Written by Hinke Osinga University of Bristol, UK
	August 8-12, 2005 Eindhoven University of Technology The Netherlands

The fifth EUROMECH Nonlinear Dynamics Conference is organised every three years since 1993 under the auspices of the European Mechanics Society (EUROMECH). This series of so-called ENOC conferences continues a tradition of twelve International Conferences on Nonlinear Oscillations (ICNO) in East-European countries, that started in 1961 in Kiev,

Ukraine. ENOC-2005 was the first conference in the series to include research areas beyond the specific context of mechanical systems, and as such there were a large number of first-time ENOC participants, including myself. In this respect, the conference was a huge success in bringing together such a broad range of researchers in nonlinear dynamics. On the other hand this meant that the programme was packed, with 14 minisymposia running in parallel! The minisymposia were series of themed talks running over several days, so that participants would mostly attend one specific minisymposium. Hence, there was too little opportunity to go to other talks and research interactions between fields were largely limited to the plenary lectures.
		The international music ensemble Barocco Locco performs during the opening ceremony; photograph by Gábor Orosz

		The real success of ENOC-2005 was the quality and breadth of research topics in the plenary lectures. All plenary speakers had gone to great lengths to provide a professional electronic presentation of the highest quality and the lecturers were delivered with great enthusiasm. Phil Holmes gave the opening lecture, where he provided a historical overview of dynamical systems theory. Of course, many of us know the story of King Oscar of Sweden who challenged the learned men of his time to proof the stability of the planetary system, and how Poincaré won it by showing that this is not true. However, Phil managed to add lots of details unknown to most: for example, he read excerpts from letter aloud in perfect French, fortunately followed by a translation. He discussed work by Cartwright and Littlewood, Smale, Kolmogorov, Arnol'd and Moser and showed examples of observations of chaotic dynamics. At the request of many in the audience, Phil has made his lecture slides available online in the DSWeb Tutorials section. During the conference, Phil Holmes was also honoured at the conference banquet on the occasion of his 60th birthday.
Edgar Knobloch and Phil Holmes at the conference banquet listen to a speech by Gábor Stépán; photograph by Alexander Vladimirsky

Leo Maas (left) and Gábor Stépán; (right); both photographs by Gábor Orosz.

Another highlight was the lecture by Jaques Laskar on "Long Term Evolution of the Terrestrial Planets Spin Axis". He discussed possibilities on why Mercury is trapped in a 3:2 spin orbit resonance, why Venus is rotating in a retrograde way, and what we can say about the past
		obliquity of Mars, even though it is now chaotic. He also gave a fascinating explanation of the effect of the spin axis of Earth on our global climate. Namely, how the position of the north pole can move away from the spin axis as a result of the moon being pushed away due to the tidal dissipation, which slows down Earth. This obliquity can vary as widely as 20° - 90°! Jaques emphasized that one can give all sorts of explanations of things that we observe today, but the point is to provide evidence why a certain explanation is actually the correct one. Since the dynamics ranges over billions of years, it is not easy to verify anything, which makes is obviously difficult to come up with convincing predictions for the future.
Jaques Laskar; photograph by Alexander Vladimirsky.				Mark Levy; photograph by Alexander Vladimirsky.

The complete list of plenary talks:

Phil Holmes (Princeton University)

Ninety plus Thirty Years of Nonlinear Dynamics: More is Different and Less is More

Leo Maas (Royal Netherlands Institute for Sea Research)

"Wave Attractors: Linear Yet Nonlinear"

Gábor Stépán (Budapest University of Technology & Economics)

"Delay, Parametric Excitation and the Nonlinear Dynamics of Cutting Processes"

Jon Juel Thomsen (Technical University of Denmark)

"Slow High-Frequency Effects in Mechanics: Problems, Solutions, Potentials"

Jacques Laskar (Institut de Mécaniques Céleste et de Calcul des Éphémérides)

"Long Term Evolutions of the Terrestrial Planets Spin Axis"

Thor Fossen (Norwegian University of Science and Technology)

"A Nonlinear Unified STate-Space Model for Ship Maneuvring and Control in Seaway"

Mark Levi (Penn State University)

"Geometry of Vibration Stabilization and Some Applications"