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Thursday 17 April 2008 (Updated Fri 18 April)

RAPID ROUNDUP: Edward Lorenz dies - Scientists comment

Mathematician, meteorologist and father of chaos theory, Edward Lorenz has died in Massachusetts at the age of 90. Australian scientists comment below.

If you wish to speak to an expert, don’t hesitate to contact the AusSMC on (08) 8207 7415.

Kurt Lambeck is Professor of Geophysics at the Australian National University (ANU) and President of the Australian Academy of Science.

"Ed Lorenz is widely known for formulating the concept of chaos theory in simple terms such that today we are amazed by its simplicity. Chaos theory helps us understand the importance of getting your starting conditions right when you are trying to predict how a system will behave in the future, for example. If you begin your calculations with numbers that are not quite correct, small anomalies can suddenly become very significant and steer your solution off track.

This is relevant in the concept of trying to understand climate change. We perturb a system by small amounts, each one seems insignificant, but the consequence could be that the whole system takes off in a different direction. Chaos theory emphasizes the instability in many physical systems, where traditionally we have thought they were stable."

David Karoly is Professor and Federation Fellow in the School of Earth Sciences, University of Melbourne, and a lead author on the IPCC 4th Assessment Report.

"Ed Lorenz is best known for his pioneering research on chaos and the predictability of weather and climate. But he was also an outstanding teacher, making sure to present complex ideas in simple ways. He showed an uncanny ability to distil the complexity of the atmosphere or the climate system into just a few simple equations, and then explain the behaviour of those systems in new and insightful ways."

Robert Dewar is Professor of theoretical physics at the Research School of Physical Sciences & Engineering at Australian National University and is convenor of the ARC Research Network Complex Open Systems Research Network.

"The title of Edward Lorenz' 1972 paper 'Predictability: Does the Flap of a Butterfly's Wings in Brazil Set Off a Tornado in Texas?' introduced the famous 'butterfly effect' metaphor to the language.

Lorenz had discovered something quite different from mere randomness or stochasticity. He had found that even his idealised, completely deterministic, computer simulations of weather, where he had control over initial conditions to machine accuracy, could become unpredictable over a finite time because the tiny initial errors grew exponentially.

Lorenz' realisation that this was not just a pesky computer bug but an important new effect started a whole new 'industry' of research into chaos which spread rapidly way beyond weather prediction and has become one of the mainstays of the new science of complex systems. Perhaps this can itself be regarded as an example of the butterfly effect, or perhaps Richard Dawkins' 'meme' idea that potent ideas can spread virus-like into the collective consciousness is more appropriate. Anyway, there is no doubt that Ed Lorenz has had a profound effect on science."

Andy Pitman is Professor and Co-Director of the Climate Change Research Centre at the University of New South Wales.

"Lorenz's contribution was to understand a fundamental property of complex systems - chaotic
behaviour. Simply, he changed the way science sees how systems work and how they can be
predicted into the future. His contribution is second to only the discovery of relitivity and quantum physics in 20th century science".

Amanda Lynch is Professor and a Fedoration Fellow in the School of Geography and Environmental Science at Monash University. She is an expert on climate change and extreme events.

“Ed Lorenz fundamentally changed how we think about the atmosphere, but his insights into the limits of determinism have influenced a broad range of fields, and I would argue that he changed the fabric of science itself - allowing us to finally put aside the clockwork universe. That had already been done at sub-atomic scales of course, but until Ed's insights we clung to the hope that the macro-universe would behave. He was also a real gentleman.”