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This cartoon bravely attacks one of the outstanding problems of heliospheric physics, namely how the solar energetic particles spread out into a large solid angle within the solar wind. This problem has always seemed especially intractable for the type-III-burst electrons, at least as conventional wisdom understands them physically. These are identifiable with highly collimated soft X-ray jets, and one also can infer a tight beam structure directly and indirectly from the radio data. So, how does a point in space and time map onto a volume (or at least, onto an area)?

The authors have "rounded up the usual suspect," to paraphrase Casablanca: in this case magnetic reconnection. This old and ill-understood concept is dressed up here with two adjectives: "slip-running" and "interchange", but it seems to be the same physics as before. The problem has always been that a current sheet is basically a sheet, ie a a 2D manifold, whereas the solar wind is 3D. The authors discuss this in terms of the "spine" field line, which is 1D. So the Archivist is still a bit perplexed.

12 October 2011