initiated by Paul Ehrenfest in 1912
currently organized by Ana Achúcarro & Luca Giomi (read about its history)

Dinner participants: 80 | Follow the live stream


Clifford Burgess

Mc Master University, Hamilton Canada

June 01

7:30 p.m.


Thinking Effectively About Gravity

We live at a time of contradictory messages about how successfully we understand gravity. General Relativity seems to work well in the Earth’s immediate neighborhood, but arguments abound that it needs modification at very small and/or very large distances. This talk tries to put this discussion into the broader context of similar situations in other areas of physics, and summarizes some of the lessons which our good understanding of gravity in the solar system and elsewhere has for proponents for its modification over very long and very short distances. The main message is mixed: On one hand short-distance quantum effects are notoriously difficult to control in gravity and cosmology seems to like features (like light scalars and small vacuum energies) that are not generic to the long-wavelength limit of fundamental theories. These are crucial clues that would be silly to ignore. On the other hand, General Relativity successfully passes many stringent new observational tests and also seems to be almost unique in its ability to reconcile quantum effects with gravity on longer distances without being inconsistent. Neither of these seems to offer much scope for modification. I try to organize what the successes of GR might be telling us, and provide a score-card about it says about the various alternatives that have been proposed.

The Colloquium Ehrenfestii takes place Wednesday evenings starting at 19:30 hours in the main auditorium of the Oort building. Before the Colloquium, there is a common dinner in the canteen located on the ground floor of the Oort building. This dinner starts at 18:00 hours sharp and is free of charge, under the condition that one attends the colloquium and that one has made a reservation before noon on the Tuesday preceding the colloquium.

Meal registrations may close earlier, when 80 persons have signed up.

Colloquium Ehrenfestii Program 2022

30 Mar

Michiel van den Broeke (Universiteit Utrecht, Professor of Polar meteorology)

Big ice and Sea level rise

06 Apr

Cristiane Morais Smith (University of Utrecht)

Atom-by-atom engineering of novel states of matter

01 Jun

Clifford Burgess (Mc Master University, Hamilton Canada)

Thinking Effectively About Gravity

06 Jul

Markus Aspelmeyer (Faculty of Physics, University of Vienna)


Search the CE archive or explore the past programs

The search form accepts only one keyword and no special characters are allowed.