As a preamble to an understanding of magnetic reconnection, I defined field lines & flux tubes in my previous post
. Here I present several definitions and descriptions of magnetic reconnection as a physical process. Once again, I have tried to stick to unimpeachably authoritative & reliable sources. I present several, rather then just one, because the process is complicated and there are different ways to describe it. Hopefully everyone will find at least one explanation that resonates with their understanding.
I have highlighted
what I think are the key points, but I have tried to cite enough language to provide proper context, as well as to avoid insufficiently brief descriptions. Any other emphasis besides the highlight is carried over from the original text. I encourage the reader to pay attention to the full text of the quotes, and to refer directly to the original sources, which I have linked to as best I can, wherever possible.
Magnetic Reconnection Defined and Described
, Russell Kulsrud
and Hantao Ji
; Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas, Princeton Plasma Physics Laboratory, Princeton University
Reviews of Modern Physics 82(1): 603-664, January 2010.
Originally Posted by Yamada, Kulsrud & Ji, 2010, first two paragraphs of introduction
Magnetic Reconnection in Astrophysical and Laboratory Plasmas
Ellen G. Zweibel
Originally Posted by Yamada, Kulsrud & Ji, 2010, Third and fourth paragraphs of Appendix A: "The Nature of Reconnection"
and Masaaki Yamada
Annual Review of Astronomy and Astrophysics 47: 291-332 (2009)
Fundamentals of Plasma Physics
Paul M. Bellan
Originally Posted by Zweibel & Yamada, 2009, abstract
, Bellan Plasma Group
, California Institute of Technology
; Cambridge University Press 2006
Magnetic Reconnection: MHD Theory and Applications
Originally Posted by Bellan 2006, page 410, 2nd paragraph of chapter 12, "Magnetic reconnection"
& Terry Forbes
; Cambridge University Press, 2000
Originally Posted by Priest & Forbes, 2000, from the Preface
Review of controlled laboratory experiments on physics of magnetic reconnection
Originally Posted by Priest & Forbes, 2000, from the Introduction, page 1
Journal of Geophysical Research, Space Physics, 104(A7): 14529-14542, July 1999
Originally Posted by Yamada, 1999, First two paragraphs of the Introduction
Deiter Biskamp (Max Planck Institute for Plasma Physics
); Cambridge University Press 1993
Originally Posted by Biskamp, 193, Page 127, first paragraph of chapter 6, "Magnetic Reconnection"
Note his comment "thin flux tubes, properly speaking". Flux tubes are defined in section 2.2, "Conservation laws in ideal MHD", specifically on pages 13-14. I have used that as the definition for flux tubes in my previous post
Relaxation and magnetic reconnection in plasmas
, Abingdon, Oxfordshire, England
Reviews of Modern Physics 58(3): 741-763, July 1986
Originally Posted by Taylor, 1986, First two paragraphs of Introduction
As we already know, magnetic field lines are mathematical objects not physical objects. Therefore, the reconnection of magnetic field lines is, strictly speaking, a mathematical process not a physical process. This is a distinction that I have made before, on 19 November 2011 ...
Originally Posted by Tim Thompson
I think my opinion then is justified by the definitions & descriptions I have posted here. The twin themes of a change on topology and a transition from a higher to a lower energy state are consistent in the definitions provided by multiple reliable sources. The change in topology is a mathematical process, the transition from higher to lower energy is a physical process. This is where the intimate relationship between mathematics and physics is well illustrated. We can pretend that the lines of force are physical, rather than mathematical, and we can likewise pretend that the reconnection of field lines is a truly physical process. If we do that, and make predictions regarding anticipated physical observations, our predictions are verified. And so one might ask, while there is a difference between the mathematics and the physics in principle, what is the real, practical difference, if the two are literally interchangeable, if the mathematical objects can be treated as if they were physical objects?
The fact remains, as demonstrated here, that magnetic reconnection
is well defined, both as a physical process and a mathematical process.