1. Symétrie et asymétrie dans la musique classique (1750 – 1820)

Eugenia Duta.
La symétrie irrégulière pratiquée dans la musique classique, mélange de symétrie et d’asymétrie, a des conséquences importantes quant au processus de la construction musicale. Sous l’apparence du déroulement linéaire inévitable à un art du temps, ce processus est une amplification, un développement semblable à une croissance. Chaque moment de ce développement devient la conséquence de tout ce qui l’a précédé et pas uniquement du moment qui le précède immédiatement ; il devient aussi cause de tout ce qui s’ensuit et pas uniquement du moment suivant ; tout moment est lié à tous les autres dans l’accomplissement d’un destin commun qui est l’équilibre de l’ensemble. L’unité, la cohérence et la cohésion de ce processus de construction musicale rappelleront à juste titre celles des processus organiques.

2. Asymmetric Exchanges

Caroline Bouissou ; Michel Petitjean.
We emphasize the asymmetric character of exchanges between artists and scientists or mathematicians in the framework of multidisciplinary collaborations. As an example, we look at the perception of asymmetry in an artwork presented at the First European Asymmetry Symposium (FEAS), Nice, 15-16 March 2018, and its potential connection with the unsolved mathematical problem of maximal or asymptotically maximal asymmetric figures and distributions.

3. Philae Landing on Comet 67P/Churyumov-Gerasimenko – Planned Chirality Measurements and Ideas for the Future

Stephan Ulamec ; Fred Goesmann ; Uwe Meierhenrich.
Philae is a comet Lander, part of the ESA Rosetta Mission to comet 67P/Churyumov-Gerasimenko. After a ten year cruise through the solar system it successfully landed on the nucleus of the comet on November 12, 2014. Philae's payload consists of ten scientific instruments, including COSAC, an evolved gas analyser with the capability to differentiate chiral molecules. After the touchdown of Philae, the anchoring harpoons, which were expected to fix the lander to ground, did not work, Philae bounced in the low gravity environment, and only came to rest after a 2 hours " hop " in an unforeseen area on the comet surface. Although, the scientific instruments, including cameras, mass spectrometers (including the one of COSAC), a magnetometer and a radar instrument could be operated, and fascinating, unprecedented scientific results were obtained, it was not possible to collect a sample of the surface material and no gas chromatography measurement could be performed. Thus, the measurement of the chirality of molecules on comets is still to be done in the future. The paper gives an overview of the Philae mission and the attempts to measure chiral molecules with COSAC, and suggests future measurements with returned samples from the primitive asteroids (162173) Ryugu and (101955) Bennu with the spacecraft Hayabusa 2 (JAXA) and OSIRIS-REx (NASA), respectively. Both will reach their targets in 2018.