Good evening. Thank you for coming.

It is my pleasure to introduce our speaker today.

Matthew Deady, Professor of Physics at Bard College.

Professor Deady holds BS degrees in Physics and Mathematics, from the University of Illinois at Champaign-Urbana, an MS degree in Math from the same institution, and a PhD in Physics from MIT.

His research background is in Nuclear Physics, and while at the University of Illinois, he had one of the coolest job titles you can imagine as Chief Accelerator Operator at the Nuclear Physics laboratory.

Even many years later that's a great thing to have on your resume.

He also did research at the Bates Accelerator laboratory at MIT for 18 years, and has collaborated with scientists at CERN where the Higgs work was done.

He's been a member of the Physics Department at Bard since 1987.

Matthew teaches an enormous variety of courses, everything from a very popular non-major acoustics course, in general physics to advance courses in physics and mathematical methods.

He's one of the most sort after teachers at Bard. When Bard instituted a teaching award recently, he was the consensus choice across the campus to be the inaugural recipient.

If you known anything about faculty, to have multiple faculty simultaneously agree on one thing is somewhat miraculous.

He continues to direct undergraduate research projects and everything from acoustics, to theoretical physics, to recently a micro hydroelectric project on the Saw Kill river over in Red Hook.

A bit of an explanation for why I'm actually doing the introduction.

Usually we have someone who actually knows something about the field, and I'm an inorganic chemist and I know nothing about nuclear physics, but Matthew has bean a good friend for almost 25 years.

From when I started my academic career at Bard in 1992.

I think I was 15 at the time.

[LAUGHTER] We connected very quickly on many levels.

Starting with our background at large Midwestern Universities, to similar tastes in music.

A fondness for quoting Monty Python.

Most importantly, a deep, very geeky interest in science and all things related to it.

As a teacher, Matthew was and has been my roll model for how to do it right.

There is generally no right way to teach.

I think when it's done well, it's an expression of your own personality.

When you first start out though, it's really helpful to have someone who teaches the way you want to teach and try to emulate them, and for me that was Matthew.

A lot of people go into teaching as much to continue to learn as to teach.

I think Matthew really exemplifies this by really continuing to learn new things all the way through his career.

Beyond math/physics and incredible variety of physics and mathematics courses, he taught and directed the Bard first-year seminar program, where he taught humanities and social sciences.

In addition to teaching the other faculty how to teach Galileo and Darwin.

He also regularly teaches in

Bard's Citizen Science Program, which mainly focuses on biology. The subject of his talk is the .

What, how, and why we care?

I will finish my introduction with won of the lamer jokes in the history of science.

If you don't get it, you will buy the end of the lecture.

A Higgs boson walks into a church.

The priest says, "We don't allow Higgs bosons in here."

The Higgs bosons says,

"But without me, how can you have mass?"

Without further ado, please join me in welcoming Matthew Deady.

You're set.

That's me. In case you wondered you're into the wrong room.

You're hoping for the NCAA feed finals or something like that.

I'm going to talk about the Higgs boson as Dan said.

I am in this field, but not quite.

This is the very highest of high-energy physics.

I am what is known as an

Intermediate Energy Nuclear Physicist.

They have hierarchies within everything.

I worked at much smaller energies, but what we're going to bee talking about, as Dan said, is mass.

Mass is one of the fundamental quantities that we explain everything in terms of.

In fact, every mechanical quantity we can talk about how fast something goes?

How much energy it takes? How much power it has?

Can be described in terms of these three variables.

The time we measure in seconds, distance we measure in meters, mass we measure in kilograms. Oops sorry.

You'll notice something interesting about this.

Physicists a few years ago defined light to be exactly

299,792,458 meters per second.

The second and the meter are actually defined in terms of physical processes.

Whereas, the kilogram is defined in terms of a chunk of stuff that sits in a lab in Paris.

It's the only physical constant, that is actually defined by a thing, not a process.

That shows you how far we are from having a handle on mass, the way we have on everything else.

If like me, you follow Jeopardy.

You might remember a few years ago, the final question in the tournament of champions was, what is the only element of science that is defined by a physical object, and it was the kilogram.

If you're wondering why did I come here? You're getting material for

Jeopardy the next time you're watching.

When we talk about mass, historically, there's just a lot of confusion about how to really describe what we mean by it.

On my shelf I have books and history and philosophy of science.

I have a book about the evolution of the concept of force, evolution to the concept of time evolution of the concept of how we measure distances astronomically.

I have three separate books about mass, and they all disagree with each other, about what it says.

But historically, people looked at mass as well.

How much stuff do we have?

That's what they were trying to capture.

If you read Newton,

Newton says the mass of an object is its density times its volume.

Which puzzled a lot of people because they were thinking, well, that's defining things in terms of the secondary quantity.

But Dan is a chemist, would know why they did it this way and I'm amazed the philosophers didn't figure this out.

You can measure density directly by looking at displacement, by looking at its relationship to water.

You can figure out the density of an object, and then using that in the volume, you can actually figure out what the mass is.

But actually mass has three different roles in physics.

I'm putting up here just about the only equations you're going to see today so you're not going to get freaked out and

I'd put subscripts on them.

There are actually three different concepts of mass that get involved in Intro Physics.

One of them is in Newton's Second Law,

F equals MA, where this is what we call the inertial mass.

Force you should think of is how hard it is to push or pull on something, acceleration is we measure how fast can you get it to move.

This is something that we extrapolate from our understanding of simple pushing and pulling to actually make things more rigorous.

Acceleration is something we can measure by how much its velocity changes and this quantity here, the inertia, is a measure of how hard is it going to get to make that thing move.

As I tell my students, if I tell you, you can move this piece of paper or you can move this, which one do you want to move?

They say, well this one because it's not as massive, it doesn't have as much inertia.

It's easier to move.

You don't have to exert as much force to get it to move somewhere and that's what inertia is.

That's the main star of our talk today, inertia, the concept of inertia, the idea of how hard something is to move.

Whereas the other place you might have encountered mass and an Intro Physics course is for instance, in Newton's law of gravity, where he says, the force of gravity is sum constant which had to be measured experimentally,

50 years after Newton came,

Cavendish measured that, there's the mass of the object.

Let's say the earth is the mass of the object pulling on something so that's the active mass element.

There's the passive mass element, that thing that fills it and then the force drops off as one over r squared because the strength of the gravitational force spreads out over space as it expands like that.

What I'm saying is that if something drops like this,

I can't give a physics lecture without a tennis ball. If something drops like this, it's because the gravity of the earth, that's the big MA, The active of mass of the earth is pulling on this mass and pulling it down.

Well, what's curious about this and Galileo was the one who figured this out and those of you who like me grew up

Catholic are going to understand how this happened.

Galileo was sitting in an interminable Easter service and they had a pendulum going back and forth like this, spreading the incense, it's called a censer from my altar boy days and this being a big cathedral, the pendulum that the censer was mounted up into the sealing and it took like

10 seconds to go back and forth like this.

Galileo was nodding off during church, as you could imagine.

But he's watching this thing and he starts thinking about and he says, well, what's actually making it go back and forth?

He says, well, it's all gravity pulling down on it now he's about to up and most of the Aristotelian physics over the next 20 years and he's thinking about this and he says, well, what happens if I switch the mass out. It turns out that if you take out this mass and put it in another mass, it actually takes the same amount of time to go back and forth.

What that's saying in our modern way of saying it is that this mass here, the passive mass, and this mass here, the inertial mass, are actually equal to each other.

But they're very different things.

This is how hard gravity pulls on something.

This is how hard something is to actually make it move.

Now the idea of this mass and this mass are even the same, that you never think of it this way.

But if I drop this ball, gravity of the earth, pull the ball down, but the ball is pulling the earth upward as well.

Say, well, why don't I notice that?

That's because it's actually the same force on both of them.

But the mass of the earth is so much bigger than the mass of the ball that the acceleration of the earth is miniscule, it's not even an atom wide so you just wouldn't see this acceleration.

It's there, but you only seen it when masses are more comparable to each other.

Galileo figured out that, somehow this mass and this mass are actually connected to each other.

He made it a little more dramatic by going up into a tall building, dropping a heavy object and a light object and they hit the ground at the same time, showing that gravity pulls on everything in such a way that they all move the same.

Let me underscore that.

If I give you a 10 kilogram object and a 20 kilogram object and I drop them.

They hit the ground at the same time, which means gravity knows to pull on the 20 kilogram object twice as hard as it pulls on the 10 kilogram object.

How can this be? How can it be that gravity pays attention to not the actual mass of the thing, but just how it wants it to move.

Well, that's actually a totally different lecture.

That leads to general relativity.

The idea that the mass of the object pulling on things and the mass of the object feeling that things are actually connected to each other in a way that can make it move in this particular weigh leads to an idea that space and time are actually modified by the presence of masses.

David Nightingale here knows a whole lot more about this or not to even to try two venture to talk about general relativity, except to say, there's another interesting aspect is that this mass and this mass are actually the same thing and Newton himself said they're the same,

I have no idea why.

For Newton to admit not knowing something is worth enough.

Well, the way we known anything in the world is by interacting with it.

We tend to think that, well this is solid.

It's not solid.

It's just something exerts a force on you that doesn't let your hand go through it.

Likewise, you feel anything by interacting with it somehow and through years and years of effort, physicists have come up with all interactions are actually dependent on only these four fundamental forces.

Gravity, we've talked about here.

The electromagnetic force is the one responsible for everything in your life except gravity. These other two are nuclear forces.

Nuclear physicists get two forces.

But neither of them is all that important unless you're down at the size scale of the nucleus.

These forces explain actually everything chemical bonding, the lights in the room, the magnets that we use to get things going.

All these things are actually electromagnetic and then if you're near a very large object, you also have some gravity on it.

What we found is that these forces explain everything and these forces can be modeled by thinking of them as exchanging particles.

The way I interact with something else is by training particles back and forth.

The example that's sometimes used for this among physicists, and you'll see it in Intro physics books.

I'll get Dan to come up hear for a moment.

Dan and I are on roller-skates.

That's a horrible image, I'm sure.

But as we're going along like this, where we're standing on roller-skates and I throw a big heavy ball to him.

I'm going to recoil from that so I'm going to go back that way and when when Dan catches the ball, he's going to go back that way.

That's a model of thinking about how things interact by forces.

They trade particles back and fourth.

That's actually not a bad model.

The problem comes when you flip the page and it tries to explain attractive forces, which is, I go to throw the ball to Dan, he grabs and I decided I don't want to get rid of it so we're both tugging on it and we end up in this warm embrace.

That's two particles coming together.

That part of the model doesn't work as well.

That's just a visual model of what's going on.

We actually have a terrific system of fields to describe what's happening in the mathematics of saying how these forces work all involve the exchange of these particles.

Whether things are charged and interact electromagnetically, if they're particles that are inside the nucleus so they feel the strong force.

If something undergoes radioactive decay, it's due to the weak force or something having gravity.

Is involving just two masses somehow interacting with each other.

They all go by the exchange of these particles. The photon you've probably heard of, that's a particle of light.

The glue on is the particle that holds together things that the strong nuclear force.

The graviton has not actually been directly discovered, but we have very good evidence that this is how gravity is working by the exchange of these gravitons, and then the weak particle is exchanged by what are called the weak bosons.

All of these things, you notice all end in on, these are all bosons.

I've now explained or at least referred to one of the words in my title.

A boson is, for our purposes, a particle which gets exchanged as a way to carry a force from one thing to another.

So gluons, photons, bosons, weak bosons, gravitons, these are all kinds of bosons corresponding to these forces here.

We have a pretty good model of how these things are going.

In fact, we have figured out this is what's called the standard model of elementary particles and fields, I should say.

We have the gauge bosons, which are the things.

This is the one that works the strong force.

This works the electromagnetic force. These two kinds work the weak nuclear force, and then the graviton is actually not on here.

I'm not quite sure why they left it off.

These are the things that carry the forces, and these are the things that fill the forces.

These are the particles.

All matter, hard matter is made up of quarks.

A proton is two up quarks and a down quark, and then whizzing around that and the atom would be an electron, and then there are heavier versions of these.

These things exist only in two places that I know of.

One is in big physics labs like CERN, and the other is in the early stages of the universe.

When high energies were high enough to create these kinds of things, but we actually have not just a nice colorful diagram here, we actually have a theory about how these things interact with each other, how these different levels of them are related to each other.

For each family of quarks, there's also a corresponding lepton.

We just get fun making up names of things.

They actually have meaning.

The lepton comes from the word for, well, the on is just what we use for all particles, and the lep refers to light as unopposed to heavy.

These are all particles which are much lighter than the protons and the neutrons.

There's the electron, the muon, the tau particle, and then each one of those has its corresponding neutrino.

We can explain everything that's going on in the universe with these 12 particles, their antiparticles, so there's an antiquark and an antielectron, and so on, and these forces that are transmitted by these bosons here.

This is the result of work that started pretty much right before World War II, then we had to say take some time off the nuclear physics to do something else for awhile, we came back and started working on this again, and these ideas really came together in the 1970s about the time I was in graduate school.

Undergraduate and graduate school, people were really tying it together and making sense out of all these things.

This became a strong enough view of what we're doing that we could label it heuristically the standard model of elementary particles. But the ones sitting out here is the one we're going to talk about.

This is the one that actually is the carrier of the force that tells all of these things to have mass, tells all these things to have energy associated with trying to move them.

It's the interaction with the Higgs field through exchanges of the Higgs boson that makes this thing here heavier than this piece of paper here because this thing here has a stronger interaction with the Higgs field.

This thing is exchanging more Higgs bosons with the background Higgs field than this light tennis ball is.

That's how gravity work.

That's how we actually tell what's going on with this.

People predicted this Higgs boson as a fundamental filler or something that typified the exchange of force how these things gained the inertia that they had in the first place.

As I said, these four forces were things that gravity, of course, we've known about since ancient times.

Electromagnetism was something that started to be understood more systematically in the 1700s in particular. In the 1800s to late 1800s,

Maxwell figured out how to take electricity and magnetism and explain them in one simple force which was called the electromagnetic force, so this was the first example of taking disparate things and unifying them.

But then in the 1970s about the time I was a junior in college actually, Weinberg, Salam, and Glashow worked out a theory that showed that the electromagnetic force and the weak force, or actually two different manifestations of the same thing just like electricity and magnetism, are two different manifestations of the same thing.

What do I mean by the same thing even though they're not?

What I mean is that if you get to the right conditions, these two forces actually act the same.

If you take something that's magnetic and something that's got electric charge, the electricity is miles and miles as stronger and stronger than the magnetism under most circumstances.

But the magnetism gets stronger when you make particles go faster, and you can make the particles go faster and faster to get to the point where if they're moving really fast, the electricity and magnetism are roughly the same in magnitude.

Anybody want to guess what speed that is? Speed of light.

If things get up close to the speed of light, then the magnetism force and the electricity force are actually comparable on strength.

Here's a case where in our everyday experience they look different, but under the right conditions they actually start to look the same.

Electricity and magnetism are both manifestations of the same thing.

To give you an inkling of how something that seems very abstract, very physicsy, very of interest only two people out of every thousand on the street, it was when Maxwell figured out that electricity and magnetism tied together in this particular way at the speed of light that he realized light itself is an electromagnetic wave.

He said, "Light is an electromagnetic wave and [NOISE] we should be able to show the public matter about the electromagnetic wave."

I loosed my wire. [NOISE]

Okay, can you hear me now? All right.

Okay. When Maxwell figured out that light itself is an electromagnetic wave, he said, "There should be other electromagnetic waves."

Few years later, Heinrich Hertz actually made this happen, he actually made electromagnetic waves in the laboratory.

Marconi figured out how to make money off of it by turning it into radio and all the other electronic things that we have sending things.

These fundamental discoveries in physics often end up sometimes quickly, sometimes much later, and engendering advances in how we can do various things in the universe.

Where was I? There we go. The electromagnetic force 1973, it's when people worked out a theory of how these two things are held together.

We had been working on the strong nuclear force and pulling these together.

This job of bringing these together in what's called a

Grand Unified Theory is about 95 percent dumb.

I'm pretty sure that within my lifetime we'll have all the details worked out on this.

Then the idea of a theory of everything would be to bring gravity together with this and to have all these be one equation that could fit on a t-shirt. [NOISE] Without being pessimistic,

I am not confident that this will happen within the lifetime of anybody in this room.

This is such a difficult problem mathematically and experimentally that it's not likely to take place the way they happen.

How do physicists get at these things, how do they try to understand things that we can't directly think about?

Well, I'm an experimentalist,

I build big machines or I'm involved in building big machines to try to look at what's going on or building something that allows us to see it's small levels or manipulate individual atoms, something like that.

Theorists have other tools.

One of there strongest tools is symmetry.

What they start doing is looking at the way different particles interact or different systems interact, and they try to find ways that they are same.

For instance, the fact that it doesn't really cost me any energy to move back and fourth like this, is a translational symmetry in the room.

I can turn that translational symmetry mathematically into a principle of something being conserved, in this case being momentum.

The fact that moving around doesn't change anything, actually gives me momentum conservation.

The fact that moving around in time doesn't usually change things, gives me energy conservation.

There are symmetries in the electromagnetic equations which show you that something should be conserved, that's electric charge.

We come up with these symmetries to try to generate ideas about something that is held fixed, something that we can really count on in the system, but no symmetry is perfect for instance, symmetry of the electric and magnetic fields should be perfectly accurate except if things aren't moving that fast, the symmetry is broken.

It turns out that you can only get to that symmetric situation under very particular circumstances, but that's true of any of these symmetries.

That if we managed to break the symmetry, we managed to come around with a violation of it.

It turns out that things start to look a little bit different. The way the theory goes is that in the Big Bang, all of these forces were similar, all these forces were connected to each other, but then things cooled off enough that gravity became different than the other forces.

Then as the universe got cooled off some more and became more sparse, the strong force became different than the electroweak force.

Then a little bit, a few milliseconds later, the electromagnetic force and the weak force stopped looking like each other.

Each one of these, or a point at which the universe was no longer as symmetric as it used to be.

That's actually something we're all fairly familiar with.

That ties into what I'm going to talk about, the Higgs Boson, for instance, if I had something like this and my motor skills were absolutely perfect,

I might be able to balance this thing so that it was perfectly vertical.

That's longer than I thought I could.

If I were to do that, it's because I've managed to make a symmetric situation that this eraser doesn't have any reason to go left, right, up, down any particular direction at all.

It's a perfectly symmetric situation.

It's just going to sit there forever.

Well, there's two equilibriums like that.

This one we call it stable equilibrium because if I displace it from the equilibrium, it'll go back to what it was.

It wants to go back to its fundamental state.

This one is an unstable equilibrium where this one here, if I move this to your left, the forces bring it back to your right.

Whereas this one, if the thing decides to move on its own to your left, it keeps moving to your left.

This is an example of a symmetry breaking that then runs away not because there was anything asymmetric initially, but just because this unstable equilibrium it was in, couldn't stay there forever.

When it broke, it had to go in some direction.

There's no particular reason it would go this way or this way, but once it's gone, it's not going to spontaneously go back to that old equilibrium.

From a theorist's point of view, this was the situation where these symmetries got broken. That they were sitting on a razor's edge waiting to be slightly disturbed and the cooling of the universe, or slightly non-symmetric distribution of matter in the universe.

Any of these things could have broken it in such a way that it would stop behaving totally symmetrically and now instead move off in a different direction.

What direction moved in is what we were trying to figure out.

This is what's called spontaneous symmetry breaking.

It's not because anything disturbed it, but just because being quantum systems, nothing can sit there forever.

It's always going to be trying out different things probabilistically.

Eventually a spontaneous symmetry breaking will happen.

This is what's called the Higgs field.

It was a spontaneous symmetry breaking in the early stages of the universe that lead particles to actually no longer be sitting in this perfectly massless balanced state, but instead to be in a state where different particles all had different masses depending upon how strongly they were interacting with the Higgs field. An example that someone gave me years ago about spontaneous symmetry breaking is something many of us have had to deal with if we go to a wedding banquet.

You sit down at a big circular table and there's your plate, there's your knives, forks and you remember which one's the forks are, the little ones for the salad.

I don't know what these other ones for maybe they're serving a shrimp.

I don't know. But you're looking at all this and then you notice the water glasses.

The water glasses are offset from the others.

You think is that my water glass or is that my water glass?

Until everybody sits down at the table or until somebody sits down at the table, it's a perfectly symmetric situation.

All eight plates have water glasses in exactly the same location.

Then some bold person sits down, says probably a dean sits down and says,

"Well, I'm going to start drinking water."

That person grabs a glass.

Now the symmetry is broken.

Now someone has made a decision.

Okay, it's the glass on the left. Now everybody at that table has got to take the left glass or there's going to be a fight over who got the water.

This is what spontaneous symmetry breaking is like.

Until that moment, you had a perfectly balanced symmetric situation.

Once it's broken, something else happens and now there's nothing wrong with the situation you have, but you realize that it could just as easily have gone the other way.

That person could have sat down and picked up the right water glass in which everybody would say,

"Oh, I guess it's my glass to the right is mine."

There was no reason for it.

They're just a spontaneous thing that will happen which happens in physics more often than you think.

In trying to explain the Higgs field as things were leading up at to people thinking they were going to discover the Higgs Boson, they actually sponsored a contest for coming up with the best analogy they could to what the Higgs field was like and the prize winning analogy.

My favorite one was one that was a wrap.

You can find it online, the Higgs boson wrap but this was the one that actually won.

The Higgs boson is like, well first you imagine you and a celebrity they mentioned Angelina Jolie,

I'm not sure why but they said,

"You and a celebrity are trying to walk across this room and you can walk across this room equally easily but if the room were full of people, they're going to cluster around the celebrity more than they are around you and you're going to be able to get to the cookies in the lobby much more quickly than the celebrity is, because that celebrity keeps interacting with people all along the way."

So the Higgs field is like that.

Some things have more interaction potential with them, that as they move through the Higgs field, they're going to attract more and more interactions with Higgs bosons, some things are smaller, they have less Higgs strength and so they're not going to interact it strongly.

Now, bear in mind going all the way back to what I said at the beginning, the four forces of nature, electromagnetism, gravity, strong nuclear force, weak nuclear force, these are forces.

These are the things we think of as pushing, and pulling on things.

If we are describing F equals MA,

I try to think of F as the cause and A as the result and then M is the thing in the middle that tells you how much effect you get for a particular cause.

What's unusual about that is you say,

''Well, why is there any M at all?

Why is it that some things interact in a certain way?

Why is it that some things need more force to make them push?''

In the standard model of physics it's saying, it's because the heavier things, have a stronger interaction with the Higgs field.

It's just like something that has more weight will get more gravitational pull on it.

Something that has more electric charge, will have more electric field on it.

Something that has more inertial mass, has more Higgs field interaction to it.

So this is the theory that got developed starting in the '60s, by actually in the span of about a year, six or seven different people.

Why Higgs was the name that particularly got associated with it, is up for debate.

It could be that he's the one that actually came up with a particular prediction about where, about what it should look like and how it should interact but different people had different parts of the theory.

I assure you there was a lot of arguing in

Sweden about how to split up this prize among the various people.

So what Higgs expected was that we should be looking for something that had a mass somewhere about a 135 times the proton.

It's in my contract that I have to mention the periodic table at least once every lecture, we look at these things here when we say something that has a mass of about a 135 times the proton, what are we talking about here, Dan?

Some of these heavy metals.

Something like cesium, barium, it's a pretty big atom.

This is a single particle that weighs something like a heavy metal atom.

There actually is a heavy metal band called Cesium-137, oddly enough.

I just happened to think of it because I was looking up something about cesium 137 last week and it said,

"Do you mean the element, or the heavy metal band?"

The music was horrible, it was all in Dutch for one thing but that's a different story.

So this is the prediction of a very heavy particle, considerably heavier than the other particle carriers.

One of the ironies of nuclear is, the smaller something is the bigger the machine you have to build to get it.

That's not just because we like big toys, it's because you need lots of energy.

If people know physics equations at all there's probably two they know.

One of them has already made an appearance, F equals MA.

The other equation people might know is E equals MC squared.

Most people don't know what the E, the M, the C, the squared go for but that's actually true.

If you want to make something that has a lot of mass, you need to make a lot of energy to make it happen.

So what we're saying is that mass and energy are interrelatable to each other and if you want to make something that does have a mass that's very large like the Higgs boson, you're going to need a big accelerator. So this is the CERN accelerator.

If you get the New York Times, you might notice that among there're trips that you can take with the New York Times, whether you can go look at the art galleries of

Florence or you can go towards Stonehenge and the other henges of Europe or you can take a two-week trip that mostly hangs around the CERN accelerator.

My wife Mary keeps threatening to give me this as a birthday present,

I assure her that I spent enough time around physics lab so I don't need this but the CERN accelerator is about 17 kilometers in circumference like this.

It's a series of accelerating sections that speed up the particles and then superconducting magnets to bend them into a circle.

So you give them a burst, bend them, give them a burst, bend them, give them a burst, bend them.

So what they do is they actually run two separate beams.

They actually run protons in both directions so they run protons one way and then they reverse the fields on things and make another burst of protons go the other way.

Then there are four sites around the accelerator where these two beams of protons collide with each other.

Protons are example of strongly interacting particles which are called hadrons so we're taking hadrons, we make a very large thing to accelerate them and then we have them smash into each other which is the which is the accelerator that is usually referred to when people are talking about measuring the Higgs boson at CERN.

So among these four places where the particles intersect and create new particles when they smash together, two of them were used for measuring the Higgs boson.

One of them was the CMS, the detector.

So compact, is ironic.

This thing is about five stories high.

Muons are subatomic particles, you're actually being bombarded with muons that are created in the atmosphere.

You're probably being hit with a few dozen of these per second.

They don't do you any harm,

I was just touring the new new science center in the physics labs in there and they've got a muon decay system setup for students to look at them muons, that's great.

Solenoid, just refers to a particular shape for the magnet.

As the muons are created, what they do is they follow the traces of the muons as they go out and see what paths they took and from that infer the energies that they have.

So this is one of the detectors, the other one is the one that was on the poster for this talk, the ATLAS detector.

As Dan said, I used to be the Chief Accelerator Operator at the lab at

University of Illinois and whenever they were taking photographs to send off to the funding agencies because of my small stature, they would put me in a lab coat and have me stand next to the equipment to make it look bigger.

So this guy is actually only 245,

[LAUGHTER] but this detector here really is as big as it looks.

It's about the size of this entire building and everything that's crowded around there, that's where the collisions take place in the middle there and what we have here clustered around it.

I actually have a list of what all these numbers correspond to but it's not so important to list through all of them.

So what happens is particles collide here and as you would expect, if you smash together two things at high-energy, lots of pieces come flying out.

All these detectors are designed to follow the traces of the particles as they go out.

So you end up with an event that looks like this.

You end up with there's where the collision took place, the particles are going through a magnetic field so they bend, by knowing the curvature of how they bend we can tell it their momentum is, by seeing how far they go before they decay into something else, we can usually infer what they might have been.

As most physics or science speakers are,

I use we collectively as if I actually did some of this and the truth is, this is the work I did but at a much smaller scale in my nuclear physics work, where I would follow how a particle went through a detector and from seeing where it went when I ran it through a magnet or how far it got or what energy it deposited in different places,

I could infer from that what kind of particle it was, what its energy was, what its mass was and these are the kinds of events that people were looking at.

This is actually one of the events that was regarded as evidence for discovery of the Higgs field.

So the ATLAS detector as I said, is this whole set of about 15 different detectors.

The number of people involved in making this thing run, is something on the order of 5,000 PhD physicists.

So this was an enormous amount of work over about 20 years to actually build this system.

Interestingly enough, these are the two papers that announced it.

The one from the ATLAS collaboration and one from the CMS collaboration and both of these papers, before listing the 5,000 names of people involved, this star is actually referring to a footnote that says,

"This paper is dedicated to the hundreds of physicists who died before this project was completed."

If you've ever watched

Particle Fever the movie about this, there are people who are in their 70s, who we're hoping, "Am

I still going to be around when this happens, when this thing goes on?"

The only two fields I know like that, are particle physics where these detectors take forever to build and astronomy and astrophysics where you might send up a probe that takes 15 years to get where it's going to get and you don't know that you're going to be around to see what the results are.

So both of these found as Higgs had predicted, something in the 125-130 GeV range so that's something around the size of a cesium atom with these two detectors.

This is probably the only time the front page of

The New York Times carried a picture of celebrating physicists on the cover.

But a number of my colleagues got up at three o'clock in the morning to be up at 09:00 a.m

CERN time to actually watch when the announcement happened, and when the Atlas Collaboration showed their results, there was jubilation in the streets, shall we say.

It really was an incredible event for people.

Higgs is actually sitting off here based on what I've seen, so he was actually there but he was not involved in the experiment, he was a theorist that worked on it.

What we have done is found the last missing piece of the standard model.

We have an idea that this is how the particles and fields that make up everything around us work.

This is not getting a new device, getting something of an even better iPhone than there was before, this is about fundamental knowledge.

I like to think that this is something we aspire to do as scientists, as humans to actually explain what's going on.

But as is true of every discovery, we also then open up the door to new things that we couldn't have expected, or things that we still don't know.

Let's talk about the things that are still out there and that this kind of work, whether with the CERN, whether what the Higgs boson or similar kinds of things are going to help us understand. I talked about the standard model.

This explains everything in our everyday universe.

Well, there are two things that aren't really known.

Ones called dark matter, the other is called dark energy.

The dark here refers to the fact that we don't know anything about them.

They don't glow enough for us to see them.

We don't really have any idea what's going on with dark energy, where it comes from.

But to give you a rare moment of humility from science, we know the everyday matter that's around us all the time.

That comprises about 30 percent of all the matter in the universe.

Seventy percent of the matter in the universe is dark matter.

Stuff that we know is there because we see planets, we see stars orbiting around their galaxies in such a way that we know how much mass is there, but we can't see most of it,

70 percent of it.

Maybe it's just really dim stars that we can't see.

Maybe it's the latest theory, maybe it's black holes that are small enough that there's lots and lots of them that were created at a certain stage in the Big Bang, and that's why we can't see them because they're black holes.

Maybe they are other kinds of particles.

The two candidates for this were the weakly interacting massive particles, physicists love making up names.

The other one which I took off was the massive compact halo object, which people thought clustered in the halos up above and below our galaxy, and those were ruled out last year by some measurements.

MACHOs went off the list,

WIMP state up there.

We think that studying something like the Higgs field will help us understand, maybe we can figure out what this other matter is that we haven't been able to see somehow.

People have built detectors for trying to detect dark matter, but no takers so far on what's been happening.

It may be that they're entirely different kinds of particles that we hadn't thought of before.

The better we understand the Higgs field, the better we understand how things get the mass they do, hopefully, we should be able to get a handle on what these things are here.

Well, it could be some people we're really hoping that the Higgs particle either wouldn't be found or would be found to be totally different from what they expected, because this would give us a clue as to what's still missing from the standard model.

For my point of view, what's missing from the standard model is limitations.

We know the masses of all these particles, but we don't know why this particle has this mass and this particle has that mass.

Is it just accidental?

Is it something fundamental that it has to be that way?

We don't really know, so people have ideas about how to go beyond the standard model.

One of the leading candidates is called , where there are a host of other more massive particles which mirror ours.

The Higgs field, the way it was found does not really give encouraging results for that.

You probably heard about , the idea that all particles are actually excitations of some more fundamental things called strings. It's a really good mathematical system, there's no experimental evidence for it so far.

Some people talk about the multiverse.

They say, well, it's not that these particles have this mass for any given reason, they're actually zillions of universes and they all have different arrangements.

Some of them have more mass of this, some of them have five fields, some of them they have only two fields.

There's no why, it's just we happen to be in the universe like that.

Some people look for how we could actually access whether there are extra dimensions to think about, or even entirely different universes that we could access.

There are different theories about how to combine the quantum fields of the strong, weak, and electromagnetic fields with the gravity field.

There are a couple of different candidates for that.

As I said, dark energy, just as 90 is going to be just as

70 percent of matter is actually stuff we don't understand.

Going by E equals mc squared, something like 90 percent of the energy in the universe is something we don't understand. We know our local universe pretty well, but there's a whole lot of stuff we really can't figure out, and so hopefully by pushing the limits of what we do know with experiments like the Higgs field, we can actually come to understand these more.

But I'm going to close with this.

This is from a hearing when Fermilab was the accelerator outside of

Chicago was under consideration, and a senator asked Robert Wilson, who had worked on the Manhattan Project and became the first director of Fermilab, basically asked, "What is this good for?"

Wilson's answer basically says, finding out how the universe works, that's because we're human.

That's because we want to know things just like we want to get a particular music that appeals to us, or find exactly the right way to phrase something or take a hike and understand nature at a level that we couldn't have but we just read about it or looked at it in a book.

These are things that are fundamental to the way we exist.

When asked, "Will this help the defense of our country?" He said, "It'll make the country more worth defending."

A touch arrogant, but it's actually worthwhile to think about, especially in this day and age when so many things are equated with what monetary gain will it give.

A lot of times the most important things in life aren't monetary, the most important things are ethical, are aspirational, so studying the Higgs field is an example of one of those.

If you want to know a lot more about this from people who know a lot more than I do,

I really recommend the film Particle Fever, which is available on Netflix.

This is about the Higgs experiment itself.

It goes pretty lightly on the theory.

They do talk to theorists a lot, but mostly for them to say, well, we are able to actually know what's going on.

The excitement of the people actually making the accelerator work is pretty thrilling to watch and something that I highly recommend.

There are dozens of books out about the Higgs particle.

I've read four of them, this is the one that I think is the best.

Sean Carroll is a gravity theorist who actually has written about four really good books.

This one, The Particle at the End of the Universe is particularly good this way at trying to explain the Higgs field and what all this is about and so on.

This has been a very brief overview of both the theory, the experiment, and most of all the motivation of why we want to know these things, and what we think it's told us about it.

I'm sure I've raised more questions than answers for you, which is why I left time hopefully to answer as many of your questions as I can.

Thank you.

[APPLAUSE]

There are plans of the question is if the cern accelerator is setup to go to the next level to discover more things.

Within the cern accelerators actually shut down at the moment to scale it up to double its energy.

People think that by doubling the energy, they may actually be able to see evidence of dark matter.

They're hoping for that, or perhaps see deviations.

Perhaps there's a higher resonance, a higher excitation of the Higgs field could have been seen so far.

To be honest though, a lot of people are very pessimistic that maybe they're going to turn this thing on and run it for a few years and not see anything which would tell us something.

It would tell us that we can't actually get to what we want by building bigger and more powerful accelerators, we are going to have to think of some other way to get at it.

But we're actually pretty well set up now to double the energy and see what that tells us.

So thanks for that question. In the back there.

Yeah [BACKGROUND].

Correct. [BACKGROUND] Yes.

[BACKGROUND] Right.

So some who would say, well, if the Higgs particles, what gives everything mass, how does the Higgs gets its own mass?

Which is your question I believe.

That's one of the things that people don't really understand.

I used to joke about it when I first started teaching at a college,

I looked at the 15, actually they're probably 25 different committees and I asked, ''Well, how do people end up on these different committees?'' and he said, ''Well, there's a committee to appoint committees.'' and I said, ''Well, who appoints them?'' and they very solidly looked at me and said,

''They're self appointing, '' and I said, ''Oh, okay.''

[LAUGHTER] So perhaps the Higgs field is self-generating that it interacts with itself.

If so, it would be the only particle like that and so that in itself would be interesting but it's something that isn't actually in the theory or the experimental tests so far.

So your question was very insightful.

It saying, well, where did this thing gets its mass in the first place?

But perhaps, and this is my guess, is the people are going to find, it's going to go back to giving us some insights into the very earliest moments of the Big Bang, that the spontaneous symmetry breaking took place in a particular way that generated a self referencing field.

So that's my guess, is that it's going to give us some clues about the early Big Bang.

Right now, people are working on that saying, if the Higgs is self-generating, that it eliminates these possible theories, but it's still the other ones are alive.

So that's the kind of thing that people are hoping to measure. Great question.

Absolutely. Yeah [BACKGROUND] Sure.

[BACKGROUND] Well, what you need to do is disturb the thing somehow. [BACKGROUND] Yeah.

For instance, I'm going to draw this out two different ways.

So let's say I got an equilibrium here.

[NOISE] I could do it, write it out in terms of the force that's involved.

Or I could do it in terms of the potential energy that's involved and I'm not even going to mark,

I know scientists are always telling you mark the axis.

I don't even care what this axis is.

Maybe it's distance, maybe it's time, maybe it's mass of the particle.

I don't know. So whatever it is, if something is at an equilibrium, what do we know about its force?

[BACKGROUND] It's equal, so it actually balances.

That's telling us that the force is like that.

If you disturb it and you get something that when I go to the right, I get a positive force and if I go to the left,

I get a negative force, that's going to be an unstable equilibrium because if I move to the right, it gets pushed even farther to the right by this positive force.

So this would be an unstable equilibrium, whereas this one would be a stable equilibrium.

So a stable equilibrium is one whose force equation looks like this, which means you can't just probe what's going on right here.

You have to probe what's going on in the neighborhood.

Of course, one of the problems is there's a third possibility, which is that the force is zero here, and it actually comes in like this.

So it's stable in one direction and unstable on the other.

But discerning these, which of these three possibilities involves you not just looking at the equilibrium itself, but shaking it to see what happens.

If you map this out in terms of potential energy, then you can think of this thing as being like a roller coaster.

So if I have a roller coaster like this, it is possible that you could sit up here at the top of this hill and sit there forever.

But that's an unstable equilibrium.

Because if the wind comes and blows you this way, you're going to go that way, whereas the wind blows this way, you're going to go that way, whereas this is a stable equilibrium.

Because if you've got displaced a little bit this way, you're going to roll back to where you came from.

So whether a potential energy looks like this or this, whether a force looks like this or this, that's how we tell the difference between a stable and an unstable equilibrium.

So for instance, just the aspect of us standing up.

You may think, that's a stable equilibrium.

While if you balance on one foot, you actually have to do a lot of work to keep balanced like that.

That's actually not a stable equilibrium and you can tell that because if you start to tip one way, you keep tipping.

So for any of these things, you don't just look at what's going on right here, you actually have to sample in the region around or another way to say that is, you need to know the derivative at that point, not just the value and whether the derivative is positive or negative, that's what determines the stability of the equilibrium.

That good? [BACKGROUND].Yeah. [BACKGROUND] Correct.

[BACKGROUND]

So when those chemists use of the word dynamic equilibrium, what they mean is the forces are in balance.

[BACKGROUND] Dynamic refers to force in that case [BACKGROUND].

It's certainly not involved except that it's the sense that everything has mass and so they interact with the Higgs field.

So the dynamic equilibrium there is really a question of the electromagnetic forces between things are in a particular balance with each other [BACKGROUND].

The electromagnetic forces themselves aren't influenced by the Higgs field because the proton doesn't have mass but the particles, the protons and electrons that are feeling those forces, sure they're influenced by the Higgs field, but I think that's at a scale that is about 10 to the tenth smaller than the size of the atom.

So those kinds of interactions are going on inside the protons and neutrons inside the electrons [BACKGROUND]. Brownian motion is actually, for you who don't know,

Brownian motion is the zigzagging you notice if you look under a microscope.

Brown was looking at dust particles in a fluid and he's watching them bounce around and Einstein actually figured out how to take that calculation and show that this showed that what was happening was the jittering around of little atoms.

I think a Brownian motion is actually being more connected to chaotic, unstable behavior rather than an equilibrium of any kind.

But that's my own sense of what Brownian motions like.

Yeah.

[BACKGROUND]

Correct.

[BACKGROUND] Well, presumably it does.

That's all the setups where people are trying to measure it, are looking for it that way.

The fact that it exerts gravitational mass and everything we know that has gravitational mass also has inertial mass, suggests that the Higgs field would be interacting with these particles.

That's one of the reasons that people think, well maybe if we jacked up the accelerator at the cern to higher energies, we're going to be able to create things which decay in a weird way that we can trace back to saying,

''Oh, this was some exotic particle and maybe that's the dark energy that we weren't able to see before.''

[BACKGROUND] I'm saying that inertia, the first kind of mass I talked about, involves the Higgs field and what we have found is that the amount of inertia, something has an amount of gravitational mass something has, are equal to each other at a level which has proven to be true and everything we've looked at.

So the assumption is that it would carry through to these kinds of particles as well.

Yes. But, if Newton felt humbled by not being able to explain why these things were the same thing,

I don't feel bad about bailing on that one either [LAUGHTER].

Yeah [BACKGROUND].

The inertia of the expanding universe, can you tell me what you mean?

[BACKGROUND]

So you're saying the fact that in a sense the Big Bang started and things keep moving because the inertia keeps them moving [BACKGROUND].

[NOISE] But no, actually that's not quite right because the gravity actually is coming not from the Higgs field, but from the gravitational field, which is a different particle being exchanged all the time.

Now perhaps there's a symmetry that the amount of gravitational exchange, the amount of Higgs exchange, are proportional to each other for something that has to do with the way particles are made, in the same way that electricity and magnetism have proportional interactions with each other.

So that's possible [BACKGROUND].

Yeah, it could be, it could very well be that that's the kind of connection we're looking for.

Yeah, in the back please [BACKGROUND].

I'm sorry that they broke off a piece of [OVERLAPPING] right.

So what they're saying is that they made something interact so strongly that a Higgs bows on itself, got marooned away from the field and then it decayed in a split second into a bunch of other particles,

[BACKGROUND] Correct. [BACKGROUND] Yeah.

[BACKGROUND]

Presumably, it's being exchanged between particles all the time, but the exchange goes from the particle to the field and that interaction takes place in such a short distance that we haven't been able to actually catch it in the act, if that's a way to think about it.

[inaudible 01:04:58]

The mass of an antiproton is exactly the same as the mass of a proton.

There are actually experiments, a buddy of mine was on the first experiment to show that antiprotons fell exactly the same way protons fell.

The anti part refers to what types of particles they are, what spins they have, what their charges are, but mass is a positive number and it's always a positive number, so that one doesn't actually change. Yeah.

It's probably a silly question.

Probably not.

[inaudible 01:05:39]

It's not a silly question at all.

The [inaudible 01:05:45] zone does not have any electric charge.

It doesn't have any strong charge, so it doesn't feel the strong force.

It doesn't feel the electromagnetic force.

The question that was being raised up there, which I don't know the answer to, is if it actually experiences the gravitational field as well.

It's one of the great things about giving a talk is you start to say,

"Wait a minute, I never thought about that aspect."

That one I won't know, but certainly the weak, the strong and the electromagnetic force of the Higgs field does not experience those. Yeah.

[inaudible 01:06:20]

Now, that's extremely unlikely to be a result of the work.

I think if you actually ask on a practical level what everyday benefits come out of this kind of research, it's that in the process of trying to study these things, physicists run up against the limits of whatever technology we have.

We've got something that can measure down to femtoseconds while we need something that goes to 100th of a femtosecond.

We've got things which can discern between two particles which are only this much different in mass, while we need to triple that.

By pushing constantly on that, we end up generating new technologies, which in very short order end up being in the general public's usage not because you guys needed.

An example that's often given is that the entire World Wide Web started at CERN because they were taking these massive datasets and they needed to share them with each other without having to put them on a tape, fly them across the country, and do something else.

So they had to come up with ways to transfer these data through, at that time phone lines, and someone said,

"We should be able to find a way where you can search around and find what you need."

All of that early work was done at

CERN not because physicists thought,

"Let's make something that's going to revolutionize information technology."

It's because they were trying to figure out what to do with their big datasets and their giant computing that they wanted to be able to log into a supercomputer somewhere else.

It was the fact that we kept pushing up against the technological limitations that ended up spawning off these other kinds of results. I think that's more likely to be what's going to happen, not the discovery itself, but the technologies we had to come up with to make those discoveries, like what's true of NASA as well.

Many of the things that came out of

NASA were because they were trying to solve particular technological problems and those pretty quickly generated into Texas Instruments and Hewlett-Packard, and all the rest.

[inaudible 01:08:55]

Higgs boson?

Yes

There is a minority of people who think that these don't show that particular signature.

It isn't just that we saw a bump at a particular mass, but people predicted how the particles should decay, what the spectrum of the decay particles should be.

There were a host of predictions beforehand, and not all of them agreed with each other and as the Higgs particle was discovered, actually filtered them out and said, these particular theories are still viable and these ones are no longer consistent with what we actually measured.

Beforehand, there were people who said we're not going to see the Higgs at all, and people who said, "When we see it, it's not going to be what you think it is."

I would say that if there is a group still feeling that way, it's probably a few percent of the particle physics community, so I wouldn't say it's zero but it's pretty small. Yes.

[inaudible 01:10:10]

Very good question.

I mentioned supersymmetry before.

This is the idea that every particle has a shadow particle which is bigger and has slightly other properties to it.

If we were to make us an accelerator to produce these supersymmetric particles directly using our current technology, a bigger ring like that and so on, this ring would be larger than the circumference of the earth.

We are going to find out that we're not going to build a bigger accelerator than this is so it's just not going to happen.

Now the positive side of that, and here I go back to a talk I heard by, ironically, Sheldon Lee Glashow, one of the founders of the Standard Model Theory.

What I found out was that historically, whenever we made some new important breakthrough, we then go and realize, we could have figured it out if we just looked at this thing differently.

That's what's going to happen.

We've got tons of things where we were focusing on the big picture and we weren't worried about this little tale that we couldn't figure out what it meant.

What's going to have to happen for the next breakthrough is not some bigger accelerator or some faster computer.

It's going to be a new conception of how to look at the little clues of things that don't exactly work out.

The most famous example of this is, most of us lived through the turn from the 20th to 21st century, turning from the 19th to the 20th century was also lot of celebrations, lots of things, "What's our new century going to hold?"

There's a famous talk by a physicist who said,

"Physics in the 20th century."

It starts out with,

"These are the triumphs of physics in the 1800s and in the 19th century." He lists out these things and at the bottom he says,

"There's a couple little things here we don't really know what they are."

He really said, "We know all this, we just don't know these couple of things down here."

Those couple of things led to relativity and to quantum theory.

These couple of things that they hadn't figured out, and they were perfectly justified in feeling very confident and how much they had explained.

Relativity overthrows our entire idea of what space and time are.

Quantum theory actually overthrows our idea of how things work at a small level and the basic idea of causality itself.

The fact that those hints were there, the fact that if you understood the line spectra that eventually led to us understanding what the periodic table was, the way if you understood why it is that when you heat up a body, it glows in a particular temperature.

There were clues in there, they didn't come around from faster and bigger and more powerful machines, it came from harder thinking or people coming at it from a different way. That's what's going to be required for the next breakthrough.

There is not going to be a super CERN built.

You'll be happy to know, not just because of the technology, but also you can't justify it experimentally or financially.

I wouldn't want to justify it as noble as

Robert Wilson's comments were.

Should we wrap up soon here?

Yeah.

Okay.

One more question.

Yeah.

[inaudible 01:14:10]

[LAUGHTER] The reason I talked about that, that's why WIMPs won out over MACHOs, the reason I bring that up is because I'm usually joking about it because I'm trying to get students to understand the concept of inertia.

Among the other things that barred,

I'm legendary for being the only person who teaches at 8:30 every day, and my students drag into the class and, "Oh, God.

Is this the class at 8:30?" Yes, it is.

But I'll be energetic enough for all of us. What I tell them is, I say,

"What do you think of when you think of inertia?"

They say, "How hard it was for me to get out of bed to come here."

That's what inertia is, how hard it is to get moving.

But the point I'm trying to make is that inertia is also about how hard it is to stop something from moving or change how it's moving.

Just as this is harder to move than this is, if I threw these things at you, this would be harder to stop than this would be.

[LAUGHTER] Both of those are examples of inertia.

This was the point that the gentleman out there was making about the expansion of the universe.

The fact that things keep expanding on their own, that they keep moving because nothing's stopping them, that's an example of inertia, and the fact that we really need to understand how it is that things maintain that motion.

Now, this Higgs field also keeps things moving the way they are, not just making them heavier to get going in the first place.

I think you were joking about the names of the particles, but it actually does point out that there's still a lot conceptually we have to figure out about inertia.

I think we've come full circle to talking about mass at the end, the way we talked about at the beginning.

So that's a great place to stop. Thank you so much.

Thank you very much.

[APPLAUSE]