told than he was early fascinated by the things in our everyday lives that relate to science and its laws. He mentioned how unexplainable events like the impossibility of breaking a string of spaghetti in just two pieces made him very curious. Furthermore, his curiosity concentrated itself towards friction and foams.

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Students from all over Caen came to listen to the scientists talk about their study courses.
(Torje & Costa)

After the round table, we attended a conference about friction with Frédéric Restagno.
Friction is the force that opposes motion between any surfaces that are in contact. There are four types of friction. Artrosis is a kind of friction, or the friction of a car motor or when you’re stroking your dog.

Frédéric showed us that friction can create huge forces throught three experiments.

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The first experiment consisted in a stick in sand and with the friction of sand’s grain the stick is like glued to the sand and it can lift the system.
Then, the second experiment was with a long horizontal stick and there was a thread hanging and holding a bottle of water at one side and a lighter weight on the opposite side. When he let the bottle fall, this one winded around the stick really fast. The bottle did not fall on the ground. To demonstrate this phenomenon, we saw that the same experiment had been done by a Norwegian guy. He was hanging and let down a weight from a high structure and the weight rolled up around the stick, creating a force so strong that he could have carried an extremely heavy weight.
He was really making the conference entertaining, he asked for volonteers to come and help o do the experiments.

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For the last one he took two books whose pages were mixed up together and each book was related to a thread and the goal was to separate the two books. It was really funny when eight people were desperatly trying to separate them because no matter how hard they try, in the end only tanks could.
We can all say that we learned a lot in this conference, we are truly grateful Frédéric Restagno came.

(Vérane & Juliette)

This day was very interesting because the accessibility to understanding, made the theme discussed clear. It was very fun to understanding the physical phenomena of everyday life. We thank Frédéric Restagno, the other speakers and our teachers for this moment of knowledge and sharing. It was a great opportunity to meet.

It will be good for the future clelabistes !
(Maël & Agathe)

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