Listener Questions 55: Time and waves!

Daniel and Jorge answer questions from listeners like you. Get your questions answered: [e-mail]

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Episode Transcript

Speaker 1 (00:08):
Hey, Daniel, do you think going to space will make
you older or younger?

Speaker 2 (00:12):
I think it's going to be a rough trip, so
you'll probably come back feeling pretty worn down and older.

Speaker 1 (00:16):
Yeah, but it's probably pretty exhilerating. So when don't you
come back younger in spirit?

Speaker 2 (00:23):
I mean you might feel wiser, which is just going
to make you feel older.

Speaker 1 (00:26):
Wiser is good. But what does physics say? What does
relativity say? If you go to space, are you going
to get older or younger?

Speaker 2 (00:33):
Physics says you're going to be a tiny bit younger,
probably not enough to compensate for the decades of wear
and tear.

Speaker 1 (00:38):
But you're in space and you're floating. What wears you
down the danger of dying at any moment. Perhaps that's
the same here on Earth.

Speaker 2 (00:48):
The lack of gravity, the intense radiation, and yes, the
danger of dying, which is much higher up in space.

Speaker 1 (00:55):
But if you can gain a second, I mean, isn't
time priceless? It's all we have.

Speaker 2 (01:00):
You gain one second and you lose ten years.

Speaker 1 (01:02):
But what of you? Hi? I'm Jorge, I'm a cartoonist
and the author of Oliver's Great Big Universe.

Speaker 2 (01:21):
Hi, I'm Daniel I'm a particle physicist and a professor
at UC Irvine, and I'm gonna enjoy every second of
life here on Earth.

Speaker 1 (01:28):
Yeah, presumably hopefully even these seconds where we are recording
this podcast.

Speaker 2 (01:33):
Oh these are some of my favorite seconds. Absolutely.

Speaker 1 (01:35):
Would you rather be like floating off an island in
the Pacific drinking some drinks? I mean, this is really cool,
But how does that compare sitting on a private island.

Speaker 2 (01:47):
That would be so selfish, you know, just thinking about
my needs. We're here to talk about physics with everybody
and help everybody understand the universe better. That's so much
more valuable.

Speaker 1 (01:56):
Well, actually, I am sitting in a pool in my
private island right now recording this, So I think I
think that means I win, is.

Speaker 2 (02:03):
Your garage a private island or is it just like
a mental island.

Speaker 1 (02:06):
I'm not a I am floating around somehow.

Speaker 2 (02:14):
You're floating in cyberspace.

Speaker 1 (02:16):
But anyways, welcome to our podcast, Daniel and Jorge Explain
the Universe, a production of iHeartRadio.

Speaker 2 (02:21):
In which we float your brain through an ocean of
crazy physics ideas. We try to take you through the
private island of understanding, hoping to marinate your brain in
these ideas and percolate some of them down into your consciousness.
We think that the deepest questions in the universe, how
it started, how big is it, how it all works,
are things that can be understood and deserved to be understood,

(02:43):
or at the very least, we can explain to you
what we do and do not yet understand.

Speaker 1 (02:47):
That's right, because it is an amazing universe, and we
like to take your sense of wonder on a vacation
siteeing through the universe and the cosmos, looking at things
that are already understood by humankind and things that are
still a huge.

Speaker 2 (03:00):
Because science is a never ending list of questions, We're
always going to be curious about the way the world
works and why it is the way that it is.
And it's those questions that power science. Questions asked by
people working in the very forefront of human knowledge, and
questions asked by everybody looking up at the night sky
or looking down between their toes wanting to understand how

(03:20):
everything works.

Speaker 1 (03:21):
Don't you ever want to take a vacation, Daniel from
asking questions? Well, I guess this podcast is sort of
your vacation, because you're answering questions.

Speaker 2 (03:29):
Vacations are just more questions. Where should we go, how
should we organize it, how should we get there? What
should we eat tonight? There's no end of questions.

Speaker 1 (03:37):
What should we not do? That's my favorite question on
a vacation. But yeah, the universe is full of questions.
Things we can ask about it, things we can wonder
about it, things we can try to find the answers to,
and sometimes on the podcast we like to answer these questions.

Speaker 2 (03:50):
If you have questions about the nature of the universe,
how things work, or if ideas aren't just not clicking
in your mind right to us, we would love to
help you understand it. Answer all of our emails to
questions at Danielandjorge dot com. And sometimes I get a question,
I think, ooh, I bet other people want to hear
the answer to this, or I want to hear what
Jorge has to think or joke about this topic. So

(04:13):
then we answer them here on the podcast, so do.

Speaker 1 (04:15):
They on the program we'll be tackling listener questions number
fifty five. Fifty five doesn't seem like a very big number,
but we are pretty deep into our production run.

Speaker 2 (04:31):
Fifty five is a pretty big number. There are lots
of podcasts out there that don't even have fifty five episodes.

Speaker 1 (04:37):
Fifty five seventy five.

Speaker 2 (04:40):
Time to take a vacation.

Speaker 1 (04:43):
But yeah, we'd like to ask our listener questions, and
so we have three great questions here about space travel,
but the nature of light, and about quasi particles, not
queasy particles, those are particularly uneasy.

Speaker 2 (05:00):
We will not be talking about Burbon's today.

Speaker 1 (05:02):
Yeah, or bar Fonds. But yeah, we have three awesome questions,
and so let's dive into our first one. This one
comes from Dan.

Speaker 3 (05:10):
I'm Dan, and I have a question about space travel
and time. If we're able to send a spaceship to
Mars and back, wouldn't the astronauts be a different age
than the rest of us when they returned, And would
the difference be caused by how fast they traveled or
how long they were gone?

Speaker 1 (05:26):
Interesting question from Dan. I guess the main thing is
is that a lot of people maybe associate space travel
with differences in time, like the famous twin Paradix.

Speaker 2 (05:36):
Yeah, it sounds like Dan is planning a vacation in
Mars and he's wondering how many shirts he's got a pack,
how long will that trip be for him?

Speaker 1 (05:44):
Yeah, I guess if he's not aging, he won't need
as many shirts, or he doesn't need to go to
that rejuvenating spot on Mars.

Speaker 2 (05:51):
Or maybe he's wondering about renting his place out while
he's gone. If he's gone for one year, does he
need to AIRBNBA for two years? Or how does that
all work?

Speaker 1 (05:59):
It's confusing here on Earth if you're changing time zones.

Speaker 2 (06:01):
That's right, exactly. But then it is right to worry
about this because clocks do run differently out in space
and on space travel, but for two reasons, both of
which will affect the answer.

Speaker 1 (06:13):
Interesting. There are multiple factors here that the universe throws
at you.

Speaker 2 (06:17):
Yeah, there's two different ways that time can flow differently.
One is based on relative velocity moving clocks run slow,
and the other is an absolute one. It's just based
on space curvature. When space is bent, time is also bent,
so clocks tend to run more slowly when space is
more curved. These are two separate effects with different causes

(06:40):
and importantly different behaviors, but both of them will cause
clocks to run more slowly.

Speaker 1 (06:44):
I meaning that time depends not just on how fast
you're moving, which is maybe the one people are more
familiar with, but also just how close you are to
heavy things, things that bend space and time, including.

Speaker 2 (06:54):
The Earth, including the Earth, and including the Sun. This
is why, for example, if somebody is you're a black hole,
distant observers will see their time running super duper slowly,
not because they're moving at some high speed, but just
because they are in place of high curvature. They are
near a big, massive object, and time will run more slowly.
That's called gravitational time dilation. So there's velocity based time

(07:18):
dilation and gravitational time dilation.

Speaker 1 (07:22):
Well, so then when you're leaving Earth, you're basically experiencing
both at different degrees and at different times, right, because
you're leaving the Earth, which is has a gravitational field,
but you're also going potentially really fast out there in space.

Speaker 2 (07:35):
Yeah, exactly, And so it depends a little bit on
the details, but we can do some approximate calculations to
give Dan a rough answer.

Speaker 1 (07:42):
All right, well, let's start with I guess the first
factor velocity. How fast do you think Dan is going
to Mars?

Speaker 2 (07:49):
This is a good question. It depends a lot on
what you assume, but I thought, let's crank it to
the extreme. Let's think about like the fastest possible trip
you could make to Mars to have the most dramatic
impact on time.

Speaker 1 (08:01):
You mean, like to calculate the speed, We're just going
to draw a straight line from here to Mars.

Speaker 2 (08:04):
Yeah, and we're also going to assume that we have
super heavy duty engines and excellent power, because you could
get to Mars really slowly, Like you could go to
Mars at like walking speed, it would take you a
zillion years and you'd have no time dilation effects. Or
you could get to Mars super duper fast if you
have really powerful engines that push you up above a
tiny fraction of the speed of light, then you'd have
more time dilation effects. So the time dilation effects depend

(08:27):
on your top speed in the journey, which depends a
little bit on the technology you have to get to
that top speed.

Speaker 1 (08:34):
But in reality, I guess when we send things to Mars,
they usually take this roundabout way, right, Like you try
to use orbital dynamics and you try to use maybe
the gravity of other planets to assist you and push
you along, and so it takes a while but even
though you're going pretty fast, Yeah, it.

Speaker 2 (08:47):
Takes a while. It can take like six months to
get to Mars. And you are going pretty fast relative
to like the speed of a Lamborghini on Earth, but
you're not going very fast relative to the speed of light.
And that's the issue. And the speed of light is easy,
super duper fast, and to see real time dilation effects,
you got to get somewhere near the speed of light,
and that's pretty challenging. So I thought, how fast can

(09:07):
we get to Mars to maximize this effect?

Speaker 1 (09:10):
I see you thought that it was not an interesting answer,
So let's crank it up.

Speaker 2 (09:13):
Yeah, let's crak it up.

Speaker 1 (09:14):
Crack it up and make it more fun.

Speaker 2 (09:16):
Yeah, let's assume Elon Musk or somebody else develops like
a really powerful engine, one that uses like antimatter fuel,
that uses like antiprotons or anti electrons that totally annihilate
perfectly efficiently into energy and can pour that directly into
the acceleration of your spacecraft.

Speaker 1 (09:35):
It doesn't have to be an antimatter engine. It just
has to be a powerful engine, right.

Speaker 2 (09:38):
Just has to be a powerful engine. But you want
an efficient fuel source so that you minimize the amount
of fuel you have to bring along, so the fuel
is mostly pushing the spaceship and not the other fuel.

Speaker 1 (09:48):
I feel like you're worrying about a real life consequences
in an imaginary scenario. Like I guess maybe you calculated
to the distance to Mars.

Speaker 2 (09:57):
What's that distance at the closest approach the Earth to
Mars distance is about half of the Earth the Sun distance,
So it's like forty five million miles.

Speaker 1 (10:06):
So we have a distance, and so how did you
calculate how fast we need to go to get there
in a reasonable scenario.

Speaker 2 (10:13):
Well, I imagine that we could build an engine out
of anti matter, And I thought, what are the practical
limitations for launching that kind of ship? But how much
engine power could it produce? And you know, if you
spent like a few years generating antimatter, you'd have enough
engine power at launch that's like more than a thousand
times the electrical power output of the United States, which

(10:33):
would require like five tons or so of antimatter, which
is totally unrealistic. But if you did that, then you
would be able to get to Mars in just a
couple of days. Like that kind of super powerful engine
would get you up to like a third of one
percent of the speed of light for a pretty zippy
trip to Mars.

Speaker 1 (10:51):
Would that run into like acceleration limits, Like our bodies
can only tolerate so many g's.

Speaker 2 (10:56):
That's right, humans can only tolerate like eight to ten
g and even that's pretty extreme. So I was assuming
we have like super robust astronauts that can tolerate about
eight to ten gs.

Speaker 1 (11:06):
Okay, so then you calculated the trip for Dan and
you get up to about point to eight c's.

Speaker 2 (11:13):
Yeah exactly. Then that's at the halfway point because you've
got to speed up and then you're going to turn
around and slow down so that when you get to
Mars you're not just zipping by it at half a
percent of the speed of light, because that's kind of
beside the point. So this top speed is at the
halfway point.

Speaker 1 (11:28):
Now, this is a very small percentage of the speed
of light, less than a third of a percent. So
I'm guessing maybe time didn't move that much slower for
Dan because of the speed.

Speaker 2 (11:37):
Yeah exactly. And relativity is very nonlinear, so if you're
still at very low velocities, there's basically no effect. The
effect gets stronger as you get closer to the speed
of light. As you get very close to the speed
of light, it gets much more dramatic. So when you're
going at this pretty respectable speed compared to Lamborghinians on Earth,
but still very very slow compared to photons.

Speaker 1 (11:57):
How fast are we going relative to a Lamborghini.

Speaker 2 (12:00):
Yeah, so that's about eight hundred and forty thousand meters
per second, which is something like one point eight million
miles per hour, so a lot faster than a Lamborghini.

Speaker 1 (12:12):
Yeah, by a large amount. But even though you're going
over a million miles per hour, the time dilation is
not dead much.

Speaker 2 (12:19):
The time dollation factor is one point zero zero zero
zero zero four, meaning like every million seconds somebody traveling
at that speed experiences four seconds fewer at the peak speed.
At the peak speed.

Speaker 1 (12:34):
Yeah, but Dan is not going at the peak speed
the whole time. So like if he goes around back,
how much time is a younger relative to his twin
who was born at the same time here on Earth
and that didn't go.

Speaker 2 (12:43):
If he goes there in forty eight hours and back
in forty eight hours, that's like roughly one hundred hours,
which is not even a million seconds, so the difference
is going to be less than a second overall.

Speaker 1 (12:53):
But he's also had to accelerate up to the speed
and accelerate down to zero, so it's probably even less
than that, maybe maybe like a tenth of that.

Speaker 2 (13:01):
Yeah, it's going to be less than a second for sure.

Speaker 1 (13:03):
So Dan's gonna go to Mars come back. He's going
to be at eight to ten g's the whole time,
and he'll only be younger by about less than a second.

Speaker 2 (13:13):
Yeah, less than a second, exactly. That's only considering the
velocity effects.

Speaker 1 (13:17):
Right right, like starting from orbit or something.

Speaker 2 (13:19):
Mm hmm, exactly, that's not considering the gravitational time dilation.

Speaker 1 (13:24):
All right, Well let's get into that. What are the
gravitational effects of a time due to gravity?

Speaker 2 (13:29):
So there's two effects here to think about. One is
that you're leaving Earth's gravity and time passes more slowly
when you're close to earth gravity. We know this because
like satellites in orbit that keep our GPS systems in sync,
their clocks run faster than clocks on Earth. This is
something we've measured, so we know this very very well.

Speaker 1 (13:47):
They've measured this in with mountains too, right, like you
can tell the difference between someone at the bottom of
a mountain and a clock running at the top of
the mountain.

Speaker 2 (13:54):
Yeah, exactly. They have atomic clocks that are like two
meters apart in altitude, and they can tell the difference
in how they run. It's very very precise. It's super awesome.

Speaker 1 (14:02):
Yeah, which means like your feet are moving through time
slower than your head if you're standing up.

Speaker 2 (14:07):
Yes, but the size of this effect is tiny. Like
time passes on Earth more slowly than out in deep
space by like point seven parts per billion. That means
in a billion seconds, time on Earth will have ticked
by point seven seconds more slowly.

Speaker 1 (14:23):
So if Dan just went up to orbit Earth's orbit,
we would be a little bit younger, but not by much,
Like I have a part per billion.

Speaker 2 (14:30):
Yeah exactly. A billion seconds is like thirty two years,
So if you've been thirty two years, like in deep
deep orbit, then your clock will have run faster by
one second.

Speaker 1 (14:39):
So it's a very negligible effect.

Speaker 2 (14:41):
It's not I don't know if it's negligible, and you
can measure it with very precise devices, but it's real.
And the interesting thing is that Mars has lower gravity
than Earth. Right, it's a smaller planet, so on the
surface the gravity is not as intense, and so this
same effect on Earth that's like point seven parts per
billion is only point one four parts per billion on Mars.

(15:02):
So if you go to Mars and spend a lot
of time there, your clock will run faster than clocks
on Earth because you're not as deep in a gravity.

Speaker 1 (15:10):
Well, well you're aging faster in Mars.

Speaker 2 (15:13):
You're aging faster on Mars exactly. But that's actually not
even the biggest gravitational effect. Mars is further away from
the Sun, so the Sun's gravity is weaker at Mars
than it is on Earth. This is actually a bigger
effect than the difference between Earth and Mars. Sun's gravity
causes a seven parts per billion effect on Mars and
a ten parts per billion effect on.

Speaker 1 (15:35):
Earth, meaning from the suns to gravity, you're aging faster
in Mars.

Speaker 2 (15:39):
Also, yeah, that's right, you're aging faster on Mars because
its gravity is weaker and because you're further from the
Sun's gravity. Overall, this effect is like six parts per
billion on Mars.

Speaker 1 (15:50):
Okay, so then what's the grand total for that? It
seems like he's gonna gain a little bit of time
due to velocity going to Mars and back, but he's
gonna lose a little bit of time by being further
away from the Sun and by being around a planet
that's smaller. What's the grand total.

Speaker 2 (16:05):
Well, it depends on how much time he spends there. Right,
If he just goes there and back, there's basically no
effect from gravitational curvature. But if he goes there and
lives there for like a thousand years, then he's going
to accumulate some effect from the curvature. So it depends
on how much time he spends there.

Speaker 1 (16:20):
On Mars, depends on how long he books that Airbnb exactly.

Speaker 2 (16:24):
But the overall story is that these are tiny, tiny effects.
You'd be a challenge to measure these things. You'd need
very precise devices. But in the assumption that we could
build crazy powerful engines that get us to Mars in
two days, then the time dilation effects are going to
be the most dramatic. But even those are parts per million.

Speaker 1 (16:44):
Yeah, they're super tiny, but what's interesting is that they're there, right,
They're measurable. Like if we synchronize our clocks and you
went out there and came back like our clocks would
be off.

Speaker 2 (16:53):
Yeah, and it really reveals that we live in an
unusual set of circumstances. You know, we're not living near
very strong gravity, not traveling at very high speeds, and
so our clocks are mostly just synchronized. But there are
places in our universe with extreme gravity where things are
traveling at very high speeds relative to each other, and
their clocks are much creasier.

Speaker 1 (17:13):
All right, Well, I guess then the answer for Dan
is that he's much better off vacationing here with me,
my private island floating at the pool, than by going
to Mars. I think my mojito will probably take more
time off with his overall age than then going to
space and then with an antimatter engine.

Speaker 2 (17:30):
Yeah, that's right, His mojito will melt one second slower
after a million mohidos.

Speaker 1 (17:35):
Well, it'd be hard to drink it going at eight
to ten g's. So again, come join me, Dan, This
is much more comfortable here.

Speaker 2 (17:45):
Dan, you just scored an invitation. Wow.

Speaker 1 (17:47):
Yeah, of course I don't know your last name, Dan,
so I'm just gonna ignore all emails from Dan's I
don't I know which one asked the question, where's this Dan, Dan?
Did I just invite you to my island?

Speaker 2 (18:04):
Yes? This is my alter ego, Dan.

Speaker 1 (18:07):
This is your twin, the twin that I wanted to
go to space.

Speaker 2 (18:10):
When I take off my glasses, I'm Dan.

Speaker 1 (18:13):
It's the twin parad doctor. All right, Well, let's get
to our two other questions. We have an awesome question
here about the nature of light and one about quasi
particles and crossword puzzles. So we'll get to that clue.
But first, let's take a quick break. All right, we're

(18:41):
asking listener questions here today and inviting people to our
private island. Apparently. All right, we have a great question
here from John Lopez about the reality and nature of light.

Speaker 2 (18:53):
Hi, Daniel len Jorge.

Speaker 4 (18:55):
My question is what is the physical reality of a
wavelength of light? Like, what is it like to have
a wavelength of nanometers versus a wavelength of tens of
meters long?

Speaker 2 (19:06):
On the graph?

Speaker 4 (19:07):
I know we represent it as the pigs and valleys
all stretched out, but what does this mean in real life?
For example, in microwaves, mesh holes block microwaves because their
wavelength is longer than the size of the holes. The
visible light passes through because the wavelength is so much smaller.
So in reality, in wavelength must be something different than

(19:31):
stretched out pigs and valleys, because otherwise it seems like
both could pass through the holes.

Speaker 1 (19:37):
Just fine, All right, great question. Basically, what exactly is light?
Is the question? Can you shed some light on this topic.

Speaker 2 (19:46):
I love this question because it's clear to me that
John is trying to like build a mental picture in
his Mind's trying to think about what happens in the
universe and trying to describe it mentally, thinking about like
are the photon zigging and zagging is like really wiggling sideways?
What is actually going on? How to think about this stuff?
It's really important that you build this mental model in
your head. That's what physics is. So I love hearing

(20:08):
him doing physics in his mind, trying to link it
all together to get a coherent picture. It's perfect.

Speaker 1 (20:13):
Yeah, I guess he's trying to get it like an
intuitive sense of what light is like, Like if you
were shrunk down to the small level of quantum level,
what would it be like to experience light?

Speaker 2 (20:22):
Yeah, that's a great question, and you know, fundamentally we
don't know what light is. Quantum mechanical things are very
hard to visualize and to think about. But John's question
actually is more about like classical physics, like thinking about
light in terms of electromagnetic waves, you know, the peaks
and the valley and the wiggles, and why that means
your microwave is not frying your brain even if you

(20:44):
stick your nose against it while you're cooking your popcorn
that you know of, Maybe that's why my brain is fried.
Oh my gosh.

Speaker 1 (20:52):
Yeah, you're too impatient from the popcorn there to go
to Mars, take a vacation, come back. It'll be ready
for you.

Speaker 2 (20:59):
And I think is a lot to learn in terms
of how to think about light as wiggles in the
electromagnetic field, because I hear a lot of misconceptions out
there and actually a lot of mistakes in popular descriptions
of how light works. So I think we can clear
up a lot of those misunderstandings, even just in the
classical picture, ignoring quantum effects, not thinking about photons, just
thinking about light as an oscillation in the electromagnetic field.

Speaker 1 (21:22):
WHOA, Okay, So this is confusing me a little bit
because I think maybe what I know what a lot
of people know is that light is both a particle
and a wave, right Like, that's kind of one of
the dualities that physics found out at some point. So
you're saying, let's ignore the fact that it's a particle,
or are we just going back in time and forgetting
quantum physics.

Speaker 2 (21:40):
We're going back in time and forgetting quantum physics because
we don't need quantum physics to explain this effect. The
reason your microwave works and the reason that doesn't fry
your brain can be explained using purely classical physics.

Speaker 1 (21:51):
So when you're talking about the wavelength of light as
a wave in classical physics, is that the same wave
as when you're talking about quantum physics and things having
a wave function for example?

Speaker 2 (22:01):
There's an evolution there from one idea to the other idea. Absolutely,
But we don't need to go into quantum physics for
this answer. And that's all digression. And you might think,
hold on a second, but you know the world is quantum,
how can you do that? But you know, physics is
all about making approximations. None of our theories of the
universe are exact and perfect. They ignore quantum gravity, because
we don't understand it. But you only need to apply

(22:22):
the physics. You need to answer the question like if
somebody asks, is this canniball going to make it over
that castle wall? You don't need to do quantum calculations.
You just need F equals MA. So part of doing
physics is applying physics judiciously. And in this case we
can just think about like Maxwell's understanding of photons and
light as waves in the electromagnetic field.

Speaker 1 (22:41):
Well, I imagine John is curious and it seems like from
his question he is about the nature of light. Yeah, so,
like is light a wave? Is light a not a wave?
We can think of it as not a wave or
as a wave or only a wave. What is the
classical picture of light?

Speaker 2 (22:55):
Yeah? So the classical picture of light. Maxwell's idea from
like one hundred and fifty years ago before quantum mechanics
is that light just wiggles in the electromagnetic field, like
an electron has an electric field, right, and if you
wiggle an electron, the field wiggles with it. That's why
wiggling electrons in an antenna will generate waves like radio waves,
which are electromagnetic waves and other charge particles wiggling more

(23:20):
quickly with higher frequency will generate waves in the electromagnetic
field that have higher frequency. Some of those are visible
light or even ultraviolet light. So all kinds of light
and radio waves, all the electromagnetic radiation are just wiggles
in the electromagnetic field. That's the classical picture.

Speaker 1 (23:39):
And the electromagnetic field in this case is not the
same as the electromagnetic quantum field that we've talked about before.

Speaker 2 (23:45):
Well, you can quantize this whole theory, right, You can
say the electromagnetic field follows rules of quantum mechanics and
so only some solutions are valid and there's minimum oscillations.
But in classical physics, it just follows standard wave equations
and it's just the electromagnetic fields. It's the same field.
It's just like which equations are using to describe it,
and are those quant mechanical or not. And here we

(24:06):
don't need to get into the quant mechanics. But it
is important to understand what that field is. Right. Sometimes
we imagine a field is this like weird physical thing
that fills space, But really what it is is a
set of numbers at every point in space. Like if
you think about an electric field. You think, well, it's
strongest near the electron, it's weaker further from the electron. Right,
there's values to the field, and those values vary across space.

(24:29):
That's how you can have a wave propagating through it.
It's like stronger here and weaker there, and stronger here,
and those values are moving through the field.

Speaker 1 (24:37):
Sort of, I guess, like a sound wave kind of,
but instead of there being like a physical air particles,
imagine they're just being nothing there, just mad.

Speaker 2 (24:45):
Yeah, exactly, just numbers. Imagine those numbers then moving through space,
Like this location is a zero and the next location
is a two, and then that two is moving through space,
and now a different location has that too. That's like
a pulse moving through a field.

Speaker 1 (24:58):
But is it too moving through space or is it
too somehow like exciting the number besides it making it
sort of like the wave in a stadium when you're
watching a game or something.

Speaker 2 (25:08):
Yeah, it's more like the wave in a stadium. Right.
The energy is moving from one spot in space to
another spot in space. It's a different place in the
field that now has that energy.

Speaker 1 (25:17):
Okay, so then before quantum physics, we thought all light
is just like the wave in a stadium. It propagates
that way. And I guess that makes sense for like
a light bulb, which is emanating light in all directions.
But then how do you think about it as a
for a laser. Is it just like one row of
the stadium is carrying the wave?

Speaker 2 (25:37):
Yeah, just like one row of the stadium exactly. And
there's an important point here. When you're visualizing that laser beam,
that photon flying through space, you probably have in your
mind some sort of like sine wave, like it's wiggling
sideways as it moves through space, right, So what is
actually wiggling sideways there? Does the laser actually have like
a sideways extent? The answer is no. The light moves

(25:57):
in a straight, perfect line. Make a laser beam that
has like zero width and is perfectly parallel, then the
light moves in a narrow line. It doesn't wiggle sideways.
What's wiggling are the values of the field, right, Because
electromagnetic fields are slightly more complicated than just numbers in space.
There are vectors in space. So now at every point

(26:19):
in the field, you don't just have a number like
a two. You have a number and a direction and
so that's what's oscillating. As the light beam moves through space,
you have like an arrow a vector from that point,
and that vector can change directions and magnitude. So when
they depict the photon like wiggling sideways, it's not physically
moving to other points of space. It's just that the

(26:40):
arrow of the electro or magnetic field is now pointing
in a different direction.

Speaker 1 (26:44):
Like its value as a direction sort of perpendicular to
the direction of the travel. Yeah, exactly is that direction changing?
Like for a regular pulse of light, That direction doesn't
really change, does it?

Speaker 2 (26:55):
Absolutely? It does, And that's what the wavelength is, right.
The wavelength is how far the life light travels before
the arrow comes back to where it was before.

Speaker 1 (27:03):
Wait, as it's going, as the pulse is going, it's
changing in both the value and it's rotating.

Speaker 2 (27:08):
That's right, because it's shifting between its electrical and magnetic components.
At one point, it's purely electrical in one direction, and
then that electrical component is shrinking as the magnetic component
is growing in a perpendicular direction. Those two fields are
always perpendicular to each other. Which direction does it rotate?
That depends on the polarization of the light. Light can
be polarized in lots of different directions, so it could

(27:30):
not rotate, or it could rotate left, or it could
rotate right. That's a whole other issue. We talked about
that in another podcast, the polarization of light. But here
we can just imagine the simplest scenario. Imagine it's not polarized.
The electric field is pointing in one direction, then it
shrinks to zero as the magnetic field is created. Then
it goes negative, so it points in the opposite direction,
and then it comes back. The wavelength of the light

(27:51):
is how far it's traveled between those peaks of the
electric field.

Speaker 1 (27:55):
All right. So then John's question was like, what does
it mean to have a nanometer wavelength and wavelength that's
maybe tens of meters long. Does that mean like the
wiggles are just shorter.

Speaker 2 (28:06):
Yeah, it just means the wiggles are shorter. So if
you generate microwave radiation, you know, with microwave wavelength, that
means like the light travels a very short distance between
those peaks and the electric field. If it's like radio
waves with tens of meters of wavelength, then it means
that You can start off with like your electric field
peaking at one place, and then it's literally tens of
meters before it osclates down and then back so that

(28:29):
it has the electric field pointing in the same direction. Again,
that really is something physical.

Speaker 1 (28:35):
But in both cases it's going at the speed of light.
It's going at the same speed. Is just that's right,
Spiraling or wiggling or changing at a different scale.

Speaker 2 (28:44):
That's right. The frequency is different, but the overall speed
of the wave is the same. It's still moving at
the speed of light. Just how many wavelengths happen when
you go one hundred meters.

Speaker 1 (28:54):
But again, I feel like this is kind of the
classical view. You preface this as being the classical view.
Is this actually what's going on? And does this actually
tell us what light is? Or is this just some
mathematics that we came up with that helps explain what's
going on with life?

Speaker 2 (29:10):
You know, some mathematics that we came up with that
helps explain what we see, could describe all the physics.
You know, we don't know what's really going on at
any level philosophically. All of our theories are just some
mathematics that help us explain what's going on. We don't
know what's true. We think that none of our theories
are true.

Speaker 1 (29:26):
Well, there's a little bit of a difference, right, Like
for example, like if you're dealing with waves in the ocean,
you can use wave equations describe those ways, but really
you know that underneath there's you know, little particles of
water bumping against each other and propagating energy and pulling
on each other. Right, So it's like the wave equations
work and they start tell you what's going on, but
they maybe don't tell you about the nature of what's

(29:48):
going on underneath.

Speaker 2 (29:49):
That's right, but sometimes they're actually better at answering questions.
Depends on the question you're asking. If you're asking questions
about waves and why they reflect or why they break,
then the answer is better described in terms of the
macroscopic why the waves break. It's because as they approach
the shore, part of them get dragged. You can't really
answer that question using the microscopic picture of waves as
tiny particles. You get lost in the details. So the

(30:12):
answer depends on the question you're asking. Which theory of
physics you want to use, which approximation, which details you
want to sweep under the rug depends on the question
you're asking, because fundamentally we don't know the deepest theory
of the universe, So in that sense, we can't answer
any questions. We always got to zoom out to some
level and give the appropriate answer based on the question.

Speaker 1 (30:30):
Right right. But I feel like John's question here is
trying to get us to like, what is the nature
of things? Right? Like, I feel like we've just repeated
his question thus far, which is like, yeah, life has
different wavelengths, and some of them are shorter, some of
them are longer. Like, then what would you say then,
is the relationship between these oscillating electromagnetic fields and arrows

(30:51):
and maybe what we know now about the quantum particle
nature of things?

Speaker 2 (30:56):
I mean, I think maybe you're more curious about the
quantum nature John wanted to know about micro wave But
you know, in terms of the quantum nature, quantum theory
of electrodynamics is a natural successor of classical electrodynamics. Like
you take Maxiwell's equations for electromagnetic fields and you quantize them.
You say, well, they can't just have any value, they
have to have limited values, And you end up with

(31:16):
photons packets minimum bundles of energy in the field instead
of arbitrary size energies. In classical theory, you can have
as dim light as you want, but in quantum theory
you can't. There's a minimum there. It's because there's additional mathematics.
So there's definitely a relationship between like the wave function
of a photon and the classical wave length of a

(31:38):
beam of light. And we're actually going to talk about
that in an episode coming up soon where we talk
about like how long is a photon? But I think
to answer John's question here about like why can mesh
holes block microwaves, we only need to use classical physics.

Speaker 1 (31:52):
All right, Well, let's answer that question then, because he
asked that directly, like why is it that some waves
can pass through holes and others not?

Speaker 2 (31:58):
This is a really cool ques question, and actually a
very difficult one. A simpler version of the question is
much more simple, like why does a metal box at
all block radiation? The microwave is encased in a metal
box to protect you from the radiation, but you might wonder,
like how do the metal box block radiation? Like when
you get into an elevator, why you have no cell
phone signal. It's the same question. And this is a

(32:20):
simple process called a Faraday cage. Anything that's a conductor
that has electrons roaming around in it. If you try
to pass an electrical signal through that conductor, the electrons
inside the conductor are going to rearrange themselves to basically
cancel out that electromagnetic radiation. Because there are electrons free
to move. The radiation creates electric fields that pushes the

(32:42):
electrons to counteract that electric field. So you basically can't
have an electric field inside a conductor. And so you
build a metal box. You can put your phone inside,
for example, it'll get no signal and also nobody can
spy on you. So that's how a Faraday cage works
if it has no holes in it.

Speaker 1 (33:00):
Because the box, i guess, is made out of stuff,
and that stuff blocks the light trying to get in.

Speaker 2 (33:05):
Yeah, exactly. And it's not just that it blocks light, right,
you know, materials can block light, but metal can also
block invisible radio waves that could pass through walls, they
just can't pass through metal.

Speaker 1 (33:16):
So for a given metal box, there's no wave of
light that can penetrate it.

Speaker 2 (33:21):
It depends on the wavelength and the thickness of the box,
Like there is a depth that electromagnetic radiation can penetrate
into various conductors. So like a super high intensity beam
or the right wavelength might be able to penetrate some
metal boxes depending on their thickness. But for a perfect conductor,
then yes, you have to have zero electromagnetic field inside

(33:42):
of it.

Speaker 1 (33:43):
Okay, So then what happens in like in my microwave
that if you punch holes in this box?

Speaker 2 (33:48):
Yeah, so you might wonder, Okay, there's holes in the box.
Why can't like go through the holes and be blocked
by the mesh?

Speaker 3 (33:53):
Right?

Speaker 2 (33:54):
Am I just getting like patchy radiation through the holes? Amazingly,
You're not. Even though there are holes in that none
of the light gets through.

Speaker 1 (34:02):
Well, some light gets through, because I can see inside
my microwave.

Speaker 2 (34:04):
That's right. None of the microwaves get through. The light
actually does get through. And so now it depends on
the frequency of the light. And I think in John's question,
he's wondering, like, is that because the light is like
oscillating sideways and so it can't fit through the mesh.
And the answer to that is no, that's misleading, right,
light is not oscillating sideways. Microwaves or visible light in

(34:25):
right through the center of one of those holes. They
can both fit through the hole. It's not a physical issue.
They're not like bumping up against the size of the hole.
It's a different effect. That's filtering out the microwaves and
not the visible light.

Speaker 1 (34:37):
So then what is that effect?

Speaker 2 (34:38):
Yeah, so what's going on there is a little bit
more subtle. What has to happen is you have to
have zero electric field inside the mesh. Like everywhere you
have metal, you have conductor, you have electrons. That's going
to zero out the field. Now you need to think
of the light not as a particle, not like as
one little thing that's like a tennis ball flying through
the hole, but like a wave. And when a wave
meets a new kind of material, like when light it

(35:00):
hits glass or when light hits water, right, then you
have to find a solution that satisfies all the wave
equations at the boundaries. What that really means is that
the waves have to line up. Remember we talked about
the waves as wiggles in the field. Well, you can't
have weird discontinuities in the field. They have to match
up at that boundary. This is why, for example, light

(35:21):
bends when it goes from air to glass or water,
because the different medium means a different index of refraction,
which means a different wavelength. So for two fields to
match at the boundary when they have a different wavelength,
one of them has to be bent relative to the
other at a different angle. The same principle applies here
with the case of the mesh, but it's much harder

(35:42):
to find solutions on both sides of the mesh because
the mesh requires the field to be zero at so
many places on it, and in this case, requiring that
the electromagnetic field is zero inside the mesh creates these
interference effects that can slowt any electromagnetic fields below a
certain wavelength on the other side of the mesh.

Speaker 1 (36:03):
Okay, you lost me a little bit there. I wonder
if we've lost our listeners. So maybe maybe a more
simple scenario. Let's say I'm a markwave and I'm flying
through space and I see a big metal sheet in
front of me with a little tiny hole in it.
Now earlier saying that I should be able to go
through it because I don't really have any width to
me right like, the wavelength of my light is not

(36:24):
sideways to me. It's more like how often I'm pulsing?
Right A, Technically I could still go through that hole.

Speaker 2 (36:33):
You have no width to you.

Speaker 1 (36:34):
Yes, yeah, I'm a beam of light. If I'm a microwave,
why can't I go through that little hole?

Speaker 2 (36:39):
Yeah, it sounds like you should be able to. But
you're actually using a particle picture, right. You're thinking of
yourself as having one location and flying through space, But
we're talking about waves, and waves have to have solutions
everywhere in space. So you have to find a solution
that satisfies all the equations everywhere in space. It's not
about an individual particle flying through space. It's like a

(37:00):
steady state. You have like waves in this box and
they're bouncing around. Can any of them escape?

Speaker 1 (37:05):
Didn't we talk about like a single beam of light
being like one row in a stadium that's doing the
wave like it's super thin. Couldn't that wave go through
a little hole?

Speaker 2 (37:15):
Yeah, it's one row, But you have to think about
the whole row, right, You have to think about the
equations of the whole row and the wather. The equations
work on one side of the mesh and the other
side of the mesh. It's a little bit unsatisfactory because
it's all about these interference terms, satisfying the equations. It's
hard to get a physical intuition on it. The best
I can do is to remind you that when you
approach that mesh, you're not just flying through it, right,

(37:38):
You're inducing electromagnetic fields in nearby and so you need
a solution on both sides, and that effectively induces light
in lots of different directions. And there's the requirement that
the electric field be zero inside the mesh, means that
you can't have wavelengths that are longer than that because
it will hit that zero requirement and get canceled out.
This is the same issue with like thinking about how

(38:00):
like it's bent at an interface, Like, how does that
actually happen? How does an individual photon get bent? How
all the photons bent the same way? It's the photon
picture that's the problem. Is really there's a wave description here,
and it's the solutions to the wave equations that dictate
what happens. So the problem is thinking about it in
terms of like a little particle flying through.

Speaker 1 (38:19):
You're right, that is a very unsatisfied. It's hard to
tackle in a podcast, but I think what you're saying
is that instead of thinking about this in a time
sequential way, like I'm in one side of the wall
with a hole in it, and then later I'm on
the other side of the wall with the hole in it.
You because you're talking about waves, you kind of have
to think about it all at the same time, Like

(38:40):
the before and the after all had to be part
of the same physical consistency. And somehow if my wavelength
is too big, I just can't go through that hole,
Like there's no solution that puts me in both sides
of the hole in the timeline of the universe.

Speaker 2 (38:55):
Yeah, exactly. And you can actually escape this requirement a
tiny bit if you send little pulses, Like if you
said individual tiny little pulses are microwaves, some of them
will get through, but it's when you have a consistent
source of the microwaves. It's like the previous ones are
canceling out the future ones, and they're all interfering with
each other in just the right way to cancel any
waves that make it through. Individual pulses actually can get

(39:18):
through a little bit, so you're exactly right. You have
to think about, like the steady state solution, all the
waves working together, can any of them make it through?
So it's really it's an interference.

Speaker 1 (39:27):
Effect, like the before and the after at the same time.
So I think to answer John's question, I mean he
is asking, I think about the physical reality of wavelength
and what's really the nature of these things. Maybe the
answer is that the you know, light has this wave nature,
and this wave nature is not just in space, it's
also in time. And so for whatever reason, the nature
of light means that you have to take into account

(39:49):
the path and the future all at the same time,
and it all has to work together with the effects
of the electromagnetic interactions with the wall exactly.

Speaker 2 (39:57):
And this wave picture of light really can't explain all
these kinds of effects. Light bouncing off of water, light
refracting in water, and also light being trapped by Faraday cages.

Speaker 1 (40:08):
Well, I feel like it's a bit of an unsatisfied
answer for John.

Speaker 2 (40:10):
Here.

Speaker 1 (40:11):
Basically the answer is because you can't.

Speaker 2 (40:14):
The answer is that, like the mental picture of light
moving as a little particle isn't really the right way
to think about this problem. And unfortunately you need different
mental models to solve different problems. There's no single unifying
understanding of physics that we can use in every situation.

Speaker 1 (40:29):
All right, well, thank you John for that question. Now
let's get to our last question of the day, and
this one is about quasi particles and crossword puzzles. So
let's dig into that, but first let's take another quick break.

(40:53):
All right, we're answering questions here today, and our last
question comes from Peter.

Speaker 5 (40:58):
Hi, Daniel and Jorge from Winchester, Massachusetts. My question comes
from a crossword puzzle. The clue was type of quasi
particle and had to be seven letters. The answer turned
out to be plasmon p L A S M O N.
Could you explain what that is?

Speaker 2 (41:15):
Thank you?

Speaker 1 (41:16):
All right, interesting questions here. Peter was doing a crossword
puzzle and he came across an interesting solution, which is
a plasmon, and so he's wondering what is that? Or
maybe Peter just made a mistake on his crossword puzzle.

Speaker 2 (41:36):
No, I think he's exactly right. A plasmon is a
quaniti particle and it has seven letters. So boom boom boom.

Speaker 1 (41:41):
Oh all right, well, I would have to look at
the whole crossword puzzle to double check that answer. Sometimes
crossword puzzles have multiple answers.

Speaker 2 (41:49):
Hmm, that's true. Yeah, there might be many quasi particles
that satisfy this.

Speaker 1 (41:53):
Yeah. No, they actually designed I think they even call
them like quantum crossword puzzles where there's like multiple solutions
that can fit.

Speaker 2 (42:02):
Oh my gosh, like crosswands interfering crosswands. Yeah.

Speaker 1 (42:06):
Yeah, and they have wavelengths and time moves slower. That's
the whole thing. All right, Well, it sounds like plasmon
is a real thing. What is it, Daniel, And just
to spell it out, Peter spells it out, plasmmm.

Speaker 2 (42:22):
A plasmon is a quasi particle. It's like an oscillation
in plasmas that we can describe using the mathematics of particles.
Usually when we talk about particles, we're talking about oscillations
in fields like the electromagnetic field or an electron is
the oscillation in the electron field, and we have wave

(42:44):
equations to describe how those fields oscillate and how they vibrate,
and how the Higgs boson affects them to give them
mass and all that kind of stuff. You can imagine
like a little standing wave in the electron field. That's
what an electron is. So when we talk about particles,
we have math. It describes the oscillation of these fundamental fields.
We don't know what these fields are, what really is

(43:06):
doing the oscillating. That's the math we have. We can
take that same mathematics and we can apply it to
things that are not fundamental fields, like you can apply
it to sound waves in air, or you can apply
it to electrons moving through materials. You can apply in
lots of situations, and those are quasi particles. So particles
are these particular kinds of oscillations in fundamental fields. Quasi

(43:30):
particles are the same kind of mathematics, the same kind
of oscillations, but in something that isn't a fundamental field.

Speaker 1 (43:36):
But then you can apply that to real things that
are made out of things like water and air. Right,
you can sort of apply those wave functions to media.

Speaker 2 (43:46):
Yeah, exactly. And the cool thing about a particle is
that it's persistent, right, It's that quantized. You can count it.
It's discrete, and it like moves through the universe. An
electron as it moves to the universe, doesn't like dissipate
down into little many electron ripples. Right. It's persistent in
this way, and so sometimes you can see the same
thing happening in other media, right, Like if you can

(44:08):
make a smoke ring that's really persistent, right, it like
flows to the universe and holds itself together somehow. I mean,
I'm not an expert in how smoke rings work, but
imagine that. Then you could maybe describe that using the
same kind of mathematics you could use to describe electrons.
So you might call that a smoke on or whatever.

Speaker 1 (44:25):
But it maybe just even more typical like a wave
in the ocean. You can use wave equations to describe them,
mm hmmm, and they're just ripples in the body of water.
So in a way, they're sort of just like water ons. Right.

Speaker 2 (44:38):
Yes, not every wave phenomenon can describe a particle like
a particle's a special kind of persistent, discrete wave phenomenon.
But yeah, in the end, it's all rooted in wave
descriptions of how a medium is moving. And we talk
about sound waves as like phonons. It's like a basic
unit of the sound wave. Can you describe all sound

(44:58):
in terms of these like sound quasi particles. That's what
a phonon is.

Speaker 1 (45:05):
Where I guess if we're following the same convention here,
it would be aerons perhaps depending on what the or gasons.

Speaker 2 (45:13):
Yeah, if you want to reinvent stuff that already has
names for it so that everybody gets totally confused, then perfect.

Speaker 1 (45:18):
Yes, Yeah, to make it clearer. Perhaps there is.

Speaker 2 (45:21):
A thing called phonons, and there's lots of these quasi particles.
People are discovering new ones all the time. You know.
There's things called anions, and plasmons are an example of
a quasi particle. There are particular kinds of oscillations. But
in plasma, so plasma is just gas that's really really hot,

(45:42):
Like take hydrogen. It's got a proton and an electron.
The electron is bound to the proton because it doesn't
have the energy to fly away. Well, if you give
that electron more energy so that it's moving like too
fast to be bound by the proton, then it's free
and now you have a gas of protons and electrons
instead of a gas of hydrogen. That's a plasma.

Speaker 1 (46:02):
Now it is a plasma. Then basically a phonon in plasma.

Speaker 2 (46:06):
Well, the phonon is like a density wave, and that's
ignoring the charge distribution. Plasma is a little bit more
than that because it also has to do with the
charge distribution, because once you have a gas that has
charges in it, there's more kinds of forces that it
can feel like hydrogen pressure passes through it because the
particles are bumping up against each other. But in a plasma,

(46:28):
pressure can move through it because the charges are repelling
and attracting each other. So you have it's sort of
like two gases on top of each other. You have
a positive and a negative gas on top of each other,
and they're pushing and pulling on each other. If everything
has infinite time to sit around, it'll equilibrate, but that's
not usually what happens. You form these things in high
intensity situations. You have pulses in them, et cetera. And

(46:51):
so plasma is a description of the oscillation of mostly
the electrons, but also a little bit of protons due
to the charges of these things.

Speaker 4 (47:00):
HM.

Speaker 1 (47:00):
So you have this plasma of electrons and protons floating around,
flying around, and sometimes because of the dynamics between the
different particles, you get these weird little effects that move
around like they were particles inside of the plasma, and
that's what you call a plasma exactly.

Speaker 2 (47:16):
And that's actually related to the previous question because the
reason these electrons are moving is because there's an electric field.
Often the electric field is because the electrons are separated
from the protons, so they've created an electric field between them.
So now the electrons move to try to balance out
that electric field that they had a part in making.
But sometimes they overshoot and so they oscillate back and

(47:38):
forth and back and forth. So you get all these
sort of like oscillations of the electrons because of their
charge differential, and those oscillations we can call plasmads. This
is like people trying to make connections between different fields
of physics. They're like, oh, people have all these cool
mathematical tools they can use to describe waves as particles.
Maybe if we apply that to our situation, we'll try

(47:59):
to gain some understanding. This is all about like emergent physics,
Like should we take a step up from the microphysics
and try to understand the bigger picture immersion phenomenon. Should
you think about the water particles or should you think
about the waves? Right? It depends again on the questions
you're asking and which tools you want to bring to bear.
We don't have a fundamental theory of physics that can
answer every question we can ask, so we have to

(48:21):
sort of choose, like how to zoom in, how to
zoom out, what approximations to make, what things to focus on,
what things to ignore. So plasmas can be useful for
some kinds of questions in plasma physics.

Speaker 1 (48:32):
Like what kinds of questions? Like what are these useful for?

Speaker 2 (48:35):
Like how do keep plasma stable? You know, in magnetic
confinement fusion, when you get plasmas really really hot and
you hope that the protons will fuse sometimes and then
create more fusion, you're really interested in these kinds of oscillations.
The thing that makes magnetic confinement and fusion difficult is
that plasmas are really hard to keep stable. They're very
turbulent and very chaotic. So understanding the oscillations and a plasma,

(48:58):
how to keep those stable high, to keep those from
spiraling out of control and creating chaos that breaks up
the plasma and ruins the fusion conditions can really help
you build like a long lasting fusion reaction, which is
the whole idea of magnetic confinement fusion.

Speaker 1 (49:13):
That's kind of the holy grail of fusion, right, it
was super clean energy that will last us forever. Like
we can control plasma and then we can basically replicate
what's going on inside the sun.

Speaker 2 (49:23):
Yeah, that's exactly right. We need to understand plasma oscillations
if we have any hope of keeping plasma stable and
getting fusion, which is the energy source of the universe
in the end. So plasmas can be really helpful for
answering some questions about plasmas.

Speaker 1 (49:39):
And crossword puzzles. Apparently, I wonder which one is more
useful to humanity.

Speaker 2 (49:44):
I don't know, but maybe you and Peter can answer
these crossword puzzles as you drink mohtos on your private island.

Speaker 1 (49:50):
That sounds wonderful. It's going to be me, Dan, John
and Peter drinking mojitos solving crossword puzzles in my private
island while we get wiser and older.

Speaker 2 (50:01):
That sounds good to me.

Speaker 1 (50:02):
Wait, wait, are you Dan or not? Were you just
happy for us?

Speaker 2 (50:07):
I'm the quantum interference between Dan and Daniel.

Speaker 1 (50:10):
Yeah, I need to know which one we're getting here.
All right. Well, those are three awesome questions we've answered today.
Thank you to all of our question askers.

Speaker 2 (50:18):
And thanks to everybody who writes in with questions about
the universe. Keep thinking deeply, keep asking questions, and don't
give up until it makes sense to you.

Speaker 1 (50:26):
And or you get an answer from Daniel or us
on the podcast that's right, or maybe shows up in
a crossword puzzle. Either way to thrill.

Speaker 2 (50:34):
And if you don't hear from me, feel free to
look up poor his address and take him up on
his invitation to the private island.

Speaker 1 (50:40):
Yeah there you go. All right, Well, we hope you
enjoyed that. Thanks for joining us, See you next time.

Speaker 2 (50:50):
For more science and curiosity, come find us on social
media where we answer questions and post videos. We're on Twitter, Discord, Instant,
and now TikTok. Thanks for listening, and remember that Daniel
and Jorge Explain the Universe is a production of iHeartRadio.
For more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts,

(51:10):
or wherever you listen to your favorite shows.