---
author: Big Think
date: '2026-03-27'
guest: ''
layout: post.njk
source: https://www.youtube.com/watch?v=RGbZsE7qFgw
speaker: Big Think
tags:
- space-time
- quantum-mechanics
- relativity
- neutron-star
- holographic-principle
title: 现代物理学如何重塑我们对存在的认知：一场宇宙深空的探索
summary: NASA天文学家Michelle Thaller深入探讨现代物理学如何挑战我们对空间、时间、引力、能量和现实本质的传统理解。她通过自身对双星的观测研究，揭示天文学家日常工作的多维度，并逐步引入爱因斯坦的相对论和量子力学的前沿概念。文章重点剖析了量子纠缠如何可能构筑时空、光子视角下无时空的宇宙、质能等价的深层含义，以及中子星、快速射电暴、太阳风等宇宙现象。最终，她强调了人类大脑认知的局限性，并展望了未来物理学革命可能带来的颠覆性认知。
insight: ''
draft: true
series: ''
category: science
area: knowledge-meta
project: []
people:
- Michelle Thaller
- Albert Einstein
- Isaac Newton
- Eugene Parker
- Cecilia Payne
- Galileo
- Charles Darwin
- Aristotle
companies_orgs:
- NASA
- NOAA
- FEMA
products_models:
- Hubble Space Telescope
- Parker Solar Probe
- Solar Orbiter
- Cassini
media_books: []
status: evergreen
---
### 天文学家的双重身份：从观测到理论的跨越
天文学家Michelle Thaller在NASA戈达德太空飞行中心任职，她首先澄清了“天文学家”和“天体物理学家”这两个术语在当今的趋同性。她提到，虽然曾有明确的分工——前者侧重星体测绘，后者探究其运作机制，但如今二者殊途同归。她指出，公众常对宇宙提出宏大而推测性的问题，例如“是否存在多元宇宙”或“大爆炸之前发生了什么”。然而，她自身的博士研究则更专注于**双星**（Binary Stars: 两个恒星相互围绕旋转的系统），特别是那些质量巨大、伴随高能粒子风碰撞并产生**激波**（Shock Waves: 气体或介质中以超音速传播的扰动）的系统。这些激波不仅是宇宙中能量交换的剧烈场所，它们所形成的较冷区域还能生成水分子等生命必需的物质，为理解宇宙中分子的起源提供了重要线索。
Original English Source
My name is Michelle Thaller and I am an
astronomer. I work at NASA's
Goddard Space Flight Center.
How astronomers seek to answer the
biggest questions in the universe.
There's sort of two words that float about.
There's astronomer and astrophysicist. And
you know, it kind of depends on whether you're
trying to put on a more friendly or formal vibe.
I think they really these days mean the same
thing. I think there was a time when there was
sort of a separation of duties. There were people
that say a hundred years ago would would map the
stars and create all these wonderful catalogues
of stars and you might call those astronomers.
You know that the name is from astronomy, to
name the stars. And then there were people that
tried to figure out what the stars were and
how they worked, what the science of it was,
you know, behind all that. Those would be the
astrophysicists. And these days, the two studies
are really the same. If you're an astronomer or
an astrophysicist, you pretty much do the same
thing these days. The word that was probably
the best word, astrology, to study the stars,
that one was already taken. A lot of the questions
that I get from members of the public are these
vast conjectural questions like, you know, is
there a multiverse here? What happened before
the big bang? So, for my doctorate, you know, for
my research, um, I studied binary stars, you know,
I I studied two stars that orbit each other.
And most stars in the universe are like that,
by the way. And uh in the case of my stars, they
had these wonderful colliding winds of high energy
particles that produced these giant shocks in
the sky. The fun thing is that for for a while
at least and maybe today, uh there are some stars
in the sky that I've probably spent more time
with than anybody else in the world. You know, I
observed them for hours and hours trying to figure
out how these uh colliding atmospheres worked.
In the case of myself, I'm an observational
astronomer. I went to observatories all over the
world about 25 years ago when I was most active in
research. I did a lot of research in Australia uh
in Arizona, the Kit Peak telescopes, Mount Stromlo
in Arizona. I also used a lot of satellite data.
I I had data from X-ray satellites and uh the
Hubble Space Telescope. I actually got some time.
You see, as an astronomer, you are allowed to to
write into these observatories. It usually happens
once a year. And there is a panel that basically
assesses you know what would all these people
around the world like to do with the Hubble Space
Telescope. And the this this panel of astronomers
actually decides you know who should get priority.
One of the things about being an astronomer is you
end up doing a lot of writing. You end up doing a
lot of writing asking for time on these telescopes
and then hoping that your proposal gets selected.
Another thing is you end up asking for a lot of
time to write grants for money to support your
work. you know, if you get some time on the Hubble
Space Telescope, often it comes with an amount of
money to support the time you're going to do
that research. So, it it turns out that being
an astronomer, all of the training is about
the math and the physics and you the computer
science and then what you actually do dayto-day
is often a lot of writing and a lot of trying to
organize proposals and grants and how you're
going to support yourself doing your science.
And then if you work for a large organization like
NASA, uh, as some of your time as well is usually
assigned to some specific mission, you know, some
specific space telescope where you're going to be
helping clean up the data, figure out how we're
going to issue a call for proposals, organize the
panels that are going to vet and look at all these
different things. So in a way, you become kind of
an administrator. A lot of meetings. I think that,
you know, the normal life cycle of an astronomer
is probably 80% like business person. a lot of
meetings, a lot of grants, a lot of budgets. But
then, at least for me, there really was this
time. It doesn't happen so much when you're a
more mature astronomer, but when you're really
young and out in the field and making your own
discoveries, it really does feel like you're sort
of alone with the night sky all by yourself up up
on top of that mountain and you're you're seeing
things coming down through your telescope that,
you know, it's a it's a minor advance, but you
no human being has has ever seen before. And it's
it's a wonderful feeling of empowerment and sort
of, you know, kind of collaborating with the sky
and and seeing what we can figure out. One of the
things is when you get a doctorate, you have to
produce some kind of original research, something
that's never really been been done before. And
that's not as hard as it sounds. That sounds very
intimidating. I mean, how am I going to think of
an idea that nobody's ever thought of before? But
nothing in astronomy happens alone. You know what
happens when you're a graduate student after
college is you will join a professor doing his
or her research with them sort of as an apprentice
and uh and then over time as you get more familiar
with the work they will give you a little piece of
that research like hey you go ahead and and take
this part over yourself. You don't really need to
think of things entirely you know just off the top
of your head and and come up with brilliant ideas
out of nowhere. You start little by little working
with a group of astronomers and then slowly
you start to ask your own questions. you know,
maybe they've never had time on a telescope
### 科学真理的动态演进与日常工作的挑战
成为一名天文学家远非浪漫的星空凝望那么简单。Thaller指出，大部分工作都涉及大量的**文书写作**（Writing: 包括望远镜时间申请、科研项目拨款申请等），甚至在NASA这样的巨型机构，还需投入时间管理数据、组织评审小组，扮演近似“**行政人员**”（Administrator: 负责组织、管理和协调工作的角色）的角色。她形象地比喻，天文学家的日常是80%的“商业人士”生涯，充斥着会议、拨款和预算。
然而，在年轻时，特别是首次发现未曾被人所见的事物时，那种与夜空独处、洞悉宇宙奥秘的**赋能感**（Empowerment: 感到拥有力量和掌控感）是无与伦比的。获得博士学位要求进行原创性研究，但她解释这并非凭空想象，而是通常以学徒身份加入导师团队，在熟悉后逐渐承担部分研究。
科学认知的进步亦是循序渐进。她强调，科学真理并非一成不变，而是随着新信息的涌现而不断演进。一个多世纪前，人们坚信宇宙不膨胀，但最终被观测数据推翻。这种**动态性**要求科学家随时准备调整其“珍贵的宇宙模型”，以适应更好的信息。物理学，特别是过去一百年，迫使我们超越**常识**（Common Sense: 基于日常经验和直觉的判断），重新审视空间、时间甚至存在本身的定义。
Original English Source
to look up this little bit of it, you know,
or or this little bit of it over here is a new
question nobody thought of. And and eventually
you realize that what you're doing is something
that hasn't been done before. I guess there were
probably about a dozen stars in the sky, but there
were three that I really really focused on. And in
the in every case, these were binary stars. And
these were stars that were very massive. Stars
that were say, you know, anywhere between like
15 and 50 times the mass of the sun. big stars.
They actually only orbited around each other every
couple of days or at most about a week. So these
are very big stars in very close orbits. And so it
should make sense these stars are pouring off you
not only light but but high energy particles,
this wind of particles that we call stellar
winds. And then they collide in between these two
stars. Sometimes one of their winds will not be as
strong as the other. So the wind from one sort
of overtakes the other one and kind of blasts
away the wind from the other one. And as they turn
around each other, you actually sort of have this
wonderful kind of three-dimensional view of how
that shock wave goes all the way around. And so
I use a technique called tmography, which is the
same sort of thing you use in a CAT scan or, you
know, something like an MRI where you're trying
to produce a three-dimensional scan of inside
the human body. In this case, the instrument
goes around you. But in the case of the stars,
the stars would go around each other. And then I
could use this sort of software mainly developed
for medicine to actually try to figure out the
structure of these shock waves. This is you know
just sort of work a day astronomy you nothing
you know all that incredible or sexy about it but
it helps you understand stars better. It turns
out that these shock waves are responsible for
producing a lot of the molecules that we find
in space. You know stars create uh you know
atoms. They fuse hydrogen into helium and then
eventually helium into larger atoms over time.
But these shock waves, at least in the cooler
parts of them, can produce things like water,
the water molecule. And there are, you know, there
are some binary stars, like there are some in the
uh the Orion Nebula that are producing enough
water in a single day along these shock waves
to fill the oceans of the Earth like 60 times over
in a single day. Now, obviously, this isn't liquid
water. This is water in a in a molecular form, a
pretty hot gas, actually. But that's where a lot
of the the molecules responsible for life can come
from is from these shock waves. So it's a way of
trying to figure out just little by little how
the universe really does work, how stars work.
So my research is much more observational, much
more about stars. I certainly took classes in
cosmology, the study of the universe as a whole.
I took classes in quantum mechanics, you know,
graduate level quantum mechanics, graduate level
electromagnetism, all of that. People often start
right off with the, you know, are there parallel
universes? And I'd rather they sort of ask me,
you know, what are the importance of binary stars?
There's honestly not all that many astronomers by
number that do theoretical cosmology. You know,
most of us are trying to figure out things like
how stars are born and how they like live their
lives and die. We're trying to figure out what's
left over after a star explodes, a black hole, a
neutron star, or we're trying to figure out how
galaxies work, how many galaxies there are, how
do we observe them, how do they change over time.
There's only a few of us that are trying to answer
questions like, you know, what happened before the
big bang or, you know, are there multiveres?
We we all study that to an extent. We all go
to lectures at the conferences. I love going to
the ones on, you know, quantum theory and quantum
gravity. Most astronomers study things that are a
bit more concrete than that, if very far away. So,
it's often the case that, you know, I'm giving
some lecture on this the wonderful new images
of Saturn from one of our spacecraft like Cassini
and they're so beautiful and we're learning things
about the atmosphere and look at these pictures of
the these little moons we took in the ring system
and we're studying the ring system and we have a
wonderful lecture. I turn to the audience and say,
"Hey, any questions?" You know, and somebody
raises their hand and the first one is, you know,
are there multiple universes? It's like Saturn.
There are some words that are are really easy
to throw around and in science they become
interestingly complicated. People often say,
you know, do you believe such and such is
### 引力、时空与量子纠缠：现实构成的深层逻辑
从**艾萨克·牛顿**（Isaac Newton: 经典力学奠基人）将引力描述为一种普适力量，到**阿尔伯特·爱因斯坦**（Albert Einstein: 相对论创立者）将其重新定义为**时空**（Spacetime: 空间与时间结合形成的四维流形）的弯曲，物理学对引力的理解经历了范式转变。爱因斯坦指出，物体必须遵循弯曲的时空，即使是无质量的光线也会因时空弯曲而偏折，甚至被**黑洞**（Black Hole: 引力强大到连光也无法逃逸的天体）捕获。这种认识带来了新的问题：时空究竟是什么？
现代物理学更进一步，试图在**广义相对论**（General Relativity: 爱因斯坦提出的引力理论，将引力描述为时空弯曲）与**量子力学**（Quantum Mechanics: 描述微观粒子行为的物理学理论）之间建立联系。量子力学认为宇宙的一切都归结于概率，这与爱因斯坦的确定性理论存在冲突。然而，一种前沿观点提出，**时空本身可能就是量子力学的产物**，特别是**量子纠缠**（Quantum Entanglement: 两个或多个粒子间存在的一种特殊关联，无论相隔多远，测量一个粒子的状态会瞬间影响另一个粒子）。
Thaller通过一个关于原子中**电子自旋**（Electron Spin: 电子的一种内在角动量，具有向上或向下两个方向）的例子解释了量子纠缠：一对拥有相反自旋的电子，即使相距遥远，一个电子自旋的瞬间改变会立即影响另一个。这种“瞬间”联系超越了光速，意味着在量子系统中，空间和时间可能并不真实存在，粒子之间像是一个**统一的量子系统**（Unified Quantum System: 在量子力学规则下，两个或多个相互作用的粒子被视为一个不可分割的整体）。这引出了一个惊人的推测：我们所感知的空间和时间，可能只是宇宙中万物相互纠缠程度的体现。
Original English Source
true? You know, do do you believe the big
bang is true? You know, do you believe that the
idea of multiple universes is true? You know, a
lot of these things. And when you're a scientist,
you're aware that what what you're doing is you're
constantly trying to approach reality. you're
trying to get closer and closer to describing
something very well, but you you know you're not
all the way there yet. And it's quite possible
that we we never will be. It's quite possible that
human beings with our our limited senses, our our
limited brains even, you know, won't really
know what the true nature of reality is. It's
it's one of these kind of wonderful things that,
you know, truth can change. you know, you know,
hundred years ago, people uh were certain that the
universe was not expanding, you know, and and of
course we found out that it was. And you have to
be able sometimes to take your your very precious
images, you know, models of what the universe
is like, about what reality is like, you know,
even about what the definition of truth is. You
need to make sure that you're ready to change when
better information comes on board. in physics at
least for the last hundred hundred years that that
has really challenged us to leave behind our human
ideas of of common sense uh the very definition
and perhaps existence of space and time. The whole
idea about what is reality, what is existence, you
know, what am I is a very very complex question
now to answer. I mean to give you some ideas
about this there there are some things that are
are are very simple like what is the interior of
the sun like? It's obviously something we've never
directly observed but we see energy pouring out
of the sun. Uh there are actually uh waves almost
like earthquake waves that go around the sun that
help us to study the interior the way those waves
travel. But do we know exactly how the core of the
sun works? No. No we don't. There are things that
we get pretty close to but we just don't really
have the observational ability to do so. But then
there are questions like what are space and time
really? For so long we've just sort of taken it
for granted that space and time exist around us.
Time flows in one direction. Space extends perhaps
to infinity. But then there was also a time when
we we didn't think that air was anything. People
didn't realize that we actually live, you know,
at the bottom of this wonderful ocean of air that
is our our atmosphere. People took it for granted
that that air existed. That was actually, you
know, proven in the 18th century that this was
actually something. Einstein showed us that space
and time absolutely cannot be the simple way we
perceive them. It it all is related around the
speed of light. The speed of light is always
constant to any observer. One of the myths about
Einstein was that he pulled all of these amazing
ideas just kind of, you know, out of his head
from nowhere that he wasn't part of the scientific
establishment. Well, in fact, he was. Uh he was a
professor. uh he was actually a graduate student
trying to get a job when he was working at that
patent office that he had that miracle year where
he came up with the the theories of special and
general relativity among other things. So here's
an example about allowing yourself to define
whether something is true in kind of a bit more of
an active way. Isaac Newton was able to describe
very very well how gravity worked. He was really
one of the first people that said there's this
force of gravity and he just said that it's a
force. this force permeates the universe and this
is why the planets orbit the sun you know this is
why apples fall from trees is they're reacting to
this force and by using his equation of gravity
you could calculate that force very very well so
you had this you know great thing the force of
gravity the force exists it binds the universe
together but then you have to ask the question
okay what what do we mean by that what is the
force of gravity what is it really what what
what causes it and it took Albert Einstein to say
that that what we think of as gravity is actually
a curvature of space and time. Things have to
follow space and time. We are all embedded in the
space and time of the universe. So if that space
and time has a shape to it, a curve to it, we
have to follow that. Light has to follow that. You
know, light itself that has no mass can actually
bend and go into a black hole. And that's because
the light has to travel through space and time and
the space and time itself is bent. So all of a
sudden there was this answer. What is the force
of gravity? It's a bending of space and time. So
is that it? Is that the end of those questions
that we can ask there? Well, how about the rather
obvious next one. What is space and time? Okay,
there's this thing that Einstein called spacetime
that that you know space and time are sort of
mixed together. They're they're two sides of the
same coin. When you change one, the other has to
change. If you are in a gravitational field and
and space is bent, time actually slows down. It
actually affects time as well. We know that these
two things are bound together. But what are they?
Time can be different for different observers
depending on your velocity. If you're going very
close to the speed of light, as people observe you
going by, they see your time is very slowed down.
If you're actually a photon going at the speed of
light, time stops entirely. So what do we mean by
this thing called time? And this is now what some
of the major physicists of the world are grappling
with. And they are trying to come up with some
very interesting answers. I think answers that
will be very challenging for us. Imagine being
a physicist back in the early 1900s and having
this this young Albert Einstein tell you space
and time are bendable. You can change them. You
can manipulate them. You might have thought they
were crazy. How about looking at space and time
instead as a consequence of quantum mechanics? A
lot of people have been saying that relativity and
quantum mechanics don't match. They don't work
together. And this is true. This has been true
since the beginning of relativity and quantum
mechanics at about the same time. Relativity
says that if you have a certain amount of mass,
you can actually say space bends this much. And
quantum mechanics says that everything is down to
probabilities. The universe never has set answers,
but maybe the probabilities of a particle being
here versus there. Even the curvature of gravity
must somehow be probabilistic. And Einstein didn't
like that. there was no way to work that into his
equations that actually, you know, made them both
work at the same time. What if we were asking the
wrong question? What if we're not looking at two
different things? What if we could actually say
that spaceime itself is a consequence of quantum
mechanics, not something separate from it, not two
things that are clashing together? And this is
the idea now that perhaps quantum entanglement,
if you look at it correctly, is spaceime.
Now quantum entanglement isn't just a term
you can throw off very very easily but this is
something that we have now observed and been able
to replicate in laboratories all across the world
even in space actually. If two objects interact
together they can actually sort of become in a
sense the same system under the laws of quantum
mechanics. So let me just give you a very simple
example of this. A lot of people know the model of
an atom where you have this uh nucleus of protons
and neutrons and the electrons can be in different
orbits around there. In fact, in in a single orbit
around the nucleus, there can be two electrons,
but those electrons can't be exactly the same.
You can't have two that are identical. They have
to have opposing spins, angular momentum. It
turns out you can have two electrons in each
one of these orbits, but the electrons can't be
identical. They have to be spinning in opposite
directions. It's a strange idea that electrons
spin, but at least you can say that there's
some kind of intrinsic angular momentum. What we
think of as something spinning, that's actually
a property that a particle can have, whether or
not there's actually like a physical little ball.
Electrons are not little balls, but they do have a
property of spin of uh angular momentum. You could
have two of them in the same orbit as long as they
have opposing spins. One spinning one way, the
other one's spinning the other way. So, say that
one is spinning, you know, up and one is spinning
down. the way my thumbs are pointing, you know
that these two electrons have to have different
spins. So, what happens if you actually take
them out of that system? You take them away from
the atom entirely and now you've got these two
little electrons somewhere in space and then you
know that they have to have opposing spins because
they once were in that same orbit. Well, okay. So,
now separate them. Separate them by a couple of
feet, maybe a couple of miles. How about a couple
hundreds of miles? Maybe there's no limit. We
found out that if you use some sort of energy
to change the spin of one of these electrons, the
other one basically instantly knows that that's
happened. And it's not that there is a signal
passing between one of these to another because it
doesn't travel even at the speed of light. It is
an instantaneous flip. It's not a signal traveling
because these two things are basically the same
quantum system. In the rules of quantum mechanics,
they are the same object. So there's no signal
really to travel to a quantum system. There
really isn't any such thing as space or time. It
will adjust instantaneously because it's the same
system whether it's microscopic or whether it's
many thousands of miles apart. They're the same
thing. Could it be that everything is entangled
to everything else in some way? Well, I mean,
there once was a time when the universe was very
small. You know, the time right after the big
bang where in a way we were all kind of the same
particle. That particle has changed and expanded.
But is it possible to think that in some way we're
actually the same quantum system to everything in
the universe. And what we perceive of as space
and time is the degree to which we're entangled.
We're entangled more to things that are closer to
us that have a chance to interact with us. The air
in this room, the space that's only outside in
my yard. I'm less entangled to things that I've
not been able to interact with much for a long
time. Things like distant galaxies, I haven't been
close to them since the beginning of the universe.
Einstein asked, "What is gravity really?" And now
we have to ask, what is spaceime really? And we
know it can't be as simple as the way we perceive
it. Maybe the underlying quantum reality of the
universe is that everything in a way really is
still the same quantum system.
### 光子视角：颠覆性时空观与质能转换奥秘
如果量子纠缠构成了时空，那么**光子**（Photon: 光的基本粒子，无质量）的视角提供了理解这一概念的绝佳切入点。光子以**光速**（Speed of Light: 约每秒30万公里，宇宙中信息传递的极限速度）运动，根据爱因斯坦的理论，处于光速的物体将**不经历空间或时间**（No Space or Time: 对于光子而言，所有空间点和时间点都是一体的）。这意味着，从光子的角度看，宇宙从未膨胀，所有时空点皆为一体。这与人类所感知的、具有延伸性的时空形成了深刻的**二元性**（Duality: 两种看似对立实则统一的性质）。我们由可转换为光子的物质构成，却经验着时空，这表明我们对时空的感知并非最终答案，物理学需要一种新的视角来揭示我们大脑尚未能捕捉的现实。
进一步探究宇宙的**基本构成**（Fundamental Composition: 构成事物最基本的元素或原理），爱因斯坦著名的**质能方程**（E=mc²: 能量等于质量乘以光速的平方，揭示了质量和能量的等价性）E=mc²揭示了质量与能量的**等价性**（Equivalence: 两种不同事物在价值或性质上相同）。宇宙似乎并不区分质量与能量，只要总量守恒，它们便能相互转化。例如，**核聚变**（Nuclear Fusion: 较轻的原子核聚变为较重的原子核，同时释放巨大能量的过程）将少量质量转化为纯能量；而**粒子加速器**（Particle Accelerator: 利用电磁场加速带电粒子，使其达到高能量的装置）则能将高能转化为质量，创造出新的粒子。这表明质量可以被视为一种“凝固”的能量形式。
Original English Source
I've always thought
when people think about alien civilizations
and they say the flying saucers and UFOs and
spaceships, I kind of wonder if the next step
in really understanding reality is that there's no
such thing as distance. And maybe a very advanced
civilization that can somehow manipulate that. You
don't have to travel anywhere in a spaceship. You
simply figure out how you access this entanglement
of the rest of the universe. Could it be that you
are really the same quantum system as everything
in the universe at once? And that degree of
entanglement is what we think of as space, as
time, as gravity. That's an amazing idea and
it's one that more and more people are starting
to look at. Do we know this is true yet? No. This
is still conjectural. But the physics is working
very well. And one of the promising things is that
the equations of gravity emerge now from quantum
mechanics. They're no longer general relativity,
quantum mechanics, they don't mix. You start with
quantum mechanics and gravity emerges from it,
from the degree of entanglement. So stay put
for a couple more decades. And uh like I said,
maybe someday we're actually going to figure out
what the underlying structure of this entanglement
is and then we can actually move outside of
space and time. When you are pure energy,
you have to travel at the speed of light. A
photon has to travel at the speed of light. It
can't go any other speed. A photon can't exist in
a state where it's only moving at say 20 m hour.
It has to travel at the speed of light. And when
you're traveling at the speed of light, you don't
experience space or time. You're probably familiar
with Einstein's idea that as you go faster and
faster, closer to the speed of light, time slows
down for you compared to an observer watching you.
If I'm sitting here still on the Earth and I watch
somebody in a spaceship whizzing by at half the
speed of light, I see them very very slowed down
compared to me. And when you're actually going at
the speed of light itself, time stops. That means
that light does not experience space or time in
any kind of extended way. All points in space are
one and all time. All points in time are one. Time
and space don't exist to a photon the way it does
to us. And yet I am made of something that you
can convert to photons and back and forth. And I
experience space and time. I experience those as
extended properties. There's a duality to the
universe. And I think this is going to become
one of the most important things for modern
physics that the next revolutions in physics.
Light around us. I mean, it's coming from the sun
through my windows. It's coming at me through,
you know, the lights that we have in the studio
doesn't experience the same universe I do. to it
in a real way. The universe never expanded. All
points of time and space are still one from the
perspective of a photon. And I am made of photons
kind of. But why do I experience space and time?
Space and time as we perceive them cannot be the
end story. There has to be a different perspective
that shows us a reality that that our human brains
don't perceive yet. But the physics all around us
of something something as simple as light demands
it. The things that kind of give me chills is just
how little we understand the nature of reality
itself. If something bouncing off me right now
doesn't experience the universe as having even
expanded, what does that mean? So that equation
equals mc^2. I mean it's it's useful. You can
use it to power nuclear reactions. You can use
it for particle accelerators. But it actually
sort of claws away the fabric of reality itself
and challenges us to ask what's underneath. To
me, I think one of the the most amazing things
about the universe is the question what is energy?
And this can go very very deep. Uh you know a lot
of us are familiar with you know energy is it
takes energy to accelerate something like you
know to actually like throw a softball that takes
you know energy chemical energy from your arms or
you could say something has potential energy like
it's sitting at the top of a hill and it's prone
to roll down the hill in the gravity field of the
earth that's actually called potential energy. But
then there's also the energy that's just intrinsic
in matter. One of the things that always gets me
about this is that energy, light, you know, light
is sort of a form of pure energy and us, you know,
matter, we're made of particles like protons and
neutrons and electrons. They seem so different.
They seem to have completely different views of
the universe as well, which I think is one of
the more interesting and disturbing things I know
about in modern physics. Let's just think about
the idea that energy and mass really are somehow
the same thing. that mass is some like coagulated
stored form of energy. That means the two of them
you can actually go from energy to mass and and
back and forth. And that's the famous equation
that Einstein came up with equals mc^2 that in
any amount of mass there is an equivalent amount
of energy and the two are basically the same
things. The universe actually doesn't seem to see
much difference between mass and energy. As long
as the amount is the same, it can exist in either
form. And let me give you some examples of that.
The way a nuclear reaction works like a nuclear
fusion reaction is you convert some amount of mass
into pure energy. Nuclear fusion actually brings
particles together, slams them into larger atoms
and in the process energy is released. So a little
bit of mass is lost but energy is produced. It
also goes the other way. In a particle accelerator
you get more and more energy because of collisions
of particles colliding together. They produce so
much energy that as long as as a given particle
has that amount of energy, any particle can pop
out of that reactor. And that's how we find new
particles. As we get to higher and higher energies
in a particle accelerator, just having that amount
of energy around the universe can manifest
it now as mass takes a lot of energy equals
mc^ squ. Energy equals mass time the speed of
light squared. That's a lot. But energy and
mass pretty much are the same thing.
### 虚拟粒子与中子星：揭示空间与物质的极端状态
宇宙在质能转换方面展现出惊人的机制，其中之一便是**虚粒子**（Virtual Particles: 在短时间内凭空产生又湮灭的粒子对，由量子涨落引起）。即使是真空，也蕴含着固有的能量，这能量能够短暂地转化为**虚粒子对**（Virtual Particle Pairs: 例如电子和正电子），随后迅速湮灭。这种现象在整个宇宙中无时无刻不在发生。
然而，在极端环境中，例如**中子星**（Neutron Star: 质量巨大的恒星死亡后形成的致密天体，主要由中子构成）周围，这些虚粒子会发生更加有趣的演变。中子星拥有比普通磁铁强万亿倍的**磁场**（Magnetic Field: 磁力存在的空间区域）。如此强大的磁场能分离虚粒子对，将其加速形成能量束。当能量达到极致时，甚至会使**真空本身具有质量**（Vacuum having Mass: 在极端能量或引力场下，量子涨落产生的虚粒子密度极大，使真空表现出类似物质的特性），其密度可达到纯铁的三倍。这种超乎想象的现象揭示了能量与质量的深刻统一，以及空间本身远比我们想象的更为复杂和活跃。
中子星本身就是宇宙中的“怪物”，它们是质量巨大的恒星死亡后，未能坍缩成黑洞的产物。在极强的**引力**（Gravity: 吸引物体向地球或其他有质量的物体的力的现象）作用下，原子中的电子被压入原子核，与质子结合形成中子，因此中子星几乎完全由中子构成，其密度可与原子核相媲美。一颗直径约10英里（16公里）的中子星，其一茶匙的物质质量可达**珠穆朗玛峰**（Mount Everest: 地球上海拔最高的山峰）之巨。由于**角动量守恒**（Conservation of Angular Momentum: 物理学定律，指物体转动惯量与角速度的乘积保持不变），中子星在坍缩过程中会以惊人的速度自转，甚至能达到每秒500次。
Original English Source
One of the
ways the universe seems to do this is something
called virtual particles that if you have um you
know just just the energy you know around you the
energy of space and time itself there sort of
an inherent energy just in the universe that
energy can actually become mass it'll actually
form what we call virtual particle pairs like
an electron and its antimatter equivalent
a posetron. those two particles will just
literally pop out of the universe because there's
that amount of energy around and then pretty much
always they just annihilate each other. They
just go back. Matter and antimatter annihilate
back into pure energy. And this is happening
all around you. Everywhere around you in space,
these little virtual particles are forming and
collapsing together all the time. Some of the
more interesting things happen in the universe
when those particles get separated. Uh one example
is around a neutron star. It can actually make
a beam of energy coming off the magnetic poles
of the neutron stars by having virtual particles
be created and then accelerated by the magnetic
field. So all of a sudden you have this energy
that wasn't there before produced by the virtual
particles themselves. As you get to higher
energies, you know, say you have a very very
strong magnetic field, very high energy. Again,
we find these around neutron stars. That can start
creating lots and lots of these virtual particle
pairs. And the more energy you have, the more of
these little virtual particles you get until space
itself takes on an aspect of having mass. The
density of these virtual particles right around a
neutron star, even in empty space itself, would be
about three times the density of iron. It's just
just unbelievable. So energy and mass really are
the same thing. They're two sides of the same
coin. They can be converted back and forth to
each other, and the universe doesn't really care.
It sees them both the same way. When people think
about the most dramatic things in space, they they
tend to go immediately to black holes, which are,
you know, absolutely incredible. You know, out of
control gravity that you can actually, you know,
suck light back in. It's just amazing. But I think
neutron stars deserve a little more love because a
neutron star is also created when a massive star
dies, but it doesn't have quite enough mass to
actually collapse into a black hole. It actually
leaves behind a thing, you know, a physical thing
that you can study. So while black holes are
just sort of this bottomless pit, you know,
with neutron stars, you have this very strange
thing that you can look at them, you can observe
them, you can take real measurements of, and
you're looking at something that is mind-blowing,
and in some ways our physics really isn't ready
to describe yet. The thing about a neutron star,
you know, why why do we call it a neutron
star? For one thing, and I'm I'm going to
really oversimplify here, but basically when you
think about an atom, you have protons and neutrons
in the nucleus of the atom, and then electrons are
in in orbitals around farther away from around the
nucleus. Amazingly, the gravity of a neutron
star is so strong that it actually collapses
the electrons into the nucleus. The gravity
crushes electrons into the nucleus. And if
you crush an electron and a proton together, one
is negatively charged, one is positively charged,
you will get a neutron. A neutron actually will
naturally decay sometimes into an electron and you
know a proton. You have an object that's mainly
made of neutrons. There are some protons as well.
And it basically has the density of an atomic
nucleus, but it's about 10 miles across. I mean,
that's like one big nucleus. 10 miles across. It's
incredible. And because there was so much collapse
involved in their forming, you know, when when
you think about what they call the conservation
of angular momentum, if something is spinning and
stars actually do spin, if you collapse that down,
you actually spin up much faster. It's the classic
ice skater analogy. You have an ice skater with
her arms out spinning around and then as she draws
them in, you can watch that ice skater spin faster
and faster. Same thing happens. But in this case,
you actually have a ball that is about, you know,
10 miles across spinning 500 times a second. I
mean, I mean, that in itself is just mind-blowing
to think of, right? Something that big spinning
that fast.
### 快速射电暴：中子星震的宇宙回响
中子星在解释**快速射电暴**（Fast Radio Bursts, FRBs: 持续时间仅几毫秒，但能量极高的射电脉冲）这一宇宙谜团中扮演了关键角色。FRBs的能量巨大，一次爆发相当于太阳一周的能量总和，科学家曾一度猜测它们可能源自**高级外星文明**（Advanced Alien Civilization: 科技和发展水平远超人类的假设生命形式）。然而，通过高能望远镜的定位，FRBs的来源被指向了中子星。
目前的最佳解释是，FRBs是**中子星震**（Neutron Star Quakes: 中子星表面的剧烈震动，类似地球地震）的产物。中子星表面可能覆盖着一层晶体状的薄壳，内部则是纯中子的流体。当外壳出现裂痕或发生移动时，会产生强大的**压缩波**（Compression Waves: 介质中质点振动方向与波传播方向平行的波），瞬间释放巨大能量，形成快速射电暴。就像地球地震波揭示了地球内部结构一样，对FRBs信号的分析有望帮助我们重建中子星的内部构造，进一步理解这些宇宙中独特的天体。
Original English Source
Now, recently, neutron stars had
played this important role in explaining something
that we had no explanation for. They were very,
very mysterious. In fact, there were some people
that were wondering if we were actually looking
at might be a signal from an advanced alien
civilization. Those are called uh fast radio
bursts. Now, uh fast radio bursts have been in
the news for a couple of years because there
was so much energy in these mysterious bursts of
radio emission that we couldn't explain what was
going on. So for example, we would have uh you
know our radio telescopes would register a burst
of emission and the uh that burst would last say a
millisecond 1,000th of a second. That's about how
long these things would last. But in that 1,000th
of a second enough energy was radiated similar to
what the sun puts out in a week in a millisecond.
And so we were getting these signals from you know
all over the sky. We were trying to figure out
what that could possibly be. How could you make
that much of a tight burst of radiation in that
small amount of time at those incredibly high
energies? So, the race was on to try to figure out
what these fast radio bursts really were. Luckily,
we have many, many things that are at our disposal
to try to study these things. Right now, we have
many high energy telescopes that actually are
orbiting the Earth that measure things like X-rays
and gamma rays, the most uh energetic types of
light. light you only get if something is in the
millions or billions of degrees. It'll actually
emit X-rays and gamma rays. A wonderful thing
is that we actually started to be able to kind of
pinpoint to where these things were coming from in
the sky. And as we did that, they actually seem
to line up with neutron stars. So neutron stars
are most likely responsible for these fast radio
bursts. Now, exactly what's happening is something
that we don't really know yet, but it probably has
something to do with almost like an earthquake.
an earthquake, you know, you you have something,
you know, our something in our crust shifts and
there all these waves that go through the earth.
It's actually the way that we know the interior
of the earth is by studying those waves. You know,
we've never been able to actually take a sample of
the fact that the earth has magma all the way down
until you get to a at first a liquid metal core,
then a solid metal core. No one's ever seen
that physically, but we actually watch how
these waves of compression go through the earth
and we can put together what the interior of the
earth must be like. The same thing may be
possible for neutron stars, but on a much
more energetic scale. You have this this this
ball of of neutrons. Incredible densities,
incredible temperatures. And we think that there
must be a crust of neutrons actually that actually
forms on the outside of these stars. And inside
is probably a fluid, a fluid of pure neutrons.
We know this because neutron stars as they spin
sometimes seem to sort of slosh around almost like
a water balloon. So, we've modeled that to be sort
of a crystallin thin crust. I can't imagine what
that would be like. I mean, for one thing, that
the gravity would be so intense near that crust
that it would just crush you into just particles
basically on the surface of that neutron star.
But if that crust were to have a flaw in it and
there was some sort of uh you know a quake, it
shifted somehow, it would send compression waves
through the neutron star and release tremendous
amounts of energy in a quick little moment of the
crust actually sort of refiguring itself. So right
now our best explanation is that these amazingly
mysterious fast radio bursts are probably neutron
star quakes. And just like earthquakes have
taught us so much about the interior of the earth,
now we're looking at the signal, you know, even
in a thousandth of a second, take that signal,
pull it apart, and try to find the structure
that's going on inside that burst of radiation
and see if we can reconstruct what the inside of
a neutron star is like. Neutron stars really are
these real monsters. Unlike black holes, you
can see them. You can see their surfaces. You
can actually map how the radiation is coming off
them. When it comes to really mysterious parts of
the universe, but things that you actually can
measure, I'd say go for some neutron stars. The
closest neutron stars to us are very far away.
You know, they're on the order of many hundreds
or thousands of light years. So, luckily, they
don't really cause any uh trouble for us.
### 太阳风：塑造行星命运的宇宙风暴
除了遥远的中子星，我们近邻的太阳也释放着强大的能量流——**太阳风**（Solar Wind: 太阳日冕层不断向外抛射的等离子体流）。这种由高能质子和电子组成的粒子流，以每小时百万英里的速度横扫太阳系，深刻影响着行星的演化。例如，火星因太阳风长期剥蚀而失去大气层，成为寒冷的沙漠；金星的大气中较轻分子（如水）被吹走，留下了二氧化碳和硫酸，使其成为炼狱般的存在；甚至远在太阳系边缘的冥王星也在持续损失大气。
地球之所以幸免于难，得益于其强大的**磁场**（Magnetic Field: 磁力存在的空间区域）。地球内部熔融金属的运动产生了类似“磁瓶”的保护层，使我们免受太阳风的侵袭。然而，太阳风并非全然无害，剧烈的**太阳风暴**（Solar Storm: 太阳活动剧烈时爆发的能量和粒子喷射，如日冕物质抛射）——特别是**日冕物质抛射**（Coronal Mass Ejection, CME: 太阳日冕层抛射出大量等离子体和磁场）——可能对航天员和地球科技构成威胁。
例如，**卡林顿事件**（Carrington Event: 1859年发生的有记录以来最强的地磁暴，导致电报系统瘫痪）就展示了太阳风暴的巨大威力。如今，**NASA**（美国国家航空航天局）、**NOAA**（美国国家海洋和大气管理局）和**FEMA**（美国联邦紧急事务管理局）等机构正密切合作，通过环绕太阳和地球的卫星组成的**早期预警系统**（Early Warning System: 旨在提前发现并警示潜在危险的系统），持续监测太阳活动，以应对未来可能发生的类似事件，保护卫星和地球电网的安全。
Original English Source
But the
question I've always wondered is how close could
you actually get to one of these things and and
make a measurement before you would just be fried
by radiation? Or in in the case of a neutron star,
something stranger still. A lot of people are
familiar with Einstein's famous equation E= MC^2
which says that energy is equal to mass times the
speed of light squared. And what that really means
is that in any amount of of mass, so if I think
about like the mass of my little finger, there's a
tremendous amount of energy. So if I could convert
my little finger into pure energy, the nuclear
bombs that were dropped on Japan, you know,
converted on the order of like a dime's worth of
mass. So, you know, there would be many, many, you
know, nuclear warheads right in my little fingers
worth of energy. But E= MC^² also goes the other
way. If you have a lot of energy, that basically
starts acting the same way as mass. And it does so
in something called virtual particles. If you have
a a lot of energy in a small space, the universe
will start to actually create particles that have
the same energy in their mass. So a lot of energy
can actually become mass. And and this is how our
particle accelerators work. This is why you can
discover new particles because if you just have
a very energetic collision, like you take two
gold nuclei and you slam them together, there's
so much energy produced in that collision that it
starts to pop off particles just from the amount
of energy. And as long as you have enough energy,
you can make any particle the universe has. The
particles come off in all different flavors as
long as they have the same amount of energy that
that collision is putting out. So neutron stars
are doing something kind of like that. They're
actually becoming sort of natural particle
accelerators in a way just because of their
mass. There is so much gravitational contraction
that the magnetic field, the electric field and
magnetic field of that star is actually compressed
around this tiny little object. Now, so neutron
stars have magnetic fields that are trillions of
times more strong than a typical magnet you might
have in your home, like a refrigerator magnet.
It would actually pull regular matter apart,
just the magnetic field. But there's so much
energy in those magnetic fields. So so think about
E= MC². There's so much magnetic energy right
around a neutron star that the vacuum of space
itself starts to make these virtual particles. And
I was at a lecture one time and this just blew my
mind. You know this is what happens when you work
at NASA and you know you go into a lecture your
colleagues are having you just you know any any
day of the week. And they were saying that right
around a neutron star the density of space itself
the vacuum of space right a place where it's a
vacuum. there aren't any particles otherwise
has about three times the density of pure iron
just from that amount of virtual particles being
produced by the energy of that magnetic field.
So what's it like to fly around something where
space itself has the density of three times of
iron? What's that like? What does that look like?
I would love to see what a neutron star looks like
from a safe distance. And I'm not exactly sure
what that is. When you're dealing with so much
energy that even empty space becomes much more
dense than iron. And once again, these are real.
They're up in the night sky tonight. I mean, you
can't see them because they're they're dim and
they're small and they're far away. So, it's not
something we actually see in the night sky. But
all around us, we're getting the radiation, the
high energy radiation from these things that are
are real monsters. Our sun has this wind of high
energy particles. This is something that was only
relatively recently discovered. I mean, when
you think about the fact that the very first
satellites we put into space, you know, starting
in, you know, the very late 1950s, you know,
and 1960s, they they realized that there was this
source of of of radiation up there. There was,
you know, a lot of particles around up in space.
I actually had the honor of being next to this
man named Eugene Parker. We have a a a wonderful
mission named after him called the Parker Solar
Probe. This mission is actually orbiting around
the sun right now, closer than any human-made
thing has ever orbited the sun before. It's really
really exciting. He was I I believe 94 years old
at the time of the launch. Usually we we only name
spacecraft after people postumously after they've
died. He was the one that basically predicted the
solar wind and was the the one that figured out
how it worked. And of course, we're still figuring
out a lot of the details, but they just couldn't
think of anybody better to name it after than
him. And so that was lovely. The source of these
these these high energy particles and exactly how
they get accelerated away from the sun is is what
we're studying right now. We know that this wind
of particles, when I say high energy particles,
I'm talking electrons and protons and, you know,
sometimes, you know, as large as like the nucleus
of a helium atom, something like that. and they
uh they get blasted through our solar system at
a million miles an hour in some cases. And so,
you know, we have this very high energy wind.
It changes planets. You know, it's responsible for
Mars losing its atmosphere over time and becoming
this kind of cold dead desert. It's responsible
for for Venus becoming sort of this this hellish
thing that we know it. It actually blasted
away all of the lighter molecules like water.
It left Venus with an atmosphere of carbon
dioxide and sulfuric acid. And even Pluto,
you know, all the way out at the edge of our
planetary system, Pluto is is still losing tons
of atmosphere a day, blasted away by this wind of
high energy particles. The only reason the Earth
is not really affected by it much is because
we have a very strong magnetic field. And so,
you know, our molten metal core, all that molten
metal moving around inside the Earth generates
kind of a magnetic bottle around the Earth. And
that protects us from this solar wind. But someday
the sun will actually, you know, pretty much
blast away our atmosphere anyway. So, you know,
planets change and and one of the important
things about knowing about this wind is we have
to understand our environment in space. The solar
wind normally is at levels that humans can take
quite quite easily. You I know that some people
that are into conspiracy theories say, you know,
how could we have gone to the moon because there's
so much radiation in space. Well, the answer is we
we kind of got lucky with Apollo because a normal
day, the solar wind is a a radiation level humans
can handle quite easily, you know, up in space
or, you know, on the moon. Problem is that if you
have a solar storm, a very very violent event that
unleashes lots of this solar wind, a lot of times
we call these coronal mass ejections. The corona
is the outer layer of the sun's atmosphere and and
coronal mass ejection. All this stuff comes out
at once. It's true that if if a big one of those
happens in the direction where astronauts are
unprotected from the Earth's magnetic field, they
could die. I mean, it could actually give them
a fatal dose of of radiation. That is something
that we need to consider. And it turns out that we
got kind of lucky that, you know, in between some
of the Apollo missions when no astronauts were
up on the moon, luckily we actually had events,
solar events that would have endangered the
astronauts. That's why it's hard to go to the
moon and also to Mars is to protect people from
that that radiation. It's not that hard to protect
you from it. I mean, a good amount of water
could do it. Like if you had a water tank in your
spacecraft and you could shelter behind that. It's
just that you'd have to bring up a decent amount
of water and that's a lot of mass. Or in the case
of the moon, I think if if you could dig down just
about 10 ft below the lunar surface, that amount
of rock above you would shelter you. But then we
need to bring, you know, construction equipment to
the moon that can dig a tunnel, right? So I mean I
mean there's all kinds of things we're considering
as to how you would handle that. So what happens
with shock waves is that you have say two binary
stars close to each other and they both have a
wind of particles. You in this case we don't say
a solar wind, we say a stellar wind because we're
talking about stars. But it's really the same
thing. The main difference is that the stars
that I was studying are very massive stars. Stars
that have, you know, anywhere from, you know,
let's say 20 to 50 times the mass of the sun.
And they actually have really strong winds. much
stronger even than the sun does. So when you have
these two stars close to each other, these winds
come off and they collide. And when that happens,
I mean I mean literally the the the electric and
magnetic fields, you know, sort of entangle with
each other. The particles collide together and
that creates a very very hot area that we call a
shock wave. As all of this stuff comes together,
basically slows itself down as it collides, you
get all of this heat and radiation emitted along
that that that shock front. Those are wonderful
shock waves that are created by colliding winds.
Yeah. So, one of the big challenges right now,
especially as we consider putting astronauts back
on the moon, is there a way to predict when one
of these violent events is coming? The answer is
uh yes, in several ways. So in the in the very
simplest way, we actually have spacecraft as I
mentioned there's a spacecraft orbiting the sun
right now. There's actually two, the Parker Solar
Probe and the Solar Orbiter from the Europeans.
And we also have other spacecraft between the
Earth and the Sun. As one of these, you know, big
belches of material, charged high energy particles
comes out of the sun, it will hit different
satellites that will measure how fast it's going,
how much energy is being delivered. And usually
in the case of of say the moon, uh the the earth
has about a day or maybe two days notice. So you
could say to the astronauts, hey, something's
coming. You know, everybody go shelter. You know,
as long as you had a good shelter there. But then
there's the question of can you predict it before
it actually happens. And this of course is one of
the the huge goals all over the world of people
called helopysicists. Helio for sun and then
physicists. So people who are are physicists that
specifically study the sun. the the sun is this
incredible magnetic marvel. A magnetic field is
generated by moving charges, right? So you think
about like the the charges in moving metal that
generates a magnetic field in an engine. In the
case of the sun, the sun is made almost entirely
of hydrogen, but it is so hot on the surface that
that gas has become ionized. that what that means
is there's so much energy that electrons that
normally orbit around a nucleus, the electron gets
so much energy it just takes off and that leaves
two particles that are charged, an electron and
a proton. Anything that has an electric charge,
a magnetic field can bend. And so when you see
these wonderful like loops on the sun and and and
you know all of these beautiful shapes, that's the
very hot electrically charged gas just following
the magnetic field of the sun. The name for it,
and it's kind of a confusing name, is plasma. You
know, you can actually see the shape of the sun's
magnetic field, but it's chaotic. It's incredibly
complicated. So, you have these wonderful loops
of magnetic energy, you know, all this stuff
following it. So, how do you predict, you know,
when one of those loops is going to break open and
and actually like spew stuff out and create one of
these big ejections? We're getting better at it,
but it's still something that we don't understand.
I mean mean something that simple of you know our
own star when is there going to be a really big
storm we can't predict it down to the hour we can
say there's a very active region here that looks
like it might produce something but there's no
way to guarantee that actually it kind of reminds
me of the year uh 2012 because I was having sort
of a difficult year that year because uh people
had this idea of the Mayan apocalypse. It was
2012 apparently that was the end of some
calendar cycle in the the Mayan calendar.
The the idea was that something catastrophic was
going to happen. And I would get calls, seriously,
people would call us at NASA and say, you
know, I don't want my pets to suffer. You know,
should I euthanize? I I actually got a call
somebody wondering if they should euthanize their
pets. Other people would say things like, is the
world going to end next month? And and I' I'd say,
you know, look, okay, if I knew the world was
going to end next month, do you think I'd be here
in my office answering phone calls? I don't think
so. And we kept telling people that there was
really no reason to worry about anything. There
was nothing unusual astronomically happening. The
sun was in a naturally active period that year.
Every 11 years or so, the sun becomes very active
and then it kind of gets quieter again. One of
the reasons I know this is cuz I I love to see the
northern lights, the auroras, you know, those are
caused when you get these charged particles in our
atmosphere and uh they create these beautiful
glows around the poles. You know, for us,
that's really the only thing we really notice
for the most part. What happened actually is
that there was a colossal coronal mass ejection,
one that would have actually been dangerous to our
power grids here on Earth. It wouldn't have caused
any damage to like people or animals or plants,
but it would have actually dumped electric
current into our magnetic field and it it
probably would have taken down, you know, a lot of
power grids. It would have caused a lot of damage.
The thing though is it went off on the other side
of the sun from the earth and we had satellites
out there in that other direction out in the solar
system and and and they got knocked silly by this
big burst of charged particles from the sun. And
so we looked at that and we were able to observe
it and see what had happened and track it and all
of that. We all kind of went the the sun spins.
It actually doesn't all spin at the same rate.
The equator spins faster than the poles. It's
not a solid thing. It kind of twists itself up.
the sun, you know, on average spins about once
every 29 days. And so we don't really know. There
could be an active region that's about to blast,
but then it could spin out of our view and and
so we're safe from it. Or something could come,
you know, from the other side of the sun that
we didn't see. There's all sorts of wonderful
complexities when it comes to observing this this
phenomena we call space weather. The winds and the
storms, but in this case, winds of particles and
magnetic storms, storms of magnetic chaos on the
sun. It's a wonderful thing to think about that
our our lovely gentle star up there is is actually
very dramatic and and very volatile. Sitting here
at the bottom of the Earth's atmosphere, we're not
really aware that we're in a larger environment
in space. And the dominant thing is the sun. You
know, the sun obviously is the biggest thing in
our solar system, the most important thing. The
sun not only puts out a lot of light and heat, but
it also puts out a wind of high energy particles,
high energy protons and electrons, charged
particles. We actually are bathed in this all the
time. It interacts with our atmosphere. It creates
the northern and southern lights. In some cases,
it can even be a a risk, especially to our
technology. We're quite well protected from
these high energy particles by our atmosphere and
also by the Earth's magnetic field. The Earth has
a very strong magnetic field that surrounds our
planet and protects us from the worst of this
stuff. Even the astronauts up in the space
station, they're actually close enough to
the Earth that they're largely protected by this
magnetic field. When you go out to the moon and
farther away, that's when you're not protected by
the Earth's magnetic field and you find yourself
just basically exposed to this wind of high energy
particles. A lot of people don't realize how
significant that is and how much uh not only NASA,
but Noah and other organizations all over the the
planet are monitoring this. There is a fleet of
satellites right now and I don't know exactly
the number because it usually changes but we have
some satellites that are orbiting the sun itself.
We have some that are actually placed between the
earth and the sun. There is a place that actually
the the sun's gravity and the earth's gravity
balances out. If you're between the earth and the
sun, you're actually attracted equally to either
one gravitationally and you stick a satellite
right there and it doesn't take a lot of energy
to actually keep it in that spot. So we have this
kind of early warning system to see if there's
something dangerous coming from the sun. And then
we have all kinds of observatories both here on
the earth on in on the ground and also space-based
observatories that orbit the earth that just look
at the sun continuously. We even have satellites
around the solar systems look at different angles
of the sun. So we we've got the sun covered. Now
why is it so important? Well, the solar wind
normally doesn't really have much danger to us,
you know, or the environment in space. But when
you're dealing with space weather, sometimes
there's a really big line of thunderstorms
coming through. Right? So in the case of the sun,
the sun sometimes has very very violent storms.
And these are storms caused by the the chaotic
twisting magnetic field of the sun. Some of the
hot gas on the surface of the sun actually gets
accelerated so quickly by these magnetic fields
that it just breaks off and takes off into space.
And in one moment you could have trillions of
tons of fast highmoving charged material coming
out towards the earth. Now that's not actually
very dangerous to us biologically. But what that
can do is carry a huge amount of electrical and
magnetic energy. All of a sudden all these charged
particles hit the magnetic field of the earth and
they can actually dump electric current right into
our magnetic field. There was a famous event
in the mid 1800s called the Carrington event.
With the Carrington event, we really were just
starting to have things like telegraph lines. Now,
in order to get a telegraph to work, there has to
be electric current on the wires. And normally,
you would hook up your telegraph to a power
generator, and that would create electric current,
and you could send your signals. So, when this
Carrington event occurred, there was so much
electric current dumped into the Earth's field
that you could actually start sending signals
with no connection to power. And then eventually
as the storm went on, some of the telegraph wires
actually caught on fire just from a storm of
magnetic and electrical energy. These particles
coming from the sun. So these days, of course,
you know, we know that this could happen again. Uh
events like this are rare, but they they certainly
will happen from time to time. So there are all
kinds of organizations, you know, the uh like like
FEMA, you all these disaster relief organizations
that work with NASA and Noah to actually figure
out what happens if we think that a a dangerous
solar storm is imminent. Um in the case of
all of our satellites up above the atmosphere,
they're very at risk. So we can basically shut
them down, put them to sleep for a little while.
Of course, that that that energy burst will
hit them and it may damage their detectors,
but at least most of the electronics are shut down
at the time and we can recover them hopefully. And
then there may even be uh you know plans that
are necessary to to shut down parts of power
grids because I think the biggest danger of these
things to us is that when they actually hit the
earth's field you could have so much again energy
in that magnetic field of the earth that it could
you know fry our power grids. I mean think about
how bad it would be if all the power on earth just
went out because of one of these solar storms. I
mean that that could conceivably cause billions
or maybe even trillions of dollars of damage. So
there are people rehearsing these scenarios. There
are people uh you know trying to figure out how
we would shut things down, how we would protect
ourselves and then we have our fleet of satellites
trying to observe the sun all the time and we
would have probably about a day's notice as one of
these big storms made its way through the sun. The
sun we think of as putting off lots of light and
you know light travels at the speed of light which
takes about 8 minutes to get from the sun to us.
But this isn't light. These are charged particles,
protons and electrons. And although they may be
moving millions of miles an hour, it still will
take them about, you know, a day or more to get to
the Earth. So, we will have some warning. But yes,
I mean, all around you there are people monitoring
space weather and getting ready for a big storm.
### 小行星与星际罗盘：宇宙导航与资源探索
**小行星**（Asteroid: 绕太阳公转的小型天体）被视为太阳系早期状态的“时间胶囊”，它们保留了数十亿年前太阳系形成时的化学和物理条件。与地球这类经历了剧烈演化的行星不同，小行星内部的重元素并未完全沉降，因此被视为未来采矿的潜在资源。然而，由于技术和经济成本的限制，短期内进行商业化小行星采矿仍不现实。
在广袤的宇宙中导航，**指南针**（Compass: 利用磁场指示方向的工具）的实用性会发生变化。指南针响应磁场，地球上的指南针指向地球磁极。远离地球，如到达土星，指南针会指向土星自身的强大磁场。更进一步，即使在星际空间，整个银河系也存在一个微弱的**磁场**（Magnetic Field: 磁力存在的空间区域），原则上敏感的指南针也能感应到。然而，在星系之间，磁场几乎无法探测，且宇宙中所有物体都在运动，缺乏绝对的参照系。
在没有可探测磁场的区域，**宇宙微波背景辐射**（Cosmic Microwave Background Radiation, CMB: 宇宙大爆炸后遗留的微弱辐射，均匀分布于宇宙中）成为最佳的导航工具。CMB是宇宙中最古老的光，源自大爆炸后约40万年，均匀充斥着整个空间。通过测量我们相对于CMB的运动，可以确定我们在宇宙中的位置和方向。
Original English Source
You know, the thing that's really fascinating
to me about asteroids is that they are kind
of a preservation of the way the solar system
was billions of years ago. This is really true.
The solar system was once this kind of cloud of
gas and dust and then under the forces of gravity,
things started to clump together into smaller
bits and then larger bits that eventually
became planets. And planets like the Earth
changed so much, right? I mean, the interior
of our planet is molten. There's stuff that's
melting down there. On the surface, you've got
erosion and rain and wind. So, nothing is
really the same as it was billions of years ago.
But there were these little small building blocks
that got left behind that actually never got
made into larger things and they're pretty much
unchanged for billions of years. So scientifically
the reason these are such treasures is that
they are kind of a a time capsule of what the
chemistry the physical conditions everything was
like as the solar system formed. The question of
mining them. So the thing that happened with the
earth is that the earth has this this hot molten
core and most of anything that's heavy sinks to
the bottom. Right? So when you have a liquid,
heavier stuff sinks to the bottom. So the core of
our planet is made of iron, you know, and nickel,
but also metals like gold and silver and platinum,
anything that was heavy when the Earth was molten
would have mainly sunk to the core. So that
means that if that didn't happen to an asteroid,
an asteroid is still kind of all mixed up.
The heavier stuff hasn't actually sunk out
of it. Given a volume, there is in fact more rare
elements, more gold, more platinum, more titanium,
whatever. But asteroids are also fairly small and
of course they're in space, so they're hard to get
to. To me, it becomes kind of a a cost question.
Yes, asteroid material by and large has more rare
valuable elements than parts of our Earth's crust.
It also has a lot more iron. You can get very
expensive iron. I don't know when it will actually
become economically feasible to go all the way to
an asteroid, mine it, bring stuff back or however
you want to do that to get the tiny little bit of
gold that you'll get out of it. My guess is not
soon. I don't think we will actually be mining
asteroids in any real commercial way very soon at
all. It's a fascinating question whether you could
use a compass in space. So, let's talk first
about compasses and then maybe talk a bit more
about the idea of how we locate ourselves in space
in general. A compass is something that responds
to a magnetic field. So, the reason a compass
always points north is that it's responding to
the magnetic field of the Earth. Our planet has
this wonderful core of molten metal. That metal
moves around inside the Earth and it generates a
magnetic field that has two poles, a north pole
and a south pole. When you make a compass, you
make it out of something metal that can respond to
that magnetic field and it points to the magnetic
pole of the Earth, which is very close to our
north pole. A magnetic field directs compasses.
Obviously, if you go away from the Earth,
far away from our planet, it's no longer going to
be able to feel our magnetic field. So, a compass
will not point to the north pole of the Earth if,
say, you're out by Saturn. Saturn and Jupiter are
separate planets and they have magnetic fields
of their own. So certainly if you were actually
close to Jupiter, Jupiter has a magnetic field
much stronger than the Earth's magnetic field.
Your compass would definitely point to the
north pole of Jupiter if you were actually
around Jupiter. Now, but what if you get farther
out? What if you actually go farther from there?
Is there any magnetic field out in space itself?
Well, actually, it turns out that there are that
our galaxy does have a magnetic field as a whole,
too. This magnetic field might be hard to detect.
You might need a very, very sensitive compass,
but say you had it. you would actually see that
our galaxy does have sort of a magnetic north and
south pole and that magnetic field permeates our
whole galaxy. With compasses, you could actually
at least find out where the north and south pole
of another planet is, the north and south pole of
a star. A star has a magnetic field, too. Even the
north and south pole of a galaxy that's responding
to a local magnetic field. But then it kind of
begs the question, how do you find your direction
in space that doesn't involve a magnetic field
out between the galaxies where really there's no
detectable magnetic field at all? Everything is
moving. There's nothing to say this point is still
and this is the reference point we're going to use
and everything moves according to that point.
We're moving around the sun at uh about 66,000
miles an hour. Right now the sun is moving around
the galaxy around the core of the galaxy at about
half a million miles an hour. We are actually
falling gravitationally into the center of a
cluster of galaxies at about a million and a half
miles an hour. That's just when we say relative
to what? Relative to the sun. Relative to this
group of galaxies. There is no absolute standard
of reference in the universe. There is one thing
that is perhaps the best way of navigating your
way around the universe and that's something
called the microwave background radiation. That's
the farthest radiation we can possibly see. That's
radiation that's coming everywhere in the universe
from a time about 400,000 years after the Big
Bangs. And it fills all of space with this gentle
microwave radiation. And it's pretty much the
same in every direction. In fact, if you had an
old style television that used to have an antenna
decades ago, a lot of the static that you would
see on the screen was actually microwaves from
this background radiation. And one of the things
we can measure is our motion relative to this bath
of radiation, the microwave background. So if you
were trying to navigate with a compass in space,
just remember that compass is going to respond to
the strongest and closest magnetic field. It will
point north, north to the pole of a planet, north
to the pole of a star, even to the north and south
magnetic poles of our galaxy. But what you're
reading is a magnetic field. That's what a compass
does. And that's pretty much all it can tell you.
### 宇宙认知的边界：大爆炸、全息宇宙与人类局限
现代天文学在理解宇宙方面取得了惊人成就，例如**塞西莉亚·佩恩**（Cecilia Payne: 首次提出恒星主要由氢构成）在20世纪初证明恒星主要由氢组成，彻底颠覆了太阳是“巨大岩石”的传统观念。然而，关于宇宙起源的**大爆炸理论**（Big Bang Theory: 描述宇宙从极端炽热致密状态中膨胀演化的宇宙学模型）仍存在诸多误解。科学家并不认为宇宙“凭空产生”，而是承认现有物理学无法描述大爆炸之前的极端条件——可观测宇宙的全部物质和能量曾压缩在一个比原子还小的体积内。
另一个普遍误解是，大爆炸前的宇宙“很小”。事实上，我们所见的**可观测宇宙**（Observable Universe: 可被我们观测到的宇宙区域，受光速和宇宙年龄限制）只是整个宇宙的一小部分。宇宙在大爆炸之前可能是无限大的，这使得我们无法确切得知宇宙的真实大小和形状。
最新的物理学前沿思想之一是**全息原理**（Holographic Principle: 宇宙的信息内容可编码在其边界的二维表面上，三维现实是其投影），它源于对黑洞性质的研究，暗示我们的三维现实可能只是一个二维信息表面的投影。这意味着我们对时间流逝和空间延伸的感知，可能并非宇宙的根本属性，而是人类大脑的**感知方式**（Perception: 通过感官对外部信息进行组织和解释的过程）。
Michelle Thaller强调，作为科学家，必须接受**人类感官和大脑的局限性**（Limitations of Human Senses and Brain: 人类感知和认知能力无法完全捕捉宇宙所有现象和真实本质）。就像我们的眼睛无法看到所有光线频率，蚱蜢无法理解量子力学一样，人类大脑也可能无法完全 comprehend 宇宙的真实运作。宇宙并非为人类理解而设计，我们只是通过有限的过滤器来感知它。这种**科学谦逊**（Scientific Humility: 承认知识的局限性，对未知保持开放态度）的态度，促使我们不断探索那些看似怪异、反常识的宇宙奥秘。
Original English Source
Well, this is the thing about the power of
astronomy that kind of really does blow my mind
is how much we actually do know. There's all kinds
of things that we don't know and and astronomers,
scientists in general tend to really focus on
what we don't know because that's what we're
working on. That's that's our jobs. That's that's
how we get, you know, the grant money to sustain
ourselves is trying to answer the questions that
we don't know yet. But the things that we do know
in some ways, just how recently we know them
really kind of blow my mind. You think about
what are stars made of, right? I mean, you've
probably heard that stars are mainly made of
hydrogen and helium. You know, they're these big
sort of balls of gas, you know, very, very hot,
dense burning balls of gas. But how long ago did
we know that? It was actually really not until,
you know, times like the 20s or 30s that a young
woman named Cecilia Payne, uh, working at Harvard
wrote a PhD dissertation pretty much proving they
had to be made out of hydrogen. It was a graduate
student, a woman graduate student. At the time,
the idea was that the sun was probably something
very much like the earth. It was like a big rock.
And if you have a rock that big, and this is true,
there would be so much gravity pushing it
together that the temperature of the rock would
be very hot. So, you know, the temperature of the
surface of the sun is round about 10,000°. And if
you had a rock that big with that much gravity
pushing it together, it would be that hot. But
it would only be that hot for probably a couple
million years. And the neat thing was, you know,
around about the late 1800s, it was Charles Darwin
who had been looking at things like uh evolution,
the strata of rock like the Grand Canyon, and
he sort of had this this feeling that millions
of years certainly was a long amount of time,
but he didn't think it was long enough to for
the changes that he saw in the earth itself.
The prevailing idea, and this was a problem,
is that the sun was basically a big earth. Gravity
just just the contraction of gravity was making
it hot. it would take millions of years to cool
off. It turns out that wasn't it at all. It was
actually made of hydrogen, the lightest substance
in the universe. But now you have so much gravity
crushing together the hydrogen making the interior
very hot, millions of degrees hot, hot enough
actually to start a nuclear fusion reaction and
that can last billions of years. Certainly one
of the biggest misconceptions is that people think
that scientists feel that the big bang came out of
nothing, right? I mean, how did all of this energy
and all of this matter that made up the universe,
you're saying it just came out of nothing? No. I
I I don't think any scientist actually believes
that. The problem is when you think about
the condition the universe was in at that
point where I mean take our observable universe,
right? I mean, you can look from one side of the
universe to the other back, you know, 13.5 billion
lightyears or more. All of the stuff that we see
was actually compressed into a space smaller
than an atom, a volume smaller than an atom.
We don't have the physics that describes how that
would work. That is so much mass, so much energy
in so little volume. I mean, at this point there
wasn't even mass, just basically pure energy that
right now our physics doesn't go there. As we get
a better idea about how gravity works under very
extreme circumstances, you huge energy densities,
we may have some idea what set off the big bang
and possibly what came before the big bang. And
even that word is a little bit difficult when you
start talking about the big bang because the big
bang we believe was the creation not just of space
but of time. Whatever state the universe was in
before the big bang probably didn't have time as
we perceive it either. Space and time appear to
be some kind of a consequence that of the later
expansion. So how do you describe something that
doesn't have space and time that has huge amounts
of energy and tiny little volumes? We don't have
the physics. It's not that we will never know this
but right now we don't have any way to describe
it. Now another major misconception about the big
bang is that the universe before the big bang was
small. Okay. Now didn't I just say that everything
we see in the universe was probably contained,
you know, less than the volume of an atom. And
didn't I just say that? Well, the thing is I know
every scientist understands that we cannot see the
entire universe right now. And that's because
there's such a thing that we quantify as the
observable universe. The universe has existed, we
think since the big bang about say 13.8 billion
years. So as you look farther and farther out
into space, you necessarily have to look back
in time. If something is a million lighty years
away from you, like the Andromeda galaxy is about
two million lighty years away. The light that
you see through binoculars tonight as you look
up at the Andromeda galaxy left two million years
ago. You're seeing the Andromeda galaxy as it was.
So today we actually have telescopes that are so
powerful they can see back to a time about 400,000
years after the Big Bang. That's amazing. We can
see so far away in space that the light has taken
that long to get to us. You know, nearly 13.8
billion years. And when we look back to that time,
the universe looks very different. For one thing,
it's very hot. It's actually about as hot as the
surface of the sun. And it's so dense and hot
that we actually can't see any farther. Literally,
in any direction you look around the sky, anywhere
you look, if you look to that distance, you see
the universe as it was at that time, 400,000 years
after the Big Bang, and everything becomes just
hot hydrogen gas. So, I know this is kind of a
strange way to uh to put it because we're talking
about before the Big Bang, there may not have been
space and time the way we think they are today.
But whatever it was before the Big Bang, whatever
was there, there was a tiny little part of it,
a tiny little volume that expanded to become the
universe we see today. But that little bit wasn't
the whole universe. We don't know yet how big the
original universe was, all of it, before the big
bang happened, before something changed to make
it expand and completely change its form. So the
universe before the big bang didn't have to be
necessarily tiny. It actually could be infinitely
large. Because of that, we have no idea how big
the universe is, what shape it has. All we can
see is a tiny little bit of it. Think about my arm
being the universe before the Big Bang. you know,
in some kind of state that we can't even
describe through modern physics. The entire
observable universe that we can see now used to be
a tiny volume of it, maybe an atom in my arm. One
atom expanded and became the entire observable
universe that we see. But that's not the whole
universe. There are trillions of atoms in my arm.
Each one of those could have expand to actually
be its own entirely observable universe. So, we
can't tell yet how big the universe was before
the Big Bang or even what shape the universe
is because all we're seeing is a tiny little
bit of it that expanded to become everything that
we see. But that's not the whole universe. That's
our observable universe. There's far more out
there than what we can see. One of the most
common questions that I'm getting from the public
these days is, is our universe a simulation? I I
think that one of the things people are thinking
about is they've heard the term the holographic
universe and this is indeed a very powerful and
increasingly popular idea in modern physics but
it's a little bit unfortunately named and and let
me sort of take you through this. This all started
a couple decades ago when people like Stephven
Hawking and others were trying to figure out how
a black hole really works. We know black holes
exist. We actually observe them from a distance
very routinely. But the physics of how they work
never quite worked. They appeared to violate some
pretty important laws of physics. The universe
doesn't like to lose information. A particle has
a charge. It has a spin. There are all kinds of of
things you can say about an elementary particle.
But when it falls into a black hole, the only
thing that seems to exist anymore is mass, the
gravity that that particle had. What happened to
the information about its charge? Can you ever get
that back? As people began to do the mathematics
a bit, they noticed something very intriguing
that everything seemed to work much better if you
assumed the black hole was twodimensional. Now,
black holes are actually three-dimensional
objects. You know, a lot of times they're
portrayed kind of as things going down a drain,
but basically you have a sphere, which is the
point of no return. Gravity is so intense around
a black hole that if you get anywhere this close,
you never come back out. That's the event horizon
of a black hole. So instead of assuming that it is
a a sphere around the black hole, it all started
to act like it was a two-dimensional surface,
something that was three-dimensional became much
more understandable if it was two-dimensional.
And as scientists do, they thought, well, okay,
if this works for a black hole, is it telling
us something about the rest of the universe?
And this may be one of the most important new
revolutions in modern physics that the laws of
physics might work a lot better, might actually
work out together if you assume that our reality
is really two-dimensional. You look around, there
seems to be more than two dimensions in space and
there's time. How would that work? The example
of a hologram came up. You know, I still remember
being at a hologram museum back in the 1980s. Uh,
and the holograms were really new and really
exciting. The idea that a hologram is made out
of just a two-dimensional block of film or a block
of glass, but it seems to be three-dimensional
when you look into it. And even more than that,
I remember this one hologram that was put on a
pedestal and as you walked around the hologram,
somebody appeared to move inside and wave at
you. If you were looking at the hologram, there
appeared to be motion and even time all embedded
in just this two-dimensional surface. That's what
they mean when they say holographic principle. It
doesn't imply that anybody made a hologram or
that we are part of a projection that somebody
some evil genius is projecting reality on us.
What the holographic principle really is is
the universe may store energy in a way and
information in a way similar to a hologram.
If that's true and we really are embedded in
this two-dimensional universe that has some
pretty amazing repercussions. It probably means
that every point in time exists at once. That,
you know, our idea that things are changing and
that I'm I'm moving right now and time is flowing
in one direction. That's probably the same as
somebody just walking by a hologram and having the
perception that the image is moving. It's probably
not real. The amazing idea is that the extension
of space itself and time actually flowing may not
be real intrinsic parts of the universe. They may
be some way that we perceive it with the human
brain, but in fact there's an underlying reality
where that is not true. We say that these are
emergent properties. It's not the real story.
A hologram doesn't really move. A hologram is not
really three-dimensional, but it seems so through
our perception. That's an amazing idea that the
entire universe exists all at once as some kind
of surface of information. That's the holographic
principle. It's working quite well right now. I
can't tell you whether it's true or not, whether
there there really is some real two-dimensional
thing that we think of as the universe. So, stay
tuned. At the time that Darren was doing this, I
think there was sort of this argument between like
biblical people that said the earth was a couple
thousand years old and then the scientists said,
"Oh, no, no, it must be millions of years old."
What one of the things about being an astronomer
is you throw around very very large numbers all
the time. I mean, some of them are just kind
of, you know, stupidly large. But even things
like how many is a million, right? How many is
a billion? The the human brain, I don't perceive
that really any better than anybody else. The
human brain just doesn't go there. Instead, you
kind of find yourself getting used to swimming in
an environment where your your mind can't really
grasp all the way around a concept. It just can't.
You I can't tell you how far away a lightyear is.
I mean, one lightyear, you know, the distance
light travels in one year at 186,000 miles per
second. That's a close to about 6 trillion miles.
I I don't have the ability to actually visualize
that or feel it. And yet to me a lightyear seems
very familiar and actually actually quite close.
So maybe that's one of the reasons astronomers
are almost kind of predisposed to being able to
let go of sort of your common sense when people
say things like the inside of a neutron star,
you know, is is is so dense that a single
teaspoonful, you know, of that material would have
as much mass as Mount Everest. It's like, okay,
the laws of physics pretty much require that. or
when when people say what was the temperature
of the universe just you know 3 seconds after
the big bang that our physics really does work to
to predict that. So I think that when you start
swimming just in these big numbers and you begin
to kind of let go of the idea that the human mind
is the beall and endall. You know we have these
tools to start attacking larger problems to start
asking bigger questions. All of a sudden it comes
very natural to say things like oh yeah you know
gravity is actually a bending of space and time.
The amazing thing about that is that that started
out to be completely theoretical. You know, people
thought that Einstein's theories were very useful.
I mean, they made extremely accurate predictions
about how the planets move, about how the universe
works. But was there any really reality to the
fact that space and time could bend? I mean,
literally the space in front of me, the
space and time around me can change and bend,
even have a direction to it. It turns out that
you know our theories for the most part do lead
us to something really physically true. And you
know right now people ask me questions like are
there multiple universes? What's the shape of the
universe? You know the larger universe? All of
these things are wonderful questions and we don't
know the answer to them yet. But I have a feeling
that it's not just wasting time. You I think some
of these stranger theories will bear themselves
out over time. We just need to wait. Right now,
I think it's a little bit too soon to follow them
all the way into the rabbit hole. Let's say that
there were many, many multiple realities. Well,
how would physics work? How would this work? It's
still too much conjecture for me to invest a huge
amount in it. You know, I still remember, you
know, what's only 2,000 years ago, unless that you
had people like Aristotle who were brilliant and
they came up with this idea that all the planets
had to follow perfect spherical orbits around the
Earth in the middle and they were on these crystal
spheres that somehow moved and you know, people
all the way up into the Renaissance were trying
to figure out how those crystal spheres could
have worked and how they were supported. Well,
it turns out there weren't any crystal spheres.
There's always a bit of me as an observational
scientist that says, you know, take everything
with a grain of salt for now. Oh, I mean, airsoft
had this elegant, wonderful system. I mean, people
loved it until the Renaissance, right? It's just
that our observations didn't bear up with it. And
it was so beautiful, people hated to let it go,
but unfortunately, that's not how the solar
system works. Definitely pursue these questions,
but I'm not sure I'm ready to dive all the way
into any of those rabbit holes quite yet. I love
to think about them, but I think it's probably
a little too soon to follow them ultimately
to where they might go. So, people today have
all these wonderful questions that that modern
physics is leading us to. Questions like, are
the way we perceive space and time real? That's
even 100 years old. Albert Einstein said that
space and time could be bent. Time itself could
stop. Then there are things like the holographic
principle. Is it possible that our whole universe
is some sort of embedded information
structure on a two-dimensional surface?
These are amazing ideas and they may turn out to
actually have some physical truth to them. We're
not really sure yet. But sometimes people say,
"Well, are you scientists just absolutely crazy?
How is it that you so blightly get rid of the idea
that time has a direction or that space is real?"
One of the things you have to very deeply
accept to be a scientist is that your senses,
the human brain is just not the best instrument
to perceive the entirety of the universe. I mean,
let's take a simple example. There are many, many
colors of light, energies of light that our eyes
are not sensitive to. There are things like gamma
rays and x-rays, ultraviolet light, radio waves.
Those are all just different colors that our
eyes don't see. The universe has colors that just
weren't built for the human body to perceive. And
when it comes to a mind, a brain. Think about some
of the incredible creatures all around us. I mean,
you know, think about a grasshopper, a marvel
of evolution. It has a brain. It has a central
nervous system. But could you teach a grasshopper
quantum mechanics or general relativity? You know,
could it compose a symphony or or write a novel?
It just can't. I mean, a grasshopper's brain
just doesn't have the complexity to do that.
A grasshopper doesn't perceive those things. What
about a bacterium? A bacterium doesn't even have
a brain, but of course, the the majority of life
on Earth by mass is still bacteria. You have to
have this humility and remind yourself that it's
possible that the human brain is just as far away
from perceiving the way the universe really is as
a grasshopper is to perceiving quantum mechanics.
We are not some beall and endall of perception.
The universe was not designed, not built to be
comprehensible to the human mind. We only see a
little bit of it through the filter of what our
minds can ingest and how they do it. And so we
think that there really is such a thing as space
and time. You know, we we actually think that
there is a past, present, and a future when in
fact there may not be. And this goes all the way
back to Galileo. You know when Galileo was around
the idea that the earth had to be the center.
God made it. So God must have put the earth
in the center. But then it became proven that the
earth went around a larger object, the sun. And I
think almost more beautifully, one of my favorite
observations of Galileo is that when he invented
his little telescope, he he looked at the sky and
he realized that there were stars in the sky you
couldn't see with just the unaded human eye. There
were stars up there that we were unable to see
unless you looked through a telescope, a piece
of technology. And the question was, why would
the universe do that if the universe was designed
for us to see and us to perceive? Why would there
be things too far away and too dim for us to
see? Why are parts of the universe so strange
and so incomprehensible and make so little common
sense? Honestly, why should it be any other way?
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