the universe is really big we live in a

galaxy the Milky Way galaxy there about

a hundred billion stars in the Milky Way

galaxy and if you take a camera and you

point it at a random part of the sky and

you just keep the shutter open as long

as your camera is attached to the Hubble

Space Telescope it will see something

like this every one of these little

blobs is a galaxy roughly the size of

our Milky Way 100 billion stars in each

of those blobs there are approximately

100 billion galaxies in the observable

universe the 100 billion is the only

number you need to know the age of the

universe between now and the Big Bang is

a hundred billion in dog years which

tells you something about our place in

the universe one thing you can do with a

picture like this is simply admire it

it's extremely beautiful I've often

wondered what is the evolutionary

pressure that made our ancestors in

developed adapt and evolve to really

enjoy pictures of galaxies when they

didn't have any but we also like to

understand it as a cosmologists I want

to ask why is the universe like this one

big clue we have is that the universe is

changing with time if you looked at one

of these galaxies and measured its

velocity it will be moving away from you

and if you look at the galaxy even

further away will be moving away faster

so we say the universe is expanding what

that means of course is that in the past

things were closer together in the past

the universe was more dense and it was

also hotter if you squeeze things

together the temperature goes up that

kind of makes sense to us the thing that

doesn't make sense to us as much is that

the universe at early times near the Big

Bang was also very very smooth you might

think that that's not a surprise the air

in this room is very smooth you might

say well maybe things just smooth

themselves out but the conditions near

the Big Bang are very very different

than the conditions of the air in this

room in particular things were a lot

denser the gravitational pull of things

was a lot stronger near the Big Bang

what you have to think about is we have

a universe with a hundred billion

galaxies 100 billion stars each at early

times those hundred billion galaxies

were squeezed into a region about this

big literally at early times and you

have to imagine doing that squeezing

without any imperfections without any

little spots where there were a few more

atoms than somewhere else because if

there had been they would have collapsed

under the gravitational pull into a huge

black hole

keeping the universe very very smooth

that early times is not easy it's a

delicate arrangement it's a clue that

the early universe is not chosen

randomly there was something that made

it that way we would like to know what

so part of our understanding of this was

given to us by Ludwig Boltzmann an

Austrian physicist in the 19th century

and Boltzmann's contribution was that he

helped us understand entropy you've

heard of entropy it's the randomness the

disorder the chaoticness of some system

Boltzmann gave us a formula engraved on

his tombstone now that really quantifies

what entropy is and it's basically just

saying that entropy is the number of

ways we can rearrange the constituents

of the system so that you don't notice

so that macroscopically it looks the

same if you have the air in this room

you don't notice each individual atom a

low entropy configuration is one in

which there's only a few arrangements

that look that way a high entropy

arrangement is one that there are many

arrangements that look that way this is

a crucially important insight because it

helps us explain the second law of

thermodynamics the law that says that

entropy increases in the universe or in

some isolated bit of the universe the

reason why the entropy increases is

simply because there are many more ways

to be high entropy than to be low

entropy that's a wonderful insight but

it leaves something out this insight

that entropy increases by the way is

what's behind what we call the arrow of

time the difference between the past and

the future every difference that there

is between the past in the future is

because entropy is increasing the fact

that you can remember the past but not

the future the fact that you are born

and then you live and then you die

always in that order

that's because entropy is increasing

Boltzmann explained that if you start

with low entropy it's very natural for

it to increase because there's more ways

to be high entropy what he didn't

explain was why the entropy was ever low

in the first place

the fact that the entropy of the

universe was low is a reflection of the

fact that the early universe was very

very smooth

we'd like to understand that that's our

job as cosmologists unfortunately it's

actually not a problem that we've been

giving enough attention to it's not one

of the first things people would say if

you asked a modern cosmologists what are

the problems we're trying to address one

of the people who did understand that

this was a problem was Richard Fineman

fifty years ago he gave a series of a

bunch of different lectures gave the

popular lectures that became the

character physical law he gave lectures

to Caltech undergrads that became the

firemen lectures on physics he gave

lectures to Caltech graduate students

that became the final edges on

gravitation in every one of these books

every one of these sets of lectures he

emphasized this puzzle why did the early

universe have such a small entropy so he

says I'm not going to do the accent he

says for some reason the universe at one

time had a very low entropy for its

energy content and since then the

entropy is increased the arrow of time

cannot be completely understood until

the mystery of the beginnings of the

history of the universe are reduced

still further from speculation to

understanding so that's our job we want

to know this was 50 years ago surely

you're thinking we figured it out by now

it's not true that we figured out by now

the reason the problem has gotten worse

rather than better is because in 1998 we

learned something crucial about the

universe that we didn't know before we

learned that it's accelerating the

universe is not only expanding if you

look at that galaxy it's moving away if

you come back a billion years later and

look at it again it will be moving away

faster individual galaxies are speeding

away from us faster and faster so we say

the universe is accelerating

unlike the low entropy of the early

universe even though we don't know the

answer for this we at least have a good

theory that can explain it if that

theory is right and that's the theory of

dark energy it's just the idea that

empty space itself has energy in every

little cubic centimeter of space whether

or not there's stuff whether or not

there's particles matter radiation or

whatever there is still energy even in

the space itself and this energy

according to Einstein exerts a push on

the universe it is a perpetual impulse

that pushes galaxies apart from each

other because dark energy unlike matter

radiation does not dilute away as the

universe expands the amount of energy in

each cubic centimeter remain

the same even as the universe gets

bigger and bigger

this has crucial implications for what

the universe is going to do in the

future for one thing the universe will

expand forever back when I was your age

we didn't know what the universe was

going to do we thought some people

thought that the universe would wreak

elapsed in the future Einstein was fond

of this idea but if there's dark energy

and the dark energy does not go away the

universe is just going to keep expanding

forever and ever and ever

14 billion years in the past 100 billion

dog years but an infinite number of

years into the future meanwhile for all

intents and purposes space looks finite

to us space may be finite or infinite

but because the universe is accelerating

there are parts of it we cannot see and

never will see there's a finite region

of space that we have access to

surrounded by a horizon so even though

time goes on forever space is limited to

us finally empty space has a temperature

in the 1970s Stephen Hawking told us

that a black hole even though you think

it's black it actually emits radiation

when you take into account quantum

mechanics the curvature of space-time

around the black hole brings to life the

quantum mechanical fluctuation and the

black hole radiates a precisely similar

calculation by Hawking and Gary Gibbons

show that if you have dark energy in

empty space then the whole universe

radiates the energy of empty space

brings to life quantum fluctuations and

so even though the universe will last

forever an ordinary matter and radiation

will dilute away there will always be

some radiation some thermal fluctuations

even in empty space so what this means

is that the universe is like a box of

gas that lasts forever well what is the

implication of that that implication was

studied by Boltzmann back in the 19th

century he said well entropy increases

because there are many many more ways

for the universe to be high entropy

rather than low entropy but that's a

probabilistic statement it will probably

increase and the probability is enormous

Lee huge it's not something you have to

worry about the air in this room all

gathering over one part of the room and

suffocating us it's very very unlikely

except if they lock the doors and

kept us here literally forever that

would happen everything that is allowed

every configuration that is allowed to

be attained by the molecules in this

room would eventually be obtained so

Boltzmann says look you could start with

a universe that was in thermal

equilibrium he didn't know about the Big

Bang he didn't know about the expansion

of the universe he thought that space

and time were explained by Isaac Newton

they were absolute they just stuck there

forever

so his idea of a natural universe was

one in which the air molecules were just

spread out evenly everywhere the

everything molecules but if you're a

Boltzmann you know that if you wait long

enough the random fluctuations of those

molecules will occasionally bring them

in to lower entropy configurations and

then of course in the natural course of

things they will expand back so it's not

that entropy must always increase you

can get fluctuations into lower entropy

more organized situations well if that's

true

Boltzmann then goes on to invent two

very modern sounding ideas the

multiverse and the mprofit principle he

says the problem with thermal

equilibrium is that we can't live there

remember life itself depends on the

arrow of time we would not be able to

process information metabolize

walk-and-talk if we lived in thermal

equilibrium so if you imagine a very

very big universe an infinitely big

universe with randomly bumping into each

other particles there will occasionally

be small fluctuations in the lower

entropy states and then they relax back

but there will also be large

fluctuations occasionally you will make

a planet or a star or a galaxy or a

hundred billion galaxies so Boltzmann

says we will only live in the part of

the multiverse the part of this

infinitely big set of fluctuating

particles where life is possible that's

the regions where entropy is low maybe

our universe is just one of those things

that happens from time to time now your

homework assignment is to really think

about this to contemplate what it means

Carl Sagan once famously said that in

order to make an apple pie you must firt

first invent the universe but he was not

right in Boltzmann's scenario if you

want to make an apple pie you just wait

for the random motion of atoms to make

you an apple pie that will happen much

more frequently than the random

and motions of atoms making you an apple

orchard and some sugar and an oven and

then making you an apple pie

so this scenario makes predictions and

the predictions are that the

fluctuations that make us are minimal

even if you imagine that this room we

are in now exists and is real and here

we are we have not only our memories but

our impressions that outside there's

something called Caltech in the United

States and the Milky Way galaxy it's

much easier for all those impressions to

randomly fluctuate into your brain than

for them actually to randomly fluctuate

into Caltech the United States and the

galaxy the good news is that therefore

this scenario does not work it is not

right this scenario predicts that we

should be a minimal fluctuation even if

you get our galaxies out you would not

get a hundred billion other galaxies and

Fineman also understood this Fineman

says from the hypothesis that the world

is a fluctuation all the predictions are

that if we look at a part of the world

we've never seen before we will find it

mixed up not like the piece we've just

looked at high entropy if our order were

due to a fluctuation we would not expect

order anywhere but where we've just

noticed it we therefore conclude the

universe is not a fluctuation so that's

good the question is then what is the

right answer if the universe is not a

fluctuation why did the early universe

have a low entropy and I would love to

tell you the answer but I'm running out

of time

here is the universe that we tell you

about versus the universe that really

exists I just showed you this picture

the universe is expanding for the last

10 billion years or so it's cooling off

but we now know enough about the future

of the universe to say a lot more if the

dark energy remains around the stars

around us will use up their nuclear fuel

they will stop burning they will fall

into black holes we will live in a

universe with nothing in it but black

holes that universe will last 10 to the

100 years a lot longer than our little

universe has lived the future is much

longer than the past but even black

holes don't last forever they will

evaporate and we will be left with

nothing but empty space that empty space

lasts essentially forever however you

notice that since empty space gives off

radiation there's actually thermal

fluctuations and it cycles around all

the different possible combinations of

the degrees of freedom that exist in

empty space so even though the universe

lasts forever there's only a finite

number of things that can possibly

happen in the universe they all happen

over a period of time equal to 10 to the

10 to the 120 years so here's two

questions for you number one if the

universe lasts for ten to the ten to the

hundred twenty years why are we born in

the first fourteen billion years of it

in the warm comfortable afterglow of the

Big Bang why aren't we in empty space

you might say well there's nothing there

to be living but that's not right you

could be a random fluctuation out of the

nothingness why aren't you more homework

assignment for you so like I said I

don't actually know the answer I'm going

to give you my favorite scenario either

it's just like that there is no

explanation this is a brute fact about

the universe that you should learn to

accept and stop asking questions or

maybe the Big Bang is not the beginning

of the universe an egg an unbroken egg

is a low entropy configuration and yet

when we open our refrigerator we do not

go ha how surprising to find this low

entropy configuration in our

refrigerator that's because an egg is

not a closed system it comes out of a

chicken maybe the universe comes out of

a universal chicken maybe there is

something that naturally through the

expert through the growth of the laws of

physics give

rise to universe like ours in low

entropy configurations if that's true it

would happen more than once we would be

part of a much bigger multiverse that's

my favorite scenario so the organizers

asked me to end with a bold speculation

my bold speculation is that I will be

absolutely vindicated by history and 50

years from now all of my current wild

ideas will be accepted as truths by the

scientific and external communities we

will all believe that our little

universe is just a small part of a much

larger multiverse and even better we

will understand what happened at the Big

Bang in terms of a theory that we'll be

able to compare to observations this is

a prediction I might be wrong but we've

been thinking as a human race about what

the universe was like why it came to be

in the way it did for many many years

it's exciting to think we may finally

know the answer someday thank you

{{}}

宇宙真的很大 我们生活在一个

星系中 银河系 银河系中有大约

一千亿颗恒星

如果你拿相机把

它对准天空的随机部分，

你只要保持快门打开

只要您的相机连接到哈勃

太空望远镜，它就会看到类似的

东西 这些小

斑点中的每一个都是一个大致与

我们的银河系一样大的星系 每个斑点中有 1000 亿颗恒星 在

可观测到的星系中大约有 1000 亿个星系

宇宙 1000 亿是

你需要知道的唯一数字

从现在到大爆炸之间的宇宙年龄是

1000 亿狗年，它

告诉你一些关于我们

在宇宙中的位置的事情你可以用这样的图片做一件事

只是佩服

它非常美丽我经常

想知道是什么进化

压力使我们发达的祖先

适应和进化以真正

享受星系的照片，而他们

没有 任何，但

作为宇宙学家，

我们也想理解

它 我

想问为什么宇宙会像这样 远离你

，如果你看更远的银河系

，它会更快地移动，

所以我们说宇宙正在膨胀，

这当然意味着过去

事物更靠近

过去，宇宙更密集，它是

如果你把东西挤在一起也会更热

温度上升

对我们

来说很有意义 对我们来说没有意义的

是宇宙在大爆炸附近的

早期也非常非常平滑 你可能会

认为 这并不奇怪

，这个房间里的空气非常顺畅，你可能会

说，也许事情只是让

自己平静下来，但是

大爆炸附近

的条件与这个房间里的空气条件有很大的不同

。 物质的

密度要大得多

在大爆炸附近，物体的引力要强得多

你必须考虑的是，我们

有一个拥有

1000 亿个星系 1000 亿颗恒星的宇宙，在

早期，这些 100 亿个星系

被挤压成一个

在早期这个大的区域，你

必须想象在

没有任何缺陷的情况下进行挤压，没有任何

小点，那里的

原子比其他地方多一些，因为如果

有的话，它们会

在引力作用下坍缩成一个巨大的

黑色

保持宇宙非常非常

平滑早期并不容易这是一个

微妙的安排这是一个线索，

表明早期宇宙不是随机选择的，

有一些东西

让它这样我们想知道

我们对这个理解的一部分是什么

19 世纪奥地利物理学家路德维希·玻尔兹曼 (Ludwig Boltzmann) 给我们的

，玻尔兹曼的贡献是他

帮助我们理解 熵 你

听说过 熵 它是随机性

无序 某些系统的混乱

玻尔兹曼给了我们一个刻在

他

墓碑上的公式

系统，这样你就不会注意到，

所以

如果你在这个房间里有空气，宏观上它看起来是一样的，

你不会注意到每个单独的原子

低熵配置

是只有少数排列

看起来那样 高熵

排列是指有许多

排列看起来是这样的，这是

一个至关重要的见解，因为它

有助于我们解释

热力学第二定律，即

熵在宇宙中或在

宇宙的某个孤立部分中增加的定律

熵增加的原因

仅仅是因为

高熵的方法比低熵的方法要多得多，

这是一个很棒的见解，但是

它遗漏了一些东西

熵增加的这种洞察力是

我们所谓的时间箭头背后的东西

过去和未来之间的差异过去和未来之间的

每一个差异都是

因为熵正在增加

你的事实 可以记住过去但不记得

未来 你出生

，然后你生活，然后你死的事实

总是以这种顺序

，因为熵在增加

玻尔兹曼解释说，如果你

从低熵开始，它很

自然地增加，因为还有更多

高熵的方法 他没有

解释的是为什么熵一开始就一直

很低 宇宙

的熵

很低的

事实反映了早期宇宙非常非常平滑的事实，

我们希望 不幸的是，要了解这是我们

作为宇宙学家的工作，

实际上这不是问题，我们一直

给予足够的关注，这不是

人们会说的第一件事，如果

你问现代宇宙学家

我们试图解决的问题是什么 一个

确实明白

这是一个问题的人是理查德·费曼

五十年前他做了

一系列不同的讲座给

了流行的讲座

性格 物理法 他

给加州理工学院的本科生讲课，成为

消防员 物理讲座 他

给加州理工学院的研究生讲课

，成为万有引力的最后边缘

在每一本书中

每一组讲座 他

强调这个谜题 为什么 早期

宇宙的熵如此之小，所以他

说我不会做他说的口音，

出于某种原因，宇宙

曾经有一个非常低的熵，因为它的

能量含量从那时起

熵增加了时间之箭

不能 被完全理解，直到

宇宙历史开端的奥秘

进一步从推测减少到

理解，这就是我们的 我们

想知道这是 50 年前的工作

你肯定认为我们现在

已经解决了 我们现在发现问题不是真的

问题变得更糟

而不是更好的原因是因为在 1998 年我们

学到了一些关于

在我们

得知它正在加速之前我们不知道的

宇宙宇宙不仅在膨胀，如果你

看那个星系，它正在远离，如果

你在十亿年后回来

再看一遍它，它会以

更快的速度远离单个星系

越来越快地远离我们，所以我们

说宇宙正在加速，

不像早期宇宙的低熵，

即使我们不知道这个

问题的答案，如果这个理论是正确的，我们至少有一个很好的

理论可以解释它，

并且 这就是

暗能量的理论，它只是说

空的空间本身在每

立方厘米的空间中都有能量，

不管有没有东西，不管

有没有粒子，物质辐射还是

什么 即使在空间本身中仍然存在能量，

并且

根据爱因斯坦的说法，这种能量对宇宙施加了推动，

它是一种永久的推动力

，将星系彼此分开，

因为与物质辐射不同的暗能量

不会随着

宇宙的膨胀而稀释

即使宇宙变得越来越大，每立方厘米的能量仍然保持不变

这对宇宙未来将要做什么具有至关重要的意义，

因为一件事宇宙将

永远膨胀，回到我在你那个时代

我们没有 知道宇宙

会做什么 我们认为有些人

认为未来宇宙会发生

爱因斯坦

喜欢这个想法，但如果有暗能量

并且暗能量不消失，

宇宙只会永远膨胀

在过去的 1000 亿狗年中永远有 140 亿年，

但

同时出于所有

意图和目的，未来还有无限的年数 空间对我们来说看起来是有限的

空间可能是有限的或无限的，

但是因为宇宙正在加速

，所以它的某些部分我们看不到，

也永远不会看到有一个有限

的空间区域，我们可以进入

一个被地平线包围的空间，所以即使

时间在继续 永远的空间仅限于

我们 最终在 1970 年代空旷的空间有温度

斯蒂芬霍金告诉我们

，即使你认为

它是黑色的黑洞，

当你考虑到量子力学时，它实际上也会发出辐射

黑洞周围的时空曲率 使

量子力学涨落和

黑洞辐射栩栩如生

霍金和加里吉本斯的计算

表明，如果你在真空中拥有暗能量，

那么整个宇宙都会

辐射真空空间的能量，

从而使量子涨落变得生机勃勃，所以即使 宇宙将

永远存在 普通物质和辐射

将被稀释 总会有

一些辐射 一些热流感

即使在空旷的空间中也会发生变化，所以这

意味着宇宙就像一盒

气体，可以永远持续下去

宇宙有更多高熵

而不是低熵的方式，但这是一个

概率声明，它可能会

增加，而且概率是巨大的

Lee 巨大的，你不必

担心这个房间里的空气都

聚集在房间的一部分上

让我们窒息，这是非常不可能的，

除非他们锁上门，

让我们永远留在这里，这

将发生一切被允许的一切，

这个房间里的分子允许达到的每一种配置

最终都会得到，所以

玻尔兹曼说，看你可以 从

一个处于热平衡的宇宙开始

他不知道大

爆炸 他不知道

t 的膨胀 他认为空间

和时间是由艾萨克牛顿解释的，

它们是绝对的，它们只是永远停留在那里，

所以他对自然宇宙的看法

是，空气分子只是

均匀地分布在

所有分子的各处，但如果你是一个

玻尔兹曼，您知道，如果您等待足够长的

时间，这些分子的随机波动

偶尔会将

它们带入较低的熵配置，

然后当然在事物的自然过程中

它们会膨胀回来，

因此熵不一定总是增加，您

可以获得波动 如果那是真的，那么进入较低熵的

更有组织的情况

玻尔兹曼接着发明了两个

非常现代的想法，

多元宇宙和利润原理，他

说热平衡的问题

是我们不能在那里

生活记住生命本身取决于

箭头 如果我们生活在热平衡中，那么我们将无法

处理信息代谢

走路和说话，

所以如果 你想象一个非常

非常大的宇宙 一个无限大的

宇宙 粒子随机地相互碰撞

在低熵状态下偶尔会有小的波动

，然后它们会放松，

但偶尔也会有大的

波动 你会制造

一颗行星或一颗恒星 或一个星系或一

千亿个星系 所以玻尔兹曼

说我们将只生活在

多元宇宙的一部分

无限大的波动

粒子的一部分 那里可能存在生命 那是

熵低的区域 也许

我们的宇宙只是其中之一

现在时不时发生的事情，你的

家庭作业是认真

思考这个问题，思考这意味着什么

卡尔·萨根曾经说过

，要制作苹果派，你必须

首先发明宇宙，但他

在玻尔兹曼的场景中是不正确的 如果你

想做一个苹果派，你只需要

等待原子的随机运动来让

你成为一个苹果派，这会发生很多

比原子的随机

运动和运动更频繁地让你成为一个

苹果园、一些糖和一个烤箱，

然后让你成为一个苹果派，

所以这个场景做出了预测，

并且预测是即使你想象这个

，使我们产生的波动也是最小的

我们

所在的房间现在存在并且是真实的，而

我们在这里，我们不仅有我们的记忆

，还有我们的印象，即

在美国和银河系外面有一个叫做加州理工学院的东西

，所有这些印象更容易

随机波动进入你的大脑 而

不是他们实际上随机波动

进入美国加州理工学院和

银河系好消息是因此

这种情况不起作用这是

不对的这种情况预测我们

应该是一个最小的波动即使

你把我们的星系弄出来你也不会

得到一千亿个其他星系，

费曼也理解了这个费曼

所说的假设，即世界

是一个波动所有的公关 法令是

，如果我们看一看我们以前从未见过的世界的一部分，

我们会发现它

混合在一起，不像我们刚刚

看到的高熵部分

但是在我们刚刚

注意到它的地方，我们因此得出结论

宇宙不是波动所以这

很好问题是

如果宇宙不是波动那么正确的答案是什么

为什么早期

宇宙的熵很低，我很想

告诉你答案，但我没时间了

这里是我们告诉你

的宇宙与真实存在的宇宙

我刚刚向你展示了这张

图片 宇宙在过去

100 亿年左右正在膨胀，但它正在冷却，

但我们 现在对宇宙的未来有了足够的了解，

可以说更多如果

暗能量仍然围绕在我们周围的恒星

周围将耗尽它们的核燃料

它们将停止燃烧它们将

掉入黑洞我们将生活在一个没有任何东西的

宇宙中 g 在其中，但是

黑洞，宇宙将持续 10 到

100 年，比我们的小

宇宙寿命

长得多，未来比过去长得多，但即使

黑洞也不会永远存在，它们会

蒸发，我们将只剩下

只不过是空的空间，空的空间

基本上永远存在，但是你

注意到，由于空的空间发出

辐射，实际上存在热

波动，它围绕

着空空间中存在的自由度的所有不同可能组合循环，

所以即使

宇宙永远存在 宇宙

中可能发生的事情数量有限，

它们都发生

在等于 10 到

10 到 120 年的时间段内，所以如果宇宙持续 10 到 10 到 120 年，那么这里有两个

问题要问你第一个问题

一百二十年 为什么我们出生在它

的前 140 亿年

在大爆炸的温暖舒适的余辉中

为什么我们不在空旷的空间

你 m 好吧，没有

什么可活的，但那是不对

的 给你我最喜欢的

场景 一个低熵配置，但是

当我们打开冰箱时，我们并没有

去 哈哈，在我们的冰箱中发现这种低熵配置是多么令人惊讶

，因为鸡蛋

不是封闭系统，它来自

鸡，也许宇宙

来自普遍 鸡也许有

一些东西可以通过

专家通过物理定律的发展自然而然

地

产生像我们这样的低

熵配置的宇宙如果这是真的它

会发生 或者不止一次，我们将

成为一个更大的多元宇宙的一部分，这是

我最喜欢的场景，所以组织者

要求我以一个大胆的猜测

结束 将被

科学界和外部社区接受为真理 我们

都会相信我们的小

宇宙只是

更大的多元宇宙的一小部分，甚至更好的是，我们将更好地

理解大

爆炸中发生的事情，我们将

能够与观察结果进行比较这是

一个预测，我可能是错的，但

作为人类，我们一直在思考

宇宙是什么样的，

为什么它多年来一直

如此

总有一天知道答案 谢谢