[MUSIC].

Hi, I'm Hitoshi Murayama.

I work both the University of California, Berkeley as well as University of Tokyo.

And I'm, I'm giving four lectures about the

recent status of our understanding about the universe.

So, the title of my lectures is From the Big Bang to Dark Energy.

And the Big Bang, as everybody know, is the beginning of the universe.

So, in most of my lectures I will be

talking about how we understand how the universe began.

Starting from where things start today and gradually move back in time and

try to, reach as much as possible at the very beginning of the universe.

But towards the very end of my lectures, I'm going to talk about the future of

the universe that has to do with this

other part of the title called dark energy.

So, in in our understanding of the universe has made

a huge progress in the last 15 years or so.

And what we

used to think we knew about the universe is now totally wrong and outdated.

A, sort of, undergoing a big revolution right now.

So, what I would like to communicate to you in this lecture is,

is what we have learned in the last, you know, 20, 15 years.

And, and what we think we know about the beginning

of the universe as was the future of the universe.

And we try to put that together in, in a bigger context.

So, I organized this content in four lectures,

as I said already.

And it will be extremely helpful if you

know some calculus but I also organized the content

in such a way that if you want to skip some of the equations, you can do so.

And still you can probably get some

conceptual understanding of what's going on there.

But if you do know Calculus, then you can follow

some of the equations and get a deeper understanding that way.

And the homework will also be organized in a way

that you have some conceptual problems, which you can understand without

the need of Calculus.

And some other more advanced problems where you really need

to do some math and, and algebra to work things out.

So, hopefully this kind of combination would reach you in,

in a, to a much, much wider audience that way.

So, many of you who may not have that kind of

background you can still get something out of my lectures, hopefully.

And if you do, you can get a lot more that way.

Okay?

So, that's the way we'd like to get started.

As I said,

From the Big Bang to Dark Energy.

The kind of questions we would like to ask in these lectures are

really, sort of, questions you might have had when you were a little child.

So, if you go to, let's say, vacation and

camping, you watch up the star in the starry

sky in the evenings and, of course, one of the sense we always get is kind of awe.

We always feel that the universe is so beautiful, stars

are so beautiful, we'd like to at least understand what's

going on there.

And you tend to get into really

philosophical thoughts just by looking at the stars.

And this is kind of questions you might have asked when you were little.

How does the universe began? So, this is such a big universe out there?

But, you know, we hear that this

was actually the beginning, that's the big bang.

So, what exactly was the big bang?

How did the universe begin?

And the next question might be, what is fate?

So, we live in this

universe and, of course, for natural reasons we

would like to understand where we're heading to.

And that is about the fate of the universe.

And that has to do with this last part of my lectures called dark energy.

What is it made of?

And for us to understand how the universe works, of

course, we need to understand what the universe is made of.

And as we'll tell you as we go along, we used to think that the entire universe was

made of kind of atoms, we are made of as well.

But that actually didn't turn out to be the right understanding and you

will see that, atoms make up only less than 5% of the entire universe.

And the rest is actually unknown.

So, we will talk about these things as well.

And what is fundamental laws?

And of course, for us to understand how

universe works, we need to understand its basic laws.

So, there are laws of physics that tell you how

things fall, how things move and so and so forth.

And there are also laws that would govern the evolution of the universe as well.

So, we will talk about some of these things.

Finally, of course, we are very curious about where do we come from.

And, and in order to understand where we

come from, of course, the part of the question

may be biological or evolution but a part of

the question also has to do with what are

we made of and where did our ingredients come from?

Where did the chemical elements come from and why do we have matter in the universe?

I will also mention that anti-matter, which

could have been the anti-verse is actually

not there so that's the kind of question we would like to understand as well.

And all of these questions, as you see on this list,

used to be in the realm of, say, theology or philosophy.

But now we can address some of these really big questions,

fundamental questions in the realm of science.

And that's the kind of progress we

are making these days and that's extremely exciting.

So, I'd like to tell you what these excitements are as we go along.

So, as I told you already I organize my lectures in four lectures.

So, the first one today is from daily life to the Big Bang.

And when you think about the universe

you might have this impression that well, it's,

it's far out there, it has nothing to do with me, but that's not true at all.

What we experience in daily life actually has a

lot to do with what's going on in the universe.

And that eventually leads all the way back to the big bang.

So, that's the first lecture I am going to present today.

In, in the second lecture we'll talk about the birth of

elements and something you haven't heard about recently the Higgs boson.

So, if you think about

where we come from, we're made of chemical elements.

And unless there are chemical elements out there in

our universe we couldn't have been possibly be born.

So, where do they come from?

That actually turns out to be a real scientific question we can ask today.

And I can tell you about our recent understanding about this.

And it does have to do with this newly

discovered Higgs boson that was discovered in July fourth 2012.

And without this Higgs Boson we could not exist.

So, that's the connection I would like to make in my second lecture.

In the third lecture, we get into more mysterious side of the Universe.

The first one is called dark matter and this dark

matter is actually a bulk of matter in a Universe.

But we still don't know what it is.

At the same time, though, we know the dark

matter had played a very important role in forming

the universe as we see today.

And without it again, we could not have existed in this universe.

So, we'd like to talk about what it may be and what we're looking for so that

we may gain some understanding on the nature

of dark matter as we continue our research program.

And the second half of the lecture will be antimatter.

And antimatter may sound like something that

might show up in a science fiction movies.

But they do exist,

we can even make them.

So, they actually must have been born at the

very beginning of the universe in the Big Bang.

But fortunately antimatter doesn't seem to exist today.

And that's actually very important as well.

So, where did it go?

So, that's another very fundamental question about

where we came from, how we come

to exist and so absence of antimatter is a very important question, it turns out.

In the final

lecture, the lecture number four, we talk about inflation and dark energy.

So, if we really want to go back to very,

very beginning of the universe, we think it's still hypothesis.

But there's a very good evidence for it.

We think there was a period called cosmic

inflation that made the universe that was born

at a much, much smaller size than an atom to a macroscopic size we see today.

That's a tremendous expansion of the universe and

that idea has been borne out with the latest data.

So, we will talk about that and that was

what happened at the very beginning of the universe.

But it so happens that universe seems to

have started yet another stage of inflation very recently.

And that that has to do with this last subject called dark energy.

And depending on the nature of dark energy, the universe may have an end.

Or it may continue expanding forever.

We don't know which one is the right Future yet,

but Dark energy is definitely the key to that question.

So, we'd like to talk about this very

beginning of the universe as well as what might

be waiting for us in the future that has to do with the nature of Dark energy.

So, that will be my fourth lecture.

So, that's the way I organize my lectures for this course.

Introduction

从大爆炸到暗能量

与讲师见面