Searching For The Theory Of Everything: The Torch Podcast

An Interview with Professor Don Lincoln, Ph.D.

On this episode of The Torch, we examine the quest to discover “The Theory of Everything”—how everything in our universe is interconnected.

Here to discuss the unifying theories of physics and more is Professor Don Lincoln, Ph.D., Senior Scientist at the Fermi National Accelerator Laboratory.

The following transcript has been edited slightly for readability.

Ed Leon: So the “theory of everything,” it sounds like a big swing at science.

Don Lincoln: Well, it’s nothing if not grand. It’s the idea that we will eventually figure out all of the rules of the universe so that we can explain everything that we see stemming from a single simple theory.

Ed Leon: Is it a theory or is it an equation or does a theory lead to an equation?

Don Lincoln: Well, an equation is just, after all, a language, right? You could write something in words or you can write something in math. An equation is a compact way to express the idea. The theory is really the idea and math is just a way to manipulate it easily.

Ed Leon: Why is this such a big quest?

Don Lincoln: Well, when you read back for thousands of years in history, people have been asking these sorts of questions for a long time. How did the universe come into existence? Why are we here? What’s the meaning of life? What we’re trying to do is we’re trying to put a scientific spin on these timeless questions.

Ed Leon: All right. Where do you start, because we have pieces of it, right?

Don Lincoln: Oh, we’ve made huge progress over the past hundred years or so. We actually understand two big thrusts. One is how gravity works and one is how the quantum world works. Those two thrusts have not yet been combined, which is of course something we’d like to do. We’ve made huge progress, but there’s clearly far more that we need to understand.

Ed Leon: All right, talk about some of them. Talk about what we’ve come to understand are the breakthroughs related to gravity which is one of the areas.

Image of Isaac Newton
Isaac Newton

Don Lincoln: All right, so the first real understanding of gravity started in the 1600s with Issac Newton. People don’t realize this because we sort of understand it so much these days, but at the time people didn’t know that the gravity that keeps this cup on the table and the gravity that keeps the stars in the heavens are the same thing. Now that just seems obvious, but it wasn’t obvious in the 1600s. That was Newton’s big thing. Then of course Einstein took Newton’s ideas and added something to it and showed that the fabric of space and time would actually bend and move under the influence of mass. That’s how gravity works.

That’s what we think about that. Now on the quantum world, it’s different. On the quantum world we started out with things like James Clerk Maxwell understanding how electricity and magnetism came together, but then in the 1920s we started to realize that the quantum nature of matter had some really significant surprises.

Learn more: The Union of Electricity and Magnetism

Now most people, if they understand modern physics, they maybe stop at the quantum world so maybe 1930, but of course 1930 was almost a century ago. We’ve learned far more. Now we understand how the nucleus works.

We understand theories that will tell us how [the] sun burns, why we can’t put our hands through this table. Basically all of chemistry, all of light, all of electricity and magnetism. These are all things that we really understand pretty well. We don’t understand how those things tie to gravity yet and that, of course, is part of the theory of everything.

Ed Leon: If we’re all atoms, why can’t you put your hand through the table?

Don Lincoln: If you were to zoom in with a super microscope on this it’s mostly empty space. It’s entirely empty space. What really is the truth about matter is that this is essentially a force field and the force field is holding those things in space with empty space between it. I can’t put my hand through it because the force fields of my hand and the force fields of this table repel each other.

Ed Leon: Your career is fascinating. You split your time between the large accelerators of the world, the large hadron collider in Switzerland and the tevatron in the United States which is run by the Fermilab. Talk a little bit about that and what’s going on there?

Image of Fermilab for the theory of everything article
Fermi National Accelerator Laboratory

Don Lincoln: Well, I am essentially a professor at the Fermi National Accelerator Laboratory. That’s what I do. For many years we had the largest particle accelerator in the world. It turns out the tevatron shut down in 2011, so we are redirecting our efforts to a different set of experiments there. There, what we’re trying to do is we’re trying to make the brightest and most intense particle beams. You say, “why the heck would we do that?”

Ed Leon: Yeah, why do we need said beams?

Don Lincoln:  What we try to do is in trying to understand the rules of the universe we know the simple things. We know why we can’t put our hand through this. We know why things fall when we drop them. There are things that we do know. What we’re now trying to do is explore the mysteries where we don’t know quite as well.

One of the bizarre things about quantum mechanics is things that are sort of intuitively impossible can happen. In principle, quantum mechanics says you could take your hand and pass it through the table. Now we know that’s not true because it’s just very unlikely, but that’s why we use the beams with lots of particles because we’re studying unlikely things. If you make many, many, many collisions, you’re more likely to see a rare thing.

As an analogy, if you buy a lottery ticket you’re not probably going to win the lottery, but if you bought a thousand lottery tickets you improve your chances. If you buy a million tickets, you might be the winner. More beam, more intensity allows you to see these rare things and makes a discovery more likely.

Ed Leon: In layman’s terms, talk about what the particle accelerator actually does.

Don Lincoln: Oh, the particle accelerator well, some people who are hearing this remember old style TVs, like from when I was a kid. In there, what you do is you heat up some metal and electrons shoot out to the front of the system and you end up seeing light. What we do of course is much bigger than that. For instance the accelerator at Fermilab is four miles in circumference and the one at the CERN Laboratory that I also work at is sixteen miles around.

Ed Leon: Right. That’s the biggest in the world, right?

Don Lincoln: That’s the biggest in the world and it will be for probably twenty years at least.

Ed Leon:  Why does it need to be so big? What’s happening in that track?

Don Lincoln: Well, so it’s seventeen miles around, so only a very short distance, about eight feet on one piece of that big circle there are very, very strong electric fields. What happens is as particles go through there, they get pushed by the electric fields and they go faster. Now what the rest of the whole ring, the whole ring is just a series of magnets that brings the beam around so it can go through again.

It goes faster and faster. It’s like a kids’ playground where you put kids on those merry-go-rounds and you throw them and they spin around, you grab the handle and you throw it again and again. It goes faster and faster. Basically that’s what it is. It’s a super big merry-go-round for particles.

Ed Leon: Why do we need it to go so fast?

Don Lincoln: Well, everybody has heard Einstein’s equation E=MC2.  That says energy equals mass and mass equals energy. If you want to find heavier and heavier particles, then what you need is a lot of energy. In order to make such energy, you need to have the beam go faster and faster because it gets more and more energy. That’s one piece of it. The second piece is, remember, we’re trying to understand the theory of everything, the theory of the universe, how it came to be. The universe began in a cataclysmic explosion we call the Big Bang fourteen billion years ago.

Learn more: What Holds Each Galaxy Together: Dark Matter

At the time, the whole universe was smaller and hotter, which means there was more concentrated energy. By making bigger and bigger accelerators we’re making more and more energy. We are able to concentrate energy and recreate the conditions right after the beginning of the universe. Let me give you a cool factoid. Using the high technology that we have right now, we can recreate the conditions that were last common in the universe a tenth of a trillionth of a second after the Big Bang.

Ed Leon: Is that any relation to the gravitational waves that were discovered recently? Or is that separate?

Don Lincoln: Gravitational waves, they’re all related, but that’s not what we do. Einstein said correctly that if you take very heavy objects and you move them, they will actually shake the fabric of space and time. That’s what happened in the fall of 2015. Scientists saw that space was shaking. That is really cool.

Image of BlackholeEd Leon: Let’s go back to the collider. We hear all these kinds of scary stories about you guys creating a mini black hole and we’re all going to implode. Because that would be cool too, but it would be the last cool thing we all experience.

Don Lincoln: Not going to happen! Well, you know that can’t happen because if that did happen I’d have to fill out a ton of paperwork. You just can’t imagine what a pain that would be. No, that’s actually kind of a neat thing and we talk about it a little bit in the course. The only way that could happen is under some very unlikely conditions. If there are additional dimensions of space, which sounds weird. We know about forward, backward, up, down and right and left, but if there are additional dimensions of space, which is something we think could possibly be true, then what would happen is that as we got to …

These dimensions would be tiny small, so small; like atom sized. If we started to probe that dimension, then gravity would get strong. If gravity gets strong, then a black hole might form. We actually hope that’s true because that means we would understand how black holes work and how gravity works. Let me tell you why it’s not at all dangerous because that sounds scary. It’s like, what are these crazy scientists doing?

There is a chance. If you ask me why we know that it’s not dangerous. Here’s why we know it’s not dangerous. The large hadron collider is a very powerful accelerator. It’s by far the most powerful ever made, but it pales to the particle accelerator that’s the universe. Constantly from space, particles called cosmic rays are hitting the earth’s atmosphere and they have energy far more than we could possibly even dream of making.

They’ve been pounding the earth for, well, four and a half billion years. If there were some danger, one of those which are higher energy than we could ever hope to do would have already done something dangerous. The fact that we are being constantly being pummeled by high energy rays from space means there is no danger. That means since there’s no danger. Yeah, I actually want to see a black hole because it means that we will have found something really new and really fascinating about the universe.

Ed Leon: Let’s go back to 2012 at the collider. You found evidence of the Higgs Boson, right?

Don Lincoln: That’s true.

Ed Leon:  Talk about that a little bit. What were you looking for? What did you find? [And] I want to understand the science that has come from it since then.

Don Lincoln: In 1964, so when I was born was when this was proposed. It was fifty years in the searching; people had looked for a lot, for different ways of finding the Higgs Boson. In 2012, actually at that time the accelerator in the US, the tevatron and the accelerator in Europe were in competition.

Now it was kind of bizarre because many of us, myself included, were actually working on both experiments, so we were sort of competing with ourselves. The Fermilab accelerator made some statements that started saying well, you know, we’re ruling out this space, we’re ruling out that space. They were starting to close in on the range of what was still possible. There was some possibility that that accelerator would get there first.

As it turns out the accelerator in Europe has far more energy, [is] far more powerful, has more capabilities. On July 4th of 2012; so there was fireworks that day although of the scientific variety and not the kind we usually see. What we announced is that we had created the Higgs Boson, which was the last missing piece of the standard model. That was the thing that we were really looking for and we found it. Now, the way you find it is very complicated because what happens is you smash these particles together, the energy converts into matter because that’s what Einstein said, and matter then made a Higgs Boson, which then decays.

Now, the Higgs Boson is made in a very short fraction of a time, like a trillionth of a trillionth of a second. Then it disappears so you don’t see the Higgs Boson. What you actually see is its daughter particles. From those daughter particles you can work back using what you measure …

Ed Leon: What’s a daughter particle?

Don Lincoln: It’s just like radioactivity. You have a daughter nucleus, so uranium decays into helium and thorium. The thorium is a daughter nucleus. That’s just the name of it. If there’s a subsequent decay we call them granddaughters and so forth. The Higgs Boson can decay in many, many ways. One way is into two photons. Another way is bottom quarks. Another way is W particles. Another way is Z particles. What we were doing is we were looking for all of those different possible ways that it would decay. If we saw enough of them we were able to reconstruct and say, “Aha. There’s a Higgs Boson.”

Learn more: Electroweak Unification via the Higgs Field

Ed Leon: By the way, I’m sitting here listening to you, I am so out of my league in this interview.

Don Lincoln: Ah, it’s easy. You watch the course, you’ll understand it all.

Ed Leon: Back to Fermi, back to the Higgs Boson. It’s three years now since it was discovered. What has transpired since that discovery? Has anything changed? Have new ideas or theories come about?

Don Lincoln:  Well, in that particular subject yes and no. What we needed to do, and because science is very careful and it’s very fact-based, what we need to do is we need to verify every little piece, so there’s all these little predictions. What we’ve been doing lately is spending the time making sure that if the theory is true it predicts this, it predicts that, and so forth. Just recently–so it probably would have been in August perhaps of this year–in 2016, we published a paper that says all right, we’ve checked all of those things. We’ve crossed all the I’s and dotted all the T’s. It really does appear that the Higgs Boson that we found is the thing that was predicted fifty years ago. Let me give you something that’s really kind of exciting because people hear about the LHC. We’ve run from really 2010 till now.

We’ve taken a lot of data, we’ve done some amazing things. We’ve written nearly a thousand papers, so we’ve done really significant amount of scientific output. Here’s the thing that’s really humbling: By the end of 2017, we will shut down and fix a few things and turn back on, but by the end of 2017 we will only have recorded 3% of the data that we eventually expect to record.

Ed Leon:  Wow.

Don Lincoln: Right now we’re at like 1.5%. We’re going to do not quite one hundred times as much data that we have right at this moment. There is enormous opportunity for new discoveries.

Ed Leon: Right. How much time of your year do you spend in Switzerland?

Don Lincoln: I actually fly back and forth and don’t spend too much time there. I’ll spend a week maybe four or five times a year. The thing is to remember that the world wide web was invented at the CERN Laboratory as a way for scientists to communicate. It makes it very, very possible for us to analyze everything no matter where you are in the world. In fact, at my own laboratory at Firmilab they can, and we do, take data from the CERN Laboratory, shoot it across the Atlantic on very high speed network connections and we store it at my laboratory. In fact, my laboratory is a big computer calculation facility trying to get things going. I don’t have to go there that often and I can stay at home, which is nice.

Ed Leon: Are you ever there when the particle accelerator is shooting off?

Don Lincoln:  Oh, the particle accelerator runs, we try to run it 24/7.  We typically start around April or late March or something like that.

Ed Leon:  Are you shooting experiments into it all the time?

Don Lincoln: All the time. What happens is, you have the detector. Now the detector is impressively huge. There are two of them. My particular detector is fifty feet tall, fifty feet wide, seventy feet long. It weights twelve thousand tons.

It’s like a digital camera and the digital camera contains one hundred million pixels. Now you may say that sounds pretty good, but a Galaxy Four Samsung has thirteen million pixels. That means my detector is only about seven times bigger, but my detector can take forty million pictures a second.

What happens is, we turn the beam on and the beams collide about one billion times every single second. The beams go through and we take pictures of what happens. If they’re really interesting pictures we store them to tape. If they’re not interesting we just ignore them and don’t record them. The beams are running continuously.

We try… in the best of all worlds we would start around Easter and we would run till about first of December. We’d run continuously that entire time. Day and night, twenty-four hours a day. Of course things break. You’ve got to fix things.

Ed Leon: Who gets to decide what experiments get in?

Don Lincoln: Oh, well remember, this big detector, that’s been there. It’s going to be there for twenty years. That conversation occurred twenty or thirty years ago where leading scientists among the world get together and they had to negotiate. They had to say, “Well, I want the detector to do this or that and so forth.”

What we try to do is we build a large versatile detector that’s capable of making many, many measurements. Usually there are two detectors, so there’s another detector which is even bigger physically. That’s just engineering choices. The two of them are sort of like a sibling rivalry. They each want to do well, but just a little bit better than the other one.

Ed Leon:  Just to set the scene for us, it’s all underground, right?

Don Lincoln: It is. It is. Yeah, the accelerator tends to be at CERN, about three hundred feet underground. That’s just because if you get down in the bedrock you don’t have to worry about things like the water level changing or anything. It just stays rigid.

Ed Leon: Let’s say you had a bazillion dollars, what research project would you launch?

Don Lincoln:  The problem is I’d have to pick one. I’d certainly would like to see a bigger accelerator.

Ed Leon: Why do you need a bigger accelerator?

Image of Magnet Attracting MetalDon Lincoln: Well, I don’t know what we’ll discover. We know what we could look for and a bigger accelerator will allow us to make bigger discoveries. Remember, we’re trying to do nothing less than recreate energies near the Big Bang. If we had more energy, we would be able to actually literally recreate the beginning of the universe and understand how we got to be here. That really is the dream of scientists like me.

Then I think, to answer your question practically, the problem is these rings have to be very, very big because you can only make magnets so strong. Remember, the magnets bring the particles back around in a circle. If we were able to somehow make magnets that were a hundred times stronger, the rings would be much smaller. I think it would be nice to pour a lot of money into magnet technology because right now we’re able to double the strength of magnets like every fifteen years.

Ed Leon: Oh, so it’s like a slow Moore’s Law of magnet.

Don Lincoln: It’s a very slow thing. In the beginning, early in the ’30s, we could do it really quickly, but we know a lot and it’s getting harder and harder. We’re able to increase the strength of magnets, but I think some money into that would help us a lot.

Ed Leon:  Something that’s being brought up all the time now, dark matter, dark energy. What’s the difference?

Don Lincoln: Yes. They have similar names, but they’re different. Dark matter is a type of matter; like ordinary matter pretty much, except it doesn’t interact with light. That’s why it’s dark. That’s what the name is. Light goes right by it and ignores it. The idea is that there’s a lot of dark matter in the universe. In fact there is five times more dark matter than there is ordinary matter. We know that because galaxies spin too quickly.

Learn more: What Holds Each Galaxy Together: Dark Matter

If you just look at the matter we can see, the stars that we know of and Newton’s laws, galaxies would rip themselves apart. It has to be invisible matter there holding it together and that’s dark matter. Dark energy is nothing like that.

Instead dark energy is this energy field that permeates the universe. It has nothing to do with the force or droids you’re looking for or anything like that, but this energy field completely throughout the universe and it’s sort of like an anti-gravity. It’s pushing the universe apart.

While everybody has heard that the universe is expanding, we discovered in 1998 that the expansion is not slowing down because you would think that the Big Bang would make things expand quickly and gravity would slow it down.

About five billion years ago dark energy became the dominant form of energy in the universe and it started pushing the universe apart. Not only is it expanding, it’s expanding faster and faster and faster.

We have ordinary matter that makes up you and me, that’s 5% of the universe. Dark matter is 25% of the universe and dark energy is 70% of the universe. It is amazing. That means we don’t understand 95% of the universe, which means there’s a discovery there for some bright scientist to make.

Ed Leon: Don– Thanks for being here.

Don Lincoln: You bet.  Thank you so much for having me.

From the Lecture Series: The Theory of Everything: The Quest to Explain All Reality
Taught by Professor Don Lincoln, Ph.D.