Speaker 1: If everything is quantum fields, how do their ripples make
Speaker 1: banana peels?
Speaker 2: What's the mutation rate for the common cold? Does the
Speaker 2: virus change moving through my household?
Speaker 1: Is their mass? In pure information? Do I get heavier
Speaker 1: with more education?
Speaker 2: Whatever questions keep you up at night, Daniel and Kelly's
Speaker 2: answers will make it right.
Speaker 1: Welcome to another Listener Questions episode on Daniel and Kelly's
Speaker 1: Extraordinary Universe.
Speaker 2: Hello. I'm Kelly Wienersmith, and I study parasites and space,
Speaker 2: but not parasites in space.
Speaker 3: Not yet, at least that's all right.
Speaker 4: Hi.
Speaker 3: I'm Daniel.
Speaker 1: I'm a particle physicist, and I want to figure out
Speaker 1: the problems of the universe before the aliens come and
Speaker 1: spoil the story by telling.
Speaker 2: Us, oh, interesting, you know. The intro sort of makes
Speaker 2: it sound like maybe this is going to be an
Speaker 2: episode about Bigfoot or something. We both have gotten a
Speaker 2: little bit out there with our intros this morning, but
Speaker 2: we're going to bring it down to Earth, which reminds
Speaker 2: me of an interesting talk that I gave on Earth. Well,
Speaker 2: I don't know if it's interesting. It was my talk,
Speaker 2: the talk that I gave for Western University Space Day
Speaker 2: recently and I was giving my usual City on Mars
Speaker 2: talk and up in the balcony was an entire Girl
Speaker 2: Scout troop boom.
Speaker 1: Do you think they were looking to plan an expedition
Speaker 1: to space?
Speaker 2: I don't know. Girl Scouts can do anything. Many maybe
Speaker 2: they were. Maybe they're planning on taking over the world,
Speaker 2: but they want to know how to take over space too.
Speaker 2: They did bring delicious cookies, so that was great.
Speaker 3: Do they ask good questions?
Speaker 2: That's what I was going to say. They asked the
Speaker 2: greatest questions, so they asked fantastic questions. And I was
Speaker 2: a little bit nervous because I hadn't planned on there
Speaker 2: being kids. So I have a whole section about how
Speaker 2: the process of expanding family size might be indited by
Speaker 2: the space environment. And the first question that I got
Speaker 2: was one of the girls from the Scouts raised her
Speaker 2: hand and said, in your section on reproduction. And I
Speaker 2: immediately was like, oh God, this is not a good start.
Speaker 2: I don't want to give the birds and the bees chat.
Speaker 2: And she said something about the image you used on
Speaker 2: that slide had two adults in spacesuits holding two babies
Speaker 2: in spacesuits. Wouldn't it be expensive to make spacesuits.
Speaker 1: For babies, all right, it's an engineering question.
Speaker 3: Yeah, And I think I.
Speaker 2: Said something like I am so relieved that that's what
Speaker 2: you asked, And then I explained, like, you know, sometimes
Speaker 2: it's hard using arts to explain concepts, because we didn't
Speaker 2: actually mean that people will probably be bringing babies in
Speaker 2: space suits out on the surface because space radiation. You
Speaker 2: probably wouldn't want to expose your baby to that on
Speaker 2: the Martian surface.
Speaker 1: And then you need like constantly new spacesuits as they grow.
Speaker 1: I know, as a parent of children who once grew
Speaker 1: very rapidly, that's very frustrating how quickly they outgrow all
Speaker 1: their stuff.
Speaker 2: Oh my gosh. Yes, but I mean eventually we will
Speaker 2: need different shapes and sizes of space suits for the
Speaker 2: diversity of body types that will be up there. But
Speaker 2: my question for you is, have you ever worked with
Speaker 2: an artist or use some art that didn't at all
Speaker 2: portray what you had intended and you didn't realize it
Speaker 2: would be taken seriously because you just meant it to
Speaker 2: be like a cute, funny image about families in space,
Speaker 2: for example.
Speaker 1: Well, the stuff that I write about usually is pretty
Speaker 1: family friendly, but often it's kind of abstract, and I
Speaker 1: struggle sometimes to describe it accurately with words, and then
Speaker 1: I wonder, like, hmmm, how is my illustrator friend going
Speaker 1: to put this into a picture? Like what visual can
Speaker 1: you use to describe quantum fields and tie this all together?
Speaker 1: But I've been lucky to work with very talented illustrators
Speaker 1: who do a great job of making these exceptional visuals,
Speaker 1: taking the abstract and making a concrete so that the
Speaker 1: reader can understand the concepts.
Speaker 2: To be clear, I think my artist collaborator, slash husband
Speaker 2: does a great job. But I think sometimes you just
Speaker 2: assume that the audience will get that this is just
Speaker 2: like a fun artistic image, as like a palette cleanser
Speaker 2: for the difficult stuff we just told you. But you
Speaker 2: know it doesn't always go over the way that you intended.
Speaker 1: Yeah, well, there's another fine line there, which is sometimes
Speaker 1: you want to make jokes to lighten the mood, right.
Speaker 1: I remember in our first book, we talked about what
Speaker 1: space can do, and I'd written this space can bend,
Speaker 1: it can expand, it can ripple, and Jorge drew a
Speaker 1: hilarious little doodle of space bending and expanding and rippling,
Speaker 1: and then he added a fourth one of like space breakdancing,
Speaker 1: and you always got to wonder like, okay, is that
Speaker 1: ridiculous enough that people get Okay, that's obviously a joke
Speaker 1: to lighten the mood, or somebody out there being like, well,
Speaker 1: I don't know if space can ripple and expand maybe
Speaker 1: it could breakdance.
Speaker 3: What does that mean?
Speaker 1: We are the equations of breakdancing.
Speaker 2: Yep.
Speaker 1: So you always gott to walk that fine line.
Speaker 2: Zach and I have had so many of those conversations
Speaker 2: where he's like, people are going to get it's a joke,
Speaker 2: and I was like, maybe they won't. There are humorless
Speaker 2: people out there who will be confused.
Speaker 1: And sometimes the reality is so ridiculous people might think
Speaker 1: you're making a joke. In our latest book about what
Speaker 1: science Aliens Might do, we talk about how people tried
Speaker 1: to communicate with aliens, and there's a guy who wrote
Speaker 1: letters in the sand and set them on fire hoping
Speaker 1: that Martians would read them. And that sounds like I'm
Speaker 1: made up ridiculous example. So I remember adding a footnote
Speaker 1: being like, I know, we make a ridiculous example sometimes
Speaker 1: for humor. This is not one of those cases.
Speaker 2: Yes, everyone while humans are just so crazy you need
Speaker 2: to be like, no, this isn't a joke. I'm not
Speaker 2: going into fiction here.
Speaker 1: Amazing And if anybody's interested in that book, it's coming
Speaker 1: out in November. It's called Do Aliens Speak Physics? By
Speaker 1: it anywhere you get books, and.
Speaker 2: I read an early copy and I can tell you
Speaker 2: it's amazing.
Speaker 3: And we're gonna be talking about it a lot until
Speaker 3: it comes out.
Speaker 2: Yep. Yeah, nice to have a platform. You know what
Speaker 2: else is awesome?
Speaker 3: What's that?
Speaker 2: Our listeners, they are so awesome and they ask such
Speaker 2: amazing questions. And we've got like a question from kids
Speaker 2: theme going on today, and so let's start with our
Speaker 2: first ques question from Ryan and thirteen year old Grace
Speaker 2: from the best states in these United States.
Speaker 1: I'm confused, they're not from California.
Speaker 3: What are you.
Speaker 2: Talking about, oh, Daniel.
Speaker 1: Despite their coming from Virginia, Let's hear about Grace's question.
Speaker 4: Hey, Daniel and Kelly. My name is Ryan and I
Speaker 4: have my thirteen year old daughter, Grace here with me.
Speaker 4: We live in Virginia, and she came up with an
Speaker 4: interesting question after we discussed your episode on particles and
Speaker 4: the current understanding that they are ripples in fields?
Speaker 5: Hi, this is Grace, and here's my question. I don't
Speaker 5: understand how ripples make things. For instance, how do a
Speaker 5: bunch of ripples in a field somehow all add up
Speaker 5: to make a person or banana or sloth? Thanks for
Speaker 5: taking my question. We love the podcast all.
Speaker 2: Right, Daniel, As someone who is a huge fan of sloths,
Speaker 2: I now desperately want to understand how ripples help make
Speaker 2: up a sloth.
Speaker 1: I love this question because this is the whole point
Speaker 1: of physics, to take our everyday experience and explain it
Speaker 1: in terms of the microscopic stuff that's happening. To like
Speaker 1: pull back the veil and say what's really going on underneath?
Speaker 1: And it's cool to say, oh, what's going on underneath?
Speaker 1: Is this complicated thing with fields and particles and waves
Speaker 1: and whatever. But Grace is exactly right that the second
Speaker 1: part of that is to weave it together so that
Speaker 1: it does explain our everyday experience. You've got to give
Speaker 1: a path sort of like an intellectual ladder, from the
Speaker 1: microscopic explanation back to the macroscopic to show how they
Speaker 1: come together. So thank you Grace for asking this question.
Speaker 2: It's a fantastic question, and I love that both banana's
Speaker 2: and sloughts got featured exactly because what good is physics
Speaker 2: if it's not explaining biology.
Speaker 1: And maybe there's a banana sloth out there, oh that
Speaker 1: we could explain.
Speaker 2: One day, delicious and easy to catch.
Speaker 3: Probably why they went extinct.
Speaker 1: So let's get to particles and ripples and quantum fields
Speaker 1: and all that. Grace's question is how ripples make things.
Speaker 1: So let's zoom all the way back down to ripples,
Speaker 1: and then let's walk our way back up to the
Speaker 1: macroscopics to the sloth in the banana. So like one
Speaker 1: hundred years ago, we were trying to understand what stuff
Speaker 1: is made out of. We started taking stuff apart, and
Speaker 1: we realized it's made out of elements, and those elements
Speaker 1: are made out of atoms, and eventually we had little
Speaker 1: particles protons and neutrons and electrons, and back then, I
Speaker 1: think people were still thinking that those were little bits
Speaker 1: of stuff that you could like pack together like legos
Speaker 1: to make bigger stuff that was the sort of microscopic
Speaker 1: to macroscopic, Like the legos were super duper tiny, almost
Speaker 1: incomprehensibly tiny, and there were so many of them. You know,
Speaker 1: Avogado's number is a big number. But if you click
Speaker 1: them all together, you made macroscopic stuff. And that was
Speaker 1: our understanding, right.
Speaker 2: And on the plus side, you can step on them
Speaker 2: and it doesn't hurt.
Speaker 3: The a particle legos.
Speaker 1: Yes, But then we learned, oh, they're not really little
Speaker 1: bits of stuff. Actually, they're like waves. And quantum mechanics
Speaker 1: came around and told us that they don't have specific
Speaker 1: locations and maybe these particles are actually tiny zero volume points.
Speaker 1: And then quantum mechanics grew up and said, those waves
Speaker 1: are actually even more important because the particles themselves are
Speaker 1: just waves and quantum fields.
Speaker 3: And so that's where.
Speaker 1: We are now that we understand that all the matter
Speaker 1: that's out there, the electron, the quarks inside the proton
Speaker 1: and the neutron, all these things are actually just ripples
Speaker 1: in quantum.
Speaker 3: Fields, all right.
Speaker 2: And there are a bunch of different kinds of fields.
Speaker 2: We've talked about those before, right, And so are we
Speaker 2: talking about a very particular kind of field that makes
Speaker 2: up bananas and slots or are all the fields relevant?
Speaker 1: So you're right, there are lots of different kinds of fields.
Speaker 1: Every particle has a field. So the electron is a field,
Speaker 1: the muon has a field, the cow has a field,
Speaker 1: the top qrk has a field. Every different kind of
Speaker 1: particle has a field. We don't understand why there are
Speaker 1: so many. There're dozens of these fields. Every bit of
Speaker 1: space that's out there has all these fields sitting on
Speaker 1: top of each other in the same chunk of space.
Speaker 1: It's kind of hard to wrap your mind around because
Speaker 1: if you're thinking of like blankets, you know, blankets you
Speaker 1: stack because they can't be in the same location. But
Speaker 1: these fields are all in the same place, and they
Speaker 1: can all oscillate independently. And you asked, which fields are
Speaker 1: we talking about in this case, we're talking mostly about
Speaker 1: the fields that make up us, which are electron fields,
Speaker 1: and two of the cork fields, the upfield in the downfield.
Speaker 1: So there are dozens of those fields out there, and
Speaker 1: there's like big fundamental questions about what that means and
Speaker 1: how do we unify them, and it can be simplified,
Speaker 1: et cetera. But most of the matter in the universe
Speaker 1: is made out of particles which are oscillations in three
Speaker 1: of those fields, the electron field and then the up
Speaker 1: and down cork fields which make the proton and the neutron.
Speaker 1: And how do you understand like a particle being an
Speaker 1: oscillation of a field, what does that really mean?
Speaker 3: What are we talking about?
Speaker 1: Well, when we say an oscillation of a field, we
Speaker 1: really mean that it's vibrating, like the value of the
Speaker 1: field is going up and down, and so because it's moving,
Speaker 1: it can have kinetic energy. And as it has different values,
Speaker 1: it can have potential energy. The way they like a
Speaker 1: book on a shelf has a different potential energy if
Speaker 1: it's on a high point of the shelf or a
Speaker 1: low point on the shelf. Right, you like store energy
Speaker 1: in a book by moving to the top of the shelf,
Speaker 1: you release energy from the book when it falls off
Speaker 1: the shelf. The same way these fields oscillate. They go
Speaker 1: up and they go down, They slosh back and forth
Speaker 1: between tential and kinetic energy, and so there's energy stored
Speaker 1: in the field. So you should think of the particles
Speaker 1: as like not a little dot of stuff, but instead
Speaker 1: a little vibrating blob of energy in the field.
Speaker 2: Oh way, already, like where this is going, I'm a
Speaker 2: vibrating field of energy or made up of vibrating fields
Speaker 2: of energy, and If so, why are the sloths so slow?
Speaker 3: Exactly, they are filled with energy.
Speaker 2: They should be all right.
Speaker 1: So now we have these little vibrating fields of energy.
Speaker 1: Grace's question is how do you put that together to
Speaker 1: make a banana.
Speaker 3: Or a sloth?
Speaker 1: Basically, these things are super duper tiny, but they're not
Speaker 1: like little volume cubes like legos. How do you put
Speaker 1: them together to make something big?
Speaker 3: Right?
Speaker 1: Well, here's the crucial insight. You need the volume that
Speaker 1: we experience. The reason things take up space is not
Speaker 1: from the stuff that they make, but from their interactions
Speaker 1: with each other. So it's not like you have two
Speaker 1: particles and they have surfaces and those surfaces click together,
Speaker 1: or even that they're like two tennis balls that you're
Speaker 1: packing into a space and their surfaces are particles have
Speaker 1: interactions with each other. They exchange energy. This energy we
Speaker 1: were talking about slashing in the electron field or slashing
Speaker 1: in the quarkfield. That energy can slide from one field
Speaker 1: to another. That's when an interaction is so. For example,
Speaker 1: an electron moving through space will also make ripples in
Speaker 1: the electromagnetic field the photons field because those two fields interact.
Speaker 1: There's a connection between those two fields and the ripples
Speaker 1: in the electromagnetic field will then push or pull on
Speaker 1: other electrons. So how do two electrons interact with each other?
Speaker 1: Why do they repel? Because they are both making ripples
Speaker 1: in the electromagnetic field, which has the capacity to affect
Speaker 1: other electrons.
Speaker 2: So I'm going to try to tie this back to biology.
Speaker 2: So I'm thinking, you know, Christmas has ended and I'm
Speaker 2: feeling like my body could do with fewer interactions. Is
Speaker 2: there is there a way to think about it, like
Speaker 2: as you go into calorie deficit, can you think about
Speaker 2: it as like electrons sort of leaving the electric field?
Speaker 2: Or am I just making this too complicated?
Speaker 1: I think there's a Christmas analogy if we can do
Speaker 1: use to understand here. Think about what happens at a
Speaker 1: Christmas party. Right when you put people into a room
Speaker 1: at a Christmas party, do they stack like sardines against
Speaker 1: the wall or like physically phase on top of each
Speaker 1: other and occupy the same space. No, they talk to
Speaker 1: each other and they get like a comfortable distance from
Speaker 1: each other. Right, So you're at a party, people are
Speaker 1: sort of scattered.
Speaker 3: Through a room.
Speaker 1: You're all sipping your Christmas cocktails or whatever, and they're
Speaker 1: not squeezed and touching each other. Right, there's this comfortable
Speaker 1: distance because people are talking to each other and they
Speaker 1: respect each other's personal space. The reason that we can
Speaker 1: generate volume in a banana from a bunch of tiny
Speaker 1: little particles, which are actually ripples in the fields, is
Speaker 1: for the same reason that they have their own little
Speaker 1: personal space. Their interactions keep them apart, and so like
Speaker 1: inside your banana, are a bunch of little ripples that
Speaker 1: are keeping their space between them because of their interactions.
Speaker 1: So the volume of the material comes from the bonds
Speaker 1: between these particles, these little ripples, not from like the
Speaker 1: inherent volume of them, as they're stacked together on top
Speaker 1: of each other. So let's zoom all the way in
Speaker 1: and then out again, just to make sure it all
Speaker 1: makes sense. We zoom as far in as we understand
Speaker 1: the nature of the universe. We have these little ripples
Speaker 1: and fields which are just little buzzing blobs of energy. Right,
Speaker 1: particles are not little scoops of universe stuff. They are
Speaker 1: little blobs of buzzing energy in the field, and the
Speaker 1: fields interact with each other. So buzzing energy in the
Speaker 1: electron field also means buzzing in the electromagnetic field, and
Speaker 1: also in the Higgs field and all sorts of other fields.
Speaker 1: Whatever the electron interacts with and interactions between those fields
Speaker 1: keep these little buzzing blobs in harmony and in balance
Speaker 1: and allow you to build up bigger things. So they're
Speaker 1: not little lego bricks that you click together, but they
Speaker 1: little buzzing blobs sort of in balance with each other,
Speaker 1: keeping their space. And that's where the volume comes from.
Speaker 1: So you zoom all the way out and you look
Speaker 1: at a banana, should think of it as like a
Speaker 1: matrix of these buzzing blobs that are all somehow in
Speaker 1: balance with each other because of their interactions.
Speaker 2: It doesn't sound beautiful, but you know, I study dumb
Speaker 2: trucks full of dead fists, so who are to judge?
Speaker 1: No, but I think that is like peeling back a
Speaker 1: layer of reality, like seeing the matrix and like, oh,
Speaker 1: this is what makes up the banana. And you know,
Speaker 1: what's a banana in your mind is your experience the banana,
Speaker 1: poking on it, pushing on and tasting it, whatever, chasing
Speaker 1: that sloth, all these experiences of what build your sort
Speaker 1: of your mental construct of the banana. But it's nice
Speaker 1: to know, like mathematically, how that comes from the littlest
Speaker 1: bits it's made out of. So thank you Grace for
Speaker 1: asking that question. And we're curious if this answered your
Speaker 1: question and if you have follow ups, So we'll ship
Speaker 1: this off to Grace and we'll hear what she.
Speaker 3: Has to say.
Speaker 2: I also don't think answers have to be beautiful, but
Speaker 2: maybe that's because I'm a biologist. Our answers are rarely.
Speaker 3: Beautiful, but often they're insightful.
Speaker 2: Yeah, I wasn't implying they weren't, Daniel. I don't know
Speaker 2: why you felt you needed to say that, well.
Speaker 1: Because that's where the beauty comes from, right the inside. Like, oh, no,
Speaker 1: I understand this in a way I didn't before. Yeah,
Speaker 1: it can still be gooey, it's true.
Speaker 5: Hi, Daniel Keilly, thank you so much for answering our question.
Speaker 5: I'm still not sure I understand all of it, but
Speaker 5: it was really helpful here you explain it.
Speaker 6: I agree, it's clear I need to change my mental
Speaker 6: model of ways and particles stecking up like lego bricks
Speaker 6: to make things like sloths and instead think about blobs
Speaker 6: of energy. Thank you for all that you both do
Speaker 6: to help educate us and break down complex topics and
Speaker 6: have fun while doing it. I rate your answer a
Speaker 6: solid A plus.
Speaker 5: Thank you so much.
Speaker 7: Bye.
Speaker 2: All right, we're back and the next question is from
Speaker 2: a listener who, when they emailed us, was working through
Speaker 2: a very miserable cold. I believe they're feeling better now.
Speaker 2: But here is their question.
Speaker 8: A common COLDE seems to have a lot of variants,
Speaker 8: But how quickly does it mutate? Such as for the
Speaker 8: common I'm suffering with at the moment, Is there a
Speaker 8: quantifiable percentage of my sneezing and coughing that I accidentally
Speaker 8: spew onto others noticeably different compared to my original infection?
Speaker 8: Or are the variants pretty rare? But given the billions
Speaker 8: of us who get a cold that can create variants,
Speaker 8: a big number times a small percentage can have a
Speaker 8: surprisingly noticeable number.
Speaker 1: Help me out, all right, this is a great question,
Speaker 1: and it's sort of similar in spirit to the previous one, Right,
Speaker 1: getting a microscopic understanding of a common experience, in this case,
Speaker 1: the common cold. So let's see if biology can provide
Speaker 1: the insights to give you that sense of understanding, even
Speaker 1: if we are talking about mucus.
Speaker 2: Well, let's give it a shot, all right, So it
Speaker 2: gets complicated right from the beginning. The common cold. According
Speaker 2: to the Centers for Disease Control, this is defined as
Speaker 2: a viral infection of the upper respiratory track. Okay, okay,
Speaker 2: but it turns out it's not caused by just one
Speaker 2: kind of virus. It's caused by something like over two
Speaker 2: hundred different kinds of viruses. But depending on the time
Speaker 2: of year, between fifty to eighty percent of the common
Speaker 2: colds that people have are caused by a group of
Speaker 2: viruses called the rhinoviruses. So we're going to answer Tim's
Speaker 2: question based on data that we've gotten in labs that
Speaker 2: have looked at rhinoviruses.
Speaker 1: So this is like asking, why is my house infected
Speaker 1: with insects? Well, it turns out there's lots of different
Speaker 1: kind of insects that couldn't infest your house.
Speaker 2: That's right, that's right. And so to answer your question
Speaker 2: without taking too many lifetimes, we need to narrow down
Speaker 2: on an example. So we're narrowing down on the rhinoviruses.
Speaker 1: And so for those of us who are not biologists,
Speaker 1: remind us, like, what is a virus and how does
Speaker 1: it work?
Speaker 3: What is its plan?
Speaker 2: Yeah, So what viruses do is when they get inside
Speaker 2: of you, they have this way of injecting themselves into
Speaker 2: your cell. So they've got like some machinery that helps
Speaker 2: them move around, and then when they get to a cell,
Speaker 2: they clamp down and then they inject genetic material into
Speaker 2: the cell.
Speaker 1: This is amazing. It's empazing. It sounds so mechanical.
Speaker 2: It does. Yeah, I know, sometimes biology is just as
Speaker 2: good as Sci Fi, maybe better. So they hijack the
Speaker 2: cell's machinery and they get the cell to start replicating
Speaker 2: the virus. And this is part of where Tim's question
Speaker 2: comes in. As the virus replicates, sometimes mistakes are made,
Speaker 2: and cold viruses tend to not correct these genetic mistakes
Speaker 2: very often, and so we're going to get to that
Speaker 2: in a little bit more detail layered. So the host
Speaker 2: cell replicates the virus many times, and then the virus
Speaker 2: breaks out of the cell and goes and completes that
Speaker 2: cycle again.
Speaker 1: So the element of the cell that is taking over
Speaker 1: is the bit where it replicates the genetic material. That's
Speaker 1: what the virus can't do for itself. Yes, so this
Speaker 1: is like a hacker breaking into a publishing house. And
Speaker 1: getting it to print his personal manifesto instead of whatever
Speaker 1: it was going to print otherwise.
Speaker 2: That's right, yep. Print it's pamphlets over and over and
Speaker 2: over again. And then through some mechanism that sort of
Speaker 2: breaks the metaphor, it sneaks into another publishing house and
Speaker 2: does the same thing over and over and over again
Speaker 2: until you stop sneezing. So anyway, so it goes through
Speaker 2: this process, and it is finding cells in particular in
Speaker 2: like your nasal passage and your lungs, and it's replicating
Speaker 2: in there. And as it replicates, your immune system sort
Speaker 2: of amps up and starts attacking it. And this cold
Speaker 2: process can last for about a week, and so you
Speaker 2: get a build up of virus particles and then your
Speaker 2: immune system starts to get it in control, and the
Speaker 2: density of virus goes down over time.
Speaker 1: And so if I've had the common cold and my
Speaker 1: immune system has figured out how to combat it, why
Speaker 1: do I then get the common cold again the next
Speaker 1: year or three weeks later when my kids come back
Speaker 1: with a different one.
Speaker 2: Well, that great question brings me to mutation rates. So,
Speaker 2: as I mentioned, the virus doesn't correct mistakes as often
Speaker 2: as for example, human cells do. And so the question
Speaker 2: that we want to ask here to really address Tim's
Speaker 2: question is how many mutations do you tend to get
Speaker 2: and how much do they build up? So I found
Speaker 2: estimates that the mutation rate is you get something like
Speaker 2: ten to the negative three to ten to the negative
Speaker 2: five mutations, and ten to the negative three is one
Speaker 2: in a thousand, one in a thousand. Yeah, per nucleotide,
Speaker 2: per genome replication event. Don't worry about all of those numbers.
Speaker 2: The point is that a virus is about seven two
Speaker 2: hundred pieces long, and each time it replicates, you usually
Speaker 2: end up with about one mutation on average in that
Speaker 2: genetic code.
Speaker 1: So it's getting the cell to replicate it, but it's
Speaker 1: not a perfect copy.
Speaker 2: That's right, and then it doesn't get corrected, and so
Speaker 2: that error goes on to the next cell and that
Speaker 2: gets replicated over and over again.
Speaker 1: So already the initial virus that infected Tim, all of
Speaker 1: its little babies likely are different than it was by
Speaker 1: one nucleotide.
Speaker 2: That's right. And so then the question you want to
Speaker 2: ask yourself is does that matter? And I think a
Speaker 2: lot of the time it's not going to matter. So
Speaker 2: a lot of mutations don't change the kind of protein
Speaker 2: that ends up getting made, or they don't have any
Speaker 2: meaningful change based on this one little that flips to
Speaker 2: a different value.
Speaker 3: Right.
Speaker 1: It's not like the common cold suddenly becomes a completely
Speaker 1: different disease measles all of a sudden with one slip
Speaker 1: or something.
Speaker 2: Right. But you know, as Tim noted in his question,
Speaker 2: if this is happening many many times in your body,
Speaker 2: and then it's happening to many many people, these changes
Speaker 2: can add up over time. Amazingly. This all seems to
Speaker 2: also be temperature dependent. And I have a lot of
Speaker 2: friends who will say things like, oh, don't go outside
Speaker 2: without a coat on. It's cold out, and then you're
Speaker 2: gonna get sick. And that's not quite how it works.
Speaker 2: But there is some evidence that at colder temperatures, cold
Speaker 2: viruses do replicate more quickly in mice. I don't think
Speaker 2: this has been done in humans. It's always in mice.
Speaker 2: But it's not because that's better for the virus in
Speaker 2: some way, which I think is implied when they're like, oh,
Speaker 2: don't go outside without your coat on. It's because the
Speaker 2: immune systems in mice seem to react less strongly at
Speaker 2: low temperatures. So these replication rates that we're talking about here,
Speaker 2: they're all a little bit handwavy, and they depend on
Speaker 2: what temperature you're at, and so Tim, I hope you're
Speaker 2: staying nice and warm. Yeah, So what do we know
Speaker 2: about how much the cell replicates inside of a host?
Speaker 2: And the answer is well as complicated. So at a
Speaker 2: lot of our data come from what I think of
Speaker 2: as the wrong kinds of cells in the lab. And
Speaker 2: so the cells that are often used in these experiments
Speaker 2: are HeLa cells. So these are I think ovarian cells
Speaker 2: collected from a woman named Henriette Lex a long time ago.
Speaker 2: They were collected without her permission.
Speaker 1: Bad bad biologists.
Speaker 3: Bad.
Speaker 2: Yeah, yeah, no, bad biologists. You're right, I'll take that one.
Speaker 1: I mean, we've never gotten consent from any of the
Speaker 1: protons we've destroyed, but I don't think they are the
Speaker 1: same rights.
Speaker 2: Yeah, no, it's you're right. This was not a bright
Speaker 2: spot in the history of biology. So we stole those cells.
Speaker 2: There's a whole very interesting book on that which I
Speaker 2: recommend people check out. But anyway, so these cells are
Speaker 2: really great at surviving in the lab, and so we
Speaker 2: will infect them with cold viruses and see how they replicate.
Speaker 2: But the problem is they're ovarian cells. They're not like
Speaker 2: nasal passage cells, and the body is complicated. So just
Speaker 2: because something happens in a petri dish, does it I
Speaker 2: mean it would happen the same in a body. So
Speaker 2: when a cell explodes, how many baby viruses are made?
Speaker 2: And the answer is probably something like one hundred thousand,
Speaker 2: maybe even more than that. And then how long is
Speaker 2: the cycle of infection before you get an explosion? And
Speaker 2: you know, we don't really know. It's probably longer than minutes,
Speaker 2: but less than weeks, which is a pretty big timeframe.
Speaker 2: And thank you so much to Katrina Whitson for giving
Speaker 2: us this information, because I was having trouble sort of
Speaker 2: narrowing down the numbers to use for this question, and I.
Speaker 1: Think Coatinia would probably want me to emphasize that these
Speaker 1: are very fuzzy numbers because it's a research question. Nobody
Speaker 1: knows the answer to these things, which is sort of
Speaker 1: shocking and amazing, but it's hard to measure. And she
Speaker 1: was also telling me that sometimes a virus wants to
Speaker 1: slow down how long the process takes because it wants
Speaker 1: the cell to get like stronger and fatter before it explodes.
Speaker 1: So sometimes they like beef up the cell, sort of
Speaker 1: like fattening a calf before you kill it.
Speaker 2: That's right, And so as a group effort, I would
Speaker 2: say the Whitesn Research Institute plus adjunct faculty member or
Speaker 2: Kelly Wiener Smith decided that the virus that you sneeze
Speaker 2: out sort of towards the end of your cold probably
Speaker 2: has something like twenty mutations and is about one percent
Speaker 2: different than the virus that you were infected by GO team.
Speaker 2: But Tim wanted to know if it was noticeably variable,
Speaker 2: and we've mentioned that it really depends where those mutations
Speaker 2: are happening. But over time this is adding up. The
Speaker 2: cold virus does end up being noticeably variable enough that
Speaker 2: it's really hard to make a vaccine for the cold.
Speaker 2: And this is for a couple reasons. So one, we've
Speaker 2: already mentioned that there's like something like two hundred different
Speaker 2: kinds of viruses that can cause colds. Additionally, each strain
Speaker 2: of the cold virus is replicating pretty rapidly, so from
Speaker 2: one season to another it might be different enough that
Speaker 2: the vaccine wouldn't work. And additionally, colds don't tend to
Speaker 2: be as serious as something like the flu, So there's
Speaker 2: not a lot of impetus to try to create a vaccine,
Speaker 2: even though I sure would love to have not spent
Speaker 2: oh my gosh, when my kids started elementary school, I
Speaker 2: think I spent like sixty percent of my time at
Speaker 2: home with a cold. I would have loved to have
Speaker 2: had that time back. But what are you gonna do?
Speaker 1: And that's interesting because colds are varying constantly and it's
Speaker 1: hard to maintain immunity against them. Yet they mostly feel
Speaker 1: the same, right, Yeah, yeah, you got a head cold
Speaker 1: or a chest cold or whatever. But it's not like,
Speaker 1: oh wow, this one makes my head green, or now
Speaker 1: my thumb is swollen or something. It's basically the same disease,
Speaker 1: it feels like to me.
Speaker 2: Yeah, no, it feels that way to me as well.
Speaker 2: And just to be clear, the flu viruses are also
Speaker 2: doing quite a bit of mutating, but I think they
Speaker 2: mutate a little bit less. But every year, the reason
Speaker 2: you get a new flu vaccine is because that vaccine
Speaker 2: is meant to replicate the strains of the flu that
Speaker 2: we think are going to be most common in a
Speaker 2: given year, Given like mutations that we've seen in those
Speaker 2: flu virus strains in the past.
Speaker 1: Yeah, And I think there's a lot of detective work
Speaker 1: and guesswork that goes into the flu. Right, they're like
Speaker 1: thinking about what it might be because they obviously don't
Speaker 1: have the examples for the flu that's gonna come.
Speaker 3: In the future.
Speaker 2: Yep, exactly. I mean they're making their guests based on
Speaker 2: years of data, looking at trends and how this stuff
Speaker 2: plays out. But you're right, at the end of the day,
Speaker 2: you just need to guess which flu strains are going
Speaker 2: to be the most important ones to make vaccines against.
Speaker 2: And I hope you got it.
Speaker 1: Right thanks to folks working on the front lines of
Speaker 1: public health.
Speaker 2: Yes, oh my gosh, they're the best. All right, Tim,
Speaker 2: We hope you're feeling better, and let's find out if
Speaker 2: we were able to answer your question.
Speaker 9: Yes, that answer my question. And wow, that is rather
Speaker 9: terrifying that two hundred variants out there make up the
Speaker 9: cold virus. I don't know if I'm going to sleep
Speaker 9: well at night knowing that fact on top of all
Speaker 9: the other mutation rates. But luckily we feel a little
Speaker 9: bit on the safe side.
Speaker 3: All right.
Speaker 1: And our last question comes from Mark in Newcastle, who
Speaker 1: asks a very heavy question about something very ephemeral.
Speaker 10: Hi guys, it's Markia from Newcastle upon Tyne in the UK,
Speaker 10: and I've got a question for you about data. I
Speaker 10: was recently working on a project with my orduino writing
Speaker 10: to some SD cards and of course when you switch
Speaker 10: off the power and switch it back on, the data
Speaker 10: is retained. So these cards do store something. This storing
Speaker 10: charge and charge is electrons. Electrons have mass, So does
Speaker 10: data have mass? Would an SD card full of data
Speaker 10: way more than an SD card that didn't I guess
Speaker 10: this is an extra opulation of this question, how much
Speaker 10: does the Internet Way? Book pops for another day.
Speaker 2: This is such a great question because, well, for a
Speaker 2: variety of reasons. But I love this question because in
Speaker 2: the past on this show you have said that when
Speaker 2: a Tesla battery is charged, it weighs more than when
Speaker 2: it's not charged, And that makes sense now, but at
Speaker 2: the moment it totally surprised me and I didn't expect that.
Speaker 2: And so, yeah, how much does the Internet Way.
Speaker 3: Daniel seven at weighs seven?
Speaker 2: Oh good, I was going to guess forty two.
Speaker 1: Yeah, remember that mass as a measure of internal stored energy,
Speaker 1: So if you increase the internal stored energy of an object,
Speaker 1: then you are increasing its mass.
Speaker 3: Like if you have a.
Speaker 1: Rock and use zapp it with a photon and it
Speaker 1: gets hotter, it also has more mass. Now, so when
Speaker 1: you charge your Tesla battery, you're giving it more energy,
Speaker 1: not because you're adding more electrons, you know, like physically
Speaker 1: adding more scoops of universe stuff. Just giving more energy
Speaker 1: to that configuration does increase the mass of the battery.
Speaker 1: Since equals mc squared and C squared is a really
Speaker 1: big number, you need an enormous amount of energy to
Speaker 1: make a tiny increase in mass. So nobody really notices this,
Speaker 1: and that's why. But Mark's question is sort of related.
Speaker 1: He's asking about whether the arrangements to configuration of information
Speaker 1: on his SD card or on your hard drive or
Speaker 1: in your brain also has mass, which is a really
Speaker 1: fascinating question and touches on deep concepts about information and entropy.
Speaker 2: And we luckily have someone who is part computer scientist,
Speaker 2: part physicists who is absolutely prepared to answer this question
Speaker 2: for us.
Speaker 1: Yeah, so information is really fascinating. It's hard to think
Speaker 1: about like whether information has mass because information seems sort
Speaker 1: of subjective, right, like, if you have a hard drive
Speaker 1: and it has just random ones and zeros on it,
Speaker 1: does it have more or less information than if you
Speaker 1: put a picture of your dog on the hard drive? Well,
Speaker 1: it depends, like do you consider the picture of your
Speaker 1: dog to be useful or information in some way?
Speaker 3: Right?
Speaker 1: Or like did you encrypt the picture of your dog?
Speaker 1: Because the best encryption algorithms make data that's valuable it
Speaker 1: has some information look like random noise. So you can
Speaker 1: imagine a scenario where you, like, you take a picture
Speaker 1: of your dog, you put it on the hard drive,
Speaker 1: looks like your dog, then you encrypt it. Somebody else
Speaker 1: coming along is like, no, that's just random noise. There's
Speaker 1: no information. And what if you, like, lose the password,
Speaker 1: has the information decreased? And so information turns out to
Speaker 1: be a fascinatingly subjective concept, which makes it very hard
Speaker 1: to link to masks because mass is something physical and
Speaker 1: invariant that everybody agrees on that you can like measure
Speaker 1: without knowing about dogs or passwords?
Speaker 2: Should I be thinking about information differently than I think
Speaker 2: about like you know, before I put my PowerPoint presentation
Speaker 2: on my SD card, it has fifty megabytes of data
Speaker 2: and after the PowerPoint presentation is on there, it has
Speaker 2: one thy fifty. So how is information different than megabytes?
Speaker 1: Yeah, if you have an empty disc and then you
Speaker 1: put files on there, it's counting, like how much of
Speaker 1: the drive has information you've put on there. There could
Speaker 1: also be information on the other bits that it's not counting,
Speaker 1: maybe somebody else put it on there, but then you
Speaker 1: format it the drive, so you consider it to be empty.
Speaker 1: So it's a different question of like when you're filling
Speaker 1: up the drive, right, because it's just like using some
Speaker 1: of the bits for this rather than considering them unused.
Speaker 1: But the question of information is subtle, and we're going
Speaker 1: to have to dip into our understanding of entropy in
Speaker 1: order to understand it, because it's turns out these two
Speaker 1: concepts are closely related.
Speaker 2: So okay, So just to clarify, then, information is not
Speaker 2: how much stuff is on a card, it's how informative
Speaker 2: is the thing?
Speaker 1: Yeah, Because you could take a card and just fill
Speaker 1: it with random ones and zeros, right, there's no information
Speaker 1: there for you. So just because you put a big
Speaker 1: file in your hard drive doesn't mean you add a
Speaker 1: lot of information. It's about the contents and this seems
Speaker 1: really subjective, and physics is all about equations and crisp definitions.
Speaker 1: So how do we think about information from the point
Speaker 1: of view of science and physics. So Claude Shannon defined
Speaker 1: this in the middle of the last century. He was
Speaker 1: thinking about this and he came up with something of
Speaker 1: an arbitrary but very useful definition of information, and he
Speaker 1: defines it as how much you have learned, how much
Speaker 1: surprising information you have gained. So he was imagining like,
Speaker 1: I'm communicating to you by sending you symbols across some
Speaker 1: channel ones and zero's on a hard drive or you know,
Speaker 1: text on a phone or whatever, and you want to
Speaker 1: measure how much information is in these messages from Daniel
Speaker 1: and to his definition, if when you learn something surprising,
Speaker 1: that's high information. If you learn something you already know,
Speaker 1: that's low information. So for example, let's say every day
Speaker 1: I text you and I say, hey, Kelly, the earth
Speaker 1: didn't explode last nightew every day you look at it
Speaker 1: and you're like, Okay, that's not a surprise, right, this
Speaker 1: has happened every day so far in my life.
Speaker 2: I'm changing my phone number. Leave me alone, Daniel.
Speaker 1: Why a physicists text me about the planet's exploding.
Speaker 3: What did I do wrong?
Speaker 2: Low information?
Speaker 1: Low information exactly because it's something you expected to happen.
Speaker 1: So the fact that it happened you didn't really learn much.
Speaker 1: If one day I texted you I was like, by
Speaker 1: the way, at two am, the Earth exploded, you'd be like, wow,
Speaker 1: that's news to me, right, this is big information.
Speaker 2: But wouldn't that also be low information because I would
Speaker 2: have been exploded and I would have also been like,
Speaker 2: thanks for being late to the party, Daniel.
Speaker 1: Don't use the practical details of my analogy to confuse you, audience.
Speaker 2: Okay, whoa, Oh no, I didn't know that, Daniel.
Speaker 1: You're living in a city on Mars in this example.
Speaker 1: All right, So let's put Kelly on Mars. She and
Speaker 1: her cute babies in their baby spacesuits, and her and
Speaker 1: the girl Scout troop are camping up there on Mars awesome.
Speaker 1: And every day I wake up and my job is
Speaker 1: to text you about whether the Earth exploded. So the
Speaker 1: day that you get a text that the Earth exploded,
Speaker 1: that's big news. Why because it was unlikely and so
Speaker 1: the fact that it happened is a lot of information.
Speaker 2: Major bummer.
Speaker 1: So This is fascinating because it means a bits of
Speaker 1: information like did the Earth explode?
Speaker 3: Yes and no.
Speaker 1: It feels like one bit like either value should be
Speaker 1: equal amounts of information, but they're not because information depends
Speaker 1: on context, so bits of information are not created equally.
Speaker 1: And so Shannon said, let's define the amount of information
Speaker 1: to be the inverse of the probability for that to happen. Right,
Speaker 1: so if a high probability of it happens, one over
Speaker 1: that number is a small number, so it's a small
Speaker 1: amount of information. And if a very unlikely thing happened,
Speaker 1: then one over that number is a very big number,
Speaker 1: so that's a lot of information. And he called this surprisal.
Speaker 2: That's cute.
Speaker 1: And to make it well, behave we have the logarithm
Speaker 1: of it. So he defines information as log of one
Speaker 1: over the probability for something to happen, which just means
Speaker 1: that like more probable, lower information, less probable, more information.
Speaker 1: So now we have like a definition of information. And
Speaker 1: again this is just something Claude Shannon made up, but
Speaker 1: we're gonna see in a moment that actually connects with
Speaker 1: other concepts in physics.
Speaker 2: Would you be like taking the expected value of surprisal
Speaker 2: after accounting for the fact that people might differ in
Speaker 2: how surprised they are about some like would you have
Speaker 2: to average different people's surprisal to really get a good
Speaker 2: sense of the information.
Speaker 3: That's really cool.
Speaker 1: Yeah, so something might be information to me but not
Speaker 1: to you, right Like, what if I'm the one who
Speaker 1: destroyed the earth and then somebody texts me like the
Speaker 1: earth blew up today, I'm like, yeah, dude, I know.
Speaker 1: Then that's not information to me because I already knew happened,
Speaker 1: but it is information to you. And that kind of
Speaker 1: makes sense, right, Like, the same bit is not the
Speaker 1: same amount of information for everybody, depending on what they
Speaker 1: already knew. God, But there is a concept of expected
Speaker 1: a surprisal. So if you take the kind of surprise
Speaker 1: you might get from all the different messages you might
Speaker 1: get from Daniel, and you average them over how likely
Speaker 1: you are to get those messages, you get this other formula.
Speaker 1: And this formula is fascinating because it looks just like
Speaker 1: the formula we have in physics for calculating entropy.
Speaker 3: Remember a few.
Speaker 1: Episodes ago, we talked about what does entropy mean? And
Speaker 1: we said that entropy was a ratio between basically how
Speaker 1: much you know and how much you don't know. How
Speaker 1: many ways can you configure the micro states of a
Speaker 1: system to be consistent with the macro state you see,
Speaker 1: So you see that there's particles in a box at
Speaker 1: a certain temperature. How many ways can you arrange the
Speaker 1: particles inside? How many different configurations can there be that
Speaker 1: are consistent with the measurement that you made. And the
Speaker 1: relationship between the micro states and the macro states is
Speaker 1: also related by the formula with exactly the same structure
Speaker 1: as Shannon's formula for average surprisal. So Shannon showed this
Speaker 1: formula to John von Neumann, famous physicist and mathematics, and
Speaker 1: he said, oh, you should call this information entropy for
Speaker 1: two reasons. One because the formula looks the same. It
Speaker 1: looks like the formula for entropy, and it's conceptually sort
Speaker 1: of similar. And two because nobody really knows what entropy means,
Speaker 1: and so they can't argue with you.
Speaker 2: I like that anything that makes it impossible for people
Speaker 2: to argue with me, I'm down for exactly.
Speaker 1: And so in Shannon's information entropy, low information means low entropy.
Speaker 1: So if you're getting a bunch of signals from Earth,
Speaker 1: and you're always getting the same high probability message, like
Speaker 1: the Earth didn't explode today, The Earth didn't explode today.
Speaker 1: That's low information entropy. You're always getting the same one.
Speaker 1: But if you're always getting a different message, like maybe
Speaker 1: instead of getting texts from Daniel about whether the Earth exploded,
Speaker 1: you're getting pictures from probes that landed on exoplanets, And
Speaker 1: every time you open one of those, you're like, I
Speaker 1: have no idea what to expect. Anything I see is
Speaker 1: going to be new to me, right, and like this
Speaker 1: one has rocks, and that one has like lava, and
Speaker 1: that one has aliens on it, and like what is
Speaker 1: this over here? Oh my gosh, the way like every
Speaker 1: time we turn on a new telescope we see something
Speaker 1: weird and surprising in the universe. Right, that's very high
Speaker 1: information content because there's lots of different possible outcomes, each
Speaker 1: of which are equally likely, instead of there being like
Speaker 1: one very likely outcome. So that's high information entropy.
Speaker 2: Okay, so now let's try to connect to mass. So
Speaker 2: I'm wondering if an internet made of cat memes, which
Speaker 2: would be low information, would weigh less than an Internet
Speaker 2: that reconciles relativity with quantum mechanics, which would be a
Speaker 2: high information internet. How do you compare those?
Speaker 1: Yeah, so now we have a definition of information, right,
Speaker 1: we know how to measure information into something that's low
Speaker 1: information or high information.
Speaker 3: And you're right.
Speaker 1: If you get on the Internet and you see the
Speaker 1: same cat memes you're always seeing, then that's low information.
Speaker 1: If somebody says something really new and clever and surprise
Speaker 1: and you're like, whoa, my gosh, that's high information. That's
Speaker 1: more entropy. And we're talking about in terms of entropy
Speaker 1: because we're trying to get a graph on the physical
Speaker 1: nature of this and the consequences for it.
Speaker 3: Like does it have mass?
Speaker 1: Because we know entropy is connected to energy, right, and
Speaker 1: energy is connected to mass. So can we somehow draw
Speaker 1: a dotted line between information, cat memes and the weight
Speaker 1: of the Internet. No, unfortunately not, because increasing the information
Speaker 1: doesn't increase the mass or the energy of the system.
Speaker 1: The information content is relative to what you already know,
Speaker 1: depends on the context. You can arrange a set of
Speaker 1: sticks or bits on the hard drive to mean one
Speaker 1: thing or another. It doesn't change the mass or the energy.
Speaker 1: So it has to do with how you interpret the
Speaker 1: arrangement of the system and what you already know. It
Speaker 1: does require some mass and some energy to store that information.
Speaker 1: You want to put bits on a hard drive, you
Speaker 1: want to write numbers in the sahara and filled them
Speaker 1: with kerosene. That definitely costs energy, right, And all stored
Speaker 1: energy does have some mass, But increasing the information on
Speaker 1: something doesn't increase its mass. So connecting back to Mark's question,
Speaker 1: he's asking does data have mass? And data does not
Speaker 1: have mass? Right, And remember that when you're putting a
Speaker 1: picture of your dog onto the SD card, you're not
Speaker 1: like downloading electrons and not flowing onto there. You're just
Speaker 1: moving electrons up or down. You're just flipping switches on
Speaker 1: that card, so you're not adding matter to it in
Speaker 1: any way. You're not changing the energy of the card.
Speaker 1: You're just flipping a switch, which doesn't require any more
Speaker 1: or less energy. It requires energy to build a card,
Speaker 1: and it requires energy to change things on the card.
Speaker 1: But the card is not heavier because you put a
Speaker 1: picture of a dog rather than a picture of the
Speaker 1: Earth or a picture of an exoplanet, or like the
Speaker 1: equations of quantum gravity, which wuld be very surprising that
Speaker 1: anybody to find have a lot of information but wouldn't
Speaker 1: have any more mass than any other arrangement of those
Speaker 1: electrons or bits or sticks or flaming letters in.
Speaker 3: The Sahara course lots.
Speaker 1: But there is one other fascinating connection between information and
Speaker 1: mass which people may have heard about. It's called the
Speaker 1: beckensteam bound, which talks about the amount of information you
Speaker 1: can have in a space, because it turns out there
Speaker 1: is a limit to how much information you can put
Speaker 1: in a volume of space, and it turns out that's
Speaker 1: a black hole. Right, The most information dense arrangement of
Speaker 1: matter or energy is a black hole. So black holes
Speaker 1: have the maximum amount of information. It's called the Beckenstein bound.
Speaker 1: Beckenstein is a student who work with Stephen Hawking. Doesn't
Speaker 1: get enough credit for hawking radiation and all the black
Speaker 1: hole work that he did with Hawking, but super genius guy. Now,
Speaker 1: this doesn't mean, as you often hear in popular science,
Speaker 1: that if you have too much information something will collapse
Speaker 1: into a black hole. Like if you download enough amazing
Speaker 1: pictures of dogs under your computer, it's going to turn
Speaker 1: into a black hole. That's not the problem. It means
Speaker 1: that if you need to store a huge amount of information,
Speaker 1: the only way to do it is a black hole.
Speaker 1: A black hole is like the most information dense system
Speaker 1: you can have.
Speaker 3: So if you need to.
Speaker 1: Increase the amount of information you're storing, you might need
Speaker 1: to increase the mass of your system so much so
Speaker 1: that you get a black hole.
Speaker 2: Well, you know, DNA is also supposed to be very
Speaker 2: information dents, and there are people who are arguing that
Speaker 2: when we can easily print DNA sequences, we might want
Speaker 2: to start storing data in DNA and sticking it in freezers.
Speaker 2: That sounds complicated to me, but we'll see what the
Speaker 2: future holds.
Speaker 1: Yeah, but DNA is an amazing storage system because it
Speaker 1: lasts for a long long time compared to hard drives.
Speaker 1: You put something on a hard drive, you think, oh,
Speaker 1: it's there, but five years later you come back, it
Speaker 1: could be totally degraded. So if you have like really
Speaker 1: valuable information the secrets to quantum gravity are on a
Speaker 1: hard drive in your closet, make sure you're upgrading those
Speaker 1: every couple of years because that stuff fades.
Speaker 2: You are making me very nervous about the videos from
Speaker 2: my PhD that are still sitting in the closet a
Speaker 2: decade on that need to be analystt We.
Speaker 1: Have a real problem with digital storage. People think it's
Speaker 1: forever because it's ones and zeros, but it's not, and
Speaker 1: actually a lot of the old analog systems we have
Speaker 1: last longer. Like my favorite story is computer punch cards.
Speaker 1: My dad did his graduate thesis on the computer using
Speaker 1: punch cards. I remember being in the computer room as
Speaker 1: he would like insert them and pick them up.
Speaker 3: And the cool thing about punch cards is totally resilient.
Speaker 1: They'll last a long long time, right, yea, So he
Speaker 1: still has like stacks of punch cards that you could
Speaker 1: still run if the computer was around. But nobody has
Speaker 1: a hard drive from like nineteen eighty four that still works.
Speaker 1: So back up all your stuff, folks, and don't create
Speaker 1: black holes. The Mark, you can keep adding pictures of
Speaker 1: your dog to your SD card without making it heavier.
Speaker 1: So let's check in with Mark see if that answered
Speaker 1: his question.
Speaker 10: Thanks for answering my question, guys. I think I'm fundamentally
Speaker 10: more enlightened now. I found it interesting how the view
Speaker 10: on data and mass extended into information value and information
Speaker 10: entropy and also information density. Pops Bekenstein can have a
Speaker 10: side hustle selling high density branded SD codes. Anyway, Thanks
Speaker 10: again and keep up with the good work.
Speaker 2: All right, everyone, thanks for listening today. If you have
Speaker 2: a question you want to ask us right to us
Speaker 2: at Questions at Daniel and Kelly dot org. We answer
Speaker 2: every question we get, some of them end up on
Speaker 2: the show, and we'd love to know what you're thinking about.
Speaker 1: We really do, because it's not just our curiosity it
Speaker 1: fuels this show. It's your curiosity, your desire, your deep
Speaker 1: need to understand the nature of this extraordinary universe. So
Speaker 1: right to us two questions at Daniel and Kelly dot org.
Speaker 2: Daniel and Kelly's Extraordinary Universe is produced by iHeartRadio. We
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Speaker 1: We want to know what questions you have about this
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