Steven Weinberg: The Crisis of Big Science

A few weeks ago, via Peter Woit's excellent blog, I was alerted to a recent article in The New York Review of Books by Steven Weinberg, titled The Crisis of Big Science. Woit added his own thoughts on the article, and there are many interesting opinions expressed in the comments section there. However, I felt that a very important question was not satisfactorily answered, as I will try to discuss here.

Weinberg provides a brief and personal overview of the development of particle physics experiments, starting from Rutherford's pioneering gold foil experiment in 1911 (the "experimental team consisted of one postdoc and one undergraduate [...] supported by a grant of just £70 from the Royal Society of London"), through the invention of cyclotrons, the postwar development of accelerators and the construction of dedicated accelerator facilities at Fermilab and CERN, to the current multi-billion dollar Large Hadron Collider (LHC) which (we hope) will confirm a detection of the Higgs boson later this year, and might yet — if we are lucky — provide exciting clues about the correct particle physics theory at higher energy scales than we have yet probed.

One of the obvious themes in this short history is the enormous and growing cost of building the experimental facilities required to increase our knowledge about particle physics. Obtaining the money for these facilities is always difficult, and sometimes impossible. Weinberg reflects in particular on the cancellation in the 1990s of the Superconducting Super Collider (SSC):

Then in 1992 the House of Representatives canceled funding for the SSC. Funding was restored by a House–Senate conference committee, but the next year the same happened again, and this time the House would not go along with the recommendation of the conference committee. After the expenditure of almost two billion dollars and thousands of man-years, the SSC was dead.  

One thing that killed the SSC was an undeserved reputation for over-spending. There was even nonsense in the press about spending on potted plants for the corridors of the administration building. Projected costs did increase, but the main reason was that, year by year, Congress never supplied sufficient funds to keep to the planned rate of spending. This stretched out the time and hence the cost to complete the project. Even so, the SSC met all technical challenges, and could have been completed for about what has been spent on the LHC, and completed a decade earlier.

(The claim that projected costs only increased because of insufficient spending every year is interesting, and something I hadn't heard before. I don't know whether it is true, but it sounds plausible.)

This is not simply a problem for particle physics. The same pattern holds — though at a somewhat lower cost level — for my own field of astrophysics and cosmology. Recently, the US Congress decided to scrap funding for NASA's James Webb Space Telescope and the US has also decided to terminate the IXO (X-ray) and LISA (gravitational waves) projects, which caused the European Space Agency to choose to fund a mission to explore Jupiter's moons (known as JUICE) over projects that would have been more relevant to cosmology.

In the end, the point is that the political support for a such massive science experiments is hard to obtain. Weinberg says

During the debate over the SSC, I was on the Larry King radio show with a congressman who opposed  it. He said that he wasn't against spending on science, but that we had to set priorities. I explained that the SSC  was going to help us learn the laws of nature, and I asked if that didn't deserve a high priority. I remember every word of his answer. It was "No."

Now this is the question I'd like to focus on. Let's leave aside for now the question of whether a convincing science case can in fact be made for an SSC-like accelerator or JWST-like space mission (Peter Woit's post discusses this for a new particle accelerator); I will assume that the proposed experiment, whatever it may be, will indeed help us "learn the laws of Nature." Is this justification enough for vast government funding?

Weinberg's implicit position is that the answer to this question is self-evidently yes. Learning the laws of Nature is, in and of itself, a goal that is worth spending public money on. He doesn't want "big science" to cannibalise the budget allocation for other things, such as healthcare or education or anything else, but he argues that in general countries — specifically the US — could afford to tolerate slightly higher taxes in order to fund this search for enlightenment.

Obviously, I am somewhat sympathetic to this view. I am a physicist attempting to learn the laws of Nature myself, after all. I also think that in the grand scheme of things the amount of money required for big science is trivial compared to a lot of other useless stuff taxpayers end up paying for, and that the size of tax increases required to pay for large scientific experiments is not ruinously high. But it is wrong to imagine there is no competition with other demands for funding — even if extra tax revenue were raised, we must still choose whether to spend that money on education, the justice system, healthcare, fighting world poverty ... or physics experiments.

So we still need to answer the question of why the pursuit of scientific knowledge should be paid for by the taxpayer. I don't agree with the unnamed congressman's view, but I can accept that it is fairly commonly held and even perfectly justifiable, and that physicists need to make a good case for themselves in order to get funding. It is easy to justify funding for science with direct societal benefits, such as medical research. But particle physics and cosmology have no direct benefits, as far as I can tell, other than "advancing human understanding of the Universe." Given that we will always only have a finite sum of money to spend on all the stuff we would like to promote, why should we spend it on this?

Now, in my experience when particle physicists or cosmologists are asked this question, there are two common responses. The first is to talk about unintended spin-offs from fundamental research, such as the invention of the World Wide Web itself. Obviously this is great, but the problem, as Weinberg admits, is that serendipitous discoveries can never be guaranteed. It is also not at all clear to me that hoping for serendipitous discoveries is better value for money than directly funding research to achieve desired outcomes, such as tackling infectious diseases or producing better computer chips through solid state physics research (and these fields may well have their own spin-offs, who knows?).

The second line of defence is the one that Woit appears to adopt: that the pursuit of knowledge for its own sake is some fundamental part of what makes us human, along with things like art, music and poetry, and generally makes the world a better place. Weinberg would doubtless think the same. Again, I'm sympathetic to this argument. But I suspect the majority of humans who have no desire whatsoever to learn about fundamental physics would disagree! We also don't generally seem to think society should compulsorily support musicians or poets through taxes.

So I don't think these two common arguments are actually that convincing. To convert people like Weinberg's radio show debater, physicists will need to do better than nebulous ideas about intellectual fulfilment or promises of unspecified lucky spin-offs. Fortunately, I think we can, and I'd like to articulate what I think is a more persuasive argument in favour of fundamental physics research. (I'm not going to be particularly original here: I first heard this reasoning from Alan Barr a few years ago. But I don't see this argument made often enough elsewhere so it is worth highlighting again.)

The point is that the desire for knowledge for its own sake is part of human nature — not all humans, obviously, but some significant number. Black holes, dark matter and dark energy have no possible economic or technological application I can think of; nor does the Higgs boson or SUSY or anything else (though see here). But they are exciting. They capture the imagination of bright young people and make them consider studying physics in school or at university. They are part of the hook that draws people to science. They are the reason that Stephen Hawking can write best-sellers and Brian Cox can make TV shows.

In my own experience, exposure to these wonderful ideas is what made me, many of my classmates, and most of the students whose applications to read physics at Oxford I was involved in processing (many of whom had done summer projects at CERN), want to get a physics degree in the first place. Alan suggested the fraction of physics applicants motivated in this way was around $80\%$ or so, which sounds plausible, if a little hard to confirm. Now of course not all of these enthusiastic and impressionable young people end up working in cosmology or particle physics. A physics degree is hard work, and physics itself is a broad church. During the course of their studies they may discover some other, less well-known, areas they find even more interesting, or they may learn that physics is not for them after all. Perhaps they move into condensed matter physics, or engineering, or computer science. Perhaps they become teachers, or pilots, or advise governments on science policy. Perhaps they go into something else altogether: industry, law, medicine, even — perish the thought — investment banking.

But they will all have gained from their education some knowledge of scientific argumentation, rational thought, and interpretation of data, some understanding of probability and statistics, and some idea of how the natural world works. That is in addition to all the other general benefits of a university education, which I won't go into now. Educating more people in these things is pretty universally agreed to be of significant societal and economic benefit to everyone. All governments everywhere at least pay lip service to the goal of promoting science education, but in order to do that you must get people interested in science in the first place! If funding fundamental research is an indirect way of achieving this goal, it is surely worth every penny. This is one spin-off that can be guaranteed.

In the end, if we are to convince non-physicists of the importance of taxpayer funding of fundamental research, I think this is the most persuasive argument at our disposal. Any thoughts?