September 8, 2020 • 40 mins
Daniel and Jorge answer questions about the Universe from Jorge's daughter Elinor, and talk about their new PBS Kids TV show: "Elinor Wonders Why". Link: pbskids.org/elinor
Learn more about your ad-choices at https://www.iheartpodcastnetwork.com
See omnystudio.com/listener for privacy information.
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:08):
Hey, Daniel, do you think humans will eventually discover all
of the deep secrets of the universe? I guess I
think it depends on what you know. It depends on
how curious future generations are. If the kids growing up
today are curious enough, who knows what they might discover. Well,
that's why I give my kids plenty of vitamin C
so they'll have a strong immune system to survive the
(00:30):
next pandemic. Actually, I mean C for curiosity, so they're
not immune to amazing discovery as long as they don't
get a C in science. But see for catching it
all right, that's right. Hi am or Hey, I'm a
(00:59):
cartoonist and the career of PhD comments. Hi, I'm Daniel.
I'm a particle physicist, and I'm super curious about what
our kids will discover. Welcome to our podcast, Daniel and
Jorge Explain the Universe, a production of I Heart Radio
in which we ride that curiosity wave. We take the
power of your curiosity and we take it all the
way to the end of the universe and look backwards.
(01:20):
We try to understand the very big the very small.
We ask all the questions from the littlest ones to
the biggest ones, to the hardest ones, to the weirdest ones. Yeah,
because it seems to be part of human nature to
ask questions, you know, to ask questions about their surroundings
and even about the universe. It seems like we're all
curious at some basic level, that's right. And sometimes we
want to know the way things work around us for
(01:43):
practical reasons like wow, how fast can that leopard run?
Am I faster than it? And sometimes we just want
to know. We want to understand the context of our lives,
how should we live, what does it mean, where do
we all come from. It's a deep seated need to
understand the universe around us, and it's translated into a
pretty impressive set of knowledge about the universe and how
(02:04):
it works. But it's also shown us how much we
still have to understand. Yeah, and it's not just scientists
who have curiosity. It's kind of everyday people, right, it's everybody.
When I talk to people about what I do from
my job, their eyes light up. Well, first they say physics, Man,
I did terrible of physics in high school. And then
they go, oh, wait a second, I want to note
(02:25):
the answer to that question. What is the universe made
out of her? Where did it come from? Everybody is curious,
and on this show, we believe that wondering and curiosity
belongs to everybody. Nobody ever confuses you for a psychic
instead of a physics person. That's never happened, not even once.
They can read my mind, so they can tell that
(02:46):
I can't read theirs. Well, today we have a very
special episode because we are announcing the release of our
television show. I don't know how many of you out
there follow us on social media on our Instagram and Twitter,
but Daniel and I have made a television show for kids.
That's right. It's the next step in our adventure of collaboration.
We started with online videos and then wrote a book
(03:07):
together and we've been doing this podcast and the next
step is this TV show which celebrates and supports curiosity,
especially scientific curiosity in children. Yeah, it's a show called
Eleanora Wonders Why, and it premiers this week on PPS
Kids dot org and on the PPS Kids app and
also on the pus Kids YouTube channel and also on
(03:28):
Amazon Prime if you have the ppous Kids subscription. It
will dig into the details of what that show is about.
But basically It's about a bunch of curious kids asking
questions about the world they find themselves in and figuring
out the answers for themselves. It's a project that Daniel
and I are super excited about. We've been working on
it for years, kind of on the background of this podcast.
(03:49):
We're super excited to share with you and with all
of the kids in your lives, whether they are nieces
and nephews or grandkids or kids. So, if you're a
fan of science and you're a curious person, and you'd
like your kids or your friends kids to grow up
with a scientific mindset and explore the universe and answer
some of these deep questions that we all have about
(04:09):
the universe, maybe give it a try share with them.
And So the show is called Eleanor Wonders Why, and
it's based on our kids. But specifically, the main character
is called Eleanor, and she's the bunny rabbit in this
world of the show, but she's based a little bit
on my daughter Eleanor. And so today, to celebrate the
release of the show, we thought it'd be cool to
answer some questions that Eleanor has about the universe. That's right.
(04:34):
We were hoping in this show to model the way
that we talk to our kids about science. We answer
their questions, we reflect their questions back to them, but
also to tap into that curiosity that kids have in
its raw form. And those of you who have curious kids,
and I know many of you have written into the
show and sent in their questions, know that their questions
are wonderful because they asked the deepest but most basic
(04:56):
questions about the universe around us. Yeah, and it sort
of seems like once they can to school, a lot
of that curiosity gets sort of ground away or beaten
down a little bit. I don't want to say anything
negative about school or teachers, because they're having a hard
time these days, but it's true that that like joyful curiosity,
that wondering about the universe, there isn't always a place
(05:17):
for that in your normal, everyday school curriculum. And so
we were hoping this TV show would help supplement that,
would help inject that wonder and that excitement about the
very biggest questions and also just the world around Yeah.
And so we have two questions here today from the
real Eleanor. And these are questions that she totally just
came up out of normal conversation, like we were just
(05:40):
folding laundry and suddenly she had these She gave me
these two big questions about the universe. And she always
just like popping questions about the universe on you at
all times. Oh yes, did I mean? She inspired a
show called Eleanor Wonders Why. Those of you with curious
children will know what that's like. So we're happy to
answer Eleanor's questions today, and we hope that you and
(06:02):
or your kids have similar questions. Yeah, and if your
kid has questions about the universe, about planets, about Adams,
or anything related to science, please send them to us.
We'd be happy to try to answer them and maybe
even possibly answering them on the podcast. That's right, We
answer all of our listener questions, So write to us
with your questions. Two questions at Daniel and Jorge dot com. Alright,
(06:24):
Eleanor has two questions about nothing short of the entire universe, Daniel,
she has big thoughts. She's a little seven year old girl,
but somehow she had these questions about the universe, And honestly,
as a parent, I don't know where they where they
came from, Like I don't know what books she's reading,
what what videos are showing to her at school? But
(06:45):
she had these amazing questions about the universe. Clearly, you
have interacted with physicists too much, or she's thinking about
this maybe probably is there such a thing as too
much interaction with the obviously I think not. Alright, here's
Leonora's first question. Yes, E has two questions, one about
the multiverse and the other one about the shape of space.
(07:08):
How can I how can there be more than one
universe if the universe is probably infinite because I thought
the universe was everything that existed. That's a big question, though,
such as my brain, such a big question. I don't
(07:29):
even know how she knows about the multiverse, Like we
don't talk about it over dinner. Yeah. Well, and she
has the idea of the infinite universe, which is hard
enough for me to hold in my head. What do
you think she thinks of when she talks about infinity? Well,
that's a big question. I think I think she has
an understanding of like things that go on forever, like
they don't stop, you know, definitely they used in infinity
(07:52):
a lot, like you know, when they're When she's arguing
with her brother or something, you know, I want infinity
of these? Or how many cookies do want? For desert? Infinity? Infinity?
Yet it's definitely a concept she's familiar with. But what
do you think about her question? I think she's asking,
you know, how can there be more than one universe?
If the universe might be infinite? Like how, like where
(08:15):
are they? I think maybe she's sort of asking, like
where are these other universes if the universe is infinite? Yeah?
Or do you think she's gonna be just asking it
like a semantics question, like why how can you have
a universe and a multiverse? Wouldn't it it all just
be the universe? Yeah? Well, I think the answer there's
a scientific answer and a semantic answer there, because you know, originally,
(08:35):
I think the universe is designed to mean everything that
there is. It's just like, instead of saying the phrase
all the stuff and all of the space and all
the matter and everything, you want a more compact phrase,
and so we have universe. But then that sort of
came to define a set of ideas, and when you
want to expand on those ideas, then you need to
add a new word for a new meaning. So like
(08:57):
if universe is sort of semantically flexible and means like
our current understanding of everything that could possibly be. Then, yeah,
there's just one universe by definition. I guess you sort
of downgraded the definition of universe like youas mean everything.
But then because this were like maybe there's more to everything,
or where there's more everything everywhere else, and specifically we
had new ideas for how to get more everything or
(09:19):
where more everything could be, or in in other ways
you could have stuff, and so the sort of categorically
different kinds of stuff and places, and so that I
think is why we came up with a new word
for it. But maybe we should talk a little bit
about what it means to have more than one universe
or where that other stuff could be. Yeah, yeah, because
I think what's was sort of blowing her mind is
(09:42):
just this idea that there's everything and then there's other
Everything's like where are they? Are they next to the
other everything or are they on top? Or how does
that work? Yeah? And it's especially hard to understand if
the universe is infinite, because then how do you squeeze
all that stuff together? Right? And when people we'll talk
about universe, they often mean different things and so sometimes
(10:04):
it's just semantics. And sometimes when people say the universe,
they really mean the observable universe, like the part of
the universe that we can see, which goes out several
billions and billions of light years, right, And sometimes people
think of other universes as just like other observable universes.
If you're somewhere really, really far away, you would have
a different observable universe because you would see a different
(10:26):
like patch of the infinite universe. I think that's kind
of lame, because we already have a phrase for that
observable universe, sub universe. Yeah, exactly. It makes our observable
universe is like a sub universe of the whole universe.
So technically that's in the category of multiverse. Some people
call it multiverse, but I think it's sort of silly.
(10:47):
I think more interesting is this concept like that our
universe could be infinite and yet there could also be
other universes, right yeah, because like, well, how do you
fit it all in? How do you fit it all
in exactly? And to fit it all in you have
to have like other kinds of space. Because remember that
what we think about is our universe is the space
(11:08):
we live in the space and all the matter and
and all that stuff, and that could go on forever, right,
But then also there could be variations on it. And
really the only way to reconcile having an infinite universe
and having multi verses is to go for the quantum multiverse,
the one where our universe is splitting into different possibilities
at every moment. So this is the idea that every time,
(11:32):
like a particle makes a decision, another universe pops out. Yeah,
exactly is to try to answer the question like when
the universe makes a seemingly random decision for quantum mechanics,
why is it that one and not another one? When
the electron has to decide do I go left or
do I go right? Then you know, why is it
go left? It seems weird, It seems arbitrary. And as
(11:54):
you know, physicis don't like beings the same art jury.
We want an explanation, kind of like chilled in right,
They always want to know why why can't I have
cookies at nine pm at night? What's what's going on?
The show is really called Physicists Wonder Why, But we
wanted to make a kid's ship. It seems arbitrary, then
it seems arbitrary. So we invent this other universe to say, well,
(12:15):
maybe it's balanced. You know, we're in the left direction,
but there's another universe where the electron went to the
right direction, and that somehow satisfies your need for symmetry,
for balance, to say that it's not just arbitrary that
it went left, because it went in every direction and
we just ended up in one of those right. And
the idea is that there weren't two universes before, but
once that particle makes a decision, whether it's been right
(12:40):
or it's been left, then now there are two universes.
So before there was one, now there are two. And
that happens every time a particle in all of existence
makes a decision. Yeah, and it's crazy, right, It's hard
to imagine because there's ten to the eight particles and
they're doing stuff every you know, nanosecond or whatever, and
so the number of universe it just becomes absurd very
(13:02):
very quickly. Plus the universe is billions of years old,
so like, how do you even fathom the number of
different universes in this scenario, It's like infinity to the
infinity to the head explosion power. You know, it's just
it's just the number. We can't even really think about.
It's more cookies than even your kids could eat, even
at nine pm. Even at nine pm, they'll happily take
(13:22):
the challenge. I'm sure you gotta take data right. You
can't just make assumptions. You've got to do the experiment.
Can put limits. Doesn't really answer her question right, like
say that that's true, say that's actually happening, that that's
our reality. Then where are those other universes? You know,
where are they in space? Right? And that's not easy
(13:43):
to answer. They're not really like anywhere. You know, we
have branched. We are in the left universe and not
in the right universe. It's not like the right universe
is one we can ever interact with. We can't like
send a message to that universe. We're not causally connected.
We're separated from that universe, so we can never interact
with it in any way. It can't influence us, we
(14:04):
can't send messages, it can't change us. So from our
point of view, it doesn't exist in our space at all. Well,
how do you know that, Daniel, I guess how do
you know there that there's no way that there we
can make a connection to them, because in sciences fection
you see it all the time, like spreaking the walls
between the different universes, and you can travel to a
different universe. Are you saying I saw this in a movie,
(14:25):
So how do you know it's not possible? Basically, I
also saw flying saucers and jet packs Daniel episode. We'll
get to those later. Well, it comes from the very
construction of the multiverse. Rights the multiverse. The other universe
is created when the universe splits, when you make a
different decision. So then our universe is inconsistent with that universe.
(14:47):
It's like a copy of our universe, but with a
different decisions. So the two have like the same history,
but now a different future. And so how did the
two even talk to each other? They have like an
inconsistent history for what has happened. It's like an alternative.
It's not like, you know, a different fork in the
path while I'll go left and you'll go right, and
maybe the paths will meet again. It's like you know,
(15:09):
once you decided to press the button, you can't unpressed
the button. All right? I think now I have a
lot of questions about this Daniel, and so let's get
into where these other universes might be. But first let's
take a quick break. All right, Today we're asking questions
(15:38):
from Eleanor, my daughter, who is also the inspiration for
our new kids television show called Eleanor Wonders Why, which
is all about getting kids interested and curious about nature
and all the amazing things in it, like animals and
bugs and lizards. Maybe mosquitoes actually came over from the
multiverse because I hate them so much, but I love nature.
(16:00):
Think they come from a dark, dark universe. I imagine, like,
who would suffer if we just deleted mosquitoes from the universe? Really,
nobody would be harm Can't we just all vote to
do that? You know, I think bads eat mosquitoes, Daniel,
so that would be bad news for bad, which, by
the way, is also a character in our show. So
Eleanor in the show is a bunny rabbit, and she
(16:21):
has two best friends, are a funny and very active
bad and also Olive, who who's an elephant. And all
of it's sort of based on your daughter, right, Daniel
Alive is partially inspired by my daughter, That's right, All
of the character in the show is a real reader
and likes words, and my daughter Hazel is like that. Yeah,
so she helped inspire us. And the curiosity of all
(16:41):
of our children and of all the children we've met
out there helped inspire us. I give sometimes lectures to
elementary schools about science, and my favorite bit is the
question period afterwards, when they ask any question they have
in their mind, and they're always like surprising, mind blowing,
and sometimes it's difficult to answer questions. Yeah, So if
you have young kids, or if you have friends with
(17:02):
young kids or nieces or nephews or grandkids, we would
really encourage you to tell them about the show. It's
called Eleanor Wonders Why, and it's available right now in
the US at PBS Kids dot org, slash Eleanor E
l I n O R and also the PBS Kids app,
which you can download for free and watch all these
episodes for free. They're also available on the PBS Kids
YouTube channel and also on the Amazon Prime PBS Kids subscription.
(17:26):
Those you can put on repeat, which we hear a
lot of parents are appreciative of. So today to celebrate that,
we are answering questions from Eleanor, the real Eleanor, and
she had a question about the multiverse. So, Daniel, we
were talking about the multiverse. If the multiverse is real,
where where are all these other universes at? So you're
(17:47):
saying we can't access them, we're not connected to them,
because it's more like we're different possibilities. Is that kind
of what what do you mean? It sounds very abstract,
like are you saying we're an abstraction in that theory
the multiverse where there's a different universe created every time
a quantum mechanical particle has to roll the dice, Then yes,
we are just one of those many many many many
(18:09):
many many many to the many power universes. And so
two people in or creatures in one of those other multiverses,
we are that abstraction. And that's the part of this
theory that I don't really like because it tries to
answer this question of why are we in this universe
and not in another universe where other random decisions were made.
Doesn't like randomness and tries to answer that by saying
(18:31):
every random decision is made. But to me, it doesn't
really answer it, because you know, I'm in this universe
and not in any other one, and so it's it
goes back again to that question of consciousness, like why
am I experiencing this universe and not those universes? So
to me philosophically, it's pretty unsatisfying. Plus, it's just hard
to think about, like where are all those other universes?
(18:54):
Eleanois question is a great one. You know, how do
you have multiple infinite universes? Where are they? And you know,
the best way to think about it is that we
have an infinite pocket of space to play in here,
our universe, our quantum slice of the universe, and those
other ones they have their own inefinite pockets of space
(19:14):
to play with, but they're not connected to ours. The
only way to answer the question where is something is
to think about their physical relationships, you know, like where
is your neighbor's house? It's next to yours, Because our
brains are sort of hard wired to think about space
like that, right, like spatially, Well, that's what space is. Remember,
there's no absolute locations anywhere. It's all relative. And so
(19:36):
if there is no relative position between this universe and
the other universe, then you can't put them in any
space together. So they really have their own spaces. So
I think what you're saying is that I should tell
eleanor that Daniel doesn't know. Daniel definitely doesn't know if
those universes exist and if they do, where they are.
(19:56):
But I'm pretty sure that if they exist, we can
never talk to them or interact with them, or even
prove that they exist. And a lot of people say
that makes this not a very scientific idea because if
you can't test it, how could you prove it's true.
And if you can't prove it's true, then it's really
just speculation and not even really science, right. Yeah, you
need to be able to formulate it, right, like as
(20:18):
a hypothesis, and be able to prove it or disproven
or a design a test to prove it or disprove it. Yeah,
a lot of people like Carl Popper's theory of falsifiability,
that is an idea is not scientific if it's not falsifiable,
And then some people think that's garbage. But I just
feel like, how are you going to pick an idea, Like, sure,
you have this idea of quantum ultiverse, somebody else has
another idea. If you have competing ideas, to me, the
(20:40):
way to pick between them is to do the experiment.
That's what experimental science is about, is a way of
cornering nature into revealing what's happening by constructing a situation
where different things happen based on the reality. You know,
the experiment, that particle goes left if it's this way,
or it goes right if it's that way and that way.
The universe gives you a clue. But if there's no
way to interact with the rest of the multiverse, there's
(21:02):
no way to prove it's there, then is it really there?
And if it is, doesn't really matter all right, Well,
it sounds like the answer is we don't know, but
we may never get to these other universes. And also
maybe the answer is a little bit like don't think
about it as these other universes being anywhere like on
top of us or next to us or below us,
(21:24):
But think about it more like there's just sort of
like there as well as us, right, Like it's it's
just there. They're just they're just like we are here.
But even the word there implies a space. You're like,
they're over there. Well, I would say they are what
they are and we are. Yeah, I would stop it
are not they are there? Just they are? They are?
(21:45):
We are they are? Where are there? We don't know?
All right, well, awesome question. We also have another question
from Eleanor here we're going to try to answer, and
it's about the shape of space that's hard to shape
and event like, oh, a giant wall that is like
curves and you can't come out of it. Alright, awesome questions.
(22:08):
She's asking about what the shape of space is, and
if it has the shape, what's at the edges of it? Like,
if if it has the shape, it must have an end,
and so what's at the end. Is it a curved wall,
is it a flat wall? Is it a stuckle wall?
Who knows? I think she's been stuck inside too long.
She's thinking about edges and boundaries. Oh boy, you know
(22:32):
another I think about it. I do kind of see
the inclings of these questions, where these questions that have
came from. Like I'm thinking back over like the last
couple of months or years, I've seen her sort of
formulate this question a little by little, Like she asked
a little bit about the universe, a little bit about space,
a little bit about this, and I think it all
just been sort of marinating inside of her head. Well,
(22:53):
it's awesome. As kids grow up, they understand more and
more about the world around them, and then they're sort
of mental context rose and they can imagine this city,
other cities, the country, the whole world, the solar system,
and eventually, you know, inside their minds, they're creating this
model of the whole universe. And that's when this awesome
thing happens that they have questions about it. They're like,
(23:14):
wait a second, this model in my head doesn't really
make sense or what do I put here? And that's
where these questions come from. And that's you know, that's
science in action, right, And it's pretty cool that she
just blurted out this question, like we're just folding laundry
and she just suddenly pops out this question like it's
been building up inside of her and she just had
to let it out. Like isn't that cool that? I
feel like as adults, we would just a lot of
(23:36):
us just keep it to ourselves, Like if you're a
dinner with the date, you wouldn't be like, you know,
talk about one thing and then suddenly be like, hey,
have you ever thought about the shape of the universe.
But then again, maybe I'm not a physicist because I've
done that. It depends on the kind of person you
want to date, that's for sure, But it also depends
on the kind of person you are. If you encourage
these kind of questions and your children, if you enjoy
(23:58):
exploring them with your kids, if having kids helps you
renew this like naive curiosity, which still is driving basic
questions in science. So I think it's wonderful to tap into.
And you know, that's what we try to tap into
for our show. A lot of the episodes for our
show come from real questions asked by real kids about
their universe. Yeah, and every episode in our show, Eleanor
(24:20):
Wonders Why. We try to think about a question that
kids would have and we try to answer it, like
why do birds have feathers? And why do lizards like
to sit out in the sun, and all kinds of
fun kids questions, And why does my dad not know
the answer to my physics questions? Why does he have
to ask his friend? Why does he have to ask
you know, hundreds of thousands of people out on the internet. Well,
(24:42):
let's try to give Eleanor an answer. Yeah, so she's
asking what is the shape of space, like the space
does the universe have a shape? Like, if you keep
going long enough, what happens? Do you run into a wall?
And what does that wall look like? Is it like
a physical barrier? Is it curved? Does have a texture?
The has it heard if you slam into it? What's
(25:03):
going on? Well, it's fascinating that she asked this question
just after she asked the other question where she's assuming
an infinite universe. Now she's wondering like could the universe
not be infinite? Right? How do you understand anything other
than infinity for a universe? Right? Well, this one was
kind of a follow up question, Like she asked the
first question and then she sort of thought about it
(25:23):
for a second, and then she has this one. So
I think maybe she's also grappling with this idea of infinity.
Like you said, like infinite doesn't make sense to her,
There has to be an end to it. Actually, I
think the opposite. I think infinity is much more natural
than an edge, right, Like, as weird as infinity is,
it's hard to grapple with, but it seems sort of
natural because then you get to avoid edges and then
(25:44):
we don't have to explain the edge or the weird
shape of the universe because it just goes on forever.
But then you have to explain forever, Daniel, see how
this helps you. We'll have a very long answer for
why forever makes sense. It goes on forever. It just
goes on and on. This bit on, and then there's
that bit, and there's other bit and then yeah, this
is the longest podcast every but usually falsely before they
(26:06):
ask you for a follow up. And so to answer
her question, like one possibility, one very real possibility is
that the universe is infinite, that space is infinite, and
that it's always been infinite. The thing that's hardest for
people often to understand about the universe being infinite is
that they imagine the Big Bang having started the universe
from a point, so then how would stuff get that
(26:28):
far away? But instead, all you have to do is
imagine not just that our universe is currently infinite, but
that it always has been infinite. That the Big Bang
was just a period where the universe was denser and hotter,
and since then it's been expanding and becoming more dilute.
But it went from an infinite, hot universe to an
infinite cold universe. So that's one very real possibility, and
(26:49):
that's my sort of personal philosophical preference for which I
have no evidence. That's the Daniel interpretation of total guessing
about the universe. Total guessing is step one in science though, right,
all right, so that's one possibly. But I think she's asking, like,
what if instead of having an infinite universe, we have
(27:09):
a finite universe? And so if it's finite, what's the
shape of it? Like is it a big sphere? Is
in the shape of a duck? Is in the shape
of a giant squirrel? Is it a cube? You know?
And also like what's at the end? Like if you
keep going in one direction of the universe, what happens
(27:29):
when you hit the end of it? Do you stop existing?
Do you bounce back? What happens? Well, the basic idea
to get in your head before we get into the details,
is that space is not as simple as you thought
it was. Space is not just a place for matter
to be, like an emptiness you know, on which stuff happens.
Space itself can have shapes. And this is something we
(27:51):
already know because we see that space bends. Right. Our
understanding of gravity now is not a force between objects,
but the interaction of matter with space. Matter bends space,
and then space changes how matter moves. What that means
is that space can have a weird shape. It doesn't
just have to go on forever. It can curve, it
(28:11):
can bend. It has weird pockets in it. These things
space traps, which most of the rest of the community
calls black holes, are weird pockets of space where space
sort of has like a discontinuity and edge and like
a loop, right, Like in a black hole, you can't
you can't leave it because it's it's pulling on you.
You can't it's it's a you can't leave it because
space around a black hole is like loop right, Like
(28:34):
it's a doughnut kind of like a circle. Yeah, space
is one directional inside and black hole. So space can
do all sorts of really weird things. So first get
your sort of like mental idea of space be a
little bit you know, squishy and flexible, and so we
can fold and do weird stuff, and then we can
insert into your mind other ideas for the shape of
the universe and sort of The simplest is that the
(28:56):
universe is finite but it has no edge because it's
sort of constructed in a loop. Like if you just
keep going in one direction, eventually you'll come back to
where you were, right, kind of like a satellite in
orbit around the Earth. Or even if you just travel
on the Earth in one direction, you'll come back to
the same spot. Yeah. If you build a road around
the equator and you just keep driving on it, you'll
(29:18):
come back to where you started. And that's because of
the geometry of the Earth. Right on the surface of
a sphere, you can just keep going, you'll come back
to where you are. And you wonder where, Well, how
do you do that for three dimensions? Well, if space
is complicated, if space is a thing which can bend
and twist and be connected in weird ways, right like
around a black hole, then it can be connected in
(29:40):
this way so that one bit of space is now
connected to another bit of space on what would be
the other side of the universe. You can arrange space
in sort of a three dimensional equivalent of the surface
of a sphere, Like you can take a universe and
kind of wrap it around and connected to itself. Yeah,
and and then so you would have a shape. Yeah,
and the key thing to avoid is trying to understand
(30:01):
this by putting the universe into a higher dimension. Don't
think about the three D universe on some four dimensional sphere,
because I would create another dimension of space, which we
don't have any evidence to believe exists. Just think about
the relative connections between things in space. If this point
in space is connected to the next pointed space is
connected to the next point in space, and then just
(30:23):
imagine a ring of these points. Each one is connected
to one to the left and one to the right,
and together they construct a ring. And then imagine the
three D analog of that ring. Again, it's not like
on the surface of a three D sphere. It's just
about the ordering of the points relative to each other.
All right, well, let's I have questions about that, and also, Daniel,
(30:46):
let's get into maybe a little bit more of the
specifics and also maybe think about the alternative that maybe
space space is flat. What are the possibilities there? So
let's do that, But first let's take a quick break.
(31:10):
All right, we're answering questions from Eleanor, my daughter, who
is the inspiration for like one of the characters in
the show Eleanor Wonders why, which is our new kids
showing that is out right now and we're celebrating its
release this week. And so Eleanor had a question about
the shape of space, and Danna you were saying that
maybe space is bendable, and well, it is bendable, but
(31:33):
maybe the shape of spaces that it loops around onto
itself like it's wrapped around itself. Yeah, And that's more
like the topology of space than the shape of it.
It's like about how the points are connected to each
other rather than like, you know, how it's bent by
mass in any sort of local configuration. It's sort of like,
you know, how you put the whole thing together, And
that I think is sort of the easiest one to
(31:55):
understand because it lets you have finite space, like it
doesn't go on forever without having any sort of edges,
because people feel weird about the edge, Like, you know,
you can't imagine that coming to a brick wall with
a sign on it. This is like the universe ends here,
because then you wonder like, well, what's on the other
side of the brick? Right? Yeah, Well, yeah, I think
you know, that's a little bit of where her mind
(32:16):
is coming from, and that you know, she's probably not
aware of these ideas about bending of space, So to her,
space is just sort of like this infinite emptiness. And
so is that a possibility? Could it be that maybe
space is not curved but it does have an edge, right,
because I think we know that space is not generally curved.
(32:37):
We think it's flat. Our local part of space at
least is flat, and we think there's enough stuff in
the universe to make space generally flat. But yeah, space
could be flat, and it could be finite, and it
could have an edge. And we don't like the idea
of an edge because it's a discontinuity. We have to
explain it. What would it be like? But it's not impossible, right,
(32:59):
Space can do really weird things and and have edges,
Like you know, the event horizon of a black hole
is basically like a boundary of space, and so you
could come to some boundary and you know, it wouldn't
be some like weird thing with like flashing lights and
blue stripes or whatever is they would put it in
a movie. It would just be like, you know, space
does something weird here, so like there just isn't any
(33:21):
more space to go into, like you know, the way
in a black hole, you can't just move in any
direction you want, because space has a single direction you
can go in. It could be you come to a
point in space where there just is no more space
in that direction. It's like coming to the north pole.
There is no more northiness to go to. So that
is the possibility, is that space could be kind of
(33:44):
flat and its curving nows meanings has kind of a volume,
and that it does have an edge to it like
it does it does end like a blob. It's a possibility.
It's not a frequently discuss possibility or a popular possibility
among like current cost oologists. There's no like reason for
space to have an edge, and so it's not something
(34:05):
you need to add to your theory. It's much more
natural to just say every point in space is the same,
and therefore the universe should be infinite. But it's not
against the laws of physics as far as I'm aware,
and you know, we imagine the universe having an origin
in time. There was a moment in time when things
were created and then inflation dot dot dot dot, and
so it's not that outlandish to imagine a discontinuity or
(34:29):
an edge. Also in space well, and and then her
question was sort of like, what's the shape of it? Like,
if it is like this and it does have borders,
do you think it'd be like a sphere like a potato?
Like I think it'd be like a huge question mark,
question mark? What would be in the dot? I'll read
the dot, Daniel. We're in the dot. We're the dot.
(34:52):
That's right, that's my philosophy. No, we have no idea,
we have no idea of space as an edge, and
if it had an edge with that shape would be
I mean, your intuition would say it should be a sphere,
because that's the simplest thing, right, But we were just
really we're just really don't know how awesome would that
be though, to discover the universe had an edge and
to map it out and to understand it. You know,
(35:15):
if it's not a sphere, then probably it would be
like a randomly shaped blob controlled by some like early
quantum fluctuations or something crazy. I'm gonna go with banana.
I bet it's shape like a banana, and then I'll
be justified in all of these discussions about bananas, Daniel,
because you knew it the whole time, it wasn't just
a random guess that was later proven out to be true.
(35:35):
You knew because the universe was speaking to me. It
was crying out for, you know, some sort of recognition
of its banana. Yeah, and you know, there is another
sense in which the universe kind of does have an edge,
and that's again just back to like our observable universe.
There's only a portion of the universe that we can see.
And so if you think about the universe is like
the stuff that we can see, everything that's around us
(35:57):
that really does have an edge because there's parts of
the universe that are so far away that light hasn't
had chance to reach us from them, and so we
haven't seen them. And because the universe is expanding and
that expansion is accelerating faster than the speed of light,
we may never see them. And so this sort of
like a spherical wall past which we cannot see and
(36:20):
past which we may never be able to see or go. Right, Yeah,
but that's part of a philosophical wall, isn't it. Or
do you think maybe it's the same thing, And let's
not get philosophical on the podcast, right, Gosh forbid, we're
talking about the universal questions. No, I mean it's not fundamental, right,
Like you can imagine that there's a point out there
in space beyond which we cannot see, and if we
(36:42):
look at that point, we're seeing like the early universe
because light is taken forever to get here from there.
But it's sort of unsatisfying because there's something recent happening
at that point right now. You know, we see old
light coming from that point, but you know, stuff's been happening.
There's things going on. Alex Scenes are forming alien civilizations,
hopefully are inventing cool podcasts. So what we're seeing in
(37:06):
that direction, it's always happening now, so we think the
universe continues on even though we can only see this aging,
observable shell that surrounds us. So in that sense, it's
it's observation more than philosophical. All right, Well it sounds
like that again. The answer for Eleanor is Daniel doesn't know.
Nobody knows, Daniel doesn't know, the new name for our podcast,
(37:26):
Daniel doesn't know things. Daniel doesn't know. Basically, nobody knows, right,
I feel like we don't know at a very fundamental level,
Like it could be infinite or it could not be infinite,
and there's a big difference between infinity and non infinity.
And that's the joy of these questions. That the questions
that children ask, the very basic questions, the first questions
that come into your mind when you hear about these ideas,
(37:47):
those are questions scientists are still asking. So if you're
six years old or you're sixty years old and you're
on the forefront of cosmology, you're asking the same questions.
And that's what makes physics shockingly accessible. I would say
that our cluelessness, our lack of progress, makes us accessible.
Or if you're six years old and an alien and
(38:08):
do have the answers to these questions, please let us
know so I can tell eleanor what the answer is.
But that's one of the reasons why we wanted to
make this show is that we felt like this kind
of curiosity is wonderful and it powers scientists in their career,
and also it powers children. And we see it in
the very youngest children, and we want to nurture it,
we want to protect it. Sometimes it feels a little
(38:30):
bit fragile, and so in our show, we wanted to
encourage this kind of curiosity by showing kids on screen
how curious kids can ask questions and how they can
find the answers for themselves. And that's why we love
the show. That's why we love the show. And if
you like a mix of science and kind of corny
dad jokes, then hopefully you'll also like the show. Yeah,
(38:51):
so help us celebrate the release and the premiere, at
least the US premiere, and we're still trying to get
the show in other countries. But help us celebrate the
US premiere of Eleanor. There's why the show that Daniel
and I co created. It's for kids. It's about a
cute bunny rabbit and her friends about and an elephant
and this really beautiful and gentle but also curious and
(39:13):
funny world. And it's out now on PBS Kids dot org,
slash Eleanor, E l I and o R and also
the PBS Kids app, and also on Amazon Prime ppious
Kids subscription, and also I think they're posting episodes on
the ppous Kids YouTube channel, So there are plenty of
ways for you to watch the show, and it's all free,
(39:34):
and please help us celebrate and tell your friends, your
nieces and nephews and grandkids about the show. We think
they'll really enjoy it. That's right. It's a world we
created filled with people who are curious, who ask questions,
and who find answers to those questions. So if you
want to spend half an hour in a gentle world
filled with curiosity, please go check it out. Yeah, and
(39:55):
we hope you enjoyed Eleanor's questions today about the multiverse
and about this shape of space at really kind of
stretches your mind, right, Daniel, it definitely does. And you know,
just because the question comes from a young kid doesn't
mean it's easy to answer. As we ran today, those
are my favorite questions. We invite Eleanor to a seminar
at you see your vines physics department, she'll stump. They're
(40:17):
open to the public, so come on in. All right, Well,
thanks for joining us, see you next time. Thanks for listening,
and remember that Daniel and Jorge Explain the Universe is
a production of I Heart Radio or more podcast from
my Heart Radio visit the I Heart Radio app, Apple Podcasts,
(40:41):
or wherever you listen to your favorite shows.
Hey, Daniel, do you think humans will eventually discover all
of the deep secrets of the universe? I guess I
think it depends on what you know. It depends on
how curious future generations are. If the kids growing up
today are curious enough, who knows what they might discover. Well,
that's why I give my kids plenty of vitamin C
so they'll have a strong immune system to survive the
(00:30):
next pandemic. Actually, I mean C for curiosity, so they're
not immune to amazing discovery as long as they don't
get a C in science. But see for catching it
all right, that's right. Hi am or Hey, I'm a
(00:59):
cartoonist and the career of PhD comments. Hi, I'm Daniel.
I'm a particle physicist, and I'm super curious about what
our kids will discover. Welcome to our podcast, Daniel and
Jorge Explain the Universe, a production of I Heart Radio
in which we ride that curiosity wave. We take the
power of your curiosity and we take it all the
way to the end of the universe and look backwards.
(01:20):
We try to understand the very big the very small.
We ask all the questions from the littlest ones to
the biggest ones, to the hardest ones, to the weirdest ones. Yeah,
because it seems to be part of human nature to
ask questions, you know, to ask questions about their surroundings
and even about the universe. It seems like we're all
curious at some basic level, that's right. And sometimes we
want to know the way things work around us for
(01:43):
practical reasons like wow, how fast can that leopard run?
Am I faster than it? And sometimes we just want
to know. We want to understand the context of our lives,
how should we live, what does it mean, where do
we all come from. It's a deep seated need to
understand the universe around us, and it's translated into a
pretty impressive set of knowledge about the universe and how
(02:04):
it works. But it's also shown us how much we
still have to understand. Yeah, and it's not just scientists
who have curiosity. It's kind of everyday people, right, it's everybody.
When I talk to people about what I do from
my job, their eyes light up. Well, first they say physics, Man,
I did terrible of physics in high school. And then
they go, oh, wait a second, I want to note
(02:25):
the answer to that question. What is the universe made
out of her? Where did it come from? Everybody is curious,
and on this show, we believe that wondering and curiosity
belongs to everybody. Nobody ever confuses you for a psychic
instead of a physics person. That's never happened, not even once.
They can read my mind, so they can tell that
(02:46):
I can't read theirs. Well, today we have a very
special episode because we are announcing the release of our
television show. I don't know how many of you out
there follow us on social media on our Instagram and Twitter,
but Daniel and I have made a television show for kids.
That's right. It's the next step in our adventure of collaboration.
We started with online videos and then wrote a book
(03:07):
together and we've been doing this podcast and the next
step is this TV show which celebrates and supports curiosity,
especially scientific curiosity in children. Yeah, it's a show called
Eleanora Wonders Why, and it premiers this week on PPS
Kids dot org and on the PPS Kids app and
also on the pus Kids YouTube channel and also on
(03:28):
Amazon Prime if you have the ppous Kids subscription. It
will dig into the details of what that show is about.
But basically It's about a bunch of curious kids asking
questions about the world they find themselves in and figuring
out the answers for themselves. It's a project that Daniel
and I are super excited about. We've been working on
it for years, kind of on the background of this podcast.
(03:49):
We're super excited to share with you and with all
of the kids in your lives, whether they are nieces
and nephews or grandkids or kids. So, if you're a
fan of science and you're a curious person, and you'd
like your kids or your friends kids to grow up
with a scientific mindset and explore the universe and answer
some of these deep questions that we all have about
(04:09):
the universe, maybe give it a try share with them.
And So the show is called Eleanor Wonders Why, and
it's based on our kids. But specifically, the main character
is called Eleanor, and she's the bunny rabbit in this
world of the show, but she's based a little bit
on my daughter Eleanor. And so today, to celebrate the
release of the show, we thought it'd be cool to
answer some questions that Eleanor has about the universe. That's right.
(04:34):
We were hoping in this show to model the way
that we talk to our kids about science. We answer
their questions, we reflect their questions back to them, but
also to tap into that curiosity that kids have in
its raw form. And those of you who have curious kids,
and I know many of you have written into the
show and sent in their questions, know that their questions
are wonderful because they asked the deepest but most basic
(04:56):
questions about the universe around us. Yeah, and it sort
of seems like once they can to school, a lot
of that curiosity gets sort of ground away or beaten
down a little bit. I don't want to say anything
negative about school or teachers, because they're having a hard
time these days, but it's true that that like joyful curiosity,
that wondering about the universe, there isn't always a place
(05:17):
for that in your normal, everyday school curriculum. And so
we were hoping this TV show would help supplement that,
would help inject that wonder and that excitement about the
very biggest questions and also just the world around Yeah.
And so we have two questions here today from the
real Eleanor. And these are questions that she totally just
came up out of normal conversation, like we were just
(05:40):
folding laundry and suddenly she had these She gave me
these two big questions about the universe. And she always
just like popping questions about the universe on you at
all times. Oh yes, did I mean? She inspired a
show called Eleanor Wonders Why. Those of you with curious
children will know what that's like. So we're happy to
answer Eleanor's questions today, and we hope that you and
(06:02):
or your kids have similar questions. Yeah, and if your
kid has questions about the universe, about planets, about Adams,
or anything related to science, please send them to us.
We'd be happy to try to answer them and maybe
even possibly answering them on the podcast. That's right, We
answer all of our listener questions, So write to us
with your questions. Two questions at Daniel and Jorge dot com. Alright,
(06:24):
Eleanor has two questions about nothing short of the entire universe, Daniel,
she has big thoughts. She's a little seven year old girl,
but somehow she had these questions about the universe, And honestly,
as a parent, I don't know where they where they
came from, Like I don't know what books she's reading,
what what videos are showing to her at school? But
(06:45):
she had these amazing questions about the universe. Clearly, you
have interacted with physicists too much, or she's thinking about
this maybe probably is there such a thing as too
much interaction with the obviously I think not. Alright, here's
Leonora's first question. Yes, E has two questions, one about
the multiverse and the other one about the shape of space.
(07:08):
How can I how can there be more than one
universe if the universe is probably infinite because I thought
the universe was everything that existed. That's a big question, though,
such as my brain, such a big question. I don't
(07:29):
even know how she knows about the multiverse, Like we
don't talk about it over dinner. Yeah. Well, and she
has the idea of the infinite universe, which is hard
enough for me to hold in my head. What do
you think she thinks of when she talks about infinity? Well,
that's a big question. I think I think she has
an understanding of like things that go on forever, like
they don't stop, you know, definitely they used in infinity
(07:52):
a lot, like you know, when they're When she's arguing
with her brother or something, you know, I want infinity
of these? Or how many cookies do want? For desert? Infinity? Infinity?
Yet it's definitely a concept she's familiar with. But what
do you think about her question? I think she's asking,
you know, how can there be more than one universe?
If the universe might be infinite? Like how, like where
(08:15):
are they? I think maybe she's sort of asking, like
where are these other universes if the universe is infinite? Yeah?
Or do you think she's gonna be just asking it
like a semantics question, like why how can you have
a universe and a multiverse? Wouldn't it it all just
be the universe? Yeah? Well, I think the answer there's
a scientific answer and a semantic answer there, because you know, originally,
(08:35):
I think the universe is designed to mean everything that
there is. It's just like, instead of saying the phrase
all the stuff and all of the space and all
the matter and everything, you want a more compact phrase,
and so we have universe. But then that sort of
came to define a set of ideas, and when you
want to expand on those ideas, then you need to
add a new word for a new meaning. So like
(08:57):
if universe is sort of semantically flexible and means like
our current understanding of everything that could possibly be. Then, yeah,
there's just one universe by definition. I guess you sort
of downgraded the definition of universe like youas mean everything.
But then because this were like maybe there's more to everything,
or where there's more everything everywhere else, and specifically we
had new ideas for how to get more everything or
(09:19):
where more everything could be, or in in other ways
you could have stuff, and so the sort of categorically
different kinds of stuff and places, and so that I
think is why we came up with a new word
for it. But maybe we should talk a little bit
about what it means to have more than one universe
or where that other stuff could be. Yeah, yeah, because
I think what's was sort of blowing her mind is
(09:42):
just this idea that there's everything and then there's other
Everything's like where are they? Are they next to the
other everything or are they on top? Or how does
that work? Yeah? And it's especially hard to understand if
the universe is infinite, because then how do you squeeze
all that stuff together? Right? And when people we'll talk
about universe, they often mean different things and so sometimes
(10:04):
it's just semantics. And sometimes when people say the universe,
they really mean the observable universe, like the part of
the universe that we can see, which goes out several
billions and billions of light years, right, And sometimes people
think of other universes as just like other observable universes.
If you're somewhere really, really far away, you would have
a different observable universe because you would see a different
(10:26):
like patch of the infinite universe. I think that's kind
of lame, because we already have a phrase for that
observable universe, sub universe. Yeah, exactly. It makes our observable
universe is like a sub universe of the whole universe.
So technically that's in the category of multiverse. Some people
call it multiverse, but I think it's sort of silly.
(10:47):
I think more interesting is this concept like that our
universe could be infinite and yet there could also be
other universes, right yeah, because like, well, how do you
fit it all in? How do you fit it all
in exactly? And to fit it all in you have
to have like other kinds of space. Because remember that
what we think about is our universe is the space
(11:08):
we live in the space and all the matter and
and all that stuff, and that could go on forever, right,
But then also there could be variations on it. And
really the only way to reconcile having an infinite universe
and having multi verses is to go for the quantum multiverse,
the one where our universe is splitting into different possibilities
at every moment. So this is the idea that every time,
(11:32):
like a particle makes a decision, another universe pops out. Yeah,
exactly is to try to answer the question like when
the universe makes a seemingly random decision for quantum mechanics,
why is it that one and not another one? When
the electron has to decide do I go left or
do I go right? Then you know, why is it
go left? It seems weird, It seems arbitrary. And as
(11:54):
you know, physicis don't like beings the same art jury.
We want an explanation, kind of like chilled in right,
They always want to know why why can't I have
cookies at nine pm at night? What's what's going on?
The show is really called Physicists Wonder Why, But we
wanted to make a kid's ship. It seems arbitrary, then
it seems arbitrary. So we invent this other universe to say, well,
(12:15):
maybe it's balanced. You know, we're in the left direction,
but there's another universe where the electron went to the
right direction, and that somehow satisfies your need for symmetry,
for balance, to say that it's not just arbitrary that
it went left, because it went in every direction and
we just ended up in one of those right. And
the idea is that there weren't two universes before, but
once that particle makes a decision, whether it's been right
(12:40):
or it's been left, then now there are two universes.
So before there was one, now there are two. And
that happens every time a particle in all of existence
makes a decision. Yeah, and it's crazy, right, It's hard
to imagine because there's ten to the eight particles and
they're doing stuff every you know, nanosecond or whatever, and
so the number of universe it just becomes absurd very
(13:02):
very quickly. Plus the universe is billions of years old,
so like, how do you even fathom the number of
different universes in this scenario, It's like infinity to the
infinity to the head explosion power. You know, it's just
it's just the number. We can't even really think about.
It's more cookies than even your kids could eat, even
at nine pm. Even at nine pm, they'll happily take
(13:22):
the challenge. I'm sure you gotta take data right. You
can't just make assumptions. You've got to do the experiment.
Can put limits. Doesn't really answer her question right, like
say that that's true, say that's actually happening, that that's
our reality. Then where are those other universes? You know,
where are they in space? Right? And that's not easy
(13:43):
to answer. They're not really like anywhere. You know, we
have branched. We are in the left universe and not
in the right universe. It's not like the right universe
is one we can ever interact with. We can't like
send a message to that universe. We're not causally connected.
We're separated from that universe, so we can never interact
with it in any way. It can't influence us, we
(14:04):
can't send messages, it can't change us. So from our
point of view, it doesn't exist in our space at all. Well,
how do you know that, Daniel, I guess how do
you know there that there's no way that there we
can make a connection to them, because in sciences fection
you see it all the time, like spreaking the walls
between the different universes, and you can travel to a
different universe. Are you saying I saw this in a movie,
(14:25):
So how do you know it's not possible? Basically, I
also saw flying saucers and jet packs Daniel episode. We'll
get to those later. Well, it comes from the very
construction of the multiverse. Rights the multiverse. The other universe
is created when the universe splits, when you make a
different decision. So then our universe is inconsistent with that universe.
(14:47):
It's like a copy of our universe, but with a
different decisions. So the two have like the same history,
but now a different future. And so how did the
two even talk to each other? They have like an
inconsistent history for what has happened. It's like an alternative.
It's not like, you know, a different fork in the
path while I'll go left and you'll go right, and
maybe the paths will meet again. It's like you know,
(15:09):
once you decided to press the button, you can't unpressed
the button. All right? I think now I have a
lot of questions about this Daniel, and so let's get
into where these other universes might be. But first let's
take a quick break. All right, Today we're asking questions
(15:38):
from Eleanor, my daughter, who is also the inspiration for
our new kids television show called Eleanor Wonders Why, which
is all about getting kids interested and curious about nature
and all the amazing things in it, like animals and
bugs and lizards. Maybe mosquitoes actually came over from the
multiverse because I hate them so much, but I love nature.
(16:00):
Think they come from a dark, dark universe. I imagine, like,
who would suffer if we just deleted mosquitoes from the universe? Really,
nobody would be harm Can't we just all vote to
do that? You know, I think bads eat mosquitoes, Daniel,
so that would be bad news for bad, which, by
the way, is also a character in our show. So
Eleanor in the show is a bunny rabbit, and she
(16:21):
has two best friends, are a funny and very active
bad and also Olive, who who's an elephant. And all
of it's sort of based on your daughter, right, Daniel
Alive is partially inspired by my daughter, That's right, All
of the character in the show is a real reader
and likes words, and my daughter Hazel is like that. Yeah,
so she helped inspire us. And the curiosity of all
(16:41):
of our children and of all the children we've met
out there helped inspire us. I give sometimes lectures to
elementary schools about science, and my favorite bit is the
question period afterwards, when they ask any question they have
in their mind, and they're always like surprising, mind blowing,
and sometimes it's difficult to answer questions. Yeah, So if
you have young kids, or if you have friends with
(17:02):
young kids or nieces or nephews or grandkids, we would
really encourage you to tell them about the show. It's
called Eleanor Wonders Why, and it's available right now in
the US at PBS Kids dot org, slash Eleanor E
l I n O R and also the PBS Kids app,
which you can download for free and watch all these
episodes for free. They're also available on the PBS Kids
YouTube channel and also on the Amazon Prime PBS Kids subscription.
(17:26):
Those you can put on repeat, which we hear a
lot of parents are appreciative of. So today to celebrate that,
we are answering questions from Eleanor, the real Eleanor, and
she had a question about the multiverse. So, Daniel, we
were talking about the multiverse. If the multiverse is real,
where where are all these other universes at? So you're
(17:47):
saying we can't access them, we're not connected to them,
because it's more like we're different possibilities. Is that kind
of what what do you mean? It sounds very abstract,
like are you saying we're an abstraction in that theory
the multiverse where there's a different universe created every time
a quantum mechanical particle has to roll the dice, Then yes,
we are just one of those many many many many
(18:09):
many many many to the many power universes. And so
two people in or creatures in one of those other multiverses,
we are that abstraction. And that's the part of this
theory that I don't really like because it tries to
answer this question of why are we in this universe
and not in another universe where other random decisions were made.
Doesn't like randomness and tries to answer that by saying
(18:31):
every random decision is made. But to me, it doesn't
really answer it, because you know, I'm in this universe
and not in any other one, and so it's it
goes back again to that question of consciousness, like why
am I experiencing this universe and not those universes? So
to me philosophically, it's pretty unsatisfying. Plus, it's just hard
to think about, like where are all those other universes?
(18:54):
Eleanois question is a great one. You know, how do
you have multiple infinite universes? Where are they? And you know,
the best way to think about it is that we
have an infinite pocket of space to play in here,
our universe, our quantum slice of the universe, and those
other ones they have their own inefinite pockets of space
(19:14):
to play with, but they're not connected to ours. The
only way to answer the question where is something is
to think about their physical relationships, you know, like where
is your neighbor's house? It's next to yours, Because our
brains are sort of hard wired to think about space
like that, right, like spatially, Well, that's what space is. Remember,
there's no absolute locations anywhere. It's all relative. And so
(19:36):
if there is no relative position between this universe and
the other universe, then you can't put them in any
space together. So they really have their own spaces. So
I think what you're saying is that I should tell
eleanor that Daniel doesn't know. Daniel definitely doesn't know if
those universes exist and if they do, where they are.
(19:56):
But I'm pretty sure that if they exist, we can
never talk to them or interact with them, or even
prove that they exist. And a lot of people say
that makes this not a very scientific idea because if
you can't test it, how could you prove it's true.
And if you can't prove it's true, then it's really
just speculation and not even really science, right. Yeah, you
need to be able to formulate it, right, like as
(20:18):
a hypothesis, and be able to prove it or disproven
or a design a test to prove it or disprove it. Yeah,
a lot of people like Carl Popper's theory of falsifiability,
that is an idea is not scientific if it's not falsifiable,
And then some people think that's garbage. But I just
feel like, how are you going to pick an idea, Like, sure,
you have this idea of quantum ultiverse, somebody else has
another idea. If you have competing ideas, to me, the
(20:40):
way to pick between them is to do the experiment.
That's what experimental science is about, is a way of
cornering nature into revealing what's happening by constructing a situation
where different things happen based on the reality. You know,
the experiment, that particle goes left if it's this way,
or it goes right if it's that way and that way.
The universe gives you a clue. But if there's no
way to interact with the rest of the multiverse, there's
(21:02):
no way to prove it's there, then is it really there?
And if it is, doesn't really matter all right, Well,
it sounds like the answer is we don't know, but
we may never get to these other universes. And also
maybe the answer is a little bit like don't think
about it as these other universes being anywhere like on
top of us or next to us or below us,
(21:24):
But think about it more like there's just sort of
like there as well as us, right, Like it's it's
just there. They're just they're just like we are here.
But even the word there implies a space. You're like,
they're over there. Well, I would say they are what
they are and we are. Yeah, I would stop it
are not they are there? Just they are? They are?
(21:45):
We are they are? Where are there? We don't know?
All right, well, awesome question. We also have another question
from Eleanor here we're going to try to answer, and
it's about the shape of space that's hard to shape
and event like, oh, a giant wall that is like
curves and you can't come out of it. Alright, awesome questions.
(22:08):
She's asking about what the shape of space is, and
if it has the shape, what's at the edges of it? Like,
if if it has the shape, it must have an end,
and so what's at the end. Is it a curved wall,
is it a flat wall? Is it a stuckle wall?
Who knows? I think she's been stuck inside too long.
She's thinking about edges and boundaries. Oh boy, you know
(22:32):
another I think about it. I do kind of see
the inclings of these questions, where these questions that have
came from. Like I'm thinking back over like the last
couple of months or years, I've seen her sort of
formulate this question a little by little, Like she asked
a little bit about the universe, a little bit about space,
a little bit about this, and I think it all
just been sort of marinating inside of her head. Well,
(22:53):
it's awesome. As kids grow up, they understand more and
more about the world around them, and then they're sort
of mental context rose and they can imagine this city,
other cities, the country, the whole world, the solar system,
and eventually, you know, inside their minds, they're creating this
model of the whole universe. And that's when this awesome
thing happens that they have questions about it. They're like,
(23:14):
wait a second, this model in my head doesn't really
make sense or what do I put here? And that's
where these questions come from. And that's you know, that's
science in action, right, And it's pretty cool that she
just blurted out this question, like we're just folding laundry
and she just suddenly pops out this question like it's
been building up inside of her and she just had
to let it out. Like isn't that cool that? I
feel like as adults, we would just a lot of
(23:36):
us just keep it to ourselves, Like if you're a
dinner with the date, you wouldn't be like, you know,
talk about one thing and then suddenly be like, hey,
have you ever thought about the shape of the universe.
But then again, maybe I'm not a physicist because I've
done that. It depends on the kind of person you
want to date, that's for sure, But it also depends
on the kind of person you are. If you encourage
these kind of questions and your children, if you enjoy
(23:58):
exploring them with your kids, if having kids helps you
renew this like naive curiosity, which still is driving basic
questions in science. So I think it's wonderful to tap into.
And you know, that's what we try to tap into
for our show. A lot of the episodes for our
show come from real questions asked by real kids about
their universe. Yeah, and every episode in our show, Eleanor
(24:20):
Wonders Why. We try to think about a question that
kids would have and we try to answer it, like
why do birds have feathers? And why do lizards like
to sit out in the sun, and all kinds of
fun kids questions, And why does my dad not know
the answer to my physics questions? Why does he have
to ask his friend? Why does he have to ask
you know, hundreds of thousands of people out on the internet. Well,
(24:42):
let's try to give Eleanor an answer. Yeah, so she's
asking what is the shape of space, like the space
does the universe have a shape? Like, if you keep
going long enough, what happens? Do you run into a wall?
And what does that wall look like? Is it like
a physical barrier? Is it curved? Does have a texture?
The has it heard if you slam into it? What's
(25:03):
going on? Well, it's fascinating that she asked this question
just after she asked the other question where she's assuming
an infinite universe. Now she's wondering like could the universe
not be infinite? Right? How do you understand anything other
than infinity for a universe? Right? Well, this one was
kind of a follow up question, Like she asked the
first question and then she sort of thought about it
(25:23):
for a second, and then she has this one. So
I think maybe she's also grappling with this idea of infinity.
Like you said, like infinite doesn't make sense to her,
There has to be an end to it. Actually, I
think the opposite. I think infinity is much more natural
than an edge, right, Like, as weird as infinity is,
it's hard to grapple with, but it seems sort of
natural because then you get to avoid edges and then
(25:44):
we don't have to explain the edge or the weird
shape of the universe because it just goes on forever.
But then you have to explain forever, Daniel, see how
this helps you. We'll have a very long answer for
why forever makes sense. It goes on forever. It just
goes on and on. This bit on, and then there's
that bit, and there's other bit and then yeah, this
is the longest podcast every but usually falsely before they
(26:06):
ask you for a follow up. And so to answer
her question, like one possibility, one very real possibility is
that the universe is infinite, that space is infinite, and
that it's always been infinite. The thing that's hardest for
people often to understand about the universe being infinite is
that they imagine the Big Bang having started the universe
from a point, so then how would stuff get that
(26:28):
far away? But instead, all you have to do is
imagine not just that our universe is currently infinite, but
that it always has been infinite. That the Big Bang
was just a period where the universe was denser and hotter,
and since then it's been expanding and becoming more dilute.
But it went from an infinite, hot universe to an
infinite cold universe. So that's one very real possibility, and
(26:49):
that's my sort of personal philosophical preference for which I
have no evidence. That's the Daniel interpretation of total guessing
about the universe. Total guessing is step one in science though, right,
all right, so that's one possibly. But I think she's asking, like,
what if instead of having an infinite universe, we have
(27:09):
a finite universe? And so if it's finite, what's the
shape of it? Like is it a big sphere? Is
in the shape of a duck? Is in the shape
of a giant squirrel? Is it a cube? You know?
And also like what's at the end? Like if you
keep going in one direction of the universe, what happens
(27:29):
when you hit the end of it? Do you stop existing?
Do you bounce back? What happens? Well, the basic idea
to get in your head before we get into the details,
is that space is not as simple as you thought
it was. Space is not just a place for matter
to be, like an emptiness you know, on which stuff happens.
Space itself can have shapes. And this is something we
(27:51):
already know because we see that space bends. Right. Our
understanding of gravity now is not a force between objects,
but the interaction of matter with space. Matter bends space,
and then space changes how matter moves. What that means
is that space can have a weird shape. It doesn't
just have to go on forever. It can curve, it
(28:11):
can bend. It has weird pockets in it. These things
space traps, which most of the rest of the community
calls black holes, are weird pockets of space where space
sort of has like a discontinuity and edge and like
a loop, right, Like in a black hole, you can't
you can't leave it because it's it's pulling on you.
You can't it's it's a you can't leave it because
space around a black hole is like loop right, Like
(28:34):
it's a doughnut kind of like a circle. Yeah, space
is one directional inside and black hole. So space can
do all sorts of really weird things. So first get
your sort of like mental idea of space be a
little bit you know, squishy and flexible, and so we
can fold and do weird stuff, and then we can
insert into your mind other ideas for the shape of
the universe and sort of The simplest is that the
(28:56):
universe is finite but it has no edge because it's
sort of constructed in a loop. Like if you just
keep going in one direction, eventually you'll come back to
where you were, right, kind of like a satellite in
orbit around the Earth. Or even if you just travel
on the Earth in one direction, you'll come back to
the same spot. Yeah. If you build a road around
the equator and you just keep driving on it, you'll
(29:18):
come back to where you started. And that's because of
the geometry of the Earth. Right on the surface of
a sphere, you can just keep going, you'll come back
to where you are. And you wonder where, Well, how
do you do that for three dimensions? Well, if space
is complicated, if space is a thing which can bend
and twist and be connected in weird ways, right like
around a black hole, then it can be connected in
(29:40):
this way so that one bit of space is now
connected to another bit of space on what would be
the other side of the universe. You can arrange space
in sort of a three dimensional equivalent of the surface
of a sphere, Like you can take a universe and
kind of wrap it around and connected to itself. Yeah,
and and then so you would have a shape. Yeah,
and the key thing to avoid is trying to understand
(30:01):
this by putting the universe into a higher dimension. Don't
think about the three D universe on some four dimensional sphere,
because I would create another dimension of space, which we
don't have any evidence to believe exists. Just think about
the relative connections between things in space. If this point
in space is connected to the next pointed space is
connected to the next point in space, and then just
(30:23):
imagine a ring of these points. Each one is connected
to one to the left and one to the right,
and together they construct a ring. And then imagine the
three D analog of that ring. Again, it's not like
on the surface of a three D sphere. It's just
about the ordering of the points relative to each other.
All right, well, let's I have questions about that, and also, Daniel,
(30:46):
let's get into maybe a little bit more of the
specifics and also maybe think about the alternative that maybe
space space is flat. What are the possibilities there? So
let's do that, But first let's take a quick break.
(31:10):
All right, we're answering questions from Eleanor, my daughter, who
is the inspiration for like one of the characters in
the show Eleanor Wonders why, which is our new kids
showing that is out right now and we're celebrating its
release this week. And so Eleanor had a question about
the shape of space, and Danna you were saying that
maybe space is bendable, and well, it is bendable, but
(31:33):
maybe the shape of spaces that it loops around onto
itself like it's wrapped around itself. Yeah, And that's more
like the topology of space than the shape of it.
It's like about how the points are connected to each
other rather than like, you know, how it's bent by
mass in any sort of local configuration. It's sort of like,
you know, how you put the whole thing together, And
that I think is sort of the easiest one to
(31:55):
understand because it lets you have finite space, like it
doesn't go on forever without having any sort of edges,
because people feel weird about the edge, Like, you know,
you can't imagine that coming to a brick wall with
a sign on it. This is like the universe ends here,
because then you wonder like, well, what's on the other
side of the brick? Right? Yeah, Well, yeah, I think
you know, that's a little bit of where her mind
(32:16):
is coming from, and that you know, she's probably not
aware of these ideas about bending of space, So to her,
space is just sort of like this infinite emptiness. And
so is that a possibility? Could it be that maybe
space is not curved but it does have an edge, right,
because I think we know that space is not generally curved.
(32:37):
We think it's flat. Our local part of space at
least is flat, and we think there's enough stuff in
the universe to make space generally flat. But yeah, space
could be flat, and it could be finite, and it
could have an edge. And we don't like the idea
of an edge because it's a discontinuity. We have to
explain it. What would it be like? But it's not impossible, right,
(32:59):
Space can do really weird things and and have edges,
Like you know, the event horizon of a black hole
is basically like a boundary of space, and so you
could come to some boundary and you know, it wouldn't
be some like weird thing with like flashing lights and
blue stripes or whatever is they would put it in
a movie. It would just be like, you know, space
does something weird here, so like there just isn't any
(33:21):
more space to go into, like you know, the way
in a black hole, you can't just move in any
direction you want, because space has a single direction you
can go in. It could be you come to a
point in space where there just is no more space
in that direction. It's like coming to the north pole.
There is no more northiness to go to. So that
is the possibility, is that space could be kind of
(33:44):
flat and its curving nows meanings has kind of a volume,
and that it does have an edge to it like
it does it does end like a blob. It's a possibility.
It's not a frequently discuss possibility or a popular possibility
among like current cost oologists. There's no like reason for
space to have an edge, and so it's not something
(34:05):
you need to add to your theory. It's much more
natural to just say every point in space is the same,
and therefore the universe should be infinite. But it's not
against the laws of physics as far as I'm aware,
and you know, we imagine the universe having an origin
in time. There was a moment in time when things
were created and then inflation dot dot dot dot, and
so it's not that outlandish to imagine a discontinuity or
(34:29):
an edge. Also in space well, and and then her
question was sort of like, what's the shape of it? Like,
if it is like this and it does have borders,
do you think it'd be like a sphere like a potato?
Like I think it'd be like a huge question mark,
question mark? What would be in the dot? I'll read
the dot, Daniel. We're in the dot. We're the dot.
(34:52):
That's right, that's my philosophy. No, we have no idea,
we have no idea of space as an edge, and
if it had an edge with that shape would be
I mean, your intuition would say it should be a sphere,
because that's the simplest thing, right, But we were just
really we're just really don't know how awesome would that
be though, to discover the universe had an edge and
to map it out and to understand it. You know,
(35:15):
if it's not a sphere, then probably it would be
like a randomly shaped blob controlled by some like early
quantum fluctuations or something crazy. I'm gonna go with banana.
I bet it's shape like a banana, and then I'll
be justified in all of these discussions about bananas, Daniel,
because you knew it the whole time, it wasn't just
a random guess that was later proven out to be true.
(35:35):
You knew because the universe was speaking to me. It
was crying out for, you know, some sort of recognition
of its banana. Yeah, and you know, there is another
sense in which the universe kind of does have an edge,
and that's again just back to like our observable universe.
There's only a portion of the universe that we can see.
And so if you think about the universe is like
the stuff that we can see, everything that's around us
(35:57):
that really does have an edge because there's parts of
the universe that are so far away that light hasn't
had chance to reach us from them, and so we
haven't seen them. And because the universe is expanding and
that expansion is accelerating faster than the speed of light,
we may never see them. And so this sort of
like a spherical wall past which we cannot see and
(36:20):
past which we may never be able to see or go. Right, Yeah,
but that's part of a philosophical wall, isn't it. Or
do you think maybe it's the same thing, And let's
not get philosophical on the podcast, right, Gosh forbid, we're
talking about the universal questions. No, I mean it's not fundamental, right,
Like you can imagine that there's a point out there
in space beyond which we cannot see, and if we
(36:42):
look at that point, we're seeing like the early universe
because light is taken forever to get here from there.
But it's sort of unsatisfying because there's something recent happening
at that point right now. You know, we see old
light coming from that point, but you know, stuff's been happening.
There's things going on. Alex Scenes are forming alien civilizations,
hopefully are inventing cool podcasts. So what we're seeing in
(37:06):
that direction, it's always happening now, so we think the
universe continues on even though we can only see this aging,
observable shell that surrounds us. So in that sense, it's
it's observation more than philosophical. All right, Well it sounds
like that again. The answer for Eleanor is Daniel doesn't know.
Nobody knows, Daniel doesn't know, the new name for our podcast,
(37:26):
Daniel doesn't know things. Daniel doesn't know. Basically, nobody knows, right,
I feel like we don't know at a very fundamental level,
Like it could be infinite or it could not be infinite,
and there's a big difference between infinity and non infinity.
And that's the joy of these questions. That the questions
that children ask, the very basic questions, the first questions
that come into your mind when you hear about these ideas,
(37:47):
those are questions scientists are still asking. So if you're
six years old or you're sixty years old and you're
on the forefront of cosmology, you're asking the same questions.
And that's what makes physics shockingly accessible. I would say
that our cluelessness, our lack of progress, makes us accessible.
Or if you're six years old and an alien and
(38:08):
do have the answers to these questions, please let us
know so I can tell eleanor what the answer is.
But that's one of the reasons why we wanted to
make this show is that we felt like this kind
of curiosity is wonderful and it powers scientists in their career,
and also it powers children. And we see it in
the very youngest children, and we want to nurture it,
we want to protect it. Sometimes it feels a little
(38:30):
bit fragile, and so in our show, we wanted to
encourage this kind of curiosity by showing kids on screen
how curious kids can ask questions and how they can
find the answers for themselves. And that's why we love
the show. That's why we love the show. And if
you like a mix of science and kind of corny
dad jokes, then hopefully you'll also like the show. Yeah,
(38:51):
so help us celebrate the release and the premiere, at
least the US premiere, and we're still trying to get
the show in other countries. But help us celebrate the
US premiere of Eleanor. There's why the show that Daniel
and I co created. It's for kids. It's about a
cute bunny rabbit and her friends about and an elephant
and this really beautiful and gentle but also curious and
(39:13):
funny world. And it's out now on PBS Kids dot org,
slash Eleanor, E l I and o R and also
the PBS Kids app, and also on Amazon Prime ppious
Kids subscription, and also I think they're posting episodes on
the ppous Kids YouTube channel, So there are plenty of
ways for you to watch the show, and it's all free,
(39:34):
and please help us celebrate and tell your friends, your
nieces and nephews and grandkids about the show. We think
they'll really enjoy it. That's right. It's a world we
created filled with people who are curious, who ask questions,
and who find answers to those questions. So if you
want to spend half an hour in a gentle world
filled with curiosity, please go check it out. Yeah, and
(39:55):
we hope you enjoyed Eleanor's questions today about the multiverse
and about this shape of space at really kind of
stretches your mind, right, Daniel, it definitely does. And you know,
just because the question comes from a young kid doesn't
mean it's easy to answer. As we ran today, those
are my favorite questions. We invite Eleanor to a seminar
at you see your vines physics department, she'll stump. They're
(40:17):
open to the public, so come on in. All right, Well,
thanks for joining us, see you next time. Thanks for listening,
and remember that Daniel and Jorge Explain the Universe is
a production of I Heart Radio or more podcast from
my Heart Radio visit the I Heart Radio app, Apple Podcasts,
(40:41):
or wherever you listen to your favorite shows.
Hosts And Creators
Daniel Whiteson
Kelly Weinersmith
Popular Podcasts
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
Dateline NBC
Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com
Las Culturistas with Matt Rogers and Bowen Yang
Ding dong! Join your culture consultants, Matt Rogers and Bowen Yang, on an unforgettable journey into the beating heart of CULTURE. Alongside sizzling special guests, they GET INTO the hottest pop-culture moments of the day and the formative cultural experiences that turned them into Culturistas. Produced by the Big Money Players Network and iHeartRadio.