Concern about the future of high-energy physics research

I’m concerned about the future of high-energy physics research.

Fifty years ago, I worked on a ground-breaking high-energy physics neutrino experiment at the Conseil Européen pour la Recherche Nucléaire (better known as CERN) particle accelerator in Geneva. In July 1973, the Gargamelle collaboration presented the first direct evidence of a theory that successfully reduced the number of separate fundamental force theories in physics from four to three.

high-energy physics research: black and white photograph of Adrian Segar working at CERN in the 1970s
The author working at CERN in the 1970s. Yes, he had more hair then.

Although I haven’t been a practicing physicist for decades, I try to stay informed about progress in the field. So, when the New York Times reported that the U.S. high-energy physics community recommends we build a new kind of particle accelerator in the United States, I took a look at their recommendations. And learned that particle physicists in the United States say we should spend billions on a muon collider.

Headline and photograph from a New York Times article published December 7, 2023
Headline: Particle Physicists Agree on a Road Map for the Next Decade A “muon shot” aims to study the basic forces of the cosmos. But meager federal budgets could limit its ambitions.
Photograph: A tunnel of the Superconducting Super Collider project in 1993, which was abandoned by Congress. Credit…Ron Heflin/Associated Press

I’m skeptical this is a good use of public funds. Here’s my response, written as a comment to the NY Times article.

“I have an ancient Ph.D. in experimental high-energy particle physics from working (lucky me) on one of the most important experiments in the second half of the 20th century; the discovery of neutral currents in the Gargamelle bubble chamber at CERN. This was the first evidence that the Weinberg–Salam electroweak theory was correct, leading to the reduction of the number of separate fundamental force theories from four to three (gravity, electroweak, and strong).

I left the field in 1978 and, in retrospect, I’m glad I did. Before I left, the Higgs boson had already been predicted by the Standard Model, and its eventual discovery in 2012 did not give us any new fundamental physics.

Some would disagree, but I and many other physicists think there have been no significant advances in experimental particle physics in the last fifty years.

Meanwhile, theoretical physicists have been futzing around with string theory for the same period with little success. That doesn’t mean, of course, that there isn’t a brilliant grad student who might be making a breakthrough right now. Theoretical physics needs to continue.

Though understanding our universe through science is incredibly important, it’s hard for me to be positive about spending the kind of money described in this article on experiments _until_ we have some new physics theories we can afford to test.”

Responses

“Exactly! What theories can help us unify quantum and general relativity? What testable hypotheses do the theories imply? And what do THOSE experiments cost to run? CERN’s LHC hasn’t yielded “new physics.” Why should we believe a bigger particle accelerator will? Would we be better served say, using the same funds for space telescopes, advanced super computers, etc?”

high-energy physics research: illustration of a high-energy particle collisionFeel free to read the NY Times article and the 2023 Particle Physics Project Prioritization Panel recommendations for yourself.

But these are my concerns about the future of high-energy physics research in the United States.

What I remember from high school — and why

high school memories: Photograph of a 50-millimeter company mortar used by the Soviet Army in the early years of World War II. The mortar has holes in its tail fins.High school feels like a dream. Fifty years later, few distinct memories remain. I’ve only stayed in touch with one friend from those days, so there’s almost no reinforcement from reviewing and remembering the past. And yet some experiences still retain power. Let’s look at three and explore why they endure.

Mr. Crooke’s holes

We knew almost nothing personal about our high school teachers. So I was surprised one day when our physics teacher, Mr. Crooke, told us that during World War II he had helped to develop some of the earliest rockets. His job was to figure out the best fin designs. This was long before the days of computer simulations (or computers for that matter), so Mr. Crooke experimented by drilling holes in the fins and then firing the rockets to see how straight they flew.

This captured our schoolboy imaginations, and for the next few weeks “Mr. Crooke’s holes” were a frequent topic of conversation.

I liked physics class because we did actual experiments and it offered the possibility of understanding the strange and confusing world in a rational way that seemed comforting to me. But this unexpected personal story cut through the dry presentations of facts that filled most of my childhood education, and it stuck.

Mr. Crooke told us that one of his rockets was displayed in the London Science Museum. Fifty years later, I spent a day at the museum. I examined every rocket, but, sad to say, couldn’t find the one with Mr. Crooke’s holes.

The biology class I’ll never forget

In class one day I was asked to publicly announce my score on a ten-question biology pop quiz. “Six,” I said, and I heard loud gasps. The class of twenty-three students was shocked. I was supposed to be smarter than that. Although it has lost its emotional impact, I still remember the shame I felt at that moment.

In my school, the unspoken classroom rules were do what the teachers tell you and don’t make mistakes. Transgressions were followed by public shaming.

It took me many years to realize how much my educational environment relied on shame. Because the emotional cost is high, it’s a rotten way to motivate learning.

Inventing an electric bicycle

Back to my physics class. (Hey, I became a physicist.) One day Mr. Crooke gave us a homework assignment for the week: design something that involved physics. I remember having a hard time thinking of something that would work. The evening before the assignment was due, I thought of inventing an electric bicycle.

Although there are some Victorian-era patents for electric bikes, they were never mass-produced until recently. I certainly had never seen one when I invented mine. I remember drawing a bicycle with an electric motor bolted on, connected by a chain to the rear wheel. The battery was mounted on a little platform behind the bike. The details of the controls were conveniently omitted.

It amuses me that, thanks to the development of powerful lightweight batteries, my fanciful and impractical “invention” in the 1960s has become the commonplace e-bike of today.

High school memories

These high school memories of mine have endured because they all include an emotional component of one kind or another. We may learn wondrous facts in school, but it’s the stories, experiences, and associated feelings that trigger memories that live on.

Is that true for you?

Cooperative Learning: Lessons from neutrino physics and pair programming

cooperative learning: the famous first example of a leptonic weak neutral current. Black and white Gargamelle bubble chamber photograph showing muon neutrino interacting with an electron.

Cooperative learning

I’ve been a proponent of learning with others for many years. Here are a couple of examples of the advantages of cooperative work.

Neutrino physics

In the 1970’s I was an experimental elementary particle physicist. I was lucky enough to work on one of the most important physics experiments in the second half of the twentieth century. Labs in five countries were exploring the rare interactions of neutrinos in a huge bubble chamber at CERN, the European Laboratory for Particle Physics. We had to view and hand-digitize millions of filmed particle tracks projected onto large white tables. Only a few of these images were expected to show the crucial events we were looking for. So it was vital that we didn’t miss anything important.

Gargamelle film scanning table
Gargamelle film scanning table

When you’re staring at hundreds of similar images for hours on end it’s easy to overlook something. So how did we minimize the chance of missing an infrequent crucial particle interaction?

The answer is surprisingly simple. Different staff scanned every set of film images at least twice on separate occasions. We then checked the set of information on each image to see if everyone agreed on what was going on. If they didn’t, other staff viewed the film again to discover who was right, thus catching missing information or interpretative errors. Statistical methods then allowed us to calculate how accurate each scan operator was, and even to predict the small likelihood that all viewers would miss something significant.

This approach allowed us to be confident of our ability to catch a few, very important particle interactions. The best evidence for our results—which provided the first confirmation that a Nobel Prize winning theory unifying two fundamental forces in nature was indeed correct—was based on finding just three examples.

Pair programming

Another example of how cooperative learning can create more reliable work is pair programming: a technique that became popular in the 1990’s for developing higher quality software. In pair programming, two programmers work together at one computer. One writes code while the other reviews the code, checking for errors and suggesting improvements. The two programmers switch roles frequently. Pair programming typically reduces coding errors, which are generally difficult and expensive to fix at a later stage, at the cost, sometimes, of an increase in programmer hours. Many software companies creating complex software find that the value of the increased quality is well worth any additional cost.

While these two examples of cooperative learning concentrate on reducing critical mistakes, it doesn’t take much of a leap to see that working together on a learning task may increase the accuracy and completeness of learning. As a bonus, the two (or more) learners involved receive an opportunity to get to know each other while they share an experience together. With the right design, there is little downside but much to gain from learning with others rather than alone.