I didn’t know until today that there is a meeting going on this week at the University of St Andrews with the title 40 Years of MOND (Modified Newtonian Dynamics). Here’s a description of the conference.
The source of the gravitational field in objects ranging from individual galaxies to the largest scales in the universe is one of the biggest unanswered questions of modern physics. It is generally assumed that the gravitational field in extragalactic systems is dominated by dark matter particles occupying a dark sector that represents new physics beyond the stubbornly successful Standard Model of particle physics. So far, candidates for these particles have evaded detection in remarkably sensitive laboratory experiments: the evidence for missing mass remains entirely astrophysical in nature.
Forty years ago, Weizmann-Institute professor Mordehai Milgrom published a series of three articles in The Astrophysical Journal in which he proposed that the dark matter phenomenon is not due to unknown particles, but to a departure from the known laws of dynamics when the acceleration is about eleven orders of magnitude smaller than that on Earth’s surface (Milgrom 1983). Only one year later, in 1984, Jacob Bekenstein and Mordehai Milgrom developed this Modified Newtonian Dynamics (or Milgromian Dynamics, MOND) into a non-relativistic Lagrangian theory (Bekenstein & Milgrom 1984). During the ensuing decades, MOND has developed into a multifaceted paradigm that includes several non-relativistic and relativistic theory proposals, as well as possible connections with quantum gravity theories. Most remarkably, MOND has successfully made many striking and unique a priori predictions.
This conference will commemorate the last 40 years of this modern gravitational paradigm, of its predictive successes as well as its outstanding challenges, and will look to the road ahead.
It looks like an interesting meeting but what caught my eye in particular about it was this pic I found on Twitter today taken at the start of one of the talks:

The work presented apparently has been the focus of quite a lot of debate and several follow-up studies. I just thought I’d mention that it was published earlier this year in the Open Journal of Astrophysics:
It’s good to see work appearing in one of our publications attracting attention at an international conference!
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