Kip Thorne’s visit to AIMS

Kip Thorne visited AIMS and the AIMS Research Center on November 24 as part of his visit to the nearby Stellenbosch Institute for Advanced Studies (which, as a somewhat irrelevant aside arguably has the best food of any such institute in the world). The morning of his visit was dedicated to a very lively debate about “what is good research?” with input from AIMS lecturers Bernd Shroers, Robert de Mello Koch and distinguished visitor to the Research Center, Douw Steyn.

The debate probed the question from an international and African perspective and also within the context of a world where there is so much change around the way academic jobs are awarded, the way research is done and published, the current climate of fluctuating research funding and the new pressures on young researchers.

Kip discussing some of the finer points about good research

One of the most interesting and pertinent issues discussed was the problem of how young researchers should try to do “high impact” science while still looking after their careers.

There is a perception that either one can publish many relatively uninteresting papers, or hold out and publish something “big”, the latter being a high-risk approach, the former a low-risk approach, to getting a job.

Kip argued strongly that this “all or nothing” approach to doing high-impact science is not a  good way to go. Instead he suggested that one can work on an important research program while publishing “progress reports” along the way. While none of these papers need be ground-breaking, the sum total of the research, published over several years and multiple papers, can be extremely important. This resolves the apparent impasse between the number and quality of papers.

Bare foot cosmology and gravitation...

Too often perhaps, young researchers look at the quality or impact of individual papers, rather than looking at whether their research is really building to something. Job committees, or at least the ones I have been on, typically do look at the whole research program of the applicant, and ask, “Is this person a leader in their sub-field?”, which I think is a restatement of this approach to building important research.

After lunch and the obligatory wander on the beach, Kip gave a lecture called “Black Holes, Wormholes, and Spacetime Singularities” to a packed hall of AIMS and ARC students which summarised the progress in various areas and discussed the interesting ideas of vortex and tendex lines for the gravitational field, which has subsequently been published in this paper [1].

The key idea is that, in analogy to the electric and magnetic field lines of electromagnetism, one can construct similar quantities for the gravitational field with the electric part of the Weyl tensor related to tendex lines and the magnetic part related to vortex lines.

This is an interesting and very novel extension of the intimate analogy between gravity and electromagnetism which has already been studied in great detail. My own foray into this fascinating area showed the existence of the same U(1) symmetry in gravity under rotations mixing electric and magnetic parts as exists in electromagnetism, and the existence of ‘magnetic’ monopoles for the gravitational field, at least in the linearised case [2].

In summary, Kip’s visit was very entertaining all round and included interesting insights on Hollywood: he is working on a sci-fi film with Steven Spielberg. Wormholes will be coming back to a screen near you.

— Bruce

[1] arXiv:1012.4869; Frame-Dragging Vortexes and Tidal Tendexes Attached to Colliding Black Holes: Visualizing the Curvature of Spacetime, R. Owen et al… (2010)

[2] arXiv:gr-qc/9704059, Gravito-electromagnetism, Roy Maartens, Bruce A. Bassett, Class.Quant.Grav.15:705, (1998)