Tip:
Highlight text to annotate it
X
[ Music ]
>> Roxanne Bogucka: Good evening, welcome.
My name's Roxanne Bogucka.
I'm a librarian based at the Life Science Library and I'm pleased to bring you the first Science Study Break of the Fall 2010 semester.
First, behold the legalese.
Okay. Without restriction, throughout the universe.
Those are the key words.
Okay. All right.
[ Coughing ]
Okay. Science Study Break tonight is brought to you by P for the Physics Math Astronomy Library.
The librarian there is Molly White.
And it's in RLM.
So go visit the Physics Math Astronomy Library.
But let's say you're working from home some evening.
And you want to use some of the resources that are brought to you from the UT Libraries.
Like for example, Institute of Physics things.
Then you might go directly to the Institute of Physics site.
And do a search for something like maybe neutrino.
It just happened to occur to me.
And as you do that, maybe you would find something that you wanted to look at.
And so if you decided you wanted to see this article, and clicked on the PDF link to it, you'll find that you're being asked for some money.
[ Laughter ]
Okay.
[ Laughter ]
[ Background talking ]
Okay. Don't let this be you.
Okay. Whenever you're off campus, always use the UT library website to get to our resources.
So if you went from our databases by subject to the physics databases, and then you went from there to the Institute of Physics Journals,
you could look at the About link to see this resource described.
And then you could use the active link to enter Institute of Physics Journals.
This is what you'll see when you're off campus.
A screen that prompts you for your EID and your password.
But once you entered that you're passed through to the Institute of Physics.
And note that this is a different URL here.
It has ezproxy.lib.utexas.
That authenticates you as part of the University of Texas community so that when you do this search for this article,
and you click on the article now, you get to see this information about it.
Plus when you click on the full text PDF you actually get the full text.
And you didn't spend any money.
So that's a good thing, right?
Everybody's okay with that?
So the University of Texas Libraries, "Celebrating the life of the mind."
Now I want to tell you a little bit about Science Study Break.
We've been doing this for four years and tonight we have our first encore presentor, which is Dr. Sacha Kopp from Physics.
He was with us last year to do a wonderful presentation on angels and demons and tonight we have the movie 2012.
Plus I think maybe some surprise other clip that we'll see about.
But you can see that what we do in this program is we look at television shows and we look at movies that are in the science technology engineering medicine arena.
And we ask a researcher to come in and discuss for us and with us the validity of what's presented in these shows.
Sometimes it's pretty scary and valid.
Like one of the first shows that we did was where we looked at a season of 24 that had to do with the bio-terror and Brent Iverson came in and scared us all half to death with.
[ Laughter ]
How well they had researched that season of the show.
Sometimes it's, it's pretty laughable and we all get to poke fun and we all enjoy that, too.
Okay. So tonight we have Sacha Kopp who's going to talk about 2012, and the popular film.
And I would like to now tell you about him.
Dr. Kopp got his Bachelors and Masters and PhD at the University of Chicago and he came to UT in 2000.
He is the new Associate Dean of Curriculum and Programs, and has been active in science education for almost as long as he's been active in elementary particle physics.
Well I don't know what happened there.
As a doctoral student, he helped develop a pilot program to retrain science teachers in the Chicago public schools.
As an assistant professor at Syracuse University he started a program which he's continued here at UT
to recruit undergraduate teaching assistants to assist in large lecture courses.
He's served as associate chair for undergraduate affairs in the Physics Department and he's collaborated with several faculty in the College of Natural Sciences
to develop a new center for inquiry in math and science which is devoted to promoting and supporting the use of inquiry based methods in science and math education.
And at the same time, he and his research team study the physics of neutrinos through an experiment based at Fermilab outside of Chicago.
Please welcome Dr. Sacha Kopp.
[ Applause ]
>> Sacha Kopp: Okay.
Let's figure this out here.
[ Background sounds ]
The first time.
Cool. Thank you all so much for coming out tonight.
What a, what a great crowd to come and listen about neutrinos.
Roxanne has placed the first page of your quiz on your desk here.
[ Background sounds ]
The backside has the real hard part so I'll ask you.
No I'm just kidding.
[ Laughter ]
Fooled you.
No. There will be no quiz, but you won't get ice cream from the Physics Circus crowd unless you can answer a few key questions at the end of the lecture.
[ Laughter ]
Okay. So Roxanne mentioned that last year I, I had fun giving a lecture here at this series on the movie Angels and Demons.
And someone kind of dropped this one in my lap.
I don't know why Ron Howard got interested in a Large Hadron Collider but he was very interested in this book by Dan Brown.
And so that featured the Large Hadron Collider in it and it was a perfect opportunity to pump the public full of the exciting news about the Large Hadron Collider.
And this year, some students of mine actually came up to me and said, you know if you thought that Dan Brown book was bad, wait until you see this movie 2012.
[ Laughter ]
And so instantly I was just excited because, again, I don't really view these as science movies.
But rather excuses to give talks.
So there's lots of good stuff in, in this movie.
It's a fun movie to watch.
But it is a movie of science fiction and of course, like every piece of science fiction, there's always a little bit of, of a true story behind some
of the images or the concepts that they bring out.
It's mostly nonsense, but its fun to then talk about what is the actual reality to what's going on.
So this is the movie 2012.
And I don't know, has anyone seen the movie?
A few of us.
Half. Okay.
So not everyone's seen it.
Let me talk a little bit about first what it is.
Because then we can at least get on the same page.
So in this story, the earth is basically destroyed, okay.
So there's some giant solar eruption and this solar eruption unleashes this incredible burst of these particles called neutrinos.
And these neutrinos come whizzing throughout the universe and bury themselves like little, I don't know, what do you call them, termites in the, in the core of the earth.
And they heat up the core of the earth to such a degree that causes the core of the earth to melt.
Yes. And then.
[ Background chatter ]
Actually causes huge volcanic activity, plate tectonic motion, we're in a geology school here so I can use that word.
And all of, and there's floods and everything and lots of computer simulations and everyone's dead.
[ Laughter ]
So I wanted to talk a little bit about the, the first part of this because that's kind of the key crux of the story, you know the, the eruption of the,
the sun and how it unleashes all of these neutrinos.
But I thought what I'd first do is show a trailer from the movie.
So let's see if I can get that to work.
[ Background sounds ]
[ Laughter ]
Cool. Select audio.
Where do I select audio?
Okay. And I need to do the source.
[ Laughter ]
Just going to try to find the audio here, sorry.
How about if I pause that.
How do I select the source in the audio?
>> Roxanne Bogucka: Select the left button.
>> Sacha Kopp: That's a good question.
[ Background sounds ]
I'll figure this out.
I know. No I mean I'm assuring them.
You know what, I don't know.
No it's not doing it.
So maybe you're right.
Maybe I need to do.
>> Roxanne Bogucka: Select [inaudible].
[ Background sounds ]
>> Sacha Kopp: Oh yeah I think you did it.
[ Movie sounds ]
Oh yeah that did it.
Let's try again.
[ Movie sounds ]
Sorry about that.
We'll.
[ Movie sounds ]
>> This mass suicide adhered to the Mayan encounter which predicts the end of time to occur on the 21st of December of this year.
This year.
This year.
>> What are the odds?
[ Movie sounds ]
>> Sacha Kopp: Those neutrinos are loud.
[ Movie sounds ]
>> I thought that I had more time.
[ Movie sounds ]
>> He said that the government is building these ships.
So then we have to let the people know.
>> Our mission is to ensure that continuity of our species.
Wasn't it also decided that people have the right to fight for their lives?
[ Movie sounds ]
>> No matter what happens, we'll always be together.
[ Background sounds ]
>> Find out the truth.
[ Laughter ]
[ Background sounds ]
>> Sacha Kopp: It's all a cover up, man.
No.
[ Laughter ]
That's coming out a little dark on that screen.
Well that picture is probably one of the best pieces of computer simulation in the whole movie.
They show this aircraft carrier coming and dumping right on the White House as this huge tidal wave is overtaking the east coast.
So I forgot to mention the other sort of thematic piece of this movie is that ostensibly the whole end of civilization was predicted
at least according to the movie tellers by the Mayans.
And so this, this date of December 21, 2012 is something that corresponds to a prediction in their, in their world, or their mythology.
And I'll talk about that in a little bit too.
But what I found interesting as I was looking up a little bit about the facts about the movie is they encourage you to Google 2012 at the end of the trailer.
And in fact, this is really great PR, they did an awful lot of work setting up virtual think tanks and non-existent theology centers and what have you,
so that they would be the first Google hits that you came up with when you Googled 2012.
[ Laughter ]
And it was incredible.
Because then they told their own story of what this Mayan prediction was.
And what is the science or, or whatever.
And it, and, and now that's what or the top, I don't know, 10 things that you're going to find out about when you do in fact do this Google search.
So that's just something to be mindful of as we start thinking about researching it for ourselves.
What's going to be presented to us in a movie.
So let's talk about the first part of this story, which is the sun.
So ostensibly in this story, the sun has had some huge solar eruption.
I don't know what that means.
[ Laughter ]
And this solar eruption has unleashed an ungodly number of neutrinos at us.
Okay. So what are some important facts for us as scientists about the sun?
Well the sun is a big plasma of gas.
And it's rather heavy.
And that gravitational level of force that's inside the sun is enough to fuse atoms or nuclei more importantly together.
So in fact, the main power source in the sun that's producing all the heat, the light and other things like neutrinos, is nuclear fusion.
And actually that story is a relatively recent story, description of the sun.
Up until even I would say the early part of the 20th Century, scientists were really wondering what is it that powers the sun.
And there are some very famous physicists of the 19th and early 20th Centuries calculating various scenarios what is the, the energy source of the sun.
And they all came up with lifetimes by which the sun would extinguish itself of over a few thousand years.
That's very good if you believe in certain kinds of theology.
But if you're asking why is it the earth has been around for four billion years and what's, what's provided heat, that was really hard to understand.
So with the dawn of nuclear physics in the 20s and 30s, this finally became to be understood.
And fusion it turns out to be very important to our story because it produces lots of these particles called neutrinos.
So there are lots of fusion processes.
Fusion just as a generic term for I will take two things and fuse them together.
And in doing so, the reason we care about fusion as an energy source, it releases energy.
This energy can be in the form of, of heat, or it can be in the form of other particles.
And there are a lot of these reactions that release neutrinos.
I listed just a few of them.
Most of them come from the, the fusion of the lightest elements to protons to make an isotope of hydrogen called deuterium or deuteron.
It releases one neutrino.
And then it produces a spectrum of neutrinos that's rather intense.
There are some other processes as well that, that make contributions here.
You can take a proton and an electron and, and two protons and an electron and make again a deuteron and a neutrino.
You can take helium three and a proton and you make helium four.
And so on.
And all of these things release neutrinos.
In fact, so many neutrinos come at us from the sun, just our sun, there are about 10 trillion hitting your body every second just from our sun.
Now I add up all the other stars in the universe, there are a lot of neutrinos passing through you.
Okay. Neutrinos are a big form of the energy release of any star or any super nova.
A lot of the, the phenomena that we see out in the universe are releasing neutrinos.
They are also producing, if you noticed in this little set of reactions are produced, although it's listed here, the heavier elements.
Some of the elements that we have left to us, are left over from literally the Big ***.
We have protons and neutrons and they form slightly heavier things.
We get up to helium and lithium left over from the Big ***.
But the really heavy elements are formed in stars.
And so we in fact rely for a lot of the, the heavy minerals that we have, on the left over stardust if you like.
Things that come streaming at us or streamed at us long ago when the earth was formed.
But the big, big takeaway message for us, yes there are a whole lot of neutrinos.
In fact, neutrinos were very instrumental in confirming our picture of how the Sun actually produces its energy.
There are a set of ideas of what the Sun was relying on to produce energy and there was a chemist, actually not a physicist, but a chemist, back in the 50s
and 60s who developed a technique to actually detect neutrinos from the sun.
And this chemist went deep underground in a mine in South Dakota.
Had a large chlorine tank, so bleach basically.
And when a neutrino hits a chlorine atom or a nucleus actually, it produces argon.
It's specifically a, an isotope of argon that's radioactive.
He was such a good chemist, he could isolate single atoms of argon inside of that giant tank.
If you notice, that's him, that's Ray Davis, that's the tank.
So it's a rather big vessel that he's using to contain his big chlorine bath.
And he was to get good enough to isolate individual argon atoms.
And every time he saw one, he knew that a neutrino had interacted from the sun.
So he was counting up neutrinos to see that that would in fact explain the level of power produced by the sun.
And he got an answer that was about right.
For that he was actually awarded a Nobel Prize, because that was big stuff to actually now confirm that we see neutrinos from various celestial objects.
[ Background sounds ]
Well there are a lot of us that do neutrino experiments, and it turns out not because we don't like the sunlight.
We all go underground to do it.
Actually a few of us here at UT Austin are involved in an experiment that's in northern Minnesota.
A place that's so far north it's about a few, just a couple miles away from the Canadian border.
It's only not snowed in that area in August, it turns out.
But it's, we're about 2,700 feet below ground.
This is the detector that we built.
It's not a chlorine tank.
You see here a person, again standing next to that.
So that's about 25 feet tall.
It's about 5,000 tons of steel.
A very large neutrino detector compared to the original one by Ray Davis.
The world's deepest neutrino detector is actually in Canada.
It's about 7,000 feet below ground.
And so that's, that's about as far as anyone has dared to go because that's a lot of digging to get that far.
Let's see if this will work.
So why are we going underground?
Well it's not that these are top secret projects, as we'll see another clip I'm going to play from the movie you might, you might tend to believe that neutrino projects are sort
of top secret work by the government and, and guys in black suits.
But it's not so.
Actually, the reason we do this is that neutrinos are actually very faintly interacting particles.
It's very difficult to see the signals from a neutrino in your detector.
And particularly if you're looking at a source of neutrinos like the sun.
The sun is unleashing on us a ton of other stuff.
There are many other particles coming at us from outer space.
Protons and gamma rays and electrons.
All this stuff leaves signals in detectors.
And we need to find ways of, of shielding ourselves from that other stuff so that we're looking at just the neutrinos.
So in fact, what we do is we go deep underground.
So some of the detectors are 1,000 or 2,000, 3,000, up to 7,000 feet below ground.
And what that does is it tends to shield us from this flux of other stuff.
So on the vertical axis of this plot is the number of millions of particles per square meter per year hitting an average detector the deeper you go underground.
And so it lies on a curve it gets lower and lower the deeper you go underground.
And that's the real reason we tend to do this research in rather difficult circumstances, because it's difficult to take, build a 5,000 ton object when you have to go
down a shaft that's probably no bigger across than this room.
So it's kind of like building ships in a bottle.
Yes.
>> How far down into the Earth can these neutrinos get?
>> Sacha Kopp: Oh that's a good question and I'll come back to this a little bit further, later on.
A neutrino on average could go through about a light year of lead before it would interact.
So most neutrinos passing through you, and this is a good part of the story, don't interact at all.
Okay. Most neutrinos passing through the earth don't interact at all.
They just keep on going.
So actually to see a neutrino in the detector or whatever apparatus you're trying to build is a very rare event.
You're counting really, you're sampling a very small fraction of the neutrinos that come at us.
Okay. Good question.
Thank you.
All right.
Let's go back to the movie.
All movies need a hero.
In this case it's a physicist.
And who else really?
[ Laughter ]
Our movie starts out with Adrian Helmsley who we are told works for the Office of Science and Technology Policy.
He is using neutrinos to track activity of the sun.
And they make, in this clip, rather under expected discovery.
So let me play a clip from the movie here.
Let's see if I can do it.
[ Background sounds ]
>> You were mysterious on the phone.
Why didn't you attend the conference?
>> I will show you, Adrian, sir.
>> Stop, stop "sir"-ing me.
[ Movie sounds ]
>> Sacha Kopp: They're going down a mine shaft.
>> How deep do we need to go?
11,000 feet.
>> We searched all over India for this thing.
It used to be the deepest copper mine in the world.
[ Movie sounds ]
>> [Inaudible].
>> Smooth enough.
Remember my brother, Gurdeep?
He's a student now.
>> Namasté, Dr. Helmsley, sir.
>> Adrian, just Adrian.
>> [Speaking Hindi]
>> Just don't pour in too much.
>> How do you work in this heat?
>> You've come on a good day my friend.
Sometimes it can be 120 degrees.
Meet Dr. Lokesh, Fellow of Quantum Physics in the University in Chennai.
>> Namasté, Dr. Helmsley.
>> So what are we looking at?
>> These are neutrinos acting normally.
Miniscule mass.
No electrical charge.
They pass through ordinary matter almost undisturbed.
>> Your message said the count doubled after the last solar eruptions.
>> That was last week.
But this happened two days ago.
[ Movie sounds ]
The biggest eruptions in human history.
Causing the highest neutrino count we've ever recorded.
>>My God.
[ Laughter ]
>> Sacha Kopp: That does sound bad.
[ Laughter ]
[ Background sounds ]
Well what could that do?
[ Laughter ]
Well again, let's just talk a little bit about what actually happens with the sun.
So the sun actually does have big solar eruptions.
The sun does this all the time.
In fact, the sun goes through a rather cycle of, a rather periodic cycle of these solar eruptions.
The pictures that I'm showing over here are two snapshots of the sun about, taken about five and a half years apart.
It turns out every 11 years the sun has gone through a cycle.
In one picture you can see it looks rather smooth and uniform and the other it has lots of blotches on it.
Those are so-called sun spots.
The sun is going through a lot of turbulence all the time.
And this turbulence seems to have a periodicity where every 11 years it's going through a, a period of large amounts of activity.
And that activity manifests itself in real big fluid flow on the surface of the sun.
So called coronal mass ejections.
You see huge flares it ends up sending off huge amounts of mass from the sun streaming off from the space.
And all kinds of stuff that actually could be quite catastrophic.
In fact, the biggest solar eruption in human history is not one that took place in 2012, but rather in 1859.
And the story of that is pretty, pretty remarkable.
So in this particular solar storm back in the 1800's, there was an early observation of it just by looking up through a telescope and you could see,
gosh the surface of the sun looks pretty darn different today.
There were huge blotches on it, or huge solar, sun spots.
And then a couple days later, all of a sudden there was a huge rain of particles hitting the surface of the earth.
So I don't know if any of you have ever been up north to see the Northern Lights.
Has anyone ever seen the Northern Lights?
No. Because we're in Texas and so most of us have never seen the Northern Lights.
If you live up, let's say northern Minnesota, southern Canada or above, it would not be unusual for you to see a, a rather dramatic light display at night time.
It would happen in the day as well, but you see just so much other light from the sun.
Where high energy particles that are streaming in on the earth get directed up toward the poles.
The North Pole and the South Pole by the earth's magnetic field.
And as these things come crashing into the atmosphere they cause the gases in the atmosphere to excite and emit light.
So if you see the Northern Lights, something serious is going on.
There's a rather substantial shower of particles happening.
Now mostly that happens up in the north, or down, way down south.
So it's, so few of us live at the South Pole that that doesn't really figure into most people's terminology.
But on this particular day, back in 1859, the Northern Lights, the so-called Northern Lights were visible all throughout California,
Colorado, the Chicago area, down as far as Florida.
Never before does this happen.
Even in what would have been in Texas.
So that was really quite a sign of a violent event.
Later by a couple of days, those sun spots went from, from being sort of a dark black or brown color to being bright white.
Today we would know that that was a huge x-ray flare and a second display of Northern Lights came about as, reaching down as far south as South America.
In fact, it was so bright, this display of light at, in the night sky, that it was said that miners who were in Colorado woke up at one
in the morning thinking it was time for breakfast.
I mean it was really incredible.
So this was definitely a big event.
The impacts of such a solar storm should it happen again are pretty big.
Because what happens when all these charged particles come streaming at us, ejected by the sun, they carry with them their own magnetic field.
Those of you who have taken a physics class learn that a current, from a, a moving collection of charge emits its own magnetic field.
It starts to alter the magnetic field put out by the earth itself.
And that magnetic field from the earth is meant to be a protective layer for us.
Well I don't know if it's meant to be but it is a protective layer for us.
It tends to steer stuff coming at us away from the, the surface of the earth.
As that stream of particles gets stronger and stronger, now that weakens the magnetic field of the earth, to the point where actually the magnetic field
of the earth is exposed or broken down to the side facing the sun.
And now we, we are sort of twisting in the wind.
Today if such a thing happened, we would worry about this, because we have a lot going on that wasn't around in the 1800s.
We have technology.
For example, we have power lines out there and they carry currents.
Well currents tend to get affected by magnetic fields passing by them from all these charged particles.
And it's predicted that if such a solar storm were to happen again, we would have rather traumatic, dramatic power outages across the entire globe.
To the extent that you would probably see huge electrical fires on transformers and power lines all around the world.
That's a simulation that's not a, a, that's.
[ Laughter ]
That's Photoshop, not real life.
Okay. In fact this is a simulation of the level of power outages there would be in the United States if there was a magnetic storm as big as the one that was in 1921,
which itself was only a third or a fourth of the size of the one in the 1850's.
No one's ever bothered to do the simulation of the one in the 1850's, because that would be pretty much the entire country would be blacked out.
So the economic catastrophic, catastrophe would be pretty big if something like this happened again.
The other thing we would worry about is, in today's society, is we float a lot of stuff over the earth out there.
And it's pretty exposed as well.
And we rely on this stuff.
Like GPS and communications.
Basically everything that's electronic flying over the earth would be fried by such a solar storm.
And even in more mild solar periods, astronauts flying into space shuttle go into interior sections of the space shuttle to shield themselves against the rather regular bombardment
of the stuff that they're exposed to when the sun goes through even a modest solar flare.
So one of these things would be a rather significant event.
Now the good news is, if you're worried about 2012, the sun does this on a fairly regular schedule.
And it's not that big.
In fact, 2012, if we look at the solar cycle should be a pretty quiet year.
So this is a graph of sun spots versus year, and we had a pretty big year in the 19, in the early 60s.
We had a pretty big year in the early 80s.
But 2012, no worries.
[ Background sounds ]
Maybe we should talk about those scary neutrinos.
[ Laughter ]
So in the story, neutrinos seem to be the real problem.
It's not the other stuff coming at us from the sun, but rather the neutrinos that are emitted by the sun.
At least according to the story teller.
So I thought we'd focus on what happens with those bad neutrinos.
[ Background sounds ]
It's not going to let me do that.
[ Laughter ]
I'll show you.
[ Background sounds ]
>> Posing the highest neutrino count ever recorded.
>> My God.
[ Movie sounds ]
>> That's not what worries me, Adrian.
For the first time ever the neutrinos are causing a physical reaction.
>> That's impossible.
[ Movie sounds ]
>> Ah, that feels very good.
>> Please follow me.
[ Movie sounds ]
You won't believe this.
[Speaking Hindi].
This water tank goes another 6,000 feet.
It looks like neutrinos coming from the sun have mutated into a new kind of nuclear particle.
[ Laughter ]
[ Movie sounds ]
>> The heating of the Earth's core is suddenly acting like microwaves.
[ Movie sounds ]
>> Sacha Kopp: Boy that sounds really bad.
[ Laughter ]
Heating up the earth's core.
Okay. Here again, there's just a little bit of truth to the fiction in this movie.
You notice they walked into this chamber.
It had these kind of bulbous things all along the walls.
And there was this big tank that they referenced that goes down another 6,000 feet which looked like it contained boiling water.
Well there's almost just a little bit of truth to what they were talking about.
Almost. So let me show you want a modern neutrino detector looks like post-Ray Davis from the 1960's.
This is the world's largest neutrino detector.
It's located in Japan, and it's called the Super Kamiokande Detector.
Kamioka is the name of a mine in, in Japan.
So it's, I forget what the "n-d-e" tacked on means in Japanese.
But it's an enormous volume.
It's about 50,000 tons of water.
That's equivalent to about one gulf oil spill day.
[ Laughter ]
Put in Texas terminology.
[ Laughter ]
And it is surrounded by these bulbous objects.
They are called photomultiplier tubes.
And what a scientist in, working on this experiment is looking for are flashes of light when a neutrino from the sun or other source comes and interacts in the water,
and creates the electromagnetic equivalent of a sonic boom.
So it's a light boom.
And you see a flash of light produced in this water from a neutrino interaction.
So the entire thing you can think of as a camera facing in looking at this water target.
It doesn't, by any stretch, go down 6,000 feet.
That's really pretty darn deep.
I think that's about the thickness of an oceanic crust.
So that's, that's a pretty significant tank that they reference in the movie.
But this tank is pretty darn big.
This picture shows the tank in a fish eye camera lens.
And looking up it's just been started to fill with water.
Those folks are in a pontoon boat right there.
[ Background chatter ]
It's graduates students cleaning the surface of those little photo multiplier tubes.
[ Laughter ]
And they'll eventually fill that up.
I guess the students sit there and fill, and polish as they go.
[ Laughter ]
It's about 70 meters tall, so that's about the size of the RLM building for those of you who are familiar with the north end of campus here.
That's one of the taller buildings here on campus.
So that is a significant tank, but by no stretch 6,000 feet.
And the little bulbs are, serve a very specific purpose.
The water never boils.
Okay. It's not like the neutrinos make the whole thing warm.
The neutrinos interactions really such a small amount of energy in the water that we're looking for the light, not boiling water.
So this is what you might see in a neutrino coming in from the sun would be invisible dotted line.
And all of a sudden it would produce this flash of light and this light would propagate outwards and hit the walls of the tank.
And so you would see this rather dramatic display of a ring of light hitting the walls.
And that's actual data from that experiment where they see different types of neutrinos either electron type neutrinos or neuron type neutrinos interacting in the water.
And, and you can see the pattern of light on the walls of the tank.
[ Background sounds ]
This was an earlier experiment.
I just put it in there because it has a scuba diver in it.
But I thought that would be funny.
[ Background chatter ]
Actually, one of the things that was significant about our discoveries with neutrinos from the sun is that there's not nearly enough.
So we don't really worry about having too many to cause the earth's core to heat.
In fact, the early experiments that were looking for this so-called electron type neutrinos coming from the sun, failed to detect enough.
And when Ray Davis first discovered this, everyone thought he was wrong because he's, after all, just a chemist trying to do work in a physicist's field.
And he stuck to his guns for many years.
And this was really to his credit.
I think why he deserves the Nobel Prize.
He was consistently coming up with results that said that there are only about a third as many neutrinos as you would predict given the luminosity of the brightness of the sun.
And in fact, that remains an observation that, that other scientists have confirmed to this day.
In fact that's one of the key areas in particle physics right now is why it is that those electron type neutrinos that seem, that you would think leave the sun
in a certain number don't appear on earth in the correct number.
I'll come back to that in a little while.
Well in the movie, this becomes a big cover up.
Because they decide, well the earth is going to end.
There's going to be tidal waves and volcanoes and we're going to try to brace ourselves by building ships to protect ourselves.
And much of the story is then, most of humanity being wiped out with the small exception of a few people chosen to,
to live on protective ships or arcs by the governments of the world.
I won't bother to play this clip, because I think we're running a little bit on time.
But this is Danny Glover, and he's, plays the president in this movie.
One thing I have to say though, is this guy who plays the physicist who works for the OSTP, the Office of Science and Technology Policy, he has a job I'd love to have.
He's, he's this kind of swashbuckler guy.
He wears suits and, and dresses pretty well.
He's in these control rooms with pretty exotic panels controlling, you know, monitoring everything going on all over the earth.
You know a real guy who woks for the OSTP is kind of like a, a technology diplomat.
He tends to sign legal papers with other countries on patent infringements and advise the president on, you know, on which, which form we should take, beta or VHS.
So it's.
[ Laughter ]
So it tends to be a much more mundane job.
Although it's an important job within the government.
The other character in the movie is John Cusack and he plays your average Joe that happens to find out about the government cover up by accident.
He's gone to Yellowstone where some of the scientists are doing their work to find out where the early volcanoes are going to erupt.
And he happens to land upon *** Harrelson.
[ Laughter ]
And he's you're ultimate conspiracy guy.
He's living out there in the woods and he's, he's figured it all out.
He knows what the governments of the world are up to.
He's got a little radio broadcast.
And I'm going to let him explain the, the real goings on.
Because he explains it much better than I can.
[ Movie sounds ]
>> Sacha Kopp: Oh sorry.
[ Movie sounds ]
>> Sacha Kopp: Sorry I hit the wrong one.
[ Movie sounds ]
>> No way.
>> You're not afraid to tell the truth.
>> Thank you, Bill.
What's your question?
>> I wanted to where is all this gonna start?
>> Something like this could only originate in Hollywood, Bill.
But seriously, they got the Earth cracking under their *** already.
Our family believes in the gospel of the Lord Jesus.
We have nothing to fear, Charlie.
Good for you, Bill.
This is Charlie Frost reporting live from Yellowstone National Park, soon to become the world's largest active volcano.
I'll be right back, folks.
>> Hey, do you mind if I join you?
I just wanted to ask you something.
>> I only got a minute.
Pickle?
>> No. I was listening to the broadcast.
I was wondering what exactly is it that's going to start in Hollywood?
>> It's the Apocalypse.
End of days.
The Judgment Day.
The end of the world my friend.
Christians call it the Rapture.
But the, the Mayans knew about it.
The Hopis.
the, The I Ching.
The Bible, kind of.
Beer?
[ Laughter ]
So look, I got to eat.
Why don't you download my blog.
It's free.
Of course we do appreciate your donations.
>> In ancient times the Mayan people were the first civilization to discover that this planet had an expiration date.
According to their calendar in the year 2012, a cataclysmic event will unfold caused by an alignment of the planets in our solar system that only happens every 640,000 years.
>> Oh, not again.
[ Laughter ]
Pretty neat, huh?
I did all the animation myself.
>> Just imagine the Earth as an orange.
>> Lure them in with humor, then you make them think.
>> Our Sun will begin to emit such extreme amounts of radiation that the core of the Earth will melt.
That's the inside part of the orange.
Leaving the crust of our planet free to shift.
In 1958, Professor Charles Hapgood named it Earth Crust Displacement.
Albert Einstein did support it.
People will get it all.
The forces of Mother Nature will be so devastating, it will bring an end to this world on Winter Solstice 12-21-12.
Always remember, folks, you heard it first from Charlie Frost.
[ Laughter ]
>> You have to keep a thing like this under wraps.
>> Sacha Kopp: I'll quit there.
Yeah so ***'s got it all figured out.
In fact, according to him, the governments are all at this plot and the Mayans knew about it all along.
I don't know how the Mayans predicted the plot part.
But they did.
And they predicted also that the, that all this unleash of neutrinos were going to cause rather severe tectonic motion of the, of the earth's plates.
And we're going to be all lost due to volcanoes and floods.
So here I want to actually look at this notion of neutrinos causing heating of the earth's core.
Because that's a pretty substantial thing.
So there's one little detail that's very, very wrong in this movie.
And I, we already talked about it because we talked about neutrinos passing through us all the time.
Yes it's true, the sun unleashes a lot of neutrinos.
Every one of us has 10 trillion passing through us from just our sun.
And when they do interact, scientist do enjoy watching the rather dramatic displays in the detectors that they've built, and the rather violent collisions
of a neutrino annihilating a nucleus of an atom.
There's just one little problem.
It doesn't happen all that much.
Okay. Most of the neutrinos produced by the sun pass right through the earth.
Okay. They are extremely weakly interacting.
[ Background sounds ]
This has to do with how forces connect particles together.
When most of us are looking at each other we are looking at light.
And what is exchanged between us are the carrier particles of light, called photons.
So there are photons dancing all throughout this room.
There are some bouncing off your skin into my eye.
There's some bouncing off my shirt into you.
And that's what we see.
That's what allows us to communicate with one another via the electro magnetic interaction.
Well the electro magnetic interaction responds to something called electric charge.
Something neutrinos don't have.
Neutrinos correctly are said to be chargeless or neutral in the movie.
They don't have an electric charge, and so the only force that they are left with experiencing is the weak force.
The carrier of the weak force is called a W particle.
It's the analogy of the, of the photon.
And it weighs a lot.
It weighs as much as a krypton nucleus.
So for that neutrino to throw off one of these heavy W particles to you, actually violates the law of conservation of energy.
It can't create that thing and throw it over to you, because it doesn't even have that much energy to begin with.
And so you say well how does it allow itself to violate the law of conservation of energy?
Through one of the great things in quantum mechanics, well we allow that in, in physics, but we just don't allow it for too long.
So there's this thing called the uncertainty principle and you're allowed to violate everything in, in quantum mechanics.
[ Laughter ]
You can violate momentum conservation, you can violate energy conservation, you can violate anger momentum conservation,
you can only just do it for a little while though.
So it turns out this W particle is only allowed to travel a little while.
It's kind of like Cinderella and the glass slippers.
And what that means is that the information exchanged between a neutrino and it's neighbor will only go a short distance.
So the neutrino would have to get very close to something in order to interact with it, and that just doesn't happen.
[ Background sounds ]
In fact, the, the very fact that neutrinos interact so weakly makes them an excellent tool for science.
Because when we look at the sun, we are seeing the light from the sun and it streams at us.
But that light is pretty much the stuff that's emitted from the very surface of the sun.
Any light or other forms of energy from deep inside the sun has to get through the molasses of the rest of the sun to get out and it doesn't..
It's trapped.
If you want to see the interior core of the sun though, you look at it with neutrinos.
Because they're very penetrating.
In fact, this image here of a sort of white dot with the, the yellow corona around it is an image of the sun created with just using neutrinos.
So in a sense it's a picture of the interior of the sun.
It doesn't look like it has a lot of detail right now.
That's because the camera doesn't have a lot of neutrinos hitting it, or interacting in it.
But it is that experiment in Japan actually taking a picture of the sun using neutrinos.
Well let's do some numbers.
This is a math lecture so we're going to put some numbers together and actually ask, could these neutrinos coming from the sun actually heat up the core of the earth.
So here's my best attempt.
The sun emits about 10 trillion neutrinos per square centimeter per second.
Each neutrino carries about 10-13 Joules of energy.
And the earth is big.
It's got an area of 1018 square centimeters.
And so I tally up the total energy hitting the earth from neutrinos of any, in any form, is 1018 Joules per second.
Well that's a lot of Joules.
You'd say, phew that's pretty bad.
There's another part of this equation though.
If you want to ask will it heat up the core of the earth?
Well you've got to heat it up.
I take all that energy and I dump it into the mass of the earth.
Well it turns out the mass of the earth is awfully big too.
The mass of the earth to a good approximation is about 1027 grams.
So you take 1018 Joules per second, for one second burst, and dump it into 1027 grams, and the temperature rise
of the earth would be a massive 10-9 or one one billionth of a degree Celsius.
So there's two problems with the movie.
Only two.
[ Laughter ]
One is the neutrinos just don't stop in the core of the earth.
They don't travel through the Earth's crust and then selectively decide to stop in the core.
In fact, they wouldn't stop in the solar system.
They would keep radiating out through a light year of lead, or equivalent.
And even if they did, the Earth, the energy produced by the Sun is no where near enough in neutrinos to heat up the core of the earth or the entire Earth itself.
It's a temperature rise of less than a degree.
Well a billion times the solar output would be one degree Celsius.
That's just not enough to get worried about.
So it sounds good, but not going to happen.
Now there's this other quote in the movie that actually is kind of enticing.
It talks about what about this thing where neutrinos transmute into other nuclear particles?
Actually that's true.
They don't translate into microwaves though.
They transmit into other forms of neutrinos.
So there's another problem.
You asked if they changed into something else, you could worry about that heating up the core of the earth.
But it's more neutrinos.
So they're not going to interact in the core of the earth either.
[ Laughter ]
And there are experiments that show that this happens.
There are experiments like those of Ray Davis that say we don't see the right number of neutrinos from the sun hitting the earth.
Our supposition is that they've changed away from the type of neutrino that Davis was looking for in his experiment into another type of neutrino.
There's an experiment that some of us at UT Austin did where we made a beam of neutrinos using accelerator and we deliberately aimed it down in the ground.
Because the earth is fairly transparent and neutrinos, the neutrinos go through the Earth, you know the Earth is round.
Remember the Earth is round.
[ Laughter ]
Neutrinos go through the Earth and come out in northern Minnesota in our beam.
And so we placed a detector in northern Minnesota to look for the neutrinos launched back in Chicago where we have an accelerator to boost this beam.
And once again, not all of the neutrinos arrived.
It's not because they interacted in the Earth, but because they changed into another flavor of neutrino that we weren't looking for.
So they disappeared into another flavor.
And there have been further more experiments, oops I'm going to just skip that.
Oh, I have to show this quote.
Yeah. That's the one.
[ Laughter ]
The one news station in the United States that carried a story about our neutrino experiment said, "Physicists Lose Some Neutrinos, Gain Some Information."
Somewhere between Illinois and Minnesota the federal government lost some neutrinos.
[ Laughter ]
It makes it sound like floppy disks from Los Alamos, doesn't it?
[ Laughter ]
[ Background chatter ]
There have been furthermore experiments done that actually show that this, when you lose these neutrinos they go into something else halfway through your experiment.
They actually go back into other forms of neutrinos.
There's an experiment, excuse me, the one in Canada that plotted the number of neutrinos of the electron type versus the number of neutrinos of the other types,
and it showed that the Sun's neutrinos, although they all start out as electron neutrinos ended up being other types of neutrinos.
There's an experiment in, in Geneva Switzerland where the Large Hadron Collider is located that did the same, very similar to us.
They had an accelerator over here.
They aimed the neutrino beam down into the ground instead of going through underneath Madison, Wisconsin, they go through nice places like Milan and Venice,
and they end up in the southern boot of Italy where they have their neutrino detector.
And they found explicitly that what they see on the other side is another type of neutrino, not the one that they sent in their beam.
So we know that neutrinos do transmute to other types of particles, but those other particles are neutrinos.
And so they're not going to heat up the core of the earth either.
Now let's talk a little bit about this Mayan prediction stuff.
Because that's important.
I don't want you to get real worried about the end of days here.
Okay? In the movie it talks about that the Mayans made these predictions and that there was going to be a, a fairly significant event on December 21, 2012.
And I didn't show the clip, but the ultimate story turns out to be that all the planets will align and this will cause some big instability in the sun
and that's what's going to cause this big solar eruption.
So the grains of truth to this are that the Mayans, like a lot of other ancient peoples, were excellent predictors of the trajectories of the planets and the sky.
And they cataloged many things.
In fact, we all know that they built their calendars around the motion of celestial objects.
They even built their temples around when would you observe the various solstices and what would you observe the planet Venus doing, and so on.
So that part is true, but it's not necessarily true that that's going to cause our big cataclysmic event in 2012.
In fact, some of the other things that people get very excited about in the Mayan calendar are that it's organized into these epics called B'ak'atuns.
I think I probably pronounced it wrong.
And that one of these things goes through a complete cycle on, in 2012.
So the Mayan calendar is organized in increments of 20.
This little t-shirt that you can buy on the web sort of shows what December 21, 2012, would be in the Mayan calendar.
The first digit there is the number of days, the second digit represents the number of unials, which is an increment of 20 days about a month,
the next digit over is one Tun which is 18 unials which is 360 days.
So they fudged, they fudged on the number 20 there so it came up to about one year.
And the next digit over is called a Ka'tun and that's 20 Tuns and that turns out to be some number of days.
And then there's a thing called a B'ak'atun which turns out to be 144,000 days.
So the Mayan calendar is built in these increments of 20.
And one of these suckers is going to end on December 21, 2012.
Okay? And this is described as the big apocryphal event.
Because it is said, well the Mayans predict the end of their calendar is on this date, and we're in trouble.
Well there's a couple problems.
One I don't know that this is any different from December 31, 1999 when we had lots of confusion and, and panic about the year 2000.
And second, scholars differ whether the, the 13th B'ak'atun that's supposed to end in 2012 is actually a significant date.
Because that's not necessarily the end of the Mayan calendar.
In fact, there are some hieroglyphs in Mayan ruins that have been discovered which says that in fact there's supposed to be 20 of these B'ak'atuns
because again the calendar is built in increments of 20.
If that's true, then the end of the Mayan calendar isn't in 2012 anyway, it's in the year 4772.
[ Laughter ]
There's another hieroglyph that's been discovered in the city of Coba, this was once a major city in, in the Mayan period, in the 15, 500's and 900's.
And this actually gives more increments of 20 beyond the digits that I've showed you.
In fact there were 20 units of 20 and that would mean that the age of the universe, according to that Mayan calendar was, what was it 4 times 1028 days.
Which by the way is three quintillion times the age of our known universe.
[ Laughter ]
So it's possible the Mayans had it wrong, you know.
[ Laughter ]
We should also look at this whole story about the solar system being in alignment and throwing the Sun into some instability.
I want you to look at the picture on the right that shows the locations of the planets off this little star chart that you can get off the web.
Notice, let's see, Pluto's over there, I also call it a planet because I'm an old fart.
[ Laughter ]
There's Neptune, there's Uranus, there's Saturn and Jupiter.
The picture on the right is the same thing on 12/21/2012.
It doesn't look all that different.
Because you know what?
It takes a long time for the outer planets to go through one cycle.
So they're not going to be anymore in alignment today, then, than they are today.
Now you say oh it's the inner planets that really matter because they pull on the earth, the sun all the more.
Well here's the inner planets today and here's the inner planets in 2012.
And they kind of look no more aligned than, in fact I think they look more aligned today.
So you should kind of really be worried.
[ Laughter ]
All right.
The other thing that sometimes gets talked about is a quote unquote Mayan myth.
Is actually the invention of a new age astrologer which is that there's this thing called Planet X or Nibiru,
and that is the thing that's going to throw the sun into some instability.
Planet X fear has been around since, I don't know, time immemorial.
[ Laughter ]
But this particular astrologer points to that little hieroglyph there which has a number of stars in the upper panel, or a number of planets and this person says well
that represents Jupiter, Saturn, Pluto, Uranus, Neptune, Venus, Mars, Earth, Moon and Mercury.
And then the planet X. And there's only one, two little problems with this.
Yes.
>>I was just curious.
Is that Zecharia Sitchin you're talking about?
>> Sacha Kopp: Yes.
Very good.
You've seen that?
>> The 12th planet?
>> Sacha Kopp: Yes.
>> I've read that a long time ago.
>> Sacha Kopp: So there' a couple problems with Zecharia.
One is the Mayans didn't know about Uranus, Neptune or Saturn.
[ Laughter ]
Well no Saturn they would have known, because you can see that with your eyes.
So they couldn't have talked about this 10th planet or 12 planet because they didn't even know about planets 8 and 9, or 7 and 8.
Right. So this hieroglyph whatever it is, doesn't represent the, the existence of planet X in Mayan astronomy.
And furthermore, that's from the ancient culture in Babylonia, not from Mayan.
[ Laughter ]
So. The other thing I'll say is, there are a lot of other planets, Planet X's out there.
And we all hear about Pluto.
But Pluto is, is one of a series of so-called dwarf planets.
Which isn't even the biggest one.
There's Eris out there and it doesn't have any more likelihood of crashing into the earth than, than Pluto does.
So let's recap: where the movie is correct is that it's really true that the solar, a solar eruption does occur periodically, and these things can be fairly dramatic.
It does happen on an 11-year cycle.
It is true as stated in the movie that neutrinos are used by scientists to track the Sun.
In fact, they were instrumental in our understanding of how the sun even works.
So that's a, that's a pretty cool thing.
It is true that volcanoes and technocic or, yeah volcanoes and earthquakes all this would result as a result of plate tectonic motion.
We've lived with that for all of four billion years.
And so that's not news to us.
And it is true that the Mayan calendar is divided in such a way that there is an increment which is going to go through a roll over in 2012.
However, there is no such thing as Mayan prediction of an apocalypse.
In fact there's no clear indication that the Mayan, Mayans even had the idea of an apocalypse in their mythology.
That's very much a Judeo-Christian thing.
There's no scenario that's proposed in the movie about a planetary alignments that's even close to true.
And this whole thing about neutrinos causing the heating of the core of the earth which it just set aside as, you know, cool science fiction.
Okay. Let me just.
But I will leave you with one scary thought.
[ Laughter ]
There have been a number of interesting papers lately about radio active decay loss that are apparently changing due to neutrinos.
So we all hear about exponential decay of radioactive elements.
And that in a half-life of a nuclear element you lose one-half of that element as it changes into something else, and it goes through exponential decay.
People have noticed or plotted over time, the following curiosity, which is that the exponential lifetime of various isotopes tends to go through a little modulation.
In other words, it's one microsecond one day and its point nine microseconds the next day.
Or actually it goes through a cycle that depends on where we are in the earth's orbit around the sun.
The earth's orbit is slightly elliptical so we are getting slightly closer to or slightly a far, further away from the sun.
And furthermore, this exponential decay laws goes through rather abrupt changes whenever there's a solar flare.
So it's thought, and actually it goes through an abrupt change a couple days before there's a solar flare.
And so it's thought that neutrinos from the sun are actually messing with us a little bit in the form of interacting with these kind of radioactive isotopes such that we can see it.
So yeah, you see that.
[ Laughter ]
Okay. I just want to promote one last thing.
There is an event coming up that I want you to know about.
There's an open house in the Physics Department happening on September 28.
All of you had to take Intro to Physics know that you have to learn about the acceleration due to gravity.
We are going to measure it that day.
We are going to drop watermelons off the building and see if it really does accelerate at 9.8 meters per second squared.
There is later in the semester going to be a concert by the group Arc Attack here on campus, put on by the Physics Department.
And with one apology for me pooh-poohing on this movie for so long.
I just want to show you I'm, I'm in kind of good company.
Physicists tend to do this a lot.
Anyone ever see the movie, TV show, Big *** Theory?
>> Yeah.
>> Sacha Kopp: Yeah.
Okay. There.
A friend of mine actually is the science consultant for this TV show and.
[ Laughter ]
He sent me this clip.
[ Background sounds ]
I'm just not going to get.
Oh come on.
Sorry. Where'd it go.
>> Uh, if you don't have any other plans, do you want to join us for Thai food and the Superman movie marathon?
>> Marathon?
Wow how many Superman movies are there?
>> You're kidding, right?
[ Laughter ]
>> I do like the one where Lois Lane falls from the helicopter and Superman swooshes down and catches her, which one is that?
>> One.
[ Laughter ]
>> You realize that scene was ripe with scientific inaccuracy?
>> Yes I know.
Men can't fly.
>> No, no, let's assume that they can.
[ Laughter ]
Lois Lane is falling and accelerating at an initial rate of 32 feet per second per second.
Superman swoops down to save her by reaching out two arms of steel.
Ms. Lane, who is not traveling approximately 120 miles and hour, hits them and is immediately sliced into three equal pieces.
[ Laughter ]
>> Unless Superman matches her speed and decelerates.
>> In what space sir?
In what space?
She's two feet above the ground.
[ Laughter ]
>> Frankly if he really loved her, he'd let her hit the pavement.
It would be more a merciful death.
[ Laughter ]
[ Applause ]
>> Sacha Kopp: Well with that I'll thank you and thank you for tolerating my pooh-poohing of this movie for the last hour.
So I'll take questions if you have them.
>> Roxanne Bogucka: A couple of housekeeping notes we have here.
Right outside the door, outside the building there are recycling containers.
So if you wouldn't mind taking your cans and bottles if you're leaving now.
Otherwise, you have time to talk?
>> Sacha Kopp: Yeah I'll take the questions.
>> Roxanne Bogucka: Questions away.
>> Sacha Kopp: Oh not, because it's hot.
Yeah.
>> [Inaudible] that whole myth thing, you know, you touched on [inaudible].
>> Sacha Kopp: Yeah I think that was just straight up made up.
I don't think that exists.
Is it?
>> It does.
>> Sacha Kopp: It does exist?
>> It's been disproven, but it exists.
>> Sacha Kopp: So I mean plate tectonic motion is a real thing.
Right. I mean it's why we don't have, it's why we have five continents and not one big super continent.
It doesn't happen rapidly.
I mean the, the motion of continents happens over millions of years.
I don't much, you said Hapgood is actually a real thing?
>> He actually wrote a book.
>> Sacha Kopp: Okay.
>> Forward was by Einstein.
>> Sacha Kopp: Okay.
>> The theory has been disproven.
It was actually literally written in the 50's.
>> Sacha Kopp: Yeah.
Okay thank you for that.
So I'm, I'm wrong on this.
There is a Hapgood.
The, the thing that often gets confused about sudden reorientations of things on the surface of the earth.
It is true that magnetic poles move.
So North and South Pole have been all over the place.
And that can change over relatively short periods of time.
But the motions of the continents are extremely slow.
So. Yeah.
>> So they made the case that the solar flares are going to amp up the number of neutrinos.
>> Sacha Kopp: Yeah.
>> Since that's a surface sort of activity, is there any connection between solar flare activity and coronal mass ejection and the neutrino gas?
>> Sacha Kopp: Actually, it's true.
That was the last thing I was trying to show you.
That people do see a connection with the neutrino flux and, and these kind of things like solar flares or coronal mass ejections.
But again, we wouldn't worry because there's just not that much energy in neutrinos.
Yes sir.
>> Well I thought it was a great presentation.
But I did want to point out [inaudible].
>> Sacha Kopp: Okay.
>> That Yellowstone [inaudible].
>> Sacha Kopp: Yellowstone is?
>> Yellowstone is [inaudible].
>> Sacha Kopp: I didn't hear the end of the sentence is all.
>> Oh I say it's just due for an eruption for about 40,000 years.
>> Sacha Kopp: Yeah I didn't want to, I was feeling like I was running over time.
There is actually one little kernel of truth here which is Yellowstone is a hot spot.
A volcanic hot spot.
And it's one of several around the surface of the Earth.
Hawaii itself is, is evidence of a hot spot.
There are places where the crust is relatively thin, and there are these hot plumes coming up through the mantel of the earth.
And as the earth's moves over it, you see a string of volcanic activity, as this crust slides on by.
The hot spot doesn't move but the earth's crusts move.
So in fact the entire Hawaii Island chain, and in fact another related chain of islands that are now submerged, stringing all the way up to Alaska are evidence
of a hot spot, and the earth's motion over that, or the crust motion over that hot spot.
Yellowstone is another example.
There's a string of volcanoes that you can trace that go back, I don't know 16 million years.
And indeed, you know, one wonders why we haven't had one in a while.
But not, not, not one that's going to cause the end of the earth.
But certainly it is a source of volcanic activity.
Absolutely.
Thank you.
Other questions, or we're all.
Yeah.
>> I heard something about the polar [inaudible] South Pole changing positions.
Is that like true?
>> Sacha Kopp: Yeah I, I'm not a real expert here.
But the, the magnetic field of the earth is caused by the turbulent flow of the inner core of the earth, and that does adjust or change in some ways.
So you know the earth looks like a big bar magnet and sometimes it's tilted this way and sometimes is tilted that way.
It doesn't have to align with the spinning access of the earth.
In fact it doesn't even now.
And it does move.
So we can see the Northern Lights here some day.
>> What's that?
[ Background chatter ]
>> Sacha Kopp: Oh you're getting cozy for asking questions?
Cool. Okay.
Yes sir.
>> You said that there were many types of neutrinos.
>> Sacha Kopp: Three.
>> Three. Do they differ in reactivity with matter?
>> Sacha Kopp: They do, but not in a way that.
>> Wouldn't bother us.
>> Sacha Kopp: Not in a way it would bother us.
The orders of magnitude difference from that which would bother us and where they are is, is small.
So depending on the energy in the neutrino and the flavor of the neutrino, yes there is a slight change in, in how much they will interact with other matter.
But it's.
>> So which of the neutrinos is emitted by the sun most?
>> Sacha Kopp: It's the electron neutrino.
>> [Inaudible].
>> Sacha Kopp: And the early experiments that we're looking at neutrinos from the sun were reasonably looking for electron neutrinos.
And then they failed to detect them.
So as this hypothesis of neutrinos transmuting into other things evolved, people built other types of neutrino detectors that could see the other types of neutrinos.
And then they were found.
So hence we're not worried about what it is that they're transmuting into.
It's not evil death rays or microwaves or anything like that.
It's other types of neutrinos.
>> This is interesting for me because I took an astronomy class way, way back.
And I just happened to remember a few things.
>> Sacha Kopp: You probably would have learned about this, because neutrinos figure very prominently in astronomy.
In fact, there are more neutrinos in the universe than there are anything else.
And at one time my field of partical physics was very preoccupied with neutrinos because when we thought that they might have a mass that's a little bit bigger than those mass
of all the neutrinos added up, could have been more than the rest of the mass in the universe.
In fact, my experiment and a couple others prove that that neutrino mass is still pretty small.
And so not significant on, on a universal scale.
But you probably did hear about that in astronomy class as a result.
Yeah. Yes.
>> [Inaudible] have a [inaudible].
>> Sacha Kopp: Yes they do.
They have a corresponding, all particles have a corresponding anti-particle.
>> And have you been able to observe any interaction from that at all?
>> Sacha Kopp: Yes.
The experiment I'm working on is trying to right now to measure the difference in the mass between the anti-particle and the particle.
And well we're confused, because we don't quite have the same numbers.
So either we goofed up or, or there's something cool.
But mostly that's not expected and all particles and anti-particles the, the same mass.
Yeah one last question.
>> How do you update all the neutrinos that you guys bring in [inaudible]?
>> Sacha Kopp: Oh, you take a big blow torch of protons and you throw it at a target like a piece of graphite, and it produces a shower
of other particles that aren't very interesting.
But those other uninteresting particles decay the neutrinos.
And so it produces gas of neutrinos.
It goes bursting forward after we shoot a proton beam at this target.
So. So we do that all the time.
Okay well let me, with that, thank you all for coming out tonight.
And, and I wish you a good night.
[ Applause ]