Should we abandon the multiverse theory? | Sabine Hossenfelder, Roger Penrose, Michio Kaku 

Want to learn more about the theory behind the multiverse? Check out our newest Big Idea video with multiverse specialist Laura Mersini-Houghton! ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-kr301XpHHGA.html&ab_channel=TheInstituteofArtandIdeas

Sabine Hossenfelder is as usual the anchor of reason, Roger Pennrose the symbol of intelligence, and Michio Kaku, the representative of Hollywood.

That Sir Roger Penrose is still doing serious scientific research at his age is astounding. Long may he last!

31:20 I absolutely love and respect how Dr. Penrose doesn't mind saying "I'm confused" and using that as an argument against the gobbledygook that Kaku is putting forth.

I knew Sabine when we started to study physics. She always was extremely intelligent. It is interesting to see her becoming a public figure.

Roger Penrose has a sharper mind at the age of 91 than I have had at any point in my life.

This sounded like it ought to be interesting but, unfortunately it sounded like Michio had his selling hat on, Sabina was desparately trying to find out what it was he was actually selling and Roger decided what ever it was he wasn't buying.

Sir Roger Penrose is so quietly and confidently dominating, it's a joy to watch.

If Sir Penrose was my grandfather I would visit him every day just to talk more about theories and scientific findings. For Sabine I can’t wait for her next books, I wish I could read her ideas about new findings, new understandings for a long time.

Michio thought this was about string theory, Roger thought he'd been invited to talk about cosmology, and Sabine thought they were going to be talking about quantum mechanics... Penrose was clearly annoyed, Sabine tried to salvage it, and neither Michio nor the host seemed to understand that multiverse means different things to different scientists. This was really painful to watch.

I remember when Michio was one of the science educators who inspired me to learn more about the universe. Now he sounds like he’s trying to sell me a book or something.

It's embarrassing to see Penrose and Hossenfelder have to reply to Kaku directly. Flashbacks to teachers having to deal with freshman or sophomore year students who think they found some breakthrough idea and get high on their own supply. The number of jumps in conclusions, fallacies and other logical missteps are so blatant you can't but see the teacher get a depression inducing combination of decision paralysis on what to correct first as well as the struggle to not just make it for the door and go do something better with their time.

24:10 what a jab. I know a lot of "serious" string theorists.

Props to Hossenfelder and Penrose for their clarity and rationality, and Kaku for selling books.

Was a fan of Kaku in my youth. Now see him as a Steven Seagal of cosmology.

Starting with Prof. Michio Kaku comment that quantum mechanics predicts particles can exist in two places, its clear he is not speaking about scientific prediction but only for popularizing things. Amazing to listen to clear statements of Sir Roger Penrose.

I wasn't expecting to watch a comedy sketch, but this was ridiculously funny. I can't get over the increasingly perplexed/disappointed/incredulous expressions on Sir Roger's and Sabine's faces

It's pretty clear what Sabine and Penrose think of Michio in this, despite how diplomatic they were, lol.

A long life to Sir Roger Penrose! What a legend, at 91 years of age his mind is more agile than that of most teenagers and young adults alive today!

Thank you Sabine Hossenfelder for staying on topic and succinctly stating your postion, that ontological realness of mathematical implications should not be automatically ascribed.

Michio Kaku's theory explanation can be summed up by "just you wait and see"

I am glad there still physicists like sir Penrose and Sabina

The faces of Hossenfelder + Penrose while Kaku speaks. Priceless.

24:17 "I know lot of string theorists... serious string theorists" SHEESH 💀

Just because I don't have a better idea doesn't means that yours is a good one.

Penrose is always the brightest bulb in the room because his ego allows him to say "I don't know"

30:11 - Lawson: Do you agree? - Penrose: no. 🤣

I believe that Michio or those like him (ie: Neil deGrasse Tyson, Avi Loeb) actually need to be condemned in our new internet world of disinformation and the dangerous unmooring from reality we see out in the world at accelerating rates. It’s really unacceptable to have these types of figures maintaining memberships with otherwise credible institutions and being given just enough respect to get by grifting and selling books.

Day by day I'm more in admiration of Sabine Hossenfelder. What a mind she has! An excellent example of clear-mindedness!

I like how Penrose just calls out the whole thing "Are we talking about String Theory or the Multiverse Theory here?".

I could hear Sir Penrose speak all day. He is incredibly intelligent, articulate and humble.

What a Legend Sir. Penrose is. He is one of the few living Legends of 20th century science.

Thank you for making such an intriguing conversation public. In science, disagreements produce innovations and insights.

Sir Roger is a world treasure. He is over ninety and still doing mathematical physics.

As a layman, it seems like what Michio, and string theorists in general, have done, is, they develop a theory that then runs into a problem, and they theorize about what could solve this apparent problem, and then keep going. Its literally Theoretical Physicist Fan Fic

I love how it started as a question about the possibility of multiverse but eventually was about Mr. Maku trying to defend his theory is real thing.

I do t really understand a whole lot about phywics but i find it very interesting. This interview really does show to me that there is theoretical and practical

Great to see Roger and Sabine on the stage.

I love how Sabine and Roger so beautifully call out Michio and the other string theorists on their rubbish. Roger does it in such a classy British way. Sabine does it in an in-your-face German way. In both cases it's delightful to watch.

🎯 Key Takeaways for quick navigation: 02:33 🌌 Multiverse Theories - Discussion on the existence of the Multiverse theory. - Different perspectives on the Multiverse, with a focus on scientific testability. 08:13 🤔 The Testability of Multiverse Theories - A debate on whether scientific theories, including the Multiverse, must be testable. - Arguments about the testability of theories, with examples related to String Theory and deviations from the inverse square law. 23:47 📡 Indirect Evidence and String Theory - The mention of indirect evidence in supporting theories like String Theory. - Clarification that observations, even if they were made, would not necessarily provide direct evidence for String Theory. 00:00 📽️ Introduction - The panel discusses the topic of the Multiverse theory and its implications. - The question of whether the Multiverse theory can be tested and its popularity is raised. 02:47 🤔 Sabine Hossenfelder's Perspective - Sabine Hossenfelder highlights the importance of empirical evidence in physics. - She argues that the Multiverse theory currently lacks empirical support. - Discusses the role of string theory and the challenge of verifying the Multiverse theory. 09:29 🤯 Michio Kaku's Perspective - Michio Kaku explains the concept of the Multiverse and its connection to quantum mechanics. - He defends the Multiverse theory as a legitimate interpretation of quantum mechanics. - Kaku emphasizes the need for further experiments and observations to provide evidence for the Multiverse. 14:25 🕳️ Roger Penrose's Perspective - Roger Penrose expresses his skepticism towards the Multiverse theory, particularly its relationship to string theory. - He questions the lack of experimental support and the complexity of the Multiverse concept. - Penrose suggests that the Multiverse idea may not be scientifically fruitful. 21:03 🌌 The Multiverse and Cosmology - The panel discusses the connection between the Multiverse theory and cosmology. - The idea that a Multiverse could explain the fundamental constants and the role of experimental evidence is debated. 24:36 🌠 Possibility of Unverifiable Theories - The discussion centers on whether certain scientific theories will always contain unverifiable or untestable elements. - Examples of untested concepts like proton decay and the cosmological constant are mentioned. - The panel considers the inherent uncertainty in scientific theories. 27:24 🤨 Popularity and Fiction - The panel addresses the popularity of the Multiverse theory among the general public. - The appeal of parallel universes in science fiction and the distinction between fiction and scientific theory are discussed. 30:06 🧠 The Challenge of Uncertainty - The concept that science is limited by human inference and the possibility of the universe's laws changing are explored. - The uncertainty underlying scientific methods and theories is acknowledged. 48:54 🌌 Proposing Theories Beyond Testability - The discussion delves into the purpose of proposing theories that lack empirical evidence or are untestable. - Roger Penrose suggests that it's valuable to contemplate such theories as long as they simplify the overall picture without contradicting known data. - The limits of scientific understanding are acknowledged, particularly concerning the Planck energy. 50:16 🤔 The Mystery of Unexplained Phenomena - The panel addresses the notion that there may always be certain unexplained or untestable aspects in science. - Michio Kaku discusses the Planck energy as a point where known laws of physics break down and become challenging to describe. - Roger Penrose distinguishes between singularities in black holes and the Big Bang, noting that not all unexplained phenomena should be taken equally seriously. Made with HARPA AI

This wasn't a debate it was a beatdown

This debate was a bit of a confused disaster but kind of amazing to watch as a result. It's great to watch Sabine tackle Michio and put directly to him criticisms that everyone's been thinking for the past ten years.

"Physicists who come to believe that the mathematics they deal with is actually real." Hossenfelder just became one of my favorite people.

Before exploring multi verses we should maybe get better sound quality from a giant television

I wish everyone involved in a talk or debate would actually be there in person. The freezing on the internet connection made it frustrating to listen to and would have been so much better in person.

It's thrilling seeing Dr.Penrose and Dr.Sabine H. on the same stage!

"I know a lot of string theorists, serious string theorists..." 🙂 Sabine just made my day. Wish we all had a good moderator during meetings.

Thanks to Host this debate...facinating,❤🎉

This ranks right up there with the debate over whether we should abandon the theory that the outside of the universe is green.

Michio Kaku is actually inspiring for young teenagers who don't yet know physics, he was for me. But he is very cringe once you know a couple things about quantum mechanics etc., it is uncomfortable listening to him recite his rehearsed analogies that sell books.

I find Sabine an absolute breath of fresh air

What an amazing discussion. Sabine and Roger make a great pair

thanks Michio Kaku for this debate, now I can stop thinking and wasting my time with String Theory books and videos :)

When Penrose says he's confused, he actually means he's hearing total BS :)

Michio Kaku is more like a cheerleader for Team Multiverse than a scientist. Anything that raises questions about his pet theories is motivation for more research to raise more questions about the unresolved questions that he's raising.

The multiverse theory was developed to explain the problem of fine tuning, particularly the value for vacuum energy which is 122 magnitudes smaller than what quantum field theory predicts. If the value was higher or lower by a fraction of a magnitude there would be no universe which hints at intelligent design but since that's ruled out we have the multiverse.

I must be missing the importance of the question because we're only sure of our cosmic horizon. Meaning: The understanding of the size of the universe (and its constituents) is immensely more important to comprehend than asking a question about something where we possess even less data.

Penrose is a living legend !

Thrilled to see Sabine on the panel 😁

GREAT CONVERSATION! I absolutely do not like string theory, so I found this delightful

Thank you… It is wonderful that they can apprehend, analyse, criticise, and … each other perfectly… even though they oppose … Brain is amazing… Waves and Electrons over nerves…

great discussion, I really like how Roger And Sabine are so respectful when they are against an argument. I am not really familiar with Michio Kaku, but he seems to spread his argumentation a little all over the place without really making any real point.

24:18 "... I know a lot of string theorists, uh, serious string theorists ..." Priceless again! This is Sabine being agreeable the German way.

Seems to me that unless there is proper evidence for the multiverse, we can just approach it as phenomenon in our "uni" verse, not separate from it but a part of the one we know.

Give the host a trophy - he did a great job.

24:14 Sabine: "I know a lot of string theorists...ah, serious string theorists ..." Michio: 🥲

In a way, Kaku hijacked the conversation away from the proposed topic (as was constantly pointed out by Penrose). Kaku seems to believe that his version of string theory will eventually be proven to be that holy grail of physics: the theory of everything. But let's break down just one of his arguments: Democritus' atomic theory. Democritus believed the atom was the smallest possible unit of matter, indivisible (hence, atomos). But what have we shown over the past 2K years? Atoms exist, but most of the mass is concentrated in the nucleus with a cloud of electrons. Then we discovered nuclear fission: the nucleus is not an indivisible unit of matter either. But wait, there's more! It turns out protons and neutrons aren't indivisible either - they consist of quarks. What started with Democritus and Leucippus evolved into the Standard Model: 6 quarks, 6 leptons, 4 bosons, and a Higgs. Democritus wasn't wrong, but he wasn't exactly right either. If we're honest, science does have assumptions that are untestable: natural processes are governed by laws that can be expressed mathematically and that these laws are consistent across space and time. This assumption is baked into the scientific method in terms of reproducibility. But mathematics isn't reality - it's a model of reality that is useful to describe our experience. But as I've often said, I can create any arithmetically valid equation you like - but it may not be measuring what you think it does.

I only recently discovered Sabine Hossenfelder, but I think she is brilliant... she explains things so well and introduces unnecessary uncertainty into things like the confidence with which Michio Kaku speaks: telling laymen to come up with "a better theory" (than string theory) for grand unification (which is not be even necessary, but just a "nice to have" ideal that appeals to the human mind) is to rather tell us to put up or shut up in nicer language with a bit of humor. This was really a rather convoluted discussion... it was never clear that the topic was a multiverse, but rather the legitimacy of string theory. Sabine has a whole video where she tears apart the modern state of particle physics, which is where string theory falls, and explains very well how it seems that particle physicists are trying to overcomplicate particle physics by making wild predictions above energies that we have been able to explore yet instead of simply applying Occam's razor and remaining with the simplest theory that fits the standard model. I find the idea of the multiverse quite fascinating and appealing, but it's just a hypothetical philosophical thought experiment for now, and may always be. Having Penrose there to propose another face to the argument was good, but I wish he had had the chance to speak more.

Excelente charla.👍👏👏

Kaku seems completely unable to get away from the same 4 lines of text he's been repeating for years now. Sabine and Roger achieved a very coherent conversation

I died a little inside when Dr. Hossenfelder stressed, "I know *serious* string theorists..."

I am not at al intelligent like most of you here who are watching this . Actually im just a master builder . Yet I find myself watching everything about Sir Roger Penrose and I just am blown away by his sheer GENIUS . I have no understanding of most of this , yet I find when he talks I like get it a bit . This man is a gift to humanity and unlike these ridiculous celebrities who the world admires . Children should be shown this marvelous man .

Sabine is the bomb here, incredible intellect. Roger is so refreshing to listen to, for classic science

Sabine is an amazing scientist. Her rationality and love for fundamental science is refreshing and necessary. She is also incredibly talented in explaining complicated science.

Fascinating

BRILLIANT.......I have absolutely no idea what's going on.

In some universes we have already abandoned the multiverse theory.

host: hi Michio can you explain newton's first law to the audience in simple terms ? michio: Yeah sure, In string theory we ...

0:33: 🌌 The debate discusses the plausibility and scientific basis of the Multiverse theory. 5:15: 🌍 The video discusses the probability of waking up on Mars and the misunderstanding of physicists regarding the reality of mathematical theories. 10:27: 🔬 The video discusses the conflict between the principles of general relativity and quantum mechanics and proposes the need for a theory that combines both. 15:45: 🌌 The speaker discusses the concept of a multiverse and explains that there is only one universe that goes through a series of stages. 20:04: 🌌 The video discusses the possibility of finding a particle called fotino the funkido in a spiral chamber, the concept of higher dimensions and gravity, and the launch of Lisa to capture radiation from the early universe. 25:10: 🔬 The video discusses the challenges of proving theories like string theory and the multiverse theory, comparing it to the historical verification of the atomic theory. 29:47: 🔬 The Multiverse theory is a simpler interpretation of quantum mechanics that eliminates the need for wavefunction collapse. 34:22: 🔬 Science cannot determine the existence of other universes, but as more data is collected, we can refine our understanding of the universe. 39:09: 🌍 The idea of a multiverse is popular in the general public, but not in the physics community, and it is appealing because it involves interesting brain gymnastics. 43:58: 🤔 The speaker discusses the progress of science, the potential arguments against multiverses, and the untestability of theories. 48:50: 🤔 Is there a purpose in proposing theories without evidence or that cannot be tested? Recap by Tammy AI

Someone said this (below) and I want to amplify it: "Penrose and Hossenfelder were there for a serious scientific conversation and Kaku behaves like he just came from the Marvel Studios."

I love Roger Penrose. This dude knows his sheet. And doesn't play politics on camera. Props to this man. An inspiration brother.

Michio has staked his career on string theory, would be hard for him to accept that he might be completely wrong.

Please be advised that Kaku spends most of his time writing pop-sci books, he quits doing research 20 years ago, meanwhile Sabine and Roger are still doing cutting-edge research.

This is way too entertaining to see. Thank you. The more I watch the more I want to see Mr. Penrose and Madam Sabine roasting String theory. I don't know if people undestood what happened here.

Sir roger and Sabine know what real science is about.

Kaku: **Starts telling Penrose (who literally first theorised the concept of a singularity black hole) about singularities in black holes being similar to the birth of the universe.** Penrose: *Do not cite the deep magic to me, I was there when it was written.*

that was fire 🔥🔥🔥🔥🔥

If we detect other waves in the beginning of our universe that seem to come from other blasts, other ripples that we can then trace forward? We may be able to detect the energy signatures of other universes, and the possible laws that then differ. Our own physics could just be a conglomerate of different laws from different universes that collide and coalesce into what we know as our own laws. Just ore from different countries can differ, so too can the material of different universes. Not just laws, but the matter itself could have a whole different configuration than ours.

It would have been nice to hear more from Roger and Sabine.

I think Roger Penrose got a little irritated when Michio Kaku suddenly switched from multi-universe to many worlds!

The difference between Kaku and Penrose is mind boggling.

Whenever Michiu Kaku speaks via video link we can hear the entire New York soundscape in the background

I love Sabine's mind and am always amazed at what Penrose says. Such minds are a treasure to us all.

Michio wasn't really answering Penrose's or Sabine's arguments most of the time. He kind of just started ranting about different things every time they contradicted him and couldn't really ever explain his view properly

If there really were *infinite* universes we would have known a very very long time ago. It literally would not ever have been a topic of debate. The very fact that we haven't discovered a parallel universe proves that, even in the almost certainly unlikely event that even one exists at all, at the very least they are not infinite. Like its literally so stupid to believe that it could be possible. You can't prove it. Its embarrassingly unscientific

Regarding Occam's razor, we must be aware that it really represents a short-tail probability distribution approximation. As a simple example. Supposing I only have two ways to explain an actual event. One involve 2 elements, the probability of which are each 1 in 10. The alternative requires 3 such elements. Well, we would, a priori say the chances of the first occurence is 1 in 100, the second, 1 in 1,000. If we say that one of these had to have happened given the actual event, then given the 2 element possibility is 10 times more likely than the 3 element one -- logic dictates that this is the one we should assume. This is Occum's razor in a nutshell. However, what if introducing 3 such elements doesn't provide us with one additional possibility -- but rather 100 additional possibilities. Now it is not a 1/100 2-element possibility vs. a 1/1000 3-element possibility, but rather one hundred independent versions of the latter. Comparing the single 2-element possibility with the entire group of 3-element possibilities as a whole, the single 2-element solution possbility is still 1/100, but the 3-element possibility category represents a 1 - (0,999)^100 = 0.0952 ~ 1/10 a priori probability. Hence "a" rather than "the" more complex theory is not ten time less likely, but rather ten time MORE likely -- a complete inversion of Occam's razor. William of Ockham or Occam, was an early 14th century English Franciscan friar. His qualitative common sense concept applies well in daily life but not necessarily in scientific theorization save where the power of symmetry can reall be brought into play. So if boundary conditions imposed by existential reality permit the simpler theory and a sufficiently higher volume of more complex theories -- the weight of probability is with one of the more complex theories being correct.

I like Sabine's point of view that just because mathematics describes part of nature doesn't make that mathematics as real as nature. It's goal is to predict the outcome of experiments not to be considered the ground of reality.

Sabina and Roger rocked this conversation. I think Kaku thought he was filming an episode of Universe with Tyson and Alex Plippinpinko.

Probably you have to go with Kant's critic: The 'pure thing' is not possible to know, to realize only the appearance of the phenomenon - in your mind.

Please, Hilary! Why did you let the superficial Kaku whittle on and on, grabbing the lion's share of the debate, instead of allowing us to hear far more from the serious professionals, Penrose and Hossenfelder? You can see what the latter two think of Kaku's inanities by the looks on their faces.