Confessions of a Jewish Particle Physicist

Confessions of a Jewish Particle Physicist

This is adapted from an address given at Lawrence Park Community Church in Toronto.

Thank you for that generous introduction, and to Reverend Suk for the invitation to come to speak today.

I was at the celebrations of a Bat Mitzvah in a synagogue in Boston last month. We were having a Shabbat dinner after services on Friday evening, seated with a few friends and relatives who had come to participate in the Bat Mitzvah ceremony. As is my wont in these sorts of social situations, I reached out to chat with the person next to me. His name was Dave and he turned out to be an artist who creates beautiful soaps with gem-like properties. Turns out he had studied some geology in his day, and one thing had led to another and now he creates these unusual soaps that are valued perhaps more for their attractiveness than for their soap-like qualities.

The conversation eventually turned to me, and he asked me what I do. Now, from past experience, I know that people often feel at a loss when I start to talk about my own work, when I tell them that I’m a particle physicist. That I do my research by colliding particles together with very high energy and look at what comes out of the collisions. From this, I learn about the basic building blocks of our world and the forces that hold them together.

There are several typical reactions to that sort of introduction.

One response is an uncomfortable silence from the other party, where they don’t quite know what to say. I’ve suddenly been “outed” as someone they don’t know how to socialize with. Someone supposedly smart. Perhaps they feel they will say something stupid. I quickly recognize that response, and we start talking about those Maple Leafs or Blue Jays, depending on the season.

The second most common response goes along the lines of “You know, I did really poorly in physics. I’m not very good at math. I stopped studying it in grade 9.” Well, with that response, I often try to find some kind words to reassure them that many people have experienced this, that they are still good people, that my own wife never even took physics in high school and we are still happily married almost four decades in. We move on to some other topic of conversation.

But, this evening in Boston was not of these two types. Dave responded by saying “Wow, I’m all over this stuff! Were you involved in discovering the Higgs Boson? What do you think about this dark matter stuff? And dark energy.” Almost breathlessly, he continued: “You know, I’ve always wanted to be a physicist and I’d love to talk to you more about what you do.” He was so interested that we then spent a good part of the evening talking about particle physics.

That reaction, has been increasingly common in my experience over the last decade or so. In particular, I have had it with people that I encounter in and around the synagogue and other religious organizations. As one example, I co-organized six events last year called The Genesis Project, where we used the story of creation for the first six days to frame six discussions where we brought scientists and religious thinkers together on topics motivated by the theme of that day of creation. For the first day—when God took vohu-v’vohu—often interpreted as “chaos”—and created light, we called the program “Was God a Particle Physicist?” It attracted close to 200 people and involved a candid discussion among Rabbi Baruch Frydman-Kohl, the moderator Judy Libman, and I on how we understand our universe.

So my first confession is that I don’t understand why people who have some form of religious or spiritual identity, aren’t increasingly interested in how we understand our physical world, and how that understanding informs our identities and our sense of meaning.

Now, let me tell you what I mean by people with spiritual identities. I start with my own understanding of that concept.

I am in awe of this world. Each and every day, I am reminded of the incredible complexity of our universe, whether it is in the diversity of galaxies and cosmic structures, how the universe forged the heavier elements that make up this rocky ball called the planet Earth, or how biological life formed and developed into such intricate forms as we see around us in this room.

This sense of awe has been what has propelled me into a lifetime of working as a scientist, using the practice of science — yes, for me it is best understood as a practice and not a faith — to better understand the world around us. I’ve been given certain gifts: I like to understand how things work. I’m naturally curious. I like to work with my hands and create things. I am mathematically inclined. And I’ve had the very good fortune of being given the opportunity to pursue a path that allows me to use those gifts, as a professor at the university.

And I use these gifts to feed that sense of awe.

As a scientist, I’m not alone with a sense of wonderment and awe about our world. There are many in my profession who share a similar relationship with our world. As scientists, we tend to speak in a jargon and lingo that doesn’t use that language. We talk about experiments, about statistical interpretations, about theories and about p-values. But underlying all that focused work is a deep curiosity fed by awe. I find no better words.

In my own work, I have been trying to uncover what our world is made of. As best we know it, the particles that ordinary matter—the stuff around us—consist of are protons, neutrons and electrons. These are the building blocks of atoms. The electrons appear to be indivisible, and we’ve learned that they really look and behave like point particles. They form a cloud around a very small nucleus, which is made up of protons and neutrons. These protons and neutrons, on the other hand, have a well-defined size and structure. They appear to be made up of smaller objects that we call quarks. To describe the proton and neutron, we need two flavours of quarks, the up quark and the down quark.

If this were all we needed, it would be a tidy picture, with all of matter consisting of just three different ingredients held together with the electromagnetic and nuclear forces.

But that is not all there is. The discovery of radioactivity revealed that very occasionally a neutron will decay into a proton, electron and a fourth type of particle called a neutrino. This decay is evidence of a third force, called the weak force.

And over the last 50 years, we have discovered around 400 other elementary particles that, like the proton and neutron, have structure and are made up of quarks. Most of them have very short lifetimes and they decay before they can be observed. A third quark, the strange quark, was required in the early 1960s to describe some “strange” behaviour associated with a pair of elementary particles when they decayed. A fourth quark was discovered in 1974 – what we call charm – and a fifth quark was discovered in 1979, called beauty or bottom. These were both discovered when we collided matter together at very high energies.

I was involved in experiments in the 1980s and 1990s that collided protons and the antimatter form of protons, anti-protons, together at very highest energies possible. These collisions allowed us to simulate the temperature and pressure of the universe very early in its evolution, close to what we call the Big Bang.

After looking at 4 trillion collisions, we found several handfuls of collisions where a very heavy particle was created. That turned out to by the sixth quark, known as truth or top. This discovery, made in 1995, completed our picture of what we call the Standard Model. Alongside the six flavours of quarks, we also found that the electron had five other cousins that shared many of the electron’s properties. Together, these 12 particles are the basic building blocks of our world, as we understand it.

There was one particle that was predicted by this Standard Model, the Higgs boson. We ultimately had to build a whole new accelerator —the Large Hadron Collider in Geneva, Switzerland—to create enough collisions to finally discover it in 2012. I was on one of the two teams that found this very elusive particle; and the originators of the theory, Peter Higgs and Francois Englert, were awarded the Nobel Prize in Physics in 2013.

So, now I come to my second confession. I think this rather elegant picture I’ve painted is just not right. It is a very good approximation of reality, but it can’t be the whole story.

The theory is flawed in that it has way too many types of particles in it. Let’s think about this for a second. How many colours do we need to describe the entire rainbow? Why just the three primary ones, not 12? How many flavours of ice cream do we need to just about create every flavour we really care for? Vanilla, chocolate, strawberry? OK, maybe pistachio? Only four. Why would our world at its most fundamental level need a dozen?

I’m not in awe of this model of the world. I’m just confused.

Now that is not the only problem with this picture. When we look at our cosmos, we have found that, far from being a static universe we live in, it is quite lively. I don’t have enough time this morning to go into all the details, but astrophysicists today think about the universe as expanding. We had to give up the idea of a static universe in the early 1930s, when Edwin Hubble discovered that the farthest-most galaxies were all moving away from us very rapidly. This led to the Big Bang model. If those galaxies were receding from us in every direction, it implied that space itself is expanding.

This story was reinforced by additional observations. We discovered, in 1965, the remnant of this Big Bang in the form of microwave radiation that comes from all directions in the sky. In the late 1990s, we further discovered that not only is the universe expanding, but its expansion is increasing in rate. Sometime in the last billion years, after expanding at an ever-slower rate, the rate of growth of the universe apparently started to increase. The best way we understand this is that there is energy associated with space itself, and that as our universe grows, so does the energy associated with space. This growth in energy actually pushes the expansion along. We now call this dark energy.

There is one additional mystery. When we look at the stars in other galaxies and measure how fast they are moving around their cores, we find that these stars are whipping around far too fast to be explained by just the ordinary matter that makes up the stars and gas clouds that compose each galaxy. In fact, it looks like there is about 6 times more “stuff” holding galaxies together that we can’t see, creating a gravitational force that affects the stars and cause them to orbit faster around the galaxy centres. We call this “stuff” dark matter.

There are now many other lines of evidence that support the existence of dark matter, but to date, the information is all indirect and cosmological. We expect to see the effects of dark matter on Earth, but have not been successful, despite heroic efforts that typically take place deep underground. For example, just north of us in Sudbury, scientists are working two kilometers underground to see if dark matter can be detected.

And I have no idea what dark matter and dark energy really are. Actually, nobody knows. There are many experiments to try to find Dark Matter — I’m currently working on one myself. Maybe, one day, one of those experiments may be able to tell us something about this dark stuff.

So now I come to my third confession. There is more out there than I understand, and I don’t have faith that science will necessarily give us all the answers.

As a card-carrying scientist for close to 40 years, what I’ve just said might get me drummed out of the corps. But let me elaborate.

I often ask students what they think “science” is. This is not a simple question, given how the term is thrown around. Our government talks about making science-based decisions. We talk about science, technology, engineering and mathematics —STEM —as a shorthand for a set of careers or occupations. We also have a lot of things called “science”: natural science, political science, environmental science, architectural science, actuarial science — the list seems endless. Because I am a scientist, here is what I offer to you.

Science is a practice that enables us to make increasingly accurate observations about the things around us. The practice of science requires us to make observations that are reproducible. It is founded on our assumption that these observations reflect internal patterns and order that can be described mathematically, and that these mathematical models can be used to predict the behaviour of our world.

It is important to note that science doesn’t place value on human life, or on altruistic and other virtuous behaviours. Honesty is a requirement, but even that can be limited to being truthful in one’s observations. In other words, science doesn’t guide us in how we are to live our lives.

This is perhaps where my sense of spirituality, my sense of awe of this world, and my desire to be a good human being come together to define my spiritual identity. Being a Jew allows me to make sense of the reality I experience and allows me to speak in a coherent way about it. I’m not arguing that Judaism is the only religion in which this is possible. However, it is the one that has best fit my preoccupations with this world from a more scientific perspective.

That fit comes, I believe, from the fact that Judiasm doesn’t require a specific belief of God. Rabbi Ignaz Maybaum was the spiritual leader of a congregation in London, England, and was the teacher of Rabbi Dow Marmur, the former senior Rabbi of Holy Blossom Temple here in Toronto. Rabbi Marmur recently recalled that Rabbi Maybaum had related from his pulpit at one Yom Kippur service that “if he had asked worshipers as they were coming in if they believe in God, they’d have every right to tell him that it was none of his business. They had tickets and were card-carrying members of the congregation. That’s all that mattered.”

That brings me to my last point. And that is tied to the ideas of God and Genesis – more precisely, where God fits into my understanding of the world. My God is not the God that thunders down from Mount Sinai killing the many thousands of Jews who participated in making the idol of the golden calf. My God is not the God that sits benevolently, listening and responding to me when I pray. My God is not the God that defines what is good and evil in our world.

My God is that ineffable being or essence that must suffuse our world and make it just so – make it a world that continues to fill me with awe. It is the God that somehow —just don’t ask me how—has had a role in defining what the world around me looks like, that has allowed those emotions in me that bring me to love those around me, that compels me to leave this world a better place than when I found it.

My own scientific pursuits lead me to believe that the universe is expanding around us, and that it arose from a Big Bang. Genesis speaks about a creation process as well, but I don’t believe our Big Bang theory can or should be used as support for this text. We study this text because of the importance it has for us, having been with us for well over two millennia. Its study has helped us move forward as humanity, working to understand ourselves and give meaning to our lives. It is not a scientific description of our world. Nor should it be.

This sense of awe is not only an experience of scientists, but anyone else who spends time trying to make sense of the world around them. I’m sure all of you have experienced it also. And that is why Dave, my dinner-table conversationalist, who was so enthusiastic about string theory, multiverses and other theories of our world, was so pleased to be able to talk to me about them.

I hope that you have enjoyed these reflections this morning.


(This post is part of Sinai and Synapses’ project Scientists in Synagogues, a grass-roots program to offer Jews opportunities to explore the most interesting and pressing questions surrounding Judaism and science. This post is from their program “The Genesis Project,” run in partnership between Beth Tzedec and Temple Emanu-el).


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