So long, and thanks for all the chocolate

00:00:08
Speaker 1: Hey everyone, Daniel here. For six years and six hundred episodes, I've been talking to you about how wonderful and mysterious our universe is. I've tried to guide you in how to think about quantum mechanics, how to wrap your head around relativity, and even how to help your teenager with their chemistry homework when you have to. Or maybe that's just me. Along the way, We've made a lot of silly jokes about bananas and chocolate and anything else we could think of to keep the mood light and to make everybody feel welcome in this exploration of the universe. And it's been a pleasure an honor to host this show and to be your guide into the joys of understanding the cosmos, because I really do think that the universe can be explained, and that it deserves to be explained, and that you deserve that explanation. When we started, I had no idea how long this podcast would go for. After two hundred, three hundred or five hundred episodes, I was amazed that people still had an appetite for more physics.

00:01:08
Speaker 2: And more Dad humor. But it was never.

00:01:10
Speaker 1: Gonna last forever, and so it's with some wistfulness and a lot of gratitude that I share with you today at the news that this episode is our farewell episode. But don't worry, neither the universe nor I are going away just yet.

00:01:41
Speaker 2: Hi. I'm Daniel.

00:01:42
Speaker 1: I'm a particle physicist, and for the last few years I've been the host of this podcast, Daniel and Jorge Explain the Universe. I've had a rotating series of co hosts, starting of course with Jorge, then going solo for a bit, then Jorge came back, and then I was solo again. Then I invited Kelly and Katie to join us as co hosts.

00:02:00
Speaker 2: Jorge returned.

00:02:01
Speaker 1: But I've been here with you on every single episode because this project means something to me. It means a lot to me. I'm a physicist, of course, but I'm also a professor, and that means that part of my job is education, not just research. Of course, I teach classes here at UC Irvine, from first year classical mechanics all the way up to graduate level particle physics. But I also want to help address the unsatisfied thirst people out there have for jargon free, intuitive explanations about the universe. Because there's this wonderful moment when ideas click together in your mind, when you've understood something new and familiar, when it makes sense in a way it didn't used to. And I want to share those moments with all of you, giving you a shortcut to the intuitive understanding of the universe without having a way through years of mathematical training. That's my major goal with this podcast and with my book projects, to share the joy of understanding and the allure of all the unanswered questions.

00:03:00
Speaker 2: With all of you.

00:03:01
Speaker 1: So thank you, thank you for being there with me. And although this particular podcast won't be continuing my desire to connect with all of you to explore what we do and don't know about this incredible, bonkers, amazing universe that isn't going away. So I'm very happy to announce my new podcast, Daniel and Kelly's Extraordinary Universe. You all know Kelly one of our wonderful co hosts on this pod. She and I have always had fun talking about science and joking around, and so we are launching this new project. It's not exactly the same as explaining the Universe, but I think that fans of this podcast will also enjoy the new one. You'll recognize me, of course, and my style of explanations, and you already know Kelly, and there will be plenty of puns and silliness mixed in with the science. More about that later, because today we are here to say goodbye to Daniel and Jorge explain the universe, to celebrate what we've accomplished, to remember our best moments, and to think about all we have learned. So today on the podcast, we're saying so long and thanks for all the chocolate, to celebrate everything we have learned. I went back and listened to a bunch of old episodes to see how the podcast has changed. And you know, through the years, the podcast has evolved a bit as we found our rhythm, but you can hear the groove that we found even in the earliest episodes. Here's a couple of clips from the first two episodes of the podcast.

00:04:25
Speaker 2: I'm Daniel. I'm a particle physicist.

00:04:27
Speaker 1: I spend my days smashing protons together at the large Hadron colliders to try to reveal the secrets of the universe, mostly so that I can tell them to you in this podcast.

00:04:37
Speaker 3: Basically, only one of us is qualified to be explaining things to you on this podcast.

00:04:41
Speaker 2: That would be the cartoonist.

00:04:42
Speaker 1: Yeah, physicists are not qualified usually to be explainers. Mostly we just try to solve the mysteries of the universe. We don't try to tell anybody about them.

00:04:50
Speaker 3: Right, Mostly physicists just need explaining, that's right.

00:04:55
Speaker 2: That's where the cartoons come in, right.

00:04:56
Speaker 3: Yeah, and spouses also, spouses of physicists have to do a lot of explaining.

00:05:01
Speaker 2: You got some splaining to do, exactly. Yeah.

00:05:05
Speaker 1: You have to imagine if somebody is running our universe as a simulation, who knows what kind of computational powers they have, right, And if they are their universe, the one that our universe is running as a simulation inside of doesn't have to follow the same laws as our universe.

00:05:21
Speaker 2: Right.

00:05:22
Speaker 1: If we're in a video game inside somebody else's universe, our video game can have rules that don't exist outside the video game.

00:05:28
Speaker 3: Right, So they like f equals MA or general relativity that could have been something they just made up because they thought they would be fun or interesting, you know, like like we like we create video games with crazy physical rules. You know, Mario can jump half of the screen, he can jump twenty feet up in the air, so maybe that's that's what our physical laws are. They're just kind of like, hey, let's make this fun universe where f eqals maa. Is that kind of the idea.

00:05:56
Speaker 1: That's exactly right, Yeah, that's exactly right. And I think that's harshly the origin of this idea. You know, what is physics doing? Ask yourself that physics is trying to figure out what are the rules of this universe?

00:06:08
Speaker 2: Right?

00:06:09
Speaker 1: What are the underlying code that runs this universe? And so now that we actually have pretty powerful computer programs, people wonder, well, if you were in a computer program and you were trying to figure out what the rules of that simulated universe were, you'd essentially be trying to understand what was the physics coded into that universe.

00:06:28
Speaker 3: You would be a physicist.

00:06:29
Speaker 1: So in some sense, yeah, you'd be a physicist exactly. Physicists are trying to reverse engineer the source code of the universe. Right, regardless of whether you believe the universe is real or a simulation, it does seem to follow.

00:06:41
Speaker 3: Some rules, right, So it's like when you first.

00:06:43
Speaker 2: It's amazing that we can even discover those.

00:06:45
Speaker 3: So it's kind of like when you first play Super Mario or something, and you're just jumping around and moving around trying to figure out how Mari moves. You're essentially like being a physicist in that world.

00:06:56
Speaker 1: Right, that's exactly right. Everybody who plays a video game for the first time, exactly.

00:07:02
Speaker 3: Let's give everybody who plays video games.

00:07:07
Speaker 2: That's right.

00:07:08
Speaker 1: That you just give a whole generation of listeners or reason to stop doing their physics homework and turn on their video.

00:07:13
Speaker 4: Yes.

00:07:14
Speaker 1: Of course, by the end, people we're familiar with my opinions about chocolate, the scourge that is white chocolate, and the tragedy that is a Hershey bar. Here's me interviewing a chocolate expert on the Physics of Chocolate episode. Let's talk about the Hershey bar also because it's iconic on the podcast recently, I commented that I was not a particular fan of the Hershey bar because it has this sour flavor to it. Where does that sourness come from? Is it some property of milk chocolate? Is it some secret process that Hershey has? Why are Hershey bar so sour?

00:07:47
Speaker 5: So the story is, and I'm sure a Hershey representative may dispute my spin on this is we talked to Europeans and say, you know, they got the process of drying liquid milk wrong and that it became there's lipid catalysis that creates organic acids that gives you the sour character that you get from baby puke.

00:08:13
Speaker 1: I'm sorry, did you just say baby puke?

00:08:15
Speaker 2: I did? I did.

00:08:16
Speaker 5: And I've heard those terms from other Hershey people, so I'm not taking these terms out of context.

00:08:22
Speaker 1: So we have it on the record from an expert in chocolate that Hershey's tastes like baby puke.

00:08:27
Speaker 5: All, yeah, that'll intribution on this one.

00:08:31
Speaker 1: Of course, there were lots of moments when we dug deep into the physics and really tried to give you an understanding of how everything out there worked. Here's a snapshot from our episode about the Higgs boson and the Mexican hat.

00:08:43
Speaker 3: So then maybe the universe. It's almost like, at some point in the beginning of the universe, the universe somehow got mass like it needs to be massless everything at least the matter particles, And then something happened to this field that made suddenly everything has messed exactly.

00:08:56
Speaker 1: And that's the moment in the universe when electromagnet and the weak force split off from each other. Because that's what the Higgs boson does, is it breaks this symmetry between electromagnetism and the weak force, which we think are really all just one sort of big, happy force. But the W and the Z particles, which carry the information for the weak force, they're really really massive. And that happened at that moment when the Higgs boson sort of rolled away from the middle and settled at this large value. And we call that electroweak symmetry breaking. So there was a time in the early universe when we think the weak force was as powerful as electricity and magnetism, and then the Higgs broke it.

00:09:34
Speaker 3: Oh, man, that Higgs.

00:09:35
Speaker 2: What a bully.

00:09:38
Speaker 3: The week fourth week.

00:09:39
Speaker 1: It's just doing its job, man, it's just doing its job. But we think of it this also in terms of like phase transitions, Like the universe was very different before this and very different after this moment. And you know, people you might hear people talking about like how there were different laws of physics before this phase transition or something, and that's because you know, these things control how things offen, that things have no mass, and the weak force is very very powerful than the effective laws of physics, the things we experience would be very different. Deep down, there's still like the basic laws of physics underneath everything that are controlling how this happens. Those don't change, but you know the way the things end up interacting and the way they come together to form complex matter, that does change when you have one of these like big moments in the universe. So that's why they call it like a phase transition in the laws of physics.

00:10:28
Speaker 3: Like things click together differently, depending maybe on the size of the universe or the density of it. All right, well, let's get into what this all means. Why is it important that the Higgs field has this potential shape like a Mexican head.

00:10:41
Speaker 1: We had lots of fun talking science with Katie, of course. Here's a snippet from our episode about the length of the day.

00:10:49
Speaker 2: Hi, I'm Daniel.

00:10:49
Speaker 1: I'm a particle physicist and a professor at UC Irvine, and I get paid whether I nap or not.

00:10:55
Speaker 6: I am Katie. I am a professional napper. I am so good at naps you wouldn't even believe it. I also run a podcast called Creature Feature. I am a biology educator.

00:11:07
Speaker 1: Hmm, and have you ever had an episode about naps in the animal world.

00:11:11
Speaker 5: I actually have.

00:11:13
Speaker 6: Like there's a lot of animals that do sleep in weird ways, like little like micro naps that birds do, where they do like little tiny, itty bitty naps throughout the day in order to stay alert, or like weird giraffe sleeping schedules where it's like they sleep in these weird chunks and wake up throughout the night but sleep like a lot.

00:11:34
Speaker 2: It's very interesting the.

00:11:36
Speaker 6: Idea of this, like you know, sleep during the night, bewake during the day, and sleep in a solid chunk, is very much just like a human quirk, right, A lot of animals sleep differently.

00:11:46
Speaker 1: Well, I wonder about that with my dog. I never find him sleeping in the same place in the morning as he went to sleep in the evening, and I wonder, like, does he have a night sleep? Is he just like napping a bunch because he also like sleeps most of the day.

00:11:59
Speaker 2: So what is my dog doing in the middle of the night?

00:12:01
Speaker 6: King he's online on dog Internet.

00:12:06
Speaker 2: No, I'm recording his own podcast, wondering what I'm doing rough stuff.

00:12:12
Speaker 1: Yeah, And it was always fun to talk science with Kelly. Here's a couple of clips from episodes with her.

00:12:19
Speaker 7: And I'm Kelly Waiersmith. I'm a parasitologist who's adjunct with Rice University, and I also like power.

00:12:26
Speaker 1: Do you ever wish that you could just plug yourself into solar power?

00:12:29
Speaker 8: Like?

00:12:30
Speaker 1: Why do we still need to sleep? Why can't we just recharge the way all of our devices do?

00:12:34
Speaker 9: Yeah?

00:12:34
Speaker 7: Right, that would be like an upgrade of coffee.

00:12:36
Speaker 1: I like it electrified coffee exactly. It just seems so much more reliable. You know, those days you have, like insomnia or whatever. You're like, I wish I could just plug in and charge up today.

00:12:46
Speaker 7: I overdid the coffee and I'm feeling kind of jittery. So if I could just plug into a solar panel and get nice, steady power without overdoing it, that would be pretty solid.

00:12:56
Speaker 1: Well maybe someday in the future, I know. I'm a particle physicist and a professor at UC Irvine, and I don't like scaring children, but I do like telling them the truth.

00:13:10
Speaker 7: I'm Kelly Wainer Smith. I'm an edgeuct professor at Rice University, and I prefer lying to them.

00:13:17
Speaker 1: What you lie to your kids, What if they ask you a science question you don't know the answer, you just make one up.

00:13:22
Speaker 8: No.

00:13:22
Speaker 7: In that case, I tell them the truth.

00:13:24
Speaker 2: That's important, you know.

00:13:25
Speaker 7: But one of them does still believe in Santa and now will not be listening to this episode.

00:13:32
Speaker 1: What if they ask you a science question that has a scary answer.

00:13:36
Speaker 7: It depends on if I think they can handle it or not. And it depends on when I want to go to bed that night, because I might be up late doing the explaining. There's lots of things to consider, But.

00:13:44
Speaker 1: Welcome to the podcast Daniel and Jorge Explain the Universe, in which we try to teach you everything about the universe, scary or not, the things that will keep you up at night, worried about whether you will survive, and the things that make you feel like the universe is a comfortable, cozy place. It's all set up for you to have a good time. We talk about black holes, we talk about quarks. We talk about the future of the human race and whether it.

00:14:09
Speaker 2: Has a future or not.

00:14:11
Speaker 7: Dark stuff.

00:14:13
Speaker 1: My friend and co host Orge can't be here today, so we are joined by Kelly Weenersmith, who is trying to teach you things without scaring your children.

00:14:21
Speaker 7: That's right. I feel like maybe I need to defend that decision, but I'm just gonna let it go. Sometimes kids don't need to be scared. You get to spend your whole adulthood being scared about stuff.

00:14:30
Speaker 2: You know you're right.

00:14:31
Speaker 1: And the thing I love about the universe is that it doesn't really care about our feelings.

00:14:35
Speaker 2: It's just crazy.

00:14:37
Speaker 1: It's just bonkers. It's just doing its thing. Whether that means it's threatening to tear you apart and blow you away, or whether it's created this wonderful environment for you to relax in and sip your marker Rita while you listen to a podcast. The universe doesn't care either way.

00:14:51
Speaker 7: You know, it's really good that you went into physics and not like psychiatry or something. And how how are your kids turning out?

00:14:59
Speaker 1: My kid's so far are not sociopaths, you know, but hey, we need to collect more data. No, My strategy has always been to answer their questions honestly, though I will admit if their questions bring up something awkward or uncomfortable or maybe age inappropriate, I'll try to deflect the question once or twice. But if they really insist, if they drill in for an answer, I'm giving it to them. One of my favorite things on the podcast was getting to fan boy out and talk to science fiction authors whose work I'd been admiring for years. We got to talk to some pretty famous folks.

00:15:31
Speaker 10: I'm an lucky I'm the author, most famously, I guess, the author of the novel Ancillary Justice and it sequels Ancillary Sword and Ancellary Mercy. My name is Mary robinet Cole. I write science fiction and fantasy. I'm also an audiobook narrator and a professional puppeteer.

00:15:49
Speaker 1: Well, it's not that often that you made a science fiction author who's also a puppeteer. How did those two careers intersect.

00:15:56
Speaker 10: They're both all about theater of the possible. Anything is possible when you step into popetry or science fiction, so they're both also, I think, places that tend to naturally explore what if in imagination.

00:16:10
Speaker 1: It's my great pleasure to welcome to the podcast. Peter Harness, an English playwright, screenwriter and actor. Thanks very much for joining us.

00:16:18
Speaker 4: Thank you very much.

00:16:19
Speaker 2: I need to update Wikipedia.

00:16:20
Speaker 4: I haven't done any acting for a very long time, but it's nice.

00:16:23
Speaker 2: It's still it's nice. It still believes that I have more Once an actor, always an actor.

00:16:29
Speaker 1: We also reached out to top physicists and science communicators to come talk to us about their ideas about the most confusing and mysterious theories in physics. Here's a clip from my conversation with Sean Carroll. So it's my great pleasure to introduce Professor Sean Carroll. He's a theoretical physicist at Caltech, and he's known for his work on cosmology, general relativity, and the foundations of quantum mechanics. He's also the author of several widely acclaimed and widely read books, including Something Deeply Hidden and The Big Picture, and is the host of the podcast Mindscape, which might actually be neardier than this podcast. Today, Sean is here to talk to us about the many world's interpretation of quantum mechanics and the measurement problem in quantum mechanics. Sean, Welcome to the podcast. Thanks very much for having me here.

00:17:14
Speaker 2: Wonderful to have you.

00:17:15
Speaker 1: So I want to dive right in and before we talk about what the many world's interpretation is, I want to get your view on what problem it solves, like, why do we need so many interpretations of quantum mechanics? What problem is it that they are trying to address.

00:17:28
Speaker 3: I think there's actually two problems. I mean, this is the right question, because are we just wasting our time or honestly, it's not a lot of time compared to other physicists thinking about other things. The foundations of quantum mechanics is a minority pursuit. But I think there are two problems, and they're such looming, large problems, and quantum mechanics is so important to modern physics that I do wish we were spending more time on them.

00:17:50
Speaker 1: And I got to talk to Carlo Ravelli. So it's my great pleasure today to introduce Professor Carlo Rovelli. He's a professor of physics in Marseille, and he cut his teeth and made his name for himself developing theories of quantum gravity, mostly loop quantum gravity, if I understand correctly. He also became a household name as the author of the book Seven brief Lessons on Physics, which sold more than a million copies and was translated into forty one languages. I've read it and enjoyed it immensely and heartily recommended to you. Today, Professor Revelli is here to talk to us about his new book, Hell Go Land and a fascinating alternative take on the measurement problem in quantum mechanics. Professor Velli, welcome to the podcast and thank you for joining us.

00:18:27
Speaker 4: Thank you very much, Dadiel. It's a pleasure in honor of being here.

00:18:31
Speaker 2: Wonderful.

00:18:32
Speaker 1: Well, I always love talking about quantum mechanics and puzzling over it with other people. I feel like every time I talk about quantum mechanics with somebody else, I think of a new question I've never thought of before, or a new angle on it, or a new mystery. Frankly, like a new corner of my mind that I haven't ever really examined, and I get confused, and so it's always fun to figure things outsie of on the fly. So today we wanted to talk about your new book and Hell Go Land, and the book essentially lays out for a lay audience this idea of relational quantum mechanics, sort of a new interpretation on quantum mechanics. And the first question for you I have is if you could describe for us what is the problem that relational quantum mechanics solves, Like why do we need another quantum mechanics interpretation. What is it at the heart of relitional quant mechanics is trying to do One of.

00:19:19
Speaker 3: The difficulties of the problem of quantum mechanics is to say exactly what the problem is.

00:19:24
Speaker 1: Those are some of my favorite moments of the show, but there are so so many, way too many to mention here, and so I encourage you to go back and listen to old episodes because there's a lot of great stuff there. And also the show isn't just me, of course, so I asked all the co hosts we've had over the years to share their thoughts on their favorite moments. Here's what I heard back.

00:19:44
Speaker 6: I want to say that I really appreciate being on the show, being able to be a part of it, despite not having any any prior knowledge really about particle physics. It was really really fun to come on and learn and ask questions, and I always felt sort of like I was there with you guys the audience trying. I mean, probably a lot of you know more about particle physics than me, but still I would try to be there as the stand in for the audience, try to ask the questions that I was hoping you guys would want me to ask of Daniel and man, I just had such a good time, and I really appreciate all the love and support from you guys, and I I'm so happy I got to be a part of this amazing podcast. And I hope y'all continue to learn and continue to be physicists and scientists in your own homes and keep asking really cool questions.

00:20:46
Speaker 7: I had a lot of fun on a lot of the episodes. One of the episodes I particularly liked was when we talked about how physics might help us understand biology better. That was an episode that to me thinking long after our conversation ended.

00:21:03
Speaker 1: So we've had fun, and I hope that you've learned a lot of physics along the way. But I want you to understand that it's not just all of you who've learned a bunch of science.

00:21:12
Speaker 2: I have to you. See, physics is way.

00:21:14
Speaker 1: Too vast for any one person to understand all of it or even have time to try. So there are always things I wanted to know more about, and as I became more and more specialized in experimental particle physics, I felt myself lacking those opportunities, but still asking the questions, how do galaxies form, how do we know what's going on inside stars? Do we know what's going on inside stars? And so the podcast was a great excuse to go and learn about these things, a reason to spend an hour reading up on the latest research on intergalactic magnetic fields or whatever the topic was that week. It also helped me understand particle physics, because yeah, I certainly learned all this stuff at one point, but you really have to understand everything and have a click in your mind if you're going to explain it to non experts and answer top questions from our co hosts. So I asked our co hosts what this experience was like for them and whether they had any farewell messages for all of you.

00:22:12
Speaker 6: Here's what I heard back, Hey, this is Katie Golden. My favorite topic was the episode on which forces power the human senses, which for me was a perfect mix of biology and physics. I love looking into the physics that are behind our biological functioning like our vision, our hearing, and also getting into some of the cool evolutionary biology stuff of electromagnetism and how animals can sort of sense like electromagnetism. And it was really really fun I enjoyed kind of having that merging of my pet interest being evolutionary biology and then learning about all of the cool physics behind it from Daniel. I guess the most challenging topic for me has been and continues to be trying to visualize or understand gravity, understanding it is not a force, and sort of also the idea that it is like the curvature in space, but also that space isn't like a physical fabric that bends. I still can't really wrap my head around it. It's pretty difficult, and I'm sure I'm not alone in that, But I despite it being really challenging for me to understand or visualize or have like a concept of, it's still really infinitely fascinating to me. And my favorite moments on air definitely every time Daniel would make some comparison between food and particle physics. I feel like part of that was because we would often record sometimes like for me, like before dinner, and you would definitely make me hungry talking about spaghetification into black holes. We also recently I don't know if this will be out yet, so I'll try not to do any spoilers, but we also recently did a listener question episode about the warp drive in Star Trek, and I loved talking about the fake sciencey schmayancy stuff in Star Trek, like the science gibbers that they would talk about, like the flux capacitors, et cetera. Also, I don't want to spoil it the episode in case it's not out yet, but there's a moment in it when my mind is completely blown by sort of what would happen in reality in a situation with warp drive, And you can probably tell what it is because I don't know. I think I sound pretty excited.

00:24:41
Speaker 7: Hello, this is Kelly Wiener Smith. So to be honest, I found a lot of the topics kind of challenging. So, you know, talking to a particle physicist as someone who has absolutely no training in that area and knowing that there's an audience listening to my responses, you know, it's a bit of a humbling experience. And quite often before I'd ask a question, I'd find myself thinking, oh, is this a bad question? Does everyone know the answer to this question already? But you know, my job was to play the you know, the everyman or the every person and ask whatever was on my mind or whatever. I didn't think I was understanding quite well enough. So I got over it and it was fun and I enjoyed the challenge and I learned a lot by going through these conversations with Daniel. I really enjoyed the running joke that we had about how Daniel was always bringing up questions about how my kids might die or how you know, everybody might die, and how I couldn't let my kids listen to the podcast because they would be petrified and wouldn't be able to sleep at night. That was kind of a fun running bit. And there was an episode we recorded about uranus that it made me giggle quite a bit because I have the heart of a twelve year old. It has been so much fun, and I learned so much by getting to come on and co host every once in a while, and I really appreciate the opportunity. Thanks everyone, But.

00:26:09
Speaker 1: The podcast is much more than just me and the co hosts. It wouldn't be what it is without all of you out there listening and supporting it. And over the years, I've heard a lot about how the podcast has helped you or taught you something. A few listeners sent in their thoughts about what they have learned and the role of the podcast has played in their lives.

00:26:29
Speaker 8: Hi, Daniel, your podcast has helped me to understand the universe to a depth where I can start formulating an intellectual and emotional connection to the cosmos on the grandest or largest scale and the smallest or quantum scale. I tried to express this in a painting I made recently in which I learned two facts and combine them on the painting. One was that fungal mycelium has a filamentous network structure, and the other was something I learned from your podcast that said, in which you told us that galaxies in the universe form chains called galactic filaments that connect groups and clusters of galaxies. These sorts of repeating patterns in nature have always fascinated me, and to find that the filamentous pattern of my celium is also found at the largest scales of the universe just fills me with awe. Thank you again, Daniel for sharing your knowledge and understanding with the world through your podcast.

00:27:39
Speaker 11: I enjoyed learning about how space expands because that kind of stuff just blows my mind. Mostly, I enjoy the podcast in general and learning about all these new things that you've introduced to me because my friends are idiots and I have no one to talk to.

00:28:01
Speaker 9: Hello, Daniel and Hora, this is Walt from Tennessee. I've learned a lot from listening to your podcast, but the most significant item that I've learned is the realization of how far we are from the ultimate knowledge of how the universe really works. Plus, I really enjoy the speculations about someday being able to ask aliens for the truth after they've been around for millions of years. Unfortunately I won't be around for that.

00:28:32
Speaker 12: Once nor I had was on the July twenty fourth episode about membranes. Katie said insane in the brain, and just like we had planned and rehearsed it on my response was insane in the brain, right on top of your response. And I did get a little bit of laugh out of that, and I'll bet a lot of us had the same reaction, at least for those that remember those older times. I do roll my eyes at some of the in the beginning of the show between you and Jorge, but it's still a good portion of the show. Another thing I look forward to is listener questions, especially the younger kids.

00:29:11
Speaker 11: I love.

00:29:12
Speaker 12: I love to hear younger kids asking, you know, questions that you know I may know a lot more about than them, but still it tells me that they're asking and interested and you provoke those questions. So I think that's great. Katie and Kelly are very nice additions, and they add a lot more humor with their perspectives. Some of my favorite episodes I love anything to do with the sun. I love how the sun works and I love to learn more about it. Some of the episodes that leave my eyes glazing glazing over are the any any any podcasts dealing with particles? I just I just don't get it, but I still listen to them all, and I listened, and I also look forward to listening to the next one. Thanks for letting me play a small part, not quite as small as your portion of the Nobel Prize you want.

00:30:05
Speaker 4: Daniel Johy, I'd just like to thank you onward from Australia. I'd just like to thank you both for satisfying my quest for knowledge and trying to help me understand quantum physics, which is challenging for me. But I really appreciate what you to do and you have a perfect balance.

00:30:26
Speaker 13: Thank you so I remember the first episode that I have ever heard, and it was very special for me because it just make me laugh and I learned something new, which was something that didn't happen for me for a couple of months after I had a baby and I was just struggling to find myself again, and after I heard that episode that it was about the Gluons, every day I would listen to at least four episodes while I was taking care of my baby, and that helped me so much, especially not to feel alone. So thank you very much.

00:31:16
Speaker 14: This is Eric from Idaho. I just wanted to let you know that I discovered your show back in February and from the very first episode, I was hooked for four straight months. All he did was listen to every single episode. My kids are way into it as well. My son gave the best compliment I believe. He said, Dad, I love Daniel and Jorge. They are just a couple of dads sitting around talking about science and making some dad jokes. I'm grateful for what you guys do and look forward to another six hundred episodes.

00:31:46
Speaker 15: Hi, Daniel and Hooge and Katie and Kelly as well. My favorite moments are when you guys entered a discussion about the reality behind the physical theories. It's very important to me because it too reminds me that although being the best tools and methods we have to predict and manipulate nature, they are not an exact description of what it really is. I deeply believe in science as one of the best ways to understand and solve problems, but knowing it has its limitations is also important not to turn it into a under idealized or flawless or an unbiased institution. During the COVID nineteen pandemic, for example, it became very important to understand these limitations in a world that was craving for information but also generating lots of disinformation. Congratulations on a huge podcast you have. I hope it becomes so big it turns into a black hole someday.

00:32:50
Speaker 16: This podcast as a quite an important role for me because it makes commuting bara. It is one of the few good podcasts that get updated twice a week most of the time, and therefore helps me bearing driving my car. I very much like the possibility to chat with Daniel about some physics topics I struggle to understand and have someone who wants to share his thoughts and is willing to listen to my thoughts about debatable topics. And it's hard to find somebody like that. So this is a great plus of this podcast. For example, our exchange about the many worlds of interpretation and related topics, and also so horus commentaries on all the topics are very entertaining. By the way, we need more PhD comics, and so this podcast is one of the foundations of my spare time entertainment.

00:34:19
Speaker 2: Hi, Daniel Norge. This is Dan from Vienna, Virginia. Here.

00:34:23
Speaker 17: I've been with you guys since the beginning. At the time I was looking for a new podcast, and this just hit the mark. Early on, when Daniel would speak of the type of matter that would make up galaxies, planets, and people, he would frequently include hamsters. I figured he must have owned one, as it's always seemed top of mine. Maybe he just finds them cute. I've enjoyed the mind bending topics and learning about the largest and smallest parts of the universe. Perhaps I've had most interesting, though, were the topics that were about those things in our solar system that I never knew before.

00:34:54
Speaker 18: Keep up the great work. Ever since I was a little kid. It was fascinated astronomy, how the universe works from every scale, the smallest to the largest, And once I got into higher levels of education, I realized that the advanced mathematics was not for me. But I always remained an active spectator in the world of science and its advancements and everything. In all of that, the challenge with modern science reporting is that some of it is not great. But once I found my way to this podcast, I realized that these concepts may be incredibly complicated in the calculation of them, but in actually understanding the premise of them. It just needs somebody who can explain it. And this podcast has helped do that for me and obviously so many others. And while it's always been a delight hearing my own voice on the pod trying to answer questions poorly, the whole premise of it, the whole engagement of a global community all working together to advance curiosity, fascination, and understanding in how the world works around us and realize we're all kind of closer together than we may think. I love it and thank you for doing this.

00:36:21
Speaker 19: I don't know if I have a favorite episode per se. But I must say that when the audience participation questions were conducted in person and I had an opportunity to attend a conference in southern California, I was very, very tempted to take a day off the conference proceedings and find the UC Irvine campus and look for I don't even know what to look for, some sort of what I imagined to be a grizzly haired professor serve with a microphone and or tape recorder. However, I did not do that, And you know, perhaps it's fair to say that the silver lining of the pandemic is that it encouraged the audience participation to be expanded out into the realms of the Internet. And I really enjoy that format, and I was very very happy to have one of my listener questions even answered on the pod.

00:37:30
Speaker 20: Hi, Daniel and Jorge, congratulations on over six hundred episodes. My name is Andrea, and I'm a relatively new fan of the podcast. I think what I love most about the podcast is how you explain super complex topics in a way that is really accessible for people without dumbing it down. Though I mean there's a lot of times where I find myself having to go and do a little digging after listening to your podcasts. But what really keeps me coming back is your puerile sense of humor. It is pretty funny to have that in the mix. And finally, my very favorite part is when Daniel gets upset about white chocolate. I never realized how kind of pointless white chocolate was until I started listening to your podcast. I totally agree. I was wondering if maybe you could do a deep dive episode into the science behind and history of white chocolate, but if you did, I'd probably skip that one, so it might not be a good idea. Thanks again for sharing your knowledge.

00:38:47
Speaker 1: Thank you for validating my crusade against white chocolate. If I've achieved nothing else on the podcast, I freed one more person e from the tyranny of white chocolate, and on the topic of the science of white chocolate, there is it's scientifically disgusting. I also asked my wife, Katrina, who I've referred to many times on the podcast and whose voice you've occasionally heard, what she thinks the podcast has meant for me and for the family.

00:39:12
Speaker 2: Here's what she had to say.

00:39:14
Speaker 21: Well, I love that Daniel has been doing this podcast. I mean, I can't believe how big it's gotten and how many episodes they've made. It's just amazing to me what a life this thing has taken. And we really love. Our family loves hearing the messages from the people on the podcast. Like I remember during the pandemic there was this group of housemates in Australia who were hilarious and they sent in all these messages where they were having fun together and listening to music and we were all, you know, alone in our house and it was so fun. All that interjected into our lives. And yeah, I just I love that there are so many listeners and that it's really impacted people's lives. I've heard stories about people going back to school, or people you know, using this as companion chip. And then even in our own family, when our kids couldn't fall asleep, I would often play Daniel's podcast so they could get to hear his voice, and it is really comforting. I love that we can hear his voice on command and get to hear his fun sense of humor. In fact, some of our really good friends were backpacking on the JMT this summer and they were listening to Daniel's podcast at night, but they said it was not to fall asleep and that they loved learning about Unfortunately I don't remember, but I'm sure.

00:40:25
Speaker 8: They do, and.

00:40:28
Speaker 21: That was really fun. Also, every time I see Starbucks n True Cold Brew, I think about Daniel's ad, which is also funny. And we've had people send us amazing things, like one time we came home on a hot day to a box full of beautiful chocolate from Canada. And our lab has had a artificial intelligence microwave for several years that a listener came and brought it to us and showed us how to make salmon and broccoli in this beautiful microwave that targets the heat in an evenly and directed distributed way. So that was really fun. And I just love how much Daniel has learned. You know, he's constantly going and talking to his colleagues to learn new things. I think it's brought him, you know, really huge breadth and depth to his physics knowledge that as a researcher you often kind of get lost in your own rabbit hole, and I feel like Daniel is really not in that position. I'm sure it's been really good for his science I think you could ask Daniel to give a lecture on any topic in physics and he'd have no problem. Like we know this Italian guy who was interviewing for a physics professorship, and they would pull a topic out of a hat and you'd have to give a lecture in front of the department on it with no preparation. And that seemed so intimidating to me. But I know Daniel could just do that now because of this podcast.

00:41:49
Speaker 8: So lately I've.

00:41:50
Speaker 21: Been hearing Daniel brainstorm names for the new podcast, and I'm really glad he has a new podcast partner, Kelly. I loved her book about the possibility of colonizing Mars, and clearly she's a very thoughtful and in depth scientist.

00:42:07
Speaker 8: Oh.

00:42:07
Speaker 21: Another thing that was fun was like we would anytime we were in a new place, Daniel would start doing his like man on the Street interviews, like airport in Jerusalem, Man on Street Interviews Airport in London, asking the locals, and then you'd hear the podcast and get to hear people with accents from our trip on the podcast. I really love that whole aspect, and sometimes, like my students or people I knew would get interviewed and then get to hear them on the podcast, and I love that. So I think it's been a wonderful, wonderful thing. As our kids have been growing up, the podcast has happened, you know, starting since twenty seventeen, I think maybe twenty eighteen, so our kids were like little elementary school kids, and they've grown up getting to hear all these stories about the podcast. Now they're teenagers, and I think it's been a really cool thing to have our family.

00:43:01
Speaker 1: All right, So it's time now to say goodbye to this podcast, and I just want to say that it's been my pleasure and my honor to host this show and to share with you my joy about what we have managed to figure out and what we have not managed to figure out about the universe, and to anticipate all of those discoveries yet to come. And though of course this show is coming to an end, you can still hear me talking about the universe. So let me tell you a little bit about our new show, Daniel and Kelly's Extraordinary Universe.

00:43:32
Speaker 2: The official description is that.

00:43:34
Speaker 1: Daniel and Kelly cannot stop talking about our amazing, wonderful, weird universe. Each episode is a fun and easy to understand explanation of deep topics in science, from particles to black holes, to moon colonies, to aliens and insects and everything else in the universe. Because there are so many wonderful and amazing things in our universe, some explained and some still mysterious, it really is an extraordinary universe. And I love the world extraordinary in the title because it colls to mind extra terrestrial or extra dimensions, and as my fifteen year old daughter would say, the universe is just so extra But it also makes me think about Carl Sagan's famous line, extraordinary claims require extraordinary evidence. Because on this new podcast, we want to be very open minded, ready to learn what the universe might teach us, to ditch the dogma and accept the new ideas, from aliens to black holes to new weird parasites. But we also want to be clear eyed about what we can and cannot know, what we can prove, what we have data to support. I mean, I'd love for there to be aliens, but I also know that hard evidence for alien visitors has.

00:44:41
Speaker 2: Been pretty hard to come by.

00:44:43
Speaker 1: I'd love to unravel the mysteries of quantum mechanics, but a lot of the ideas out there are well, they're still kind of out there. So on the new podcast will embrace the craziness of the Extraordinary Universe, but will also try our best to take a healthy skepticism and use our scientific minds to sift out the kernels of truth, because the best way to honor our extraordinary universe is to understand it. So if you've enjoyed this six year journey and you're disappointed that it's coming to an end, know that I feel the same way, and I hope you'll continue the journey with me and Kelly at Daniel and Kelly's Extraordinary Universe wherever you get your podcasts. And one last little Easter egg for.

00:45:25
Speaker 2: All of you.

00:45:26
Speaker 1: We have a few extra episodes of Explain the Universe we've produced that we will share throughout the next year. So there is a little bit more explained the Universe left to hear, so stay subscribed to Explain the Universe so you can hear those when they come out. Until then, this is Daniel, your host, saying so long and thanks for all the chocolate, Thanks for listening, and remember that Daniel and Jorge explain the Universe is a production of iHeart Radio. For more podcasts from iHeart Radio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows.