In my previous musings on this topic, I noted that recently we in the HEP community had been suggested to come up with a concrete theory of spin-offs. This theory communicates the importance of funding basic research in HEP by selling the inevitability of beneficial spin-offs. I criticized the notion of being able to make concrete statements that “You should fund project Y because you can expect medical advance X or widget Z.” However, I suggested that a theory of spin-offs rooted in the notion of the “black swan” – the unexpected event that lies outside of your ability to predict but which changes the course of history – is a good idea. That theory could be phrased, “We ask much, we do much, we learn much, and we can expect that something unexpected but beneficial will come of it.”
In this piece, I want to explore the implications of such a theory on the planning process in HEP. A bit of history first. In the 1980s, the particle physics community in the U.S. was determined to define and explore the energy frontier by building the 40 TeV Superconducting Super-collider, or SSC. For a variety of reasons – some unknown mixture of politics, scientific in-fighting, design changes, and cost-overruns – the SSC was killed by the Congress in the early 1990’s while it was under construction. The European equivalent of the SSC, the Large Hadron Collider (LHC), continued to move forward through all of this and soon will turn on, with better luminosity but 1/3 the energy of the SSC.
I didn’t live through the SSC period. I was a student in grade school through most of this period, not even aware that some day I’d be interested in particle physics. However, based on the grumbling I hear from my colleagues I divine a few things. First, the SSC cost was seen as threatening sciences outside of HEP. Whether that was true or not is a point of debate, and I will not engage on that since I don’t know it. But that was a prevalent and highly lobbied perception at the time. In addition, other HEP projects that might have gone forward at the time were set aside to focus on the LHC. In many ways, the PEP-II/BaBar B-factory and the Tevatron at Fermilab wouldn’t have existed without the death of the SSC.
The SSC, and other super-projects like it, can be a signal of a failure to recognize the black swan. Again, a theory of spin-offs rooted in this notion says “Ask much, do much . . . “. Sinking all available resources into a single giant project goes against this idea, and puts an entire field at a singular risk. In preparing for and executing a big project like the SSC, you recruit a lot of students, hire a lot of post-docs and engineers, and tenure a lot of faculty. When the negative black swan comes – the cancellation – you find your field in the unenviable position of mass layoffs, job slot losses, and hemorrhaging or turning away students. The field suffers, rebounds like a collapsing star to a neutron core, and goes back into a period of distribution of resources into many projects to try to pursue the science lost with the loss of the big project.
The theory of spin-offs, the black swan idea, suggests that a better approach is to be open to the possibility of the unexpected. No doubt, many in the physics community felt that the SSC was “unkillable” because it had already been approved by Congress and was under construction. But, in the end, it was killed. The International Linear Collider, which developed out of a very strange consensus within HEP, was also seen as “unkillable” because unlike the SSC it had broad international support and, likely, funding. In addition, a lot of political groundwork was laid to make sure sciences outside of physics felt it was the right project for HEP. However, I think we can look at the politics in the U.S. right now and say that the ILC, as we thought of it, is dead.
I’m probably going to get a lot of angry responses to that last statement, but let’s look at the situation. The ILC was targeted in last year’s omnibus process for cancellation. In the year prior to that, messages from Washington indicated that the ILC was too ambitious ahead of data from LHC. That message started somewhere up in the President’s budget office and rolled down even into the Department of Energy, which until late in 2007 was giving messages of “damn the torpedos, full steam ahead”. Within the community, even at a place like SLAC, the younger members of the field aren’t clear on why the ILC was so fast-track ahead of the LHC. There is a body of people in the community who feel that not enough money has been spent to make better accelerators, and thus drive down the cost of an ILC machine. Outside the U.S., we’re starting to lose international partners like the U.K., which until recently probably spent more than other countries on accelerator research.
These are not good signs. This isn’t to say that the science isn’t right, or that an ILC can never happen. However, those signs suggest that a HEP strategy that puts all the money into one giant project could lead to the death of the field in the U.S. Again, to be prepared for the black swan – e.g. the discovery at the LHC that the appropriate machine is one 5 times more powerful than the planned ILC – we need a diverse strategy that gets us into the future. Such a strategy might look like this:
- An investment in many smaller projects targeted across the most pressing scientific questions – the origin of mass (LHC), dark matter, dark energy, the neutrino’s properties – over a period of many years. In addition, this investment portfolio involves money for an “accelerator frontier” – money to develop plasma and laser acceleration and next generation warm and superconducting accelerator technology. Make sure there’s money left over for “crazy ideas” – call it a HEP Advanced Research Program, or HARP.
Going full steam ahead on something ILC-like at a time when there is clearly less money, and no concrete signs of an improvement of that, suggests that we need to build a field that is robust against negative black swans and open to positive ones. To resist the negative black swan – the single discovery at an existing facility that renders useless a super-project – we need many smaller projects in key areas of discovery that form the foundation of the field. A larger project should be mounted to the side of that core program, with additional funding or a presidential initiative. To be open to positive black swans, diversity is needed to maximize our luck. Discovering the unexpected means needing luck, and you can win more often if you play more diverse types of games with different risks and returns.
In planning for HEP, we have to use the same advice that we use when we invest our money for retirement. You mainly want slow, steady, dependable growth. You need a diverse portfolio. But a black swan can occur at any time. It could wipe out a portion of the market, take out some our your investments. The breadth of the portfolio distributes the risk. In addition, though, you want to invest a small portion of money in high-risk ventures. Big risk, big payoff. If you lose it all, it has to only represent a small portion of the overall portfolio. If you win, you win big and you can move that reward into the diverse, “safer” investments.
Science is never safe. There are high risks in everything. HEP is no different. But clearly, there are well-defined measurements that we need to make. The mixing angle of the first and third generation neutrinos, for instance. That represents a “safe” investment – you know how to build for what you want to measure. The risk? Well, the negative black swan is that nature is cruel, and you just can’t build a good enough detector. The positive black swan is that you do measure that angle, and then you need a machine that can let you do the next measurement: CP violation in the neutrino system. So you need to have some money in that machine. You always want to be trying to get the mass of the neutrino, so you need experiments sensitive to the bare mass. That outlines a robust and complimentary neutrino investment.
We can proceed similarly to dark matter, dark energy, the energy frontier. On that front, it seems wise to have you LHC but get your precision, too. Babar is ending. Belle in Japan will upgrade and push their luminosity. Should we also plan for an even more powerful low-energy machine to make precise measurements of the LHC discoveries’ impact on the flavor sector of physics? That’s a debate going on in HEP right now, and we might know how that resolves by the end of the year. The theory of spin-offs, the idea of the black swan, suggests we ought to spend the money.
HEP in the U.S. risks another chance at death if it puts all of its money in the LHC, or in the ILC. These are worthy programs, but we risk the negative black swan in an all-or-nothing approach. It would seem wise to make many smaller investments as well, a foundation of the portfolio that balances risk and reward and grows a diverse and healthy program. We can have our super-projects, but let us never forget that in science the puzzle of nature can be solved when many pieces are brought together. Let us maximize our benefits and realize the diverse nature of the universe with an equally diverse set of experiments that lead the way into the future of HEP. If we make more planning mistakes, we risk changing U.S. HEP from a star that collapsed into a neutron star to one that turns into a black hole, and there’s really no going back from that.
I’ll close with this. It has been asked what the core of the HEP program is. What is the “floor” on our spending, the money below which there isn’t a functioning program? Why is HEP money always asked to remain flat while other programs go up and down with the problems they want to solve? I would suggest that it’s time to address that kind of concern by starting from the driving questions. It’s the core scientific questions that define the core program, and maybe it’s worth writing down a minimum dollar amount that is needed to keep progress moving on each of those questions (in the form of project budgets on each topic, each mission of the field). That would define the core program, but with the understanding that if a core program suggests that a new endeavor is needed there is room to negotiate the budget up over time to build and execute the project, then bring the budget back down afterward.
We don’t have to remain flat, or always be growing. But, we do have to maintain the core of the field with a healthy growth that accomodates scientific progress. Instead of letting others define this for us, why can’t we define it ourselves? This is the initiative we need to erase questions like, “What is needed to maintain your program?”
