Daniel and Jorge Explain the UniverseLearn about quantum spacetime foam with Daniel and Jorge
Learn more about your ad-choices at https://www.iheartpodcastnetwork.com
See omnystudio.com/listener for privacy information.
If you love iPhone, you'll love Apple Card. It's the credit card designed for iPhone. It gives you unlimited daily cash back that can earn four point four zero percent annual percentage yield. When you open a high Yield savings account through Apple Card, apply for Applecard in the wallet app subject to credit approval. Savings is available to Apple Card owners subject to eligibility. Apple Card and Savings by Goldman Sachs Bank USA, Salt Lake City Branch, Member FDIC terms and more at applecard dot Com. When you pop a piece of cheese into your mouth, you're probably not thinking about the environmental impact. But the people in the dairy industry are. That's why they're working hard every day to find new ways to reduce waste, conserve natural resources, and drive down greenhouse gas emissions. How is US Dairy tackling greenhouse gases? Many farms use anaerobic digesters to turn the methane from manure into renewable energy that can power farms, towns, and electric cars. Visit us dairy dot COM's Last Sustainability to learn more.
Everyone loves getting good at advice and staying in the know. There's nothing like getting a heads up on something before you've even had time to think about whether you need or want it. Well, Thankfully, AT and T provides personalized recommendations and solutions so you get what's right for you. Whether right for you means a plan that's better suited for you and your family or a product that makes sense for you and your lifestyle. So relax and let AT and T provide proactive recommendations to help empower your best connected life.
Hey Daniel, I've noticed that people just add quantum the word quantum do things to make them sound cool.
Oh man, I hate when they do that.
Yeah, like quantum combs, quantum serial. I mean it's it's like they put it on everything just to make it sound awesome.
Yep. I would see quantum dog food recently, and I'm pretty sure that's not a real fact.
Your dog both loves it and hates it at the same time. But does that mean that just all of quantum mechanics is like a scam.
Not all of it? Like, there really is some physics in quantum mechanics, but I'd say most things that are called quantum are probably blooney.
I am Jorge, I'm a cartoonist and the creator of PhD Comics.
Hi, I'm Daniel. I'm a quantum physicist and that is not blooney.
Oh well, just so happens. I'm a cartoon Bologny cartoonist. So this all brings it together and welcome to our podcast, Daniel and Jorge Explain the Universe, a production of Idio.
In which we explore everything that's crazy and amazing about the universe, from classical physics to quantum mechanics, and explain it to you in a way that you can explain to your friends and sound super smart.
Yeah, in ways that we do explain it and don't explain it at the same time. We're sort of like a quantum podcast in a way.
We download individual, discritized units of explanation into your brain.
We spin it up and spin it down for you guys.
But quantum mechanics is one of my favorite topics because it is so hard for people to understand usually, but there are ways to look at quantum mechanics and get a new sense of the world, to reveal the reality that underlies everything.
Yeah, it's your favorite because people don't understand it.
It's my favorite because it's a great example of how in physics, we can learn that the world is really quite different from the world we expected it to be, that the world we grew up in is not the way the world works. That to really understand the universe, we have to remove our blind and quantum mechanics is a great example of that because it requires basically tossing out your entire intuition for how the world works and accepting something very different.
Yeah. I feel like that every day that I wake up and read the news, I'm like, what is this universe we're living in?
What quantum politics is that you're talking about?
It's just the quantum news, We'll say, it's just the quantum. It makes sense and doesn't make sense at the same time. It's about a dead cat and in a life cat all at the same time.
I feel like quantum mechanics is something a lot of people are fascinated by. They've heard about it, they hear people use words to explain it that don't quite make sense to them, and so people are thirsty for a real, honest to god understandable explanation for some of this bizarre quantum phenomena.
Yeah, and it sort of seems, like you said, it almost seems like two different universes. You know. There's like the universe that you grew up in as a kid and feel you understand where you take a ball and you balance it and comes back and you can throw a baseball and it lands where you think it's going to land. And then there's is the kind of the quantum universe you learned later on in life, where like none of those things you learn as a kid seem to apply.
Yeah, precisely, because your brain develops all these ideas for how things move based on what you've experienced. Things seem to move through the universe, it seems like they have a smooth path, and so later to grow up and learn that things don't actually move, They just have these snapshots, and then those later snapshots in your brain is filling in the in between slices to make like a movie of the universe. Is quite shocking. I wonder if we had evolved to be much much smaller, if we would have sort of a quantum intuition, if we like had everyday experiences of quantum objects.
You mean, like if it's taught at the preschool level, if we try to teach kids quantum physics.
No, I can't think we should be doing shorting equations.
You know, I mean coloring one plus one, spin up, spin down, you know, just the basics that you need to deal with this crazy world we're living in.
But I think that people would still struggle because they don't have any actual experience with it. I'm talking about really experiencing quantum mechanics, Like what if there were quantum effects that were macroscopic, you know, if things that were the sides of baseballs operated under quantum rules. It's pretty hard to reveal that the universe is quantum mechanical. It took us thousands of years before we figure that out. Right, what if it wasn't so subtle, what if it was more obvious and so people actually had an intuition for this, they're like, oh, electrons, Yeah, those move just like these other quantum basketballs or whatever that.
I was playing with in my kindergarten playground. Yeah.
Yeah, maybe that's the next wave of physics education, is we need to develop some sort of technology that operates like quantum objects so kids can play with like quantum balls.
Yeah. Well, it does seem like it's kind of a separate and new universe, and it feels like there's a quantum version of almost anything. Like for anything that we have in our world used to be like a quantum version of it. Like you know, I know I can spin here in my chair, and there's also something called quantum spin, and you know my battery has charged it, but there's also something called quantum charge, and so on and so on.
Yeah, there's even quantum flavor.
Yeah, you think in kindergarten that there's only sweet and salty and sour, but there's also quantum flavor.
And we have quantum color. We had whole podcast episodes about all these properties.
Yeah, so you could go to quantum kindergarten too and earn quantum sharing and quantum quantum.
And in some cases these things are metaphors, like quantum flavor. These particles don't actually taste like anything, but we're trying to make an analogy. We're trying to extrapolate from something we know, which is flavor, and give you a sense for this weird new quantum thing. But in other case, is it really does make sense, like quantum spin. Those particles are not spinning in the same way, but they really do have angular momentum, so spin really makes sense. So in some cases the words are you know, really a stretch. In some cases they really are are applicable.
Right, Yeah, that was a pretty good way to just sput it there.
That's quantum spin, right, she.
So obvious and but yeah, but sometimes, you know, I wonder sometimes I wonder if physics are pushing it a little bit too much. And so today on the podcast, we have a great question from a listener that we're going to try to answer, and this is a question from Dale from Dublin. We had a very interesting question about another strange sounding quantum thing.
Here's Dale Dale from Toblin oiland here I heard about aything called quantum phone or spacetime phone. Could you talk about with that for a bit and let us know what it is? Cheers toning some minute. Well, I love so many things about this. First of all, I love Dale's accent awesome, and I love that Dale wrote in. This is just an email he sent me saying, Hey, could you explain this? And I asked him to send us of recording so we could talk about it on air because I thought a lot of people might be interested in the answer to this question. So thank you Dale for writing in, and thank you to everybody who writes in with their questions right.
And just as a reminder, we are on Instagram and Twitter at Daniel and Jorge And if you want Daniel to answer back, try Twitter or the email because Instagram will not answer your question.
I don't do quantum social media. Yeah, so if you have a question, send it on into questions at Danielanjorge dot com or engage with us on Twitter at Daniel and Jorge.
Yeah, so this is an interesting question. Quantum foam. It sort of sort of sounds like one of these products that you sell in late night television that will totally clean your bathroom at the molecular level.
I think a lot of times in marketing, quantum is just used to describe something to make a sound more modern or technological, you know, like like quantum dog food. That really is a thing. I mean it's not, that'sually your quant mechanical Well no, google quantum dog food. There is a product. They really do sell dog food and call it quantum. I think what they mean by that is new fancy, you know, savvy to the quantum mechanical world.
Somehow new fancy. Yeah, well that's kind of what you guys do in physics as well, isn't it. Oh, this is a charge, but it's kind of new and fancy. We'll call it quantum quantum charge.
But wait no, but it actually is new and fancy. Sometimes we do discover stuff in physics that's new and fancy. All of quantum mechanics is new and fancy. It really does happen. It's not just marketing.
Sometimes dog food is new and fancy. Why not? And coman discritized little chunks?
That's true. Yeah, all right, so I should order that product and I should evaluate it before I give my opinion on it.
You're totally right, and quantum dog food. Please give us a call. We are opening for a sponsorship.
In this podcast, I was wondering if Dale from Dublin was the only person thinking about space time foam, And so I walked around and I asked people what they thought about space time foam. Had they heard of it? Did they know what Dale was talking about? Did they have any idea what it was? And these questions again didn't happen to you, see, Irvine. This happened at a local coffee shop because I was trying to get a sense for the broader public and their understanding of this topic.
Yeah, so before you listen to these answers, think about it for a second. If a physicist approached you at a coffee shop, would you be able to answer the question what is space time?
Foam?
Here's what people had to say.
Upper layer to space time that kind of bubbles up or something. If that makes sense cool.
I have no idea.
I have no idea spacetime.
No space time, no space time for space.
I guess, but got space.
I'm all right. I feel like people were answering and they were just about to call the police on these.
You start to hear that they're like, I am so regretting answering this questions. What are you talking about?
I think? Yeah, I mean people go to a coffee shop to wake up, and you're asking them physics questions over their cappuccino.
Pham.
Well, you know, I specifically tried to choose people that looked like they were studying, like they had a book open or they were reading something, because I was hoping to find people who were, you know, like had their brains on or intellectually engaged in something or maybe curious about this kind of thing. I didn't interrupt, like couples that were smooching.
Or if they looked like they were listening to a podcast, or like that person probably knows everything already, right.
I try to avoid people who already have their earbuds in because I feel like in public, earbuds mean don't talk to me.
Well, this is kind of an interesting question. A quantum foam, and I had never heard of it. If you had approached me at a coffee shop, I would have just said, no, please go on, please, please ask me an easier question.
You would have been, like, you look like this other physicist I know, and I definitely ignore him in public, So I'm not talking to you.
Yeah, as a blanket policy, that's my decision on physicists, all right. So this is an interesting question because it's like you're marrying two words that are very common space time and foam, but that together really don't make any sense.
Yes, And that happens so much in quantum mechanics. People say things that use words together and you understand the individual words, but you don't really know what it means when you put it together.
So we'll get into what spacetime foam is and what we know about it, and how we might be able to find it in this frothy little universe we live in. But first, let's take a quick break.
With big wireless providers, what you see is never what you get. Somewhere between the store and your first month's bill, the price you thought you were paying magically skyrockets. With Mintmobile, you'll never have to worry about gotcha's ever again. When Mint Mobile says fifteen dollars a month for a three month plan, they really mean it. I've used mind Mobile and the call quality is always so crisp and so clear. I can recommend it to you. So say bye bye to your overpriced wireless plans, jaw dropping monthly bills and unexpected overages. You can use your own phone with any Mint Mobile plan and bring your phone number along with your existing contacts. So dit your overpriced wireless with mint Mobiles deal and get three months a premium wireless service for fifteen bucks a month. To get this new customer offer and your new three month premium wireless plan for just fifteen bucks a month, go to mintmobile dot com slash universe. That's mintmobile dot com slash universe. Cut your wireless bill to fifteen bucks a month at mintmobile, dot Com slash Universe. Forty five dollars upfront payment required equivalent to fifteen dollars per month new customers on first three month plan only speeds slower about forty gigabytes on unlimited plan. Additional taxi spees and restrictions apply. See mint Mobile for details.
AI might be the most important new computer technology ever. It's storming every industry and literally billions of dollars are being invested, so buckle up. The problem is that AI needs a lot of speed and processing power, So how do you compete without co spiraling out of control. It's time to upgrade to the next generation of the cloud. Oracle Cloud Infrastructure or OCI. OCI is a single platform for your infrastructure, database, application development, and AI needs. OCI has four to eight times the bandwidth of other clouds, offers one consistent price instead of variable regional pricing, and of course nobody does data better than Oracle. So now you can train your AI models at twice the speed and less than half the cost of other clouds. If you want to do more and spend less, like Uber eight by eight and Data Bricks Mosaic, take a free test drive of OCI at Oracle dot com slash Strategic. That's Oracle dot com slash Strategic, Oracle dot com slash strategic.
If you love iPhone, you'll love Apple Card. It's the credit card designed for iPhone. It gives you unlimited daily cash back that can earn four point four zero percent annual percentage yield. When you open a high Yield savings account through Applecard, apply for Applecard in the app, subject to credit approval. Savings is available to Apple Card owners subject to eligibility Apple Card and Savings by Goldman Sachs Bank USA, Salt Lake City Branch Member FDIC, terms and more at applecard dot com.
All right, Dan, and we're talking about space time foam. And it's not a weird product that you sell on late night television. It's an actual physical theory in science. And so let's get into that a little bit. And I guess let's start with the first two words to set us up for the foamy part. So let's talk a little bit about space time, because in this case, I think Dale from Dublin used the word as one word, like space time, not space comma time. He called it space time. So let's maybe refresh for our listeners what it means to say space time.
Yeah, it's like you take two words you put them together, or they mean something special, like green and house. You know, a greenhouse is not just a greenhouse, right, it has its own meaning. So in the same way space time is sort of a special word in physics. And of course you know it's space is space is just the three dimensions of movement. You know, you have X, Y, and Z. And we have a whole other episode about like what makes up space? Is it a thing because it can wiggle and dance and jiggle and expand and all this stuff. But for our purposes today, let's just think about it as sort of as the directions you can move in X, Y, and Z. So that's what space means.
Yeah, like the space we're in, like where we move around in.
Yeah, precisely, nothing special there. And time is just time, right, Time flows forwards, and you can think of time in analogy to space. You can think of us as moving through time the way you can move through space. And we have a whole podcast episode digging into how time is connected to space and how time is different from space. But Einstein is the guy who put these two things together. He's the first one to construct this idea of space time by taking three dimensions of space that you can move in and adding the time dimension to it is sort of a fourth dimension. So together space time is this four dimensional idea xyz and then time.
Right, I feel like you just said something profound though you just said time is time.
That man, time is so fascinating. I could talk endlessly about time. We could spend all of our time talking about time. But maybe it's not time to do that.
That one phrase has made me think about my whole life and where I'm going with it.
And well, can I sell you my new product if called quantum time?
Well, there you go, all right, a quantum quantum watch to keep track of the inevitability of time.
It's new and fancy and has to be charged every fifteen minutes.
There you go, all right. So space time is this idea that space and time are not separate. Like maybe if you think about them all together in one package, one four dimensional bun then it's more appropriate somehow, like they're related, like one of them affects the other, so therefore you should keep track of them all at the same time precisely.
And it was Einstein's theory of special relativity that showed us exactly how space and time are affected by each other. Specifically, how time flows depends on where you are and how fast you are going relative to something else, and so in order to understand time, you can't just have time by itself. Time is not universal. Time is local. Time depends on where you are in space, and so it makes much more sense to combine these two things together. It's like having the weather, right. The weather's not the same everywhere, so you want to talk about the weather where you are in Buffalo, or in New Delhi or in Barcelona, and so you pair the weather with the location because that makes more sense.
It's called the space time weather continue which I hear.
Listen to my new quantum weather reports.
Yeah, it's a new Doppler quantum three thousand.
That probably is a real thing. I mean, you're joking, but there's probably some local station out there with a quantum weather doppler.
Some local weatherman in the middle of Barcelona. And Einstein was not crazy, right, Like, he didn't just make this up and it didn't work. It actually works. Like bundling space and time together does tell you something about the universe, and it's there's been theories and experiments done to prove that this is all for reals.
Oh, yes, Einstein was right about this. That doesn't mean Einstein wasn't crazy. I mean, you dig into that guy's personal life. He was more than a little bit crossed. But he was also right about space time.
All right, So that's space time. And now the question from Dale was what is space time foam? And I have to say, I'd never heard of this before. Is this a new thing, is this something that's only been around for a couple of years, or is this like a fringe theory or a French theory? I don't know either one. Is what is going on with space time foam?
Well, I can't endorse your casualist slander an entire culture there, but it is a bit of a fringe theory. It's one of these things. It's like it's an idea that took hold in some people's minds, but then not a lot of progress was made, so it's sort of just been hanging out there, bubbling up in people's brains without really turning into anything concrete. So it's been around for a while, but it's not really part of the mainstream physics.
It's just been foaming up in people's research talckets.
And so I know that you keep abreast of all the latest topics in physics, and you read all the physics journals, and that's probably why you haven't heard about this recently.
Right, Well, at first I thought it was maybe an acronym, like maybe foam stands for something. It's the first of a multiverse, which is a new theory by Horheitch Haam. How about how were the most awesome of all the multiverses?
And somehow Dale from Dublin knew about your theory before you even thought about it and thought to ask in advance. Wow, good job Dale.
Yeah, well, in other multiverses he didn't, but this one, because it's the best, did all right, So let's let's talk about this. So there is something called space time foam that physicists think might be real and might actually kind of describe what the universe is like. So take us through it, Daniel. What does it mean to put the word space time and foam together?
The idea here is to try to resolve the conflict between our two great theories of physics. We talked about space time in terms of relativity and that all makes sense. And relativity has been tested out the wazoo and up the wazoo and in the wazoo, in every way around the wazoo.
Because is that another physics experiment acronym the wazoo.
The wazoo, I'm not sure what it means.
It's a collider in Italy, apparently.
It's But special relativity has been extensively tested, and so has general relativity, but we don't know if it really holds universally. That we have suspicions that it probably doesn't work on re really tiny distances. So general relativity says that space is sort of smooth, that you can chop it up into tinier and tinier bits and you'll never sort of run out of waste to cut it in half. That like in Zeno's paradox, you could take smaller and smaller steps forever. That's what general relativity says.
It predicts it, or it assumes it.
It assumes it. It uses that as its essential description of what space is. That you could have a particle or an object located at any point. You know, if you have an infinite number of locations between me and you, that a particle could be at any of those locations.
Oh, I see. It's kind of like Newtonian physics, right almost in a way, like it assumes that space is smooth and it doesn't assume anything that's that anything is quantized.
That's right, And you look at the universe around you, and the universe seems smooth, right, It seems like you could sit anywhere. It seems like if you took a ruler, you could cut it in an infinite number of ways, you know, fifty to fifty, seventy five, twenty five whatever, that there's an infinite number of ways. But just like the screen on your iPhone, it looks really crisp and smooth, but if you zoom in, you discover that there are pixels there. And so general relativity tells us that the universe is smooth, that space is infinitely sliceable, but that's in conflict with quantum mechanics. Quantum mechanics says that you can't have infinitely sliceable space.
Yeah, that at the fundamental level, it's pixelated, kind of like my iPhone screen. Although my iPhone screen these days looks kind of blurry because, as I've said before, I need reading glasses.
Now I'm not sure, that's a problem with your iPhone screen.
I think, But well it's a problem for my new quantum reading glasses.
Yeah. And so quantum mechanics has this impact on lots of things that we measure. Things that at large scales seem smooth turn out to be discretized, turned out to be sliced up into chunks. Like a flashlight beam is not a smooth, continuous beam of light. It's a stream of tiny little packets called photons. The same way your bowl of ice cream is not infinitely choppable into smaller and smaller spoonfuls. There are atoms in there. It's made out of these tiny little lego pieces. So the same concept can be applied to lots of things, and quantum mechanics says that probably it also applies to space. So we have this conflict between these two great theories of physics, relativity and quantum mechanics, and the conflict lies in a place that's really hard to spot, where things are super duper small.
So meaning that general relativity doesn't know that there is something called quantum physics and quantum mechanics. Quantum physics sort of we don't do we know that quantum mechanics takes into account general relativity or is there such a thing as bending of space in quantum mechanics.
So that's a great question. People have tried to say, let's take Einstein's theory of general relativity and let's make a quantum version of it. Can we make a version of general relativity where space is pixelated or we know quantum mechanics comes into account, and currently we have no great functioning theory like these theories. You can make a theory of general relativity that is quantized, but it doesn't work when space is really intense, like inside a black hole. When the gravity gets really really strong, then the theory breaks down and predicts things that don't make sense. It gives you like infinities and all sorts of crazy numbers. So we don't currently have a working theory of what's called quantum gravity that tries to marry all the best things from general relativity and quantum mechanics.
So does that mean that quantum mechanics operates kind of in a Newtonian or like perfect kind of pre Einstein universe.
Quantum mechanics operates often in what we call a flat space, you know space that's not bent by mass. You can do quantum mechanics in curved space, where if you're like near the Sun or near a black hole, space is curved. You can do that quantum mechanics. But if you try to do it when space is too curved, when a gravity gets really really strong, then it just doesn't work. We just don't even have a theory. We can't like even come up with a theory that makes sensible predictions, not to mention check those predictions against actual experiments.
All right, So it sounds like general relativity is good for kind of big distances and tells us how the universe works at large scales, and quantum mechanics tells us how it works in really really tiny scales. But there are situations where the two theories just don't. Neither of them work.
Yeah, and what we need to do is get inside a black hole and see what happens when you have both small distances. So quantum mechanics is relevant and really intends gravity, So general relativity is relevant. Unfortunately, all the people we've sent it to black holes have not been coming.
Yeah. I was going to say that you're using the word we there pretty broadly.
There any volunteers out there is a black.
Hole who wants to be the first person to die at a black hole.
And this is where the idea of space time foam comes from, from an attempt to try to reconcile these two theories.
I see. It's another one of these unifying theories, like theories of everything precisely.
There's one theory that says maybe the universe is made out of tiny little loops. That's called loop quantum gravity. Another one says maybe everything is just a tiny vibrating string. That's string theory. And there's even one called spin foam, where everything is like this weird spinning kind of foam. But space time foam is a particular theory that tries to unify quantum mechanics and general relativity, and it imagines space is being made of these tiny little pixels. But these pixels would be quantum mechanical, and so like bubbles in a frothing foam, they might like pop in and out of existence.
All right, let's get people in the loop of this and get a little bit more into what quantum foam or space time folam is and how we know about it and what we might discover if we poke around in the universe. But first, let's take another quick break.
When you pop a piece of cheese into your mouth or enjoy a rich spoonful of Greek yogurt, you're probably not thinking about the environmental impact of each and every bite. But the people in the dairy industry are. US Dairy has set themselves some ambitious sustainability goals, including being greenhouse gas neutral by twenty to fifty That's why they're working hard every day to find new ways to reduce waste, conserve natural resources, and drive down greenhouse gas emissions. Take water, for example, most dairy farms reuse water up to four times the same water cools the milk, cleans equipment, washes the barn, and irrigates the crops. How is US dairy tackling greenhouse gases? Many farms use anaerobic digestors that turn the methane from maneuver into renewable energy that can power farms, towns, and electric cars. So the next time you grab a slice of pizza or lick an ice cream cone, know that dairy farmers and processors around the country are using the latest practices and innovations to provide the neutral intense dairy products we love with less of an impact. Visit us dairy dot com slash sustainability to learn more.
There are children, friends, and families walking, riding on paths and roads every day. Remember they're real people with loved ones who need them to get home safely. Protect our cyclists and pedestrians because they're people too. Go Safely California from the California Office of Traffic Safety and Caltrans.
When it comes to business, the people who succeed tend to be the people who seek out partners with skills or knowledge that they don't have. And that's what Lenovo's free online membership program Lenovo Pro can do for small businesses. If you're not a tech expert, that's where Lenovo can help. So you can add Lenovo's team to yours and then lean on them for all your tech questions for free. Visit Lenovo dot com slash Lenovo Pro to sign up for free. That's Lenovo dot com slash Lenovo Pro, Leno Leo.
All right, Daniel. Quantum foam is kind of like quantum dog food in that you know you're trying to make something that your dog will both eat and enjoy at the same time, we're trying to make something that explains both general relativity and quantum mechanics and that your dog will like, I guess also at the same time. And so and that's hard because, as you said, they're sort of based on two very different views of the universe.
That's right. And you know, for relativity to work, what we need is a new imagining of it. We need to start from a different conception of what space is. Einstein assumed that space was smooth and continuous, and he built his theory upon that assumption. So we need to start from a different assumption and say, actually, space is made of these tiny grains or these little bubbles, and understand the nature of those and then build a theory on top of that. And I don't know if this is true. It's not clear that space time foam is a real description of space. You know, it might be that pixels are a better description, or loops or little strings, or we really just don't know, but we need a new idea. And so theorists are just sort of being creative and smoking banana peels and saying, well, maybe it's more like this, And you know, you look around the macroscopic universe to get inspiration, you know, and maybe some physicists was smoking a banana peel and looking at soap bubbles and thinking, huh, maybe space is just like that.
Well it's interesting because I feel like, you know, there's these two theories, and it's not like you're saying, like, oh, maybe quantum mechanics is wrong, and really we just need to extend general relativity, or you're not saying, oh, general relativity is wrong, we just need to extend quantum mechanics. I feel like you're saying that we need to throw both of these into the garbage and kind of come up with one theory, start over, reimagine the universe, and come up with one theory that you know, sort of looks like one and looks at the other, but actually kind of works continuously across the whole universe.
Yeah. Well, we don't know what the necessary process will be. It might be that we can take what we have from general relativity and from quantum mechanics and marry them, or it might be that, yeah, we have to toss it out and start all over again. The process of science is iterative, right, It's like a writer writing a draft of a screenplay. Or something. You just keep trying to make it better and better until it fits, and then at some point you realize, you know what, this is hot mess of garbage and you just got to toss it out and start all over again. So we don't know. We don't know if you know we're one more draft away from something we can publish, or if we've got to toss it all out and start on the next.
Book right, or maybe the studio head goes, well, it's too late. Let's just make this bad movie and.
Can you make it twenty five percent funnier?
And we live in that universe that should never have been made, where the plot twists don't make any sense and the acting is stiffid best.
That's even better than do we live in a simulation?
Is?
Do we live in a poorly written simulation? I like that?
Oh, we should do it.
I got notes for you simulation authors. Okay, here's how you should have done the simulation.
Here's what Rotten Tomato says about your universe.
Physicist ratings on universe simulations. I like it.
There you go, Quantum Rotten Tomatoes is the name of my new website. Check it out, all right, So step us through. What is quantum foam then? Is it? What does it foam mean? Why is it foam? Does it bubbles in it? Is it like a froth? Why is it called quantum foam?
Yeah? The idea is that quantum mechanical things fluctuate. They come in and out of existence. If you zoom into particles at the smallest scale, you can't follow them along the way you would follow a baseball. They sort of pop into existence and pop out of existence. They turn into other particles. It's like a constant mess, right, And so lots of things are happening.
Like it's bubbling at the surface, kind of like foam. Those are the things in space and times. This is saying that space time itself is like a phone, right.
And so if space itself is quantized, it's made out of these pixels, and these pixels are quantum mechanical, then it's possible that the pixels themselves are sort of bubbling in and out of existence. It's one step to go from space is smooth to space is discrete. Right, it's made of pixels. It's another to say maybe those pixels themselves are not like permanent, they're like temporary, you know, they're ephemeral. They're coming in and out of existence because in the end, a lot of quantum mechanical things.
Are Space itself is coming into and out of existence. Like yeah, like this bit of space right in front of my eyes here precisely.
You know the object in front of you, for example, whatever it is, it's in front of you right now, it's a banana, or it's an apple or whatever that's made of quantum mechanical particles. Now it seems solid, it seems like it's really there. But if you zoomed in on the little particles, the particles that make it up are popping in and out of existence. They're turning into energy, they're turning back into particles, they're changing into other particles and then coming back. You don't even notice, right, So that phone or whatever in front of you is a frothing mess, but you just don't notice it frothing because the frothing is so tiny. So if it's hard for you to imagine, like space itself could also be frothing. Remember everything around you is kind of frothing.
Oh wait, so this would be like under the quantum particles, Like you could have a quantum particle and it's really tiny, but the space it is sitting on could be bubbling underneath it. Is that what you're saying precisely.
And remember that in modern quantum mechanics, we don't even really think of particles as like the basic element of stuff in the universe. Particles are just excited states of quantum fields, and quantum fields that we had a whole episode on are a property of space itself. So you can't really separate the matter and the space because matter is just an excited state of quantum fields, which are a part of space.
But is the space time foam on the same scale as the particles, Like you know what I mean? Like, what if there's a particle that just happens to be sitting on a space time bubble and that bubble pops? Does that particle just disappear or is it like riding on top of a whole bunch of little space time bubbles.
Yeah, I think you have to think of particles as part of space because particles are again excited states of these fields, and the fields themselves are part of space. And so I think it takes a whole new way of thinking about like the nature of the universe at the smallest scale. It's not like particles are sort of filling in slots in space. They're like excited space.
Oh and you're saying that this space is actually more like foam, meaning that it's just a whole bunch of little pockets of it kind of pressed together, and each one of these pockets is a quantum of space time.
That's right. And we don't know the size of these bubbles. If these bubbles exist, and we don't know that they do, the question is how big would they be? And we suspect if they do exist, they'd be super duper duper duper tiny. But yeah, the idea is that you know, you have a localization of energy. That energy is an excited state of all the quantum fields in that space, and that localization of energy could extend across multiple bubbles of quantum space, perhaps for example, like a photon, and that you know, it could be made of these little frothing bubbles that are smaller than that packet of energy.
And so what am I doing when I'm moving through space? Am I moving from bubble to bubble? Or do I take like each one of my particles might be in this bowl roll bubble or that bubble.
Well, you are those bubbles. You're not in those bubbles. You are those bubbles.
I am the space time foam.
You are the space time boam, and so we are all one with the space time foam. Remember, you are just an excited state of the space that you are occupying. And when you move that information, then that energy then moves, you know, it excites another part of the quantum space. It's like you are the wave on the string. Right. If I'm holding a string and I wiggle it, you could say like where does that wiggle go? Well, it moves along the string the same way you are wiggling the quantum fields where you are now, and then when you travel somewhere for Thanksgiving, you're gonna wiggle those quantum fields. So don't think about it as you are particles in space somewhere. But you are excited wiggling of space.
Oh I see, I'm just an excitation from one bubble to the next bubble precisely.
And the idea of space time foam is that maybe space is discretized and those little discrete blobs are popping in and out of existence. They're like not long lasting, they're not eternal. Or permanent.
They're sort of frothing, Oh, coming in and out. But what if I get stuck in one that pops.
I wouldn't recommend that.
Does that mean I'm no longer in existence?
Then you don't have to buy a quantum fet food for your quantum dog, because a quantum out of existence. Now, these things are at a very very small scale, so unless you're a particle on the size of quantum foam, you don't have to worry about it. But also energy is conserved. So if space is frothing somewhere and energetic, if there's an excitation of space here, that energy is going to go somewhere, maybe into the next bubble of the next bubble. So the bubble itself might pop out of existence, but the energy that is represented by that excitation is not going to go away.
Oh, it's just going to move on to another bubble.
Yeah, that's what you do. When you move from place to place. You are exciting those fields, and now you're exciting these fields over here.
All right. And so there's a theory that says that there's the universe at the very core level is like a foam. But that's just one competing theory about what it looks like down there. How are we going to find out which one it is? How do we know if the universe is foamy or if it's not phoney?
Well, we need lots of money to build a huge particle collider. That's my answer to everything, right.
Right, Money just solves everything for you, doesn't it.
It sort of does you know. If you want to answer questions about high energy or heavy particles or tiny distances, what you need is a microscope to look at the really really small And the only thing that prevents us from looking at really really small spaces is having enough money to build a big enough microscope. We know how to do it, it's just really expensive. So we could probe these distances. We think the distances involved or something like ten to the minus thirty five meter, which is ridiculously tiny.
Like if you had a microscope with not just like a ten x one hundred x, but like ten to the thirty five x, we might be able to see these foam bubbles of space and time.
Yeah, we had a whole episode about how you see tiny things and microscopes and electron microscopes and particle colliders. So people should dig into that if they want more information. But basically we can see down to ten to the minus twenty right now, which is pretty impressive. We think these bubbles are ten to the minus thirty five, so fifteen orders of magnitude is actually still a lot. You know, there's a we're far away from being able to see these pixels. So that's one way is to build a really big collider. Another is to try to use like really long distances in space.
To use a space itself like a microscope.
The idea is if space is bubbling and frothing, then you know it's sort of constantly changing. That means that like the distance that light has to travel from point A to point B is not necessarily fixed. They do these crazy experiments where they look at something really really far away and they try to see it in two different ways. They try to understand, like, you know, let's look at two photons that left that really bright source of light maybe e Quasar, at the same moment, and see if they arrived here on Earth at the same time. If there's a difference, then maybe that's because there was more quantum foam bubbling up for one photon then for the other.
Oh, I see because it's foamy. That means to path you take through this foam instead of random, And so like one photon could have hit a really phoamy patch I guess, and gone through a little bit of extra space more than the other particle who just happened to go through a part of space that wasn't as phoamy. And so that would tell you like, oh, space is not consistent, it's kind of frothy.
That's the idea. I have to say that I'm skeptical because you know, on long distance scales, so you would think that these things would average out, like you're going for a billion years, then the number of random times of a coin, they're going to be pretty close to fifty to fifty. So two photons flying through incredible distances in the universe, you know we're going to have pretty even ohs to go roughly the same distance. Anyway, they look at these photons, they don't see anything, no surprise, and so they haven't discovered quantum foam.
All right, Well, do you think we'll ever discover whether the universe is made out of quantum foam or not?
I think we will. I think it'll require some really clever mathematics to come up with like how these theories might actually work. Because remember, we don't have a functioning theory. We don't have a theory we can actually go test the theory. If we ask a questions, it gives us gibberish. And so we need to come up with a good theory and then we need to be really clever about how to test it. And I think maybe sometime far in the future where we can get closer to black holes, we'll be able to test some of these theories in environments with really intense gravity. But it's pretty far off in the future. So we need clever ideas and we need awesome new experiments.
Right. I guess all of that is just to say, send Daniel more money, is the entire takeaway. Who needs sponsorship from quantum dog food when you can just have a whole podcast to ask people for money?
That's right, Email me your quantum dollars to contributions at Daniel and Jorge dot com.
Oh yeah, that does feel like my bank account. It'sup both there and not there.
To say it's constantly fluctuated.
Yeah, it's phoney. I have phone money, not phony money. Phony money. All right, Well, Thank you Dale from Doubling. We hope that answered your question about what quantum foam or space time foam is, and I guess the answer is stay tuned.
Yeah, it's a really fun idea. It's fun to speculate about what the universe might be like at the smallest scales. It's fun to take ideas from our everyday world and see if they apply at the quantum scale. But today we don't really know if quantum foam is a thing or just an idea bubbling up in the mind of physicists.
So keep on looking and keep us sending us your questions. We're happy to answer them. All right. We hope you enjoyed Dad, Thank you for joining us. See you next time.
If you still have a question after listening to all these explanations, please drop us a line. We'd love to hear from you. You can find us at Facebook, Twitter, and Instagram at Daniel and Jorge That's one word, or email us at Feedback at Danielandhorge dot com. Thanks for listening, and remember that Daniel and Jorge Explain the Universe is a production of iHeartRadio. For more podcasts from iHeartRadio, visit the iHeartRadio, app, Apple podcasts, or wherever you listen to your favorite shows. When you pop a piece of cheese into your mouth, you're probably not thinking about the environmental impact. But the people in the dairy industry are. That's why they're working hard every day to find new ways to reduce waste, conserve natural resources, and drive down greenhouse gas emissions. House US dairy tackling greenhouse gases. Many farms use anaerobic digestors to turn the methane from manure into renewable energy that can power farms, towns, and electric cars. Visit you as dairy dot COM's Last Sustainability to learn more.
There are children, friends, and families walking, riding on passing the roads every day. Remember they're real people with loved ones who need them to get home safely. Protect our cyclists and pedestrians because they're people too, Go safely. California from the California Office of Traffic Safety and Caltrans.
This is Malcolm Gladwell from Revisionist History.
eBay Motors is here for the ride with samelbow grease, fresh installs, and a whole lot of love. You transformed one hundred thousand miles and a body full of rust into a drive that's all your own, break kits, led, headlights, whatever you need, eBay Motors has it, and with eBay Guaranteed Fit, it's guaranteed to fit your ride the first time, every time, or your money back plus. At these prices, you're burning rubber, not cash. Keep your rider Die Alive at ebaymotors dot com. Eligible items only.
Exclusions apply
