IAS director Robbert Dijkgraaf will be giving the CERN colloquium tomorrow, with the title The Future of Fundamental Physics. Here’s the abstract:
The reports of the death of physics are greatly exaggerated. Instead, I would argue, we are living in a golden era and the best is yet to come. Not only did the past decades see some amazing breakthrough discoveries and show us the many unknowns in our current understanding, but more importantly, science in general is moving from studying `what is’ to `what could be.’ There will be many more fundamental laws of nature hidden within the endless number of physical systems we could fabricate out of the currently known building blocks. This demands an open mind about the concepts of unity and progress in physics.
I don’t know of any “reports of the death of physics”, but there are a lot of reports of the death of string theory (Dijkgraaf’s specialty) and of the larger subject of attempts to go beyond the Standard Model, experimentally or theoretically. CERN yesterday announced new results from LHCb testing lepton universality (a prediction of the Standard Model). LHCb sees a ratio of decays to muons vs. electrons in a certain process that is off from the Standard Model prediction by 3.1 sigma.
If this result is confirmed with better data and careful examination of the theory calculation, that will be a dramatic development, indicating a significant previously unknown flaw in the Standard Model. BSM theory and experiment would be very much undeniably alive (no known relevance of this though to the troubles of string theory). Unfortunately, the experience of the past few decades is that 3 sigma size violations of Standard Model always go away after more careful investigation (see for instance the 750 GeV diphoton excess). It’s exactly this pattern that has people worried about the health of the field of high energy physics.
Dijkgraaf’s claim that “we are living in a golden era” is an odd one to be making at CERN, which has seen some true golden eras and is now facing very real challenges. Even odder is arguing at CERN that the bright future of science is due to it “moving from studying `what is’ to `what could be.’” CERN is at its core a place devoted to investigating “what is” at the most fundamental level. I’m curious to hear what those at CERN make of his talk.
Dijkgraaf’s abstract to me summarizes the attitude that the best way to deal with the current problems of HEP theory is to change the definition of the goals of the field, thereby defining failure away. The failure of heavily promoted ideas about string theory and supersymmetric extensions of the Standard Model is rebranded a success, a discovery that there’s no longer any point to pursue the traditional goals of the subject. Instead, the way forward to a brighter future is to give up on unification and trying to do better than the Standard Model. One is then free to redefine “fundamental physics” as whatever theorists manage to come up with of some relevance to still healthy fields like condensed matter and hot new topics like machine learning and quantum computing. I can see why Dijkgraaf feels this is the way forward for the IAS, but whether and how it provides a way forward for CERN is another question.
Update: I just finished watching the Dijkgraaf talk, together with the question session afterwards. Dijkgraaf basically just completely ignored HEP physics and the issues it is facing. He advertised the future of science as leaving the river of “what is” and entering a new ocean of “what can be”, with the promising “what can be” fields biotech, designer materials and AI/machine learning. He hopes that theorists can contribute to these new fields by trying to find new laws governing emergence from complexity, perhaps via new ideas using quantum field theory tools.
With nothing at all to point to as a reason to be optimistic about HEP, a couple questioners asked whether his river of “what is” might be now hitting not an ocean but a desert, and he didn’t have much of an answer. All in all, I’m afraid that the vision of the future he was trying to sell is not one in which high energy physics has any real place. It fits well with the depressing increasingly popular view of the field, as one which had a great run during the twentieth-century, but now has reached an end.
Update: Tommaso puts his money where his mouth is.