Four fragments and a preview

Abstract

I present discussion of four problems that I have been unable to solve during my career so far, in the hope that others will succeed where I have failed. I also discuss preliminary work on a model of mean-field electrodynamics that aims to show the difficulties with the ansatz at large magnetic Reynolds numbers.

Keywords:

• Dynamo theorey
• Birfurcation

Acknowledgements

I have been fortunate to have had a large number of talented collaborators, but there is no space to thank them all here. As far as my senior colleagues go, I wish to record my particular deep gratitude to Willem Malkus, Keith Moffatt, Nigel Weiss and Ed Spiegel. Among younger colleagues, I particularly wish to acknowledge Chris Jones, Dave Galloway, David Hughes, Edgar Knobloch, Steve Tobias and Alastair Rucklidge. Finally, I am indebted to Paul Roberts and Andrew Soward for inspiration and good advice over many years.