MULTI-FACETED SUCCESS: Conversation with Sir Chris Llewellyn Smith

Director of Energy Research, Oxford University
President SESAME Council

Interview by Maria Shtilmark

Photo: courtesy John Cairns

Thank you so much for the fantastic talks you gave at the Simons Center. The Della Pietra lecture  series has also hosted David Gross, with whom you have written your article “High Energy Neutrino-Nucleon Scattering, Current Algebra and Partons,”[1] which resulted in the Gross-Llewellyn-Smith sum rule (GLS). At your birthday conference at CERN, David spoke about how “cavalier and bold you both were working on the frontiers of high energy physics when you knew almost nothing!” Could you tell us a little about your collaboration with David and the fate of this article?

In early 1969, when I was a postdoc at CERN, David arrived as a visitor. He was talking about the new ideas that were going around about deep
inelastic electron scattering experiments at SLAC. I was working on neutrino scattering on heavy nuclei (with the late John Bell, of inequality fame, who had pointed out that, very counterintuitively, neutrino scattering must exhibit nuclear ‘shadowing’). I thought, “I will test my understanding of the ideas David described by applying them to neutrinos.” I went to see David and asked whether I had the right answers, to which — to my great surprise — he replied: “Nobody has looked at it.” So we started working together on neutrinos, and came up with certain results. I followed this with some other papers[2] in which I showed that combinations of data from deep inelastic scattering of electrons and neutrinos demonstrate that partons have non-integral charges (not a fashionable idea at the time), and that about half the proton’s momentum must be carried by neutral particles. I think this was the first evidence for gluons. It all started as an accident of timing. I was in the right place at the right time thinking about neutrino scattering, which was being studied at CERN.

I am amazed by how you always manage to find yourself at the crossing of all possible borders — not only between theoretical and applied physics, or between economics, education, politics, and science, but also literal ones, like the border of USSR in 1967 — Lebedev Physical Institute…

FIAN. [Physical Institute of the Academy of Sciences]

Yes. How did that happen?

My wife, Virginia, was writing a PhD on the relationship between the treatment of women in Chekhov’s works and the women in his life, on which she later published a book[3]. She needed access to the archives in the “Biblioteka Lenina,[4]” which is probably called something else now, to read some of his correspondence. Chekhov’s letters were published, albeit in censored form, but the replies were not. This was not regarded as a suitable subject in the USSR in the 1960s. Her supervisor in MGU[5], where she was living when I arrived, told her that he’d only heard of one even more ridiculous thesis topic, on which a visiting American was working: “Pushkin kak Gastronom” (Pushkin as a Gastronome).

Nowadays there is a lot of research on Chekhov’s treatment of women. Virginia was clearly ahead of her time!

Anyway, to conclude I had just finished my PhD and applied for a Royal Society — Academy of Sciences Exchange Fellowship, so that I could join Virginia.

You were Director General of CERN, when the LHC was approved, and have been President of the Council of SESAME, which brings together countries such as Turkey and Cyprus and Iran and Israel. You’ve managed the UK fusion program, led energy research in Oxford,
and served as Provost and President of University College London. During your varied career, what have you found to be the key to successful communication between people with different economical, political and scientific backgrounds?

Communicating across disciplinary boundaries depends on learning through experience, what you can assume that others know and don’t know, and what metaphors and similes will strike a chord. The universality of science is the key to communication among scientists with diverse political and cultural backgrounds and views. As Chekhov wrote, “There is no national science, just as there is no national multiplication table. What is national is no longer science[6]”. I have observed at CERN and at SESAME that scientists, engineers and technicians who work together develop professional respect, which leads to greater tolerance of each other’s views on other matters.

David Gross also mentioned in his talk at your birthday conference at CERN how enthusiastic and hardworking you are, and how you haven’t changed in the many years he has known you. How do you do it? How do you get things done and avoid disappointment?

I think I’ve had my share of disappointments. To cite just one, I worked very hard to get funding for the final stage of the upgrade of LEP (the Large Electron Positron collider at CERN), and for an additional year of operation, because there were good reasons to think that it might discover supersymmetric particles (this was also one part of the case for building the LHC, Large Hadron Collider). It’s puzzling and disappointing that Nature seems to not make use of this beautiful option, at least in a simple way.

When Oxford University refurbished the Geography Department, its Lower Carbon Futures team, which is one of the largest collection of experts on building efficiency in the UK, wasn’t consulted. And in the end, the building uses more energy than before the refurbishment – and I am sure this is just one example of the frustrations you’ve faced.

It was ironic and ridiculous. I don’t usually work in that building and was not aware of what was going on until it was too late. Afterwards I tried to draw people’s attention to what had happened in the hope that it won’t happen again. But you can’t fight, let alone win, every battle.

If you could put your Director of Energy Research hat on for this one: As a former Director of the UK Atomic Energy Authority’s fusion laboratory at Culham, which houses JET, what is its future beyond 2018?

The UK has decided to leave Euratom along with leaving the European Union, in principle in March 2019. Continued operation of JET, and UK participation in the global fusion project ITER, will depend on putting in place some arrangement for continued UK association with Euratom, which funds the operation of JET, and through which Europe belongs to ITER. This will not be straightforward because the European Court of Justice (ECJ) is responsible for the adjudication of disputes related to Euratom. The UK has announced that it will no longer accept ECJ arbitration on any matter, but it is hard to see the EU agreeing to anything else. The lack of any form of UK association with Euratom would have very serious consequences for fusion research. In preparation for the operation of ITER, more experience is needed with a mixture of deuterium (D) and tritium (T), the fuels that are almost certain to be required if fusion is ever used as a source of power. A D-T run is planned in late 2018 at JET, which is the only device in the world that can operate with D-T.

Most alarmingly for the UK, Euratom is responsible for nuclear safeguards and movements of nuclear materials (it actually owns all non-military materials held by its members), and for overseeing nuclear safety in Europe. Unless alternative arrangements are in place by then, the nuclear power production in the UK will grind to a halt on April 1, 2019.

Today is a very dramatic time to be speaking about changes in energy system. The US had its own view first on the Kyoto Protocol and now on the Paris Accord. A lot was said today after your talk – was there a question you liked or you wish that you were asked?

The questions straight after my talk were mostly about details, but later, over lunch, someone informed me that the President was considering
reversing President Obama’s decision to strengthen Corporate Average Fuel Efficiency standards for US cars[7], which I had mentioned in my talk. This led to a discussion of the likely effects of the President’s retreat from the Paris Agreement. My own belief is that the transition to low carbon energy now has enough momentum that it will continue whatever Trump does, although it may go a bit slower. Part of the Paris Agreement was to transfer funds to developing countries to help them get away from carbon-based energy, and that will presumably suffer from US withdrawal. However, in the US, the States control energy policy as much as the Federal Government. I assume that California, which is the sixth biggest economy in the world on its own, is just going to keep going, and not going to pay any attention to Trump.

The New Yorker compared the Paris Agreement to the tale of the Stone Soup[8].

Like Stone Soup, the Paris Agreement depends on voluntary contributions, or at least pledges, but it does not require that everyone does the same thing and the analogy is not complete. In fact, rather than encouraging others to pull out, US withdrawal seems to have strengthened the resolve of China and of the European Union. In the Stone Soup case, everyone puts something in and gets something out of the pot. In the case of de-carbonization, inputs and outputs have been very unbalanced. Germany, for example, poured subsidies into wind and solar energy, which produced a lot of renewable power, in a country where the potential is limited. However, this did not have a big impact on carbon emissions, because of the decision to close down nuclear power, or, as had been hoped, benefit German renewable companies (although German machine-tools are used to make solar cells worldwide). But the rest of the world benefitted enormously because the experience of large-scale manufacturing drove down costs. Actually, China captured a lot of the solar PV market, and Denmark and others took the lead in wind. I would be surprised if US withdrawal from the Paris Agreement has a major effect on US market share. As I said, the transition to wind and solar has a momentum of its own, supported by many States. It’s interesting that not only the big tech companies, but also the oil companies have been criticizing the decision.

In your opinion, to what extent is the choice between fossil fuels and renewables more a matter of culture or economics?

Attitudes are very important. For example, I’ve noticed that among the rich in Santa Fe it’s socially unacceptable to have a green lawn when it’s very dry, whereas not so far away in Albuquerque, green lawns are seen as a desirable sign of affluence. However, in most of the world, economics will determine the speed and extent of the move to renewables.

How important is it to get the public more educated, interested and involved in sustainability and the use of renewables? Where do you start?

The more the public understands the need to move away from fossil fuels, the better. Most people have probably made up their minds about climate change. But it’s also important to decarbonize to reduce air pollution which is a major cause of death in developed countries, such as the US, as well as in countries like China and India. Also to reduce international tensions by rebalancing relations between major exporters of fossil fuels (Russia, the Gulf States) and importers. Public appreciation of these arguments can help speed up the energy transition, but the key is to develop clean alternatives to fossil fuels that are also cheaper.

I know people who have gone vegan partly because they believe modern animal agriculture is a very aggressive polluter, and livestock and their byproducts account for at least 32,000 million tons of carbon dioxide (CO2) per year, or 51% of all worldwide greenhouse gas emissions. Do you think this is true?

It’s true that if we all became vegetarians it would make a big contribution. I myself don’t know anyone who became a vegetarian because of concern about emissions – it’s interesting that you do. Those I know became vegetarians for health reasons or concern about animal welfare.

When you spoke of the dire need to decarbonize, you mentioned that one way is to rethink the industrial processes. Do you know if these attempts to rethink it are being implemented at the ITER construction at all?

While ITER is surely being built in an environmentally responsible manner, I’m not aware of any novel steps that are being taken to reduce the project’s environmental impact, but that may reflect my ignorance.

The reason I asked was this quote from the brochure on the official opening of SESAME: “When SESAME’s solar power plant comes into operation, SESAME will be the first accelerator in the world powered solely by renewable energy.[9]

The use of renewable energy is necessary to allow SESAME, which is currently paying $375/MWh for power, to operate at a cost that the Members can afford. It’s also a good example, which I hope will be followed by others — accelerators use a lot of power. While SESAME is not the highest energy or the brightest synchrotron radiation facility in the world, it will be a good facility that will enable good experiments by a large community which up to now has not had access to a light-source, and someone with the right idea could use it to win a Nobel Prize. It’s good that it will also lead the world in at least one way.

In 2015, my colleague Elyce Winters spoke with Eliezer Rabinovici, whom you also mentioned in your talk. He spoke of three things critical for SESAME’s success: that science is a common language; that SESAME has top science; and that the members participate on an equal basis. Would you like to comment on the various difficulties — political, financial, even inclement weather — that the project encountered, which you mentioned in your presentation?

I was President of the SESAME Council for 8.5 years. You would expect some difficulties over a period like that. But the really remarkable thing is how few there have been and that we’ve managed to get around them and surmount them. When the political situation in the Middle East was particularly bad a few years ago, someone asked whether we should give up. My reaction was that the worse the situation, the more we need SESAME, as it shows that people of goodwill can work together to achieve common ends across some of the deepest divides on the planet, in the most dire of circumstances.

If we could go back to ITER – it is obviously not the project for someone who likes instant results. How do you deal with such a timeline?

That’s a very interesting question. I was surprised that nobody asked me about the prospects for fusion after my talks here. Let me deal with that unasked question first. Ten years ago, I would have replied that I’m reasonably confident that we will be able to make a fusion power plant, although we need ITER to be sure, and the real question is can we make one that’s reliable and competitive? The question of reliability will remain unanswered until we try, although operation of ITER will provide clues. I used to think there was a reasonably good chance that fusion could compete with other low carbon sources of power, but, while I would not say that it’s impossible, the situation has changed. The cost of wind and solar power has decreased faster than anyone could have dreamt. Meanwhile ITER has gone way over budget, partly because of the way that the project was set up and because it’s the first of a kind, but probably also because fusion reactors will be intrinsically more expensive that we thought a decade ago. I think we need to finish ITER and establish once and for all whether fusion really is a viable option. We will then have to reassess the likely cost of fusion power in the light of the experience gained with ITER and in comparison with the cost of alternatives before deciding whether to go ahead and build a real fusion power station.

On the timescale, the ITER management are now talking about deuterium-tritium plasmas in ITER in 2035. So it’s a very long time before we will be able to establish the viability of fusion. Your question whether people will be willing to commit to projects with such long time scales is a good one. Can you, should you, motivate people to get involved, and devote their careers to projects that won’t produce results until after they’ve retired? A similar question arises in high-energy physics. I gave the first major talk on what physics it might be possible to do with the LHC if we ever built it in 1984, but it didn’t start to operate until 2008, and even then not properly. How do you deal with these long-time scales?

This issue is not new. During the Middle Ages, people in Europe designed and started building cathedrals, which often took hundreds of years to complete, knowing they would never see them finished. They presumably considered that they were doing it for the glory of God and the spiritual benefit of succeeding generations. Likewise, people may be willing to devote their lives to fusion, or other very long-term projects, with no expectation of seeing them working in their lifetimes, if they are convinced that they may provide a better world for their great grandchildren. On the other hand, people work in high-energy physics to satisfy their intellectual curiosity, and presumably want to live to know the answers to the questions they are addressing. If the timescales get very much longer, I think it will become increasingly difficult to attract people to such fields. I certainly would not have wanted to become Director General of CERN in order to start a project which I knew would not be finished for
50 years.

Thank you very much, good luck and hope to see you again at the Center. ·


[1] High Energy Neutrino-Nucleon Scattering, Current Algebra and Partons (D. Gross C. Llewellyn Smith), Nuclear Physics B14 337 (1969).


[2] Current Algebra Sum Rules Suggested by the Parton Model, Nuclear Physics B17 277 (1970). Inelastic Lepton Scattering in Gluon Models, Physical Review D4 2392 (1971).

[3] Anton Chekhov and the Lady with the Dog, Virginia Llewellyn Smith, Oxford University Press (1973).

[4] The Lenin State Library, now the Russian State Library. The Moscow subway station is still called the Library Named after Lenin, though – M.S.

[5] MGU – The Moscow State University.

[6] (Quoted by

[7] On 16 March Trump said he was ordering the EPA to reopen a mid-term review of Corporate Average Fuel Economy Standards that currently require the industry to deliver a fleet average of at least 54.5 mpg by 2025. The President’s goal is to make Detroit “the car capital of the world again” and save automotive jobs, which would be lost if (as claimed by some in the industry) meeting the standard were to increase vehicle prices and hence depress sales.



[9]  SESAME Official opening under the patronage of His Majesty King Abdullah II, 16 May 2017, pg.13.