WEBVTT - What is quantum spacetime foam? 0:00:08.440 --> 0:00:12.080 Hey, Daniel, I've noticed that people just add quantum the 0:00:12.119 --> 0:00:16.120 word quantum to things to make them sound cool. Oh man, 0:00:16.280 --> 0:00:19.720 I hate when they do that. Yeah, like quantum combs, 0:00:19.800 --> 0:00:23.439 quantum um cereal. I mean it''s like they put it 0:00:23.440 --> 0:00:26.520 on everything just to make it sound awesome. Yep. I 0:00:26.560 --> 0:00:30.360 was seeing quantum dog food recently, and I'm pretty sure 0:00:30.680 --> 0:00:35.519 that's not a real fact. Your dog both loves it 0:00:35.560 --> 0:00:38.960 and hates it at the same time. But does that 0:00:39.000 --> 0:00:41.960 mean to just all of quantum mechanics is like a scam, 0:00:41.960 --> 0:00:44.960 not all of it, Like, there really is some physics 0:00:44.960 --> 0:00:47.680 in quantum mechanics, but I'd say most things that are 0:00:47.680 --> 0:01:07.480 called quantum are probably bologny. Hi am Jorge. I'm a 0:01:07.560 --> 0:01:11.640 cartoonists and the creator of PhD Comics. Hi I'm Daniel. 0:01:11.720 --> 0:01:15.640 I'm a quantum physicist and that is not bologny. Oh well, 0:01:15.680 --> 0:01:21.240 it just happens. I'm a cartoon bologny cartoonists. So all 0:01:21.280 --> 0:01:24.240 brings it together and welcome to our podcast, Daniel and 0:01:24.319 --> 0:01:27.400 Jorge Explain the Universe, a production of I Heart Radio 0:01:27.480 --> 0:01:31.360 in which we explore everything that's crazy and amazing about 0:01:31.400 --> 0:01:35.360 the universe, from classical physics to quantum mechanics and explain 0:01:35.400 --> 0:01:37.440 it to you in a way that you can explain 0:01:37.440 --> 0:01:40.479 to your friends and sound super smart. Yeah, in ways 0:01:40.520 --> 0:01:43.520 that we do explain it and don't explain it at 0:01:43.560 --> 0:01:46.399 the same time. We're sort of like a quantum podcast 0:01:46.560 --> 0:01:50.560 in a way. We download individual, discretized units of explanation 0:01:50.760 --> 0:01:53.600 into your brain. We spin it up and spin it 0:01:53.680 --> 0:01:57.160 down for you guys. But quantum mechanics is one of 0:01:57.200 --> 0:02:00.280 my favorite topics because it is so hard for people 0:02:00.320 --> 0:02:03.560 to understand usually, but there are ways to look at 0:02:03.640 --> 0:02:06.000 quantum mechanics and get a new sense of the world, 0:02:06.080 --> 0:02:10.160 to reveal the reality that underlies everything. Yeah, it's your 0:02:10.160 --> 0:02:13.600 favorite because people don't understand it. It's my favorite because 0:02:13.880 --> 0:02:16.799 it's a great example of how in physics we can 0:02:16.919 --> 0:02:19.600 learn that the world is really quite different from the 0:02:19.639 --> 0:02:21.799 world we expected it to be. The world we grew 0:02:21.880 --> 0:02:24.000 up in is not the way the world works. That 0:02:24.240 --> 0:02:27.000 to really understand the universe, we have to remove our blinders, 0:02:27.040 --> 0:02:29.400 and quantum mechanics is a great example of that because 0:02:29.680 --> 0:02:33.560 it requires basically tossing out your entire intuition for how 0:02:33.600 --> 0:02:36.960 the world works and accepting something very different. Yeah, I 0:02:37.000 --> 0:02:39.080 feel like that every day that I wake up and 0:02:39.120 --> 0:02:42.480 read the news, like, what is this universe we're living in? 0:02:42.680 --> 0:02:45.840 What quantum politics is that you're talking about? It's just 0:02:45.880 --> 0:02:49.200 the quantum news will say, it's just the quantumy. It 0:02:49.200 --> 0:02:52.200 makes sense and doesn't make sense at the same time. 0:02:52.320 --> 0:02:54.160 It's about a dead cat and in a life cat 0:02:54.520 --> 0:02:56.720 at the same time. I feel like quantum mechanics is 0:02:56.760 --> 0:02:59.119 something a lot of people are fascinated by. They've heard 0:02:59.160 --> 0:03:02.720 about it, they hear people use words to explain it 0:03:02.760 --> 0:03:05.480 that don't quite make sense to them, and so people 0:03:05.480 --> 0:03:09.640 are thirsty for a real, honest to god understandable explanation 0:03:09.720 --> 0:03:12.720 for some of this bizarre quantum phenomena. Yeah, and it 0:03:12.800 --> 0:03:14.600 sort of seems, like you said, it almost seems like 0:03:14.639 --> 0:03:17.360 two different universes. You know. There's like the universe that 0:03:17.440 --> 0:03:20.160 you grew up and as a kid and feel you 0:03:20.240 --> 0:03:22.160 understand where you take a ball and you bounce it 0:03:22.200 --> 0:03:24.400 and comes back and you can throw a baseball and 0:03:24.440 --> 0:03:26.600 it lands where you think it's gonna land. And then 0:03:26.639 --> 0:03:29.360 there's there's the kind of the quantum universe you learned 0:03:29.440 --> 0:03:32.880 later on in life, where like none of those things 0:03:32.880 --> 0:03:35.720 you learned as a kid seem to apply precisely because 0:03:35.720 --> 0:03:38.560 your brain develops all these ideas for how things move 0:03:38.640 --> 0:03:42.440 based on what you've experienced. Things seem to move through 0:03:42.440 --> 0:03:44.920 the universe, it seems like they have a smooth path, 0:03:45.480 --> 0:03:47.640 and so later to grow up and learn that things 0:03:47.680 --> 0:03:50.640 don't actually move. They just have these snapshots and then 0:03:50.680 --> 0:03:53.680 those later snapshots in your brain is filling in the 0:03:53.720 --> 0:03:56.600 in between slices to make like a movie of the universe. 0:03:56.800 --> 0:03:59.080 Is quite shocking. I wonder if we had evolved to 0:03:59.080 --> 0:04:01.480 be much much smaller, if we would have sort of 0:04:01.480 --> 0:04:04.480 a quantum intuition, if we like had everyday experiences of 0:04:04.600 --> 0:04:07.480 quantum objects. You mean, like if it's taught at the 0:04:07.680 --> 0:04:10.880 preschool level, if we try to teach kids quantum physics, 0:04:12.400 --> 0:04:13.800 I don't think we should be doing short in your 0:04:13.840 --> 0:04:21.520 equation um one plus one, spin up, spin down, you know, 0:04:21.640 --> 0:04:24.359 just the basics that you need to deal with this 0:04:24.560 --> 0:04:27.400 crazy world we're living in. That's one approach, but I 0:04:27.400 --> 0:04:29.560 think that people would still struggle because they don't have 0:04:29.560 --> 0:04:33.360 any actual experience with it. I'm talking about really experiencing 0:04:33.440 --> 0:04:36.320 quantum mechanics, Like what if they were quantum effects that 0:04:36.320 --> 0:04:39.159 were macroscopic, you know, things that were the sizes of 0:04:39.160 --> 0:04:43.800 baseballs operated under quantum rules. It's pretty hard to reveal 0:04:43.880 --> 0:04:46.600 that the universe is quantum mechanical. It took us thousands 0:04:46.600 --> 0:04:49.039 of years before we figure that out. What if it 0:04:49.120 --> 0:04:51.760 wasn't so subtle, what if it was more obvious and 0:04:51.839 --> 0:04:55.360 so people actually had an intuition for this, they're like, oh, electrons, Yeah, 0:04:55.480 --> 0:04:58.960 those moves just like these other quantum basketballs or whatever 0:04:59.120 --> 0:05:03.760 that I was playing in within my kindergarten playground. Yeah. Yeah, 0:05:03.800 --> 0:05:07.200 maybe that's the next wave of physics education, is we 0:05:07.200 --> 0:05:10.640 need to develop some sort of technology that operates like 0:05:10.720 --> 0:05:16.119 quantum objects so kids can play with like quantum balls. Yeah. Well, um, 0:05:16.200 --> 0:05:18.520 it does seem like it's kind of a separate and 0:05:18.960 --> 0:05:22.680 new universe, and it feels like there's a quantum version 0:05:22.880 --> 0:05:25.640 of almost anything. Like for anything that we have in 0:05:25.680 --> 0:05:28.640 our world, there seems to be like a quantum version 0:05:28.720 --> 0:05:30.920 of it. Like you know, I know I can spin 0:05:31.000 --> 0:05:34.480 here in my chair, and there's also something called quantum spin, 0:05:34.720 --> 0:05:36.840 and you know, my battery has charged at it, but 0:05:36.880 --> 0:05:39.720 there's also something called quantum charge and so on and 0:05:39.760 --> 0:05:42.960 so on. Yeah, there's even quantum flavor. Yeah, you think 0:05:43.000 --> 0:05:47.040 in kindergarten that there's only sweet and salty and sour, 0:05:47.160 --> 0:05:50.440 but there's also quantum flavor, and we have quantum color. 0:05:50.520 --> 0:05:55.240 We had a whole podcast episodes about all these. Yeah, 0:05:55.360 --> 0:05:58.080 so you can go to quantum Kindergarten too and learn 0:05:58.200 --> 0:06:04.600 quantum sharing and quantum And in some cases these things 0:06:04.640 --> 0:06:09.640 are metaphors, like quantum flavor. These particles don't actually taste 0:06:09.680 --> 0:06:11.960 like anything, but we're trying to make an analogy. We're 0:06:11.960 --> 0:06:14.880 trying to extrapolate from something we know, which is flavor, 0:06:15.080 --> 0:06:18.279 and give you a sense for this weird new quantum thing. 0:06:18.480 --> 0:06:21.080 But in other cases it really does make sense, like 0:06:21.160 --> 0:06:24.240 quantum spin. Those particles are not spinning in the same way, 0:06:24.320 --> 0:06:27.239 but they really do have angular momentum, so spin really 0:06:27.279 --> 0:06:31.200 makes sense. So in some cases the words are you know, 0:06:31.279 --> 0:06:35.960 really a stretch. In some cases they really are applicable, right, Yeah, 0:06:36.000 --> 0:06:37.520 that was a pretty good way to you just sput 0:06:37.520 --> 0:06:44.680 it there, right, so obvious and clear. But but yeah, 0:06:44.720 --> 0:06:47.080 but sometimes you know, I wonder, sometimes I wonder if 0:06:47.080 --> 0:06:49.280 it are pushing it a little bit too much. And 0:06:49.360 --> 0:06:51.680 so today on the podcast, we have a great question 0:06:51.800 --> 0:06:54.520 from a listener that we're going to try to answer. 0:06:55.200 --> 0:06:58.320 And this is a question from Dale from Dublin. We 0:06:58.400 --> 0:07:03.679 had a very interesting question and about another strange sounding 0:07:03.800 --> 0:07:08.480 quantum thing. Here's Dale Dale from Toblin oiland here I 0:07:08.560 --> 0:07:11.640 heard about a thing called quantum phone or spacetime phone. 0:07:12.120 --> 0:07:14.120 Could you talk about that for a bit and let 0:07:14.160 --> 0:07:16.840 us know what it is? Chairs Well, I love so 0:07:16.880 --> 0:07:18.840 many things about this. First of all, I love Dale's 0:07:18.880 --> 0:07:22.480 accent awesome, and I love the Dale wrote in. This 0:07:22.560 --> 0:07:24.600 is just an email he sent me saying, hey, can 0:07:24.680 --> 0:07:26.920 you explain this? And I asked him to send us 0:07:26.920 --> 0:07:28.800 a recording so we could talk about it on air 0:07:28.880 --> 0:07:30.960 because I thought a lot of people might be interested 0:07:31.000 --> 0:07:33.320 in the answer to this question. So thank you Dale 0:07:33.320 --> 0:07:35.320 for writing in, and thank you to everybody who writes 0:07:35.360 --> 0:07:38.040 in with their questions. Right, and just as a reminder, 0:07:38.080 --> 0:07:42.560 we are on Instagram and Twitter at Daniel and Jorge 0:07:42.840 --> 0:07:45.760 and if you want uh Daniel to answer back, try 0:07:45.840 --> 0:07:49.240 Twitter or the email because Instagram will not answer your question. 0:07:51.080 --> 0:07:53.640 I don't do quantum social media. Yeah, so if you 0:07:53.680 --> 0:07:56.240 have a question, send it on into questions at Daniel 0:07:56.240 --> 0:07:58.880 and Jorge dot com or engage with us on Twitter 0:07:59.240 --> 0:08:02.200 at Daniel in Jorge. Yeah, so this is an interesting question. 0:08:02.320 --> 0:08:05.920 Quantum foam. It's sort of sounds like one of these 0:08:05.960 --> 0:08:09.920 products that you sell in late night television that will 0:08:10.080 --> 0:08:14.720 totally clean your bathroom at the molecular level. I think 0:08:14.760 --> 0:08:17.040 a lot of times in marketing, quantum is just used 0:08:17.080 --> 0:08:20.760 to describe something to make a sound more modern or technological. 0:08:21.280 --> 0:08:24.200 You know, like like quantum dog food. That really is 0:08:24.240 --> 0:08:28.520 a thing. I mean, it's your mechanical No, Google, quantum 0:08:28.520 --> 0:08:30.680 dog food. There is a product they really do sell 0:08:30.760 --> 0:08:33.800 dog Foodn't call it quantum. I think what they mean 0:08:33.840 --> 0:08:37.120 by that is new fancy, you know, savvy to the 0:08:37.160 --> 0:08:41.920 quantum mechanical world somehow new fancy. Yeah, well that's kind 0:08:41.920 --> 0:08:44.160 of what you guys do in physics as well, isn't it. Oh, 0:08:44.240 --> 0:08:45.960 this is a charge, but it's kind of new and fancy. 0:08:46.000 --> 0:08:49.720 We'll call it quantum quantum. Wait, no, but it actually 0:08:49.840 --> 0:08:53.400 is new and fancy. Sometimes we do discover stuff in physics. 0:08:53.400 --> 0:08:56.240 It's new and fancy. All the quantum mechanics is new 0:08:56.280 --> 0:08:59.200 and fancy. It really does happen. It's not just marketing. 0:08:59.440 --> 0:09:02.760 Sometimes dog food is new and fancy. Why not and 0:09:02.880 --> 0:09:07.640 coming districted little chunks? That's true? Yeah, alright, so I 0:09:07.640 --> 0:09:10.240 should order that product and I should evaluate it before 0:09:10.280 --> 0:09:12.280 I give my opinion on it. You're totally right and 0:09:12.440 --> 0:09:14.840 content doct food. Please give us a call. We are 0:09:15.200 --> 0:09:20.040 opening for sponsorship. In this podcast, I was wondering if 0:09:20.080 --> 0:09:24.080 Dale from Dublin was the only person thinking about spacetime foam, 0:09:24.120 --> 0:09:26.600 and so I walked around and I asked people what 0:09:26.760 --> 0:09:29.040 they thought about space time folm, had they heard of it? 0:09:29.200 --> 0:09:31.160 Did they know what Dale was talking about? Did they 0:09:31.160 --> 0:09:33.840 have any idea what it was? And these questions again 0:09:33.840 --> 0:09:35.640 didn't happen to e c Irvine. This happened at a 0:09:35.640 --> 0:09:37.360 local coffee shop because I was trying to get a 0:09:37.400 --> 0:09:41.280 sense for the broader public and their understanding of this topic. Yeah, 0:09:41.320 --> 0:09:43.719 so before you listen to these answers, think about it 0:09:43.760 --> 0:09:46.560 for a second. If a physicist approached you at a 0:09:46.559 --> 0:09:49.559 coffee shop, would you be able to answer the question, 0:09:50.240 --> 0:09:53.200 what is spacetime foam? Here's what people had to say, 0:09:53.400 --> 0:09:57.040 upper layer to spacetime that kind of bubbles up or something. 0:09:57.400 --> 0:10:01.160 If that makes sense, Well, I'm no idea. I have 0:10:01.200 --> 0:10:08.200 no idea spacetime phone, no spacetime phone, no spacetime phone 0:10:09.240 --> 0:10:15.640 for space. I guess, but I don't um space. I'm 0:10:15.679 --> 0:10:20.000 not all right. I feel like people were answering and 0:10:20.040 --> 0:10:21.840 they were just about to call the police on you. 0:10:22.080 --> 0:10:26.720 On these you can sort of hear that in responses. 0:10:27.240 --> 0:10:30.400 They're like, I am so regretting answering this questions. What 0:10:30.520 --> 0:10:33.600 are you talking about? I think, yeah, I mean people 0:10:33.760 --> 0:10:36.880 go to a coffee shop to wake up, and you're 0:10:36.920 --> 0:10:41.480 asking them physics questions over their cappuccimo phone. Well, you know, 0:10:41.679 --> 0:10:44.240 I specifically tried to choose people that looked like they 0:10:44.240 --> 0:10:46.400 were studying, like they had a book open and they 0:10:46.440 --> 0:10:49.120 were reading something, because I was hoping to find people 0:10:49.120 --> 0:10:52.000 who were, you know, like had their brains on or intellection, 0:10:52.080 --> 0:10:55.040 engaged in something, or maybe curious about this kind of thing. 0:10:55.440 --> 0:10:57.960 I didn't interrupt, like couples that were smooching, or if 0:10:57.960 --> 0:10:59.960 they looked like they were listening to a podcast, You're like, 0:11:00.720 --> 0:11:04.800 that person probably knows everything already, right. I try to 0:11:04.840 --> 0:11:07.040 avoid people who already have their earbuds in, because I 0:11:07.040 --> 0:11:10.480 feel like in public, earbuds mean don't talk to me. Well, 0:11:10.559 --> 0:11:14.040 this is kind of an interesting question. Quantum foam and 0:11:14.120 --> 0:11:15.679 I I had never heard of it. If you have 0:11:16.000 --> 0:11:17.680 approached me at a coffee shop, I would have just 0:11:17.720 --> 0:11:21.400 said no, please, go on, please please asked me an 0:11:21.400 --> 0:11:23.400 easier question. You would have been like, you look like 0:11:23.440 --> 0:11:25.840 this other physicist I know, and I definitely ignore him 0:11:25.840 --> 0:11:28.480 in public. So I'm not talking to you as a 0:11:28.520 --> 0:11:33.520 blanket policy. That's my decision on physicists. All right, So 0:11:33.800 --> 0:11:35.880 this is an interesting question because it's it's like you're 0:11:35.880 --> 0:11:41.599 marrying two words that are very common space time and foam, 0:11:41.640 --> 0:11:44.600 but that together really don't make any sense. Yes, And 0:11:44.640 --> 0:11:48.120 that happens so much in quantum mechanics. People say things 0:11:48.120 --> 0:11:51.880 that use words together and you understand the individual words, 0:11:51.960 --> 0:11:53.600 but you don't really know what it means when you 0:11:53.640 --> 0:11:56.680 put it together. So we'll get into what spacetime foam 0:11:56.880 --> 0:11:59.200 is and what we know about it and how we 0:11:59.280 --> 0:12:01.800 might be able to find it in in this frothy 0:12:01.880 --> 0:12:04.599 little universe we live in. But first let's take a 0:12:04.679 --> 0:12:21.360 quick break, all right, Dannel, we're talking about spacetime foam, 0:12:21.440 --> 0:12:25.280 and it's not a weird product that you sell on 0:12:25.440 --> 0:12:30.480 late night television. It's an actual physical theory in science, 0:12:31.280 --> 0:12:33.120 and so let's get into that a little bit. And 0:12:33.120 --> 0:12:35.680 I guess let's start with the first two words to 0:12:35.720 --> 0:12:38.360 set us up for the foamy part um. So let's 0:12:38.360 --> 0:12:41.040 talk a little bit about spacetime, because in this case, 0:12:41.120 --> 0:12:46.240 I think Dale from Dublin used the word as one word, 0:12:46.559 --> 0:12:50.360 like spacetime, not space common time. He called it spacetime. 0:12:50.520 --> 0:12:53.280 So let's maybe refresh for our listeners what it means 0:12:53.559 --> 0:12:55.959 to say spacetime. Yeah, it's like you take two words 0:12:55.960 --> 0:12:58.720 you put them together. They mean something special, like green 0:12:58.880 --> 0:13:02.600 and house. Greenhouse is not just a greenhouse, right, has 0:13:02.640 --> 0:13:05.320 its own meaning. So in the same way space time 0:13:05.360 --> 0:13:08.160 is sort of a special word in physics, and of 0:13:08.200 --> 0:13:11.760 course you know it's spaces. Space is just the three 0:13:11.800 --> 0:13:14.400 dimensions of movement. You know, you have X, y, and Z. 0:13:14.640 --> 0:13:17.200 And we have a whole other episode about like what 0:13:17.320 --> 0:13:19.880 makes up space? Is it a thing because it can 0:13:19.960 --> 0:13:22.760 wiggle and dance and jiggle and expand and all this stuff. 0:13:23.080 --> 0:13:25.040 But for our purposes today, let's just think about it 0:13:25.000 --> 0:13:27.960 as sort of as the directions you can move in X, Y, 0:13:28.040 --> 0:13:30.920 and Z. So that's what space means, like the space 0:13:30.960 --> 0:13:33.920 we're in, like where we move around in. Yeah, precisely, 0:13:33.960 --> 0:13:37.439 nothing special there. And time is just time, right, time 0:13:37.480 --> 0:13:40.520 flows forwards, and you can think of time in analogy 0:13:40.559 --> 0:13:43.160 to space. You can think of us as moving through 0:13:43.200 --> 0:13:45.160 time the way you can move through space. And we 0:13:45.200 --> 0:13:48.840 have a whole podcast episode digging into how time is 0:13:48.840 --> 0:13:51.480 connected to space and how time is different from space. 0:13:52.000 --> 0:13:55.040 But Einstein is the guy who put these two things together. 0:13:55.360 --> 0:13:58.240 He's the first one to construct this idea of space 0:13:58.280 --> 0:14:01.400 time by taking three dimensions of space that you can 0:14:01.440 --> 0:14:03.839 move in and adding the time dimension to it is 0:14:03.880 --> 0:14:06.840 sort of a fourth dimension. So together space time is 0:14:06.880 --> 0:14:11.760 this four dimensional idea X y Z and then time. Right, 0:14:11.800 --> 0:14:13.680 I feel like you just said something profound though you 0:14:13.679 --> 0:14:18.320 just said time is time. That man, time is so fascinating. 0:14:18.400 --> 0:14:21.120 I could talk endlessly about time. We could spend all 0:14:21.120 --> 0:14:23.520 of our time talking about time. But maybe it's not 0:14:23.600 --> 0:14:25.720 time to do that. That one phrases made me think 0:14:25.720 --> 0:14:28.360 about my whole life and where I'm going with it. 0:14:28.400 --> 0:14:31.320 And well, can I sell you my new product. It's 0:14:31.360 --> 0:14:35.920 called quantum time the There you go, alright, quantum quantum 0:14:35.920 --> 0:14:40.880 watch to keep track of the inevitability of time. It's 0:14:40.920 --> 0:14:43.280 new and fancy and has to be charged every fifteen minutes. 0:14:43.600 --> 0:14:48.640 There you go, alright. So spacetime is this idea that um, 0:14:48.840 --> 0:14:51.840 space and time are not separate, like maybe if you 0:14:51.880 --> 0:14:56.760 think about them altogether in one package, one four dimensional bundle. 0:14:57.480 --> 0:15:02.840 Then it's more appropriate somehow like uh like the related 0:15:02.920 --> 0:15:04.880 like one of them affects the other, so therefore you 0:15:04.880 --> 0:15:07.520 should keep track of them all at the same time precisely. 0:15:07.720 --> 0:15:10.360 And it was Einstein's theory of special relativity that showed 0:15:10.400 --> 0:15:14.680 us exactly how space and time are affected by each other. Specifically, 0:15:14.720 --> 0:15:18.000 how time flows depends on where you are and how 0:15:18.120 --> 0:15:21.320 fast you are going relative to something else, and so 0:15:21.360 --> 0:15:24.240 in order to understand time, you can't just have time 0:15:24.280 --> 0:15:27.560 by itself. Time is not universal. Time is local. Time 0:15:27.600 --> 0:15:30.520 depends on where you are in space, and so it 0:15:30.520 --> 0:15:33.160 makes much more sense to combine these two things together. 0:15:33.720 --> 0:15:36.080 It's like having the weather, right. The weather is not 0:15:36.120 --> 0:15:38.160 the same everywhere, so you want to talk about the 0:15:38.160 --> 0:15:40.800 weather where you are in Buffalo, or in New Delhi 0:15:41.200 --> 0:15:44.280 or in Barcelona, and so you pair the weather with 0:15:44.360 --> 0:15:47.200 the location because that makes more sense. It's called the 0:15:47.280 --> 0:15:52.120 space time weather continuum, which you hear listen to my 0:15:52.200 --> 0:15:56.040 new quantum weather reports. It's a new Toppler quantum three 0:15:56.040 --> 0:15:58.440 thousand that probably is a real thing. I mean, you're joking, 0:15:58.720 --> 0:16:02.240 but there's probably some will station out there with quantum weather. 0:16:02.280 --> 0:16:06.920 Dobbler some local weatherman in the middle of Barcelona. And 0:16:07.080 --> 0:16:10.160 Geinstein was not crazy, right, Like, he didn't just make 0:16:10.200 --> 0:16:12.840 this up and it didn't work. It actually works, Like 0:16:13.320 --> 0:16:17.600 bundling space and time together does tell you something about 0:16:17.600 --> 0:16:21.480 the universe, and it's there's been theories and experiments done 0:16:21.520 --> 0:16:23.880 to prove that this is all for real. Oh, yes, 0:16:23.920 --> 0:16:27.120 Einstein was right about this. That doesn't mean Einstein wasn't crazy. 0:16:27.160 --> 0:16:28.960 I mean, you dig into that guy's personal life. He 0:16:29.040 --> 0:16:30.920 was more than a little bit across. What do you mean. 0:16:31.000 --> 0:16:34.200 He was also right about spacetime, all right, So that spacetime. 0:16:34.480 --> 0:16:38.880 And now the question from Dale was what is spacetime foam? 0:16:39.000 --> 0:16:41.400 And I have to say, I've never heard of this before. 0:16:41.600 --> 0:16:44.640 Is this a new thing? Is this something that's only 0:16:44.640 --> 0:16:46.400 been around for a couple of years, or is this 0:16:46.480 --> 0:16:49.480 like a fringe theory or French theory? I don't know 0:16:49.560 --> 0:16:54.640 either one. What is what is going on with spacetime phoam? Well, 0:16:54.680 --> 0:16:57.720 I can't endorse your casual slander of entire culture there, 0:16:58.160 --> 0:17:00.600 but it is a bit of a fringe in theory. 0:17:01.080 --> 0:17:03.400 It's one of these things. It's like it's an idea 0:17:03.840 --> 0:17:06.919 that took hold in some people's minds, but then not 0:17:07.000 --> 0:17:08.960 a lot of progress was made, so so HA just 0:17:09.000 --> 0:17:12.720 been hanging out there, bubbling up in people's brains without 0:17:12.800 --> 0:17:16.040 really turning into anything concrete. So it's been around for 0:17:16.080 --> 0:17:18.640 a while, but it's not really part of the mainstream physics. 0:17:18.760 --> 0:17:21.919 It's just been foaming up in people's research dockets. And 0:17:21.960 --> 0:17:23.560 so I know that you keep abreast of all the 0:17:23.640 --> 0:17:25.919 latest topics in physics and you read all the physics journals, 0:17:25.920 --> 0:17:29.160 and that's probably why you haven't heard about this recently. Right, Well, 0:17:29.400 --> 0:17:32.000 at first I thought it was maybe an acronym, like 0:17:32.080 --> 0:17:35.840 maybe fo a M stands for something. It's the first 0:17:35.920 --> 0:17:39.240 of a multiverse, which is a new theory by Jorge 0:17:39.320 --> 0:17:43.120 Cham about how we're the most awesome of all the multiverses. 0:17:44.440 --> 0:17:47.280 And somehow Dale from Dublin knew about your theory before 0:17:47.320 --> 0:17:50.679 you even thought about it and thought to ask in advance. Wow, 0:17:50.800 --> 0:17:53.679 good job, Dale. Yeah, well, in other multiverses he didn't, 0:17:53.800 --> 0:17:57.879 but this one, because it's the best he did, all right, 0:17:57.920 --> 0:18:00.760 So let's let's talk about this. So there is something 0:18:00.800 --> 0:18:05.439 called spacetime foam that physicists think might be real and 0:18:05.600 --> 0:18:09.199 might actually kind of describe what the universe is like, 0:18:09.680 --> 0:18:12.880 so take us through it, Daniel, what does it mean 0:18:13.280 --> 0:18:16.000 to put the word spacetime and foam together? The idea 0:18:16.040 --> 0:18:19.320 here is to try to resolve the conflict between our 0:18:19.400 --> 0:18:22.840 two great theories of physics. We talked about space time 0:18:22.920 --> 0:18:25.359 in terms of relativity, and that all makes sense. And 0:18:25.440 --> 0:18:27.919 relativity has been tested out the wazoo and up the 0:18:27.920 --> 0:18:30.800 wazoo and in the wazoo in every way around the wazoo. 0:18:30.880 --> 0:18:33.600 Because is that it's a great theory. Is that another 0:18:33.680 --> 0:18:38.320 physics experiment acronym the wazoo, the wazoo, I'm not sure 0:18:38.320 --> 0:18:46.240 what it means collider in Italy apparently, but special relativity 0:18:46.240 --> 0:18:49.879 has been extensively tested, and so has general relativity. But 0:18:50.119 --> 0:18:53.320 we don't know if it really holds universally. That we 0:18:53.400 --> 0:18:57.199 have suspicions that it probably doesn't work on really really 0:18:57.240 --> 0:19:00.680 tiny distances. So general relativity said is that space is 0:19:00.720 --> 0:19:03.320 sort of smooth, that you can chop it up into 0:19:03.400 --> 0:19:06.640 tinier and tinier bits and you'll never sort of run 0:19:06.680 --> 0:19:08.879 out of ways to cut it in half. That like 0:19:08.880 --> 0:19:12.199 in Zeno's paradox, you could take smaller and smaller steps forever. 0:19:12.760 --> 0:19:16.159 That's what general relativity says. It predicts it, or it 0:19:16.240 --> 0:19:18.959 assumes it. It assumes that it it uses that as 0:19:19.000 --> 0:19:21.480 its essential description of what space is. That you could 0:19:21.480 --> 0:19:24.399 have a particle or an object located at any point. 0:19:24.680 --> 0:19:26.720 You know, if you have an infinite number of locations 0:19:26.760 --> 0:19:29.200 between me and you, that a particle could be at 0:19:29.200 --> 0:19:32.000 any of those locations. Oh, I see. It's kind of 0:19:32.040 --> 0:19:34.840 like Newtonian physics, right almost in a way, like it 0:19:34.920 --> 0:19:39.600 assumes that space is smooth, and it doesn't assume anything 0:19:39.640 --> 0:19:42.960 that's that anything is quantized. That's right, And you look 0:19:43.000 --> 0:19:45.800 at the universe around you, and the universe seems smooth, right, 0:19:46.040 --> 0:19:48.960 It seems like you could sit anywhere. It seems like 0:19:49.240 --> 0:19:51.399 if you took a ruler, you could cut it in 0:19:51.440 --> 0:19:56.320 an infinite number of ways. Whatever that there's an infinite 0:19:56.359 --> 0:19:59.239 number of ways. But just like the screen on your 0:19:59.240 --> 0:20:02.440 iPhone looks really crisp and smooth, but if you zoom in, 0:20:02.840 --> 0:20:05.679 you discover that there are pixels there. And so general 0:20:05.680 --> 0:20:08.719 relativity tells us that the universe is smooth. That's space 0:20:09.119 --> 0:20:13.800 is infinitely sliceable. But that's in conflict with quantum mechanics. 0:20:14.040 --> 0:20:18.359 Quantum mechanics says that you can't have infinitely sliceable space. Yeah, 0:20:18.400 --> 0:20:22.520 that at the fundamental level, it's pixelated, kind of like 0:20:22.640 --> 0:20:26.720 my iPhone screen. Although my iPhone screen these days looks 0:20:26.800 --> 0:20:28.720 kind of blurry because as I've said before, I need 0:20:28.720 --> 0:20:31.280 reading glasses. Now I'm not sure that's a problem with 0:20:31.280 --> 0:20:34.119 your iPhone screen, but well it's a it's a problem 0:20:34.160 --> 0:20:36.840 for my new quantum reading glasses. Yeah. And so quantum 0:20:36.880 --> 0:20:39.760 mechanics has this impact on lots of things that we measure. 0:20:40.080 --> 0:20:43.480 Things that at large scales seem smooth turn out to 0:20:43.520 --> 0:20:46.560 be discretized, turned out to be sliced up into chunks. 0:20:46.600 --> 0:20:50.120 Like a flashlight beam is not a smooth, continuous beam 0:20:50.119 --> 0:20:54.040 of light. It's a stream of tiny little packets called photons. 0:20:54.400 --> 0:20:56.560 The same way your bowl of ice cream is not 0:20:56.960 --> 0:21:00.640 infinitely chopped herble into smaller and smaller spoonful. There are 0:21:00.680 --> 0:21:02.840 atoms in there. It's made out of these tiny little 0:21:02.920 --> 0:21:05.840 lego pieces. So the same concept can be applied to 0:21:05.920 --> 0:21:08.960 lots of things, and quantum mechanics says that probably it 0:21:09.000 --> 0:21:12.399 also applies to space. So we have this conflict between 0:21:12.440 --> 0:21:16.800 these two great theories of physics, relativity and quantum mechanics, 0:21:16.840 --> 0:21:19.639 and the conflict lies in a place that's really hard 0:21:19.640 --> 0:21:23.080 to spot where things are super duper small, so meaning 0:21:23.119 --> 0:21:27.320 that general relativity doesn't know that there's something called quantum 0:21:27.359 --> 0:21:33.240 physics and quantum mechanics. Quantum physics sort of we don't. 0:21:33.640 --> 0:21:37.520 Do we know that quantum mechanics takes into account general 0:21:37.600 --> 0:21:40.280 relativity or is there such a thing as bending a 0:21:40.359 --> 0:21:43.639 space and quantum mechanics. So that's a great question. People 0:21:43.680 --> 0:21:46.359 have tried to say, let's take Einstein's theory of general 0:21:46.400 --> 0:21:49.200 relativity and let's make a quantum version of it. Can 0:21:49.280 --> 0:21:52.720 we make a version of general relativity where space is 0:21:52.800 --> 0:21:56.840 pixelated or we know quantum mechanics comes into account, and 0:21:56.920 --> 0:22:01.400 currently we have no great functioning theory like these. Reason um, 0:22:01.440 --> 0:22:04.399 you can make a theory of general relativity that is quantized, 0:22:04.640 --> 0:22:08.119 but it doesn't work when space is really intense, like 0:22:08.200 --> 0:22:11.359 inside a black hole. When the gravity gets really really strong, 0:22:11.680 --> 0:22:13.640 then the theory breaks down and predicts things that don't 0:22:13.680 --> 0:22:15.879 make sense. It gives you like infinities and all sorts 0:22:15.880 --> 0:22:19.000 of crazy numbers. So we don't currently have a working 0:22:19.040 --> 0:22:22.919 theory of what's called quantum gravity that tries to marry 0:22:23.000 --> 0:22:26.560 all the best things from general relativity and quantum mechanics. 0:22:26.840 --> 0:22:29.919 So does that mean that quantum mechanics operates kind of 0:22:29.960 --> 0:22:35.120