The Multiverse: Science, Religion, or Pseudoscience?

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This video comes with a quiz: quizwithit.com/start_thequiz/...
Why do physicists think that our universe isn't the only one? And should you believe them? In this video, I explain what the multiverse is and what the problem is with it. I have talked about this before but in hindsight I think I made it too confusing. This is my new and hopefully improved attempt to summarize the important points.
Correction: At 5 minutes 20 seconds, the text on screen says "Enternal Inflation" -- that should have been "Eternal Inflation"! Sorry about that!
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00:00 Intro
00:24 What is a Multiverse?
01:41 The Many Worlds Interpretation
04:33 Eternal Inflation
06:00 The String Theory Landscape
07:35 The Problem with the Multiverse
10:28 Answers to the Usual Objections
15:03 Conclusion
15:30 Sponsor Message
#physics #philosophy #universe #quizwithit

[@SabineHossenfelder]

This video comes with a quiz that lets you check your knowledge! quizwithit.com/start_thequiz/1689229798710x820116508313118700

[@dithy]

Don't worry about multiverse enthusiasts not agreeing with your video, because there is a multiverse in which they do.

[@Achrononmaster]

No. The multiverse religionists _think_ there is a universe where they do agree with Sabina --- that's a bit different to claiming _there _*_is_* a universe where they agree with her. In fact that's the whole point, this difference is the difference between objective and subjective (roughly similar to science versus religion). NB: I am not opposed to religious belief, just annoyed by stupid religious belief (a subjective annoyance to be sure, manifested in my objective behaviours).

[@samuelowens000]

Im pretty sure it was meant to be a joke...

[@maxlamda1826]

This joke is deeper that I thought at firt glance because it contains somehow a paradox.

[@pasadenaphil8804]

I wish I had thought of this. Great comment!

[@philipadams4343]

If there are an infinite number of parallel universes, isn't it inevitable that there exists at least one universe in which parallel universes don't exist, and is it not possible that ours is one of them?

[@thegreatgazoo2334]

Thank you for specifically pointing out that just because something exists mathematically does not mean it exists in reality. Too many people fail to grasp that concept.

[@michaelmueller260]

Exactly! Same thing applies to the big bang and cosmic inflation theories though...

[@thegreatgazoo2334]

@@michaelmueller260 Absolutely.

[@doubledee9675]

@AKrutikoff So?

[@doubledee9675]

@@kensho123456 At the moment, I'm thinking that he probably isn't, but I'd like to hear what AKrutikoff says to help me work towards a final decision

[@doubledee9675]

@@kensho123456 I shall see what AKrutikoff says

[@hwica2753]

Sabine nailed it. Mathematics is a tool to simulate reality, but it can also be used to simulate fantasy.

[@TeaParty1776]

Math IDENTIFIES the IDENTITY of reality. Its not mystical or subjective. Introduction To Objectivist Epistemology-Ayn Rand

[@SaSayed90]

@@TeaParty1776 That’s wrong. Not every mathematical construct has ontological reality.

[@TeaParty1776]

@@SaSayed90 The power of math to identify reality requires methods which dont identify reality. Eg, imaginary and irrational number, square root. These methods are not subjective, not emotion, imagination or invalid concepts. They are indirect methods needed to identify reality.

[@TeaParty1776]

@@SaSayed90 do u c my prior reply?

[@martinhorodrigues3809]

I wonder if Sabine will ever discuss the complex topic - Ego. It often gets in the way of knowledge

[@D_Archives]

It's impossible to overstate how great this channel is.

[@omp199]

"It's just as good as Sean Carroll's."

[@TeaParty1776]

In another universe, its possible.

[@covid19alpha2variantturboc7]

@@TeaParty1776 and in others this channel doesn't even exist

[@MARGATEorcMAULER]

Weren't you listening? Nothing is impossible 🤔

[@luiggiphilipi]

So now we know this is the oposite particle to: "It's only possible to understate how great this channel is." Probably first time an entanglement was observed on a YT coment section.

[@gregcampwriter]

As a writer of science fiction, I observe that the concept of the multiverse is a powerful tool that one must use sparingly lest it become a cheap trick to save sagging ratings or a plot that's going nowhere.

[@WildVoltorb]

This

[@mikicerise6250]

Honestly I wish they'd use it more in time travel stories instead of the never-ending paradoxical nonsense about how we changed the timeline but somehow we're still ourselves and now we have to change it back. It'd be lazy, but at least it would make logical sense.

[@stylis666]

@@mikicerise6250 Like in Rick and Morty, I suppose :p I think it might be hard to come up with a good reason to time travel if multiverses are a thing. I mean, The Terminator basically ended up with a multiverse, but if you start off with that premise, then would you go back in time to save people from a different universe, knowing your universe will still be completely dead? I do find that an interesting question, but i think there won't be too many of such interesting questions or answers, so it quickly becomes just more nonsense to add to the paradoxical "solutions". All though I did like the idea of that time travel movie where some kids made a machine to make money in the past or future or some shit. It's a time travel movie so it's dumb so who cares. I do like dumb movies though :) Let's not mix up dumb with not fun :) The movie Decoherence dabbled in such what if questions. Not with time travel though, but it did an amazing job telling a story and giving a lot of solutions to a lot of questions about what we might do in their situation. I definitely recommend it. It might rid you of your desire for a time travel movie with multiverses though, because, why bother? If the character already knows it's a different universe it's Rick and Morty allover again but probably not nearly as fun, and if they don't know, good luck thinking up an original story anyone could care about.

[@johnnytass2111]

The multiverse is most powerful in choose your own adventure tales.

[@Azarilh]

DC and Marvel right here. XD

[@MightyDrunken]

It's a shame that we live in the only Universe where the multiverse does not exist.

[@ashroskell]

Very clever. Underrated comment. The more I read it the more my eyes cross and I disappear into a puff of logic . . .

[@WilliamParkerer]

@@ashroskell Agreed. Gotta be mighty drunken to think of such sentence.

[@socratesuffer2765]

In the parallel universe, you’re commenting on the right youtube video.

[@rifwalker6807]

Universes were observed in the hotel

[@tepan]

Underrated comment.

[@fonkyfesh]

Thank you Sabine, for bringing all this tabloid-level "science" back down to earth.

[@commodoor6549]

Tabloid level science?... like that guy Leonard Susskind? Easy there Fonky Fonk, Sabine is a relative novice in the field of theoretic physics, who does her KZbin channel as a side hustle because her science gig isn't paying the bills. Btw, this year's Nobel Prize winners experimentally pushed Bell's Theorum out of the shadows and into the daylight, and apparently the Universe may not be locally real. All Sabine has is a KZbin channel. Btw, I didn't see Sabine's name listed on that Nobel Prize. _There are more things in heaven and Earth, Horatio, Than are dreamt of in your philosophy_ .

[@ravimishra4914]

At sme stage evry science is tabloid level... Even the argument presented against multiverse aren't convincing...big bang enthusiasts don't hve any real logical answers wen smebdy asks them about beginning of time and wat before big bang... The multiverse theory has it origins in ancient Indian science and is the only logical answer to the mysteries of the universe...ancient Indian Hindu scientific texts tells a lot about cyclical nature of time and universe...

[@rationalsceptic7634]

kzbin.info/www/bejne/Z56thJ6spq52j5o

[@donaldkasper8346]

It is not tabloid science, it is gibberish crap.

[@commodoor6549]

@@donaldkasper8346 Sure, go to Stanford and have that discussion with Dr. Leonard Susskind. You might want learn to read at the 6th grade level first kzbin.info/www/bejne/jX2WaXl9n7tgq5o

[@raffaeledivora9517]

Zuckerberg candy... that's an excellent german joke 🤣 (Zucker=sugar in german)

[@CAThompson]

Google Translate tells me that 'zucker berg' is a pile of sugar, which is not what I'd say to describe some of Facebook's business practices.

[@Flavia1989]

@@CAThompson yes „berg“ means mountain, (which makes her joke even better😂)… And Zuckerbergs buisness practices certainly make me feel like i ate a whole mountain of sugar 🤮

[@AboveEmAllProduction]

Haha very funny....

[@mr88cet]

Ha! I can’t believe I didn’t notice that! I guess he’s a “mountain of sugar,” actually!

[@CAThompson]

@@Flavia1989 I'm reminded of the tune 'Big Rock Candy Mountain' when I think of 'zuckerberg'.

[@AlexanderGieg]

I'd add a fourth category to Science, Religion, and Pseudoscience: Philosophy. Simplicity arguments referring to Occam's Razor, as well as those based on Popper (or Kuhn, Feyerabend, Lakatos, etc.), are all about the conditions of possibility of scientific research, that is, they pertain to Philosophy of Science. Therefore, those arguing for the multiverse hypothesis on the basis of the simplicity of axioms (vs those who oppose it on the basis of the simplicity of outcomes), are doing so from a Philosophical perspective, more than from a Scientific, Religious, or Pseudoscientific one.

[@SgtSupaman]

I don't think that warrants a new category. It falls under the purpose of her "religion" category. Philosophy is merely considering the possibility. Once one starts "arguing for the multiverse hypothesis", it is a matter of personal belief, which is exactly what the "religion" category is for. Calling it "religion" may seem like a strange label, so perhaps you could use "philosophy" as a stand in for that category if it suits you better, but the category definitely includes what you're suggesting.

[@theultimatereductionist7592]

Why not make your list: Entertainment, Science, Politics, Capitalism, Communism, Religion, Pseudoscience, Engineering, Coding, Law Enforcement, Medicine, Mathematics? There exist many many many different categories of human activity. What is this narrow-minded closed-minded obsession with having to compare the human activity of science with the (utterly useless unimportant unnecessary garbage) activity of religion?

[@Slasgo]

@@SgtSupaman I think philosophy suits it better, since it doesn't imply actual belief or any kind of ethical code. Of course this is more of a subjective perception and up for debate.

[@TheoWerewolf]

Mmm, this is one of those "technically true.. but" ideas. You have to have some kind of framework or everything becomes permissible. The frameworks for science weren't defined arbitrarily, but evolved out of 6000 years of trying different approaches. Popper's model is the most current model and it, not surprisingly, reflects the process by which the refinement of the process itself went through. In the end, testing a hypothesis works because it requires that the person making the claim "show their homework", so to speak. You can't just propose ANYTHING and have it accepted as valid, you have to propose a way to test it in such a way that if it fails, your hypothesis is either wrong, or incomplete. But science isn't like a game show, you don't lose and go home, you're free to refine the hypothesis and give it another try, as many times as you like. And Occam's Razor isn't a "law", it's a tool for choosing where to start. Start with the easiest possible model - but if that doesn't work, start making the model more complex, but only where absolutely needed. If you have two models and both work and have *identical* predictive properties, but one is more complex, go with the simpler one because nothing you have in front of you says the more complex one is better, AND it's... more complex. But if later you discover the simpler model is flawed, go to the more complex model and start over by seeing if it *isn't* flawed. The idea of testing is technically a philosophical concept, but the thing is, it works, kind of by definition. It's a tautology: "if it works, it works". If you want to see if something works, try it and see if it works. Is it a flawed approach? Yes. If it's possible that there are phenomena which are real, but untestable in any possible way, then it breaks down. But here's the thing... how will you know such a thing exists and is real?

[@AlexanderGieg]

@Evi1 M4chine Actually, Philosophy is neither scientific nor unscientific, it's prescientific, in the sense of encompassing, not of being less. An analogy: no matter what scientific research discovers, it'll be something that can be summed up in a set of equations. In that way math encompasses physics, which can be seen as a subset of math. When scientists employ concepts such as causality, falseability, reductionism etc., they're using conceptual "tools" developed by philosophical inquiry. Science, even theoretical science, is the application of those tools in the investigation of the world our senses perceive. And while scientific research goes on using the tools developed by philosophy, philosophy itself proceeds developing more such tools, which may or may not eventually be employed in scientific research and other areas.

[@fritzwardrodriguezprep5747]

Part of what makes this series so great is even my middle school science students can grasp most of the argument. They have all seen Marvel movies about the multiverse and find the concept interesting. It's great that they can understand that a concept science can still have value as a literary device. Hossenfelder does a wonderful job in explaining that just because science cannot address a topic does not mean the topic itself is without value.

[@ananthan8951]

"The manifest universe is a mental construction"

[@joeltunnah]

But its value is only as a science fiction plot or escapist daydream. As she states, the theory of multiverses has no scientific value or evidence.

[@lordgarion514]

No value or evidence now. Who knows what will happen in, dozens, hundreds, or thousands of years. But it's an absolute fact that if we never research anything we don't currently know, we won't learn anything. And likewise, it's also a fact that if we only research things that work out, we'll never learn anything either.

[@billwehrmacher3842]

I love your channel and enjoy the overview of various inventions. In so many, like this one, for which finding the correct answer, have zero impact on anything...in our universe. You have the absolutely correct view of this. :)

[@Quidisi]

One of your BEST videos ever! My takeaways: 1. If it can't be empirically observed, it may not be wrong, but it's not science, it's faith-based. 2. Just because some math describes reality does not mean that all math describes reality. (Math is a sub-set of Reality, not the other way around)

[@brothermine2292]

Don't you have that last sentence backward? Assuming all of reality can be described using mathematical laws, but some math doesn't describe reality, this implies the math that describes reality is a subset of math... or to say it less precisely, reality is a subset of math.

[@Redsauce101]

@@brothermine2292 You can use maths to describe anything just like you can use words to describe anything, it doesn't mean that set of maths or words is true to reality.

[@brothermine2292]

@@Redsauce101 : You're agreeing with what I wrote, right? You didn't explicitly use a word such as "agree" though, so perhaps one of us is failing to communicate clearly.

[@jhoughjr1]

Or is it?

[@Redsauce101]

@@brothermine2292 Disagree. Maths are a language and are merely a way to attempt to express an understanding of reality.

[@garysteven1343]

Your videos are always a treat for rational thinking, thank you Sabine!!! ❤️

[@ICANTOUCHTHESUN]

Rational thinking is a myth, a fiction like Santa Clause or Bugs Bunny. And that revelation is a finding of the sciences! Stop living the fiction of the past like Sabine and her colleagues do.

[@garysteven1343]

@@ICANTOUCHTHESUN Claiming something without presenting any valid arguments to support it, whatever your claims maybe, is illogical. Also, "a finding of the science" is usually something highly regarded. At least for people who understand how science works and are not blinded by religious beliefs.

[@alexd.6551]

hmm, rational thinking has to do with arguments rather than facts, what we call science is the relation between the two which we humans enforce axiomatically (i.e. belief). If I live all my life in a cave and I see an elephant shadow on the cave wall, is it science to assume there is actually an elephant? If I am to understand correctly the shadow I must consider the elephant even if I have no interaction with it (apart from seeing the shadow). The elephant is the broader reality even if I could assume other simpler explanation for the shadow. Is it worth making the effort to understand the elephant for little to no practical benefit? @Sabine would say no. Others would argue science is about knowledge and not practical results. Math for instance is less than half practical and we still call it science. About the multiverse I have one observation to make: Our universe is very, very, very specific. It is so specific that the possibility for it to exist without anything else outside is about zero. The fact that we have this universe makes the universe itself to be the shadow on the cave wall example. This kind of compels us to rationalize the multiverse approach.

[@reasonerenlightened2456]

but, Why is she constantly insisting that the measurer must have consciousness in order to have determinism of the measured?

[@reasonerenlightened2456]

​@@kensho123456 she never explains it. Clearly determinism emerges from the interaction between two entities but she insists that one of them must have consciousness. how come?

[@paulm5443]

Great video. Nice to see you weren't too judgemental on people believing in the multiverse if they want to. It's interesting to consider complex ideas but it's really good how you point out they are not science or theories.

[@jeremyrice5091]

I never thought a explanation of the multiverse theory could be so funny! Absolutely brilliant.

[@Relocrian]

I really love how SH gets right to the point, destroys and then leaves you a message with some love in case your beliefs were broken. Frontier science is bloody, but necessary.

[@daddyleon]

And cracks some lovely jokes!

[@KaiseruSoze]

lol - you've been to a physics convention eh?

[@tradde11]

@@daddyleon Love her jokes.

[@notwhatiwasraised2b]

well said

[@bitkurd]

The “belief” is just an illusion including Sabine’s opinion. As soon as she stops judgment, her entire universe will collapse and will be withdrawn back into singularity. Human intellect can not understand anything bigger than human’s brain, unfortunately it’s the sad truth.

[@TheSkystrider]

I love how rational Sabine is. Very satisfying ways of explaining what things are and what things are not, regularly.

[@stopthephilosophicalzombie9017]

She's rational until you get her talking about trans people. Then all of a sudden she gets real woke/irrational.

[@Richter647]

@@stopthephilosophicalzombie9017 Real woke? In other words, she treats trans people as equal human beings with respect and dignity. While you intentionally treat them with hate, ignorance, intolerance, and incivility. And why? Because you're a disgusting, uneducated, and uncivilized, asshole.

[@tinkeringtim7999]

It is very satisfying, unfortunately though, she should rip into a mirror sometime. Everything she lambasts in everyone else's work, appears to be in her own too. I used to love her until I discovered she's just yet another popularist hypocrite.

[@stopthephilosophicalzombie9017]

@@tinkeringtim7999 Could you expand on that comment? I know that she lost her grant funding recently which certainly would lead to a change in attitude.

[@tinkeringtim7999]

@@stopthephilosophicalzombie9017 she has equally arbitrary and unclear lines about what counts as "real" in maths, but speaks and acts as if she's doing different. She asks and answers a lot of philosophical questions while in her videos and books lambasting philosophers for being useless, believing she is guided by the maths and experiments, but when others do the same just with a different perspective she correctly calls it pseudo-science. Anyone who thinks maths directly connects to nature without philosophy in between is just unaware of what science was when it earned the prestige which it has been frittering away ever since it denounced philosophy and adopted Hilbert's fundamentalist neo-platonic cult philosophy as its new and unquestionable foundation.

[@CalikL]

Just discovered this channel and can't stop watching your videos!

[@donaldcarter6252]

Thank you Sabrine, for explaining difficult physics problems in ways your everyday average Joes with a high school education like myself can understand. I'm so glad to hear that I'm not the only one who thinks that (although fun to discuss) the multiverse has a nice home in science fiction, but not one just yet in physics! You rock Sabrine, keep the videos coming!

[@HasanFiziks]

Sabrine 😂😂

[@ParisTrois]

Saline **

[@frank327]

Such an impressive intellect, and even more impressive to be able to communicate these ideas with such clarity!

[@lrvogt1257]

I would love to see a conversation/debate with Ms Hossenfelder and Sean Carroll who seems to be more comfortable with the multi-verse concept.

[@rossmcleod7983]

Yes it would be a thing alrighty. Big fan of Sean Carroll, has a fantastic channel.

[@KirkpatrickSounds]

Eagerly awaiting this to become a reality

[@scar0815]

I would definitely watch that.

[@annamyob4624]

Sabine is perfectly comfortable with the concept. She's just enough of a scientist to know it's not science. Either Sean (however enamored he may be of the concept) is also enough of a scientist, or is not.

[@jcolvin2]

An instrumentalist vs a scientific realist is not a very interesting debate. Because instrumentalists (such as SH) aren't very interesting. All they really do is shut up and calculate (SH makes a lot of noise about it tho)

[@gcingia]

You are absolutely spectacular, Sabine. Just discovered you recently. Now subscribed. Your *Sense of Humor* is just amazing. And love how to share your knowledge with very little Jargon. Love it! John -- #NZL

[@majesticmartian7038]

Love the video, I've been hoping someone would make a good video explaining alot of this for awhile. Ive never thought most of these theories held much weight. Something else I'd like to hear about if you get around to it, that's related to this is theories about alternate timelines. It seems like they have alot more evidence that suggests they exist, and they honestly sound pretty much the same as a multiverse to me.

[@whatsapp-.3481]

Appreciate your feedback It's a great pleasure hearing from you. Stay tuned for more videos,for participating our online investment Community⬆️reach out the number above

[@riverstun]

Have her explain to you how a cat that is simultaneously alive and dead in a box for decades after poison was or was not released, how that overlapped cat suddenly "updates" when you open the box. Either she is saying that the cat was alive OR dead, and you only know when you open the box (and she therefore abandons the Copenhagen interpretation) OR her "update" is simply a phony way to say that the wavefunction magically collapses when you look.

[@Aarkwrite]

I used to ignore the elephant in the room but thanks to Sabine I made a new friend.

[@carmenmccauley585]

Lol! Nice!

[@jcork3460]

Sabine, I love your humour! You still bring the information to us but in such a brilliant way. Please carry on in your way!

[@prakashms9621]

You have raised most important and relevant points. Thank you.

[@emergentform1188]

Brilliant, love it. Most humans tend to confuse their internal thoughts/theories with external reality, and it's not only theists who have this problem. It seems to be a very common issue for most people, I've noticed.

[@Prayukth]

Lack of interest in our universe is the reason for the interest in other universes..

[@sofilove...20]

:)(:..

[@thebomber7641]

Meh. As the video points out its just a matter of "poetry". One of the topics that is easy to use as a media entertainment and has nothing to do with real universe. Similar to how the characters in all the entertainments are shown in a totally unrealistic ways, or being used as an instrument for anything (developing the plot or other characters) and doesnt really exist as an independent characters.

[@juanjoseescanellas3798]

As always, very clear explanation of a relevant topic, even out of Physics. Great.

[@redcleon]

Question: You say, "We know that black holes evaporate, so they eventually reveal their inside," but isn't that something we believe due only to mathematics? I was under the impression that hawking radiation had never been observed. Love your work. Thank you.

[@ruprecht9997]

Stuff falls into black holes, and they have a boundary towards space around them, and there is the gravity thingy, so it is at least fair to say there probably is an inside, and to reason about it. :-)

[@fullfungo4476]

An analogue of Hawking radiation has been observed in sonic black holes. Not a direct evidence, but it’s something, I guess.

[@schawo2]

@@fullfungo4476 We observed something else, and after some nice philosophical deductions we can now belive in Hawking Radiation. HR is now just a synonym of God. Going overrationalized in Physics has its own pitfalls. We have to think out of the box to find new physics.

[@fullfungo4476]

@@schawo2 what are these “philosophical deductions” you are referring to?

[@tinyprince]

@@schawo2 I don't think that's how scientific theory works.

[@martinhorodrigues3809]

I'm enthralled by your presentations. Thank you so much.

[@KutWrite]

Fascinating, as usual. Kudos on your graphics. They really pop! I feel sorry for any universe in which there is no Sabine Hossenfelder.

[@aquacruisedb]

As Karl Pilkington once said concerning the study of gravity "It's not a problem so don't worry about it...we're not all floating about, so leave it". I feel the same way regarding the multiverse!

[@chbe6945]

The great Karl Pilkington might have a different view on multiverses. His edict 'so leave it' for gravity might not necessarily transfer over to multiverses. Someone should consult the great man on this question.

[@marcforrester7738]

An attitude that ages like milk the moment someone stumbles on a practical application.

[@dlevi67]

@@marcforrester7738 How does milk age the moment someone stumbles on a practical application?

[@euanthomas3423]

Now that would be a video. Sabine in conversation with Karl Pilkington.

[@JoeCensored]

Somewhere out there, someone was surprised by an elephant while watching this video, and is now convinced of many worlds.

[@Linguae_Music]

I very much enjoyed your reducteo ad absurdum about the simplest theories lmao Good show!

[@yt.personal.identification]

In the mind of every person you have ever met exists a different and distinct version of you and no two are identical. Every observation gave a different measurement to each observer.

[@mrdownboy]

Beautiful comment, almost poetry. Thank you for this, it has changed my perspective completely. Thank you.

[@robertosans5250]

Fantastic video. In these days it is essential to have someone to call BS for what it is. Thank you for that. You do science a good service.

[@craigbettencourt1021]

Sabine, your now my role model. Your confident and unapologetic verbal expression of the truth in the face of what others might say to the contrary is very admirable and brave.

[@evazauner]

oje sabine, du zerstörst grad meinen traum. ich liebe diese multiversumsgeschichten, und hoffe doch sehr, dass sie nicht nur "geschichten" sind. immerhin sind ja einige der grossen in der physik davon überzeugt.

[@kevinfarrellUK]

Always fascinating and interesting, and as an ignorant in the sciences and maths, I still find much that helps me find a very small grip to the subjects that educate and make me think. Thank you. Off topic but I am sometimes left with a question in my head about what science says and does with ‘random’. It it used or useful in science, and if so, how? I would be very interested in your thoughts on this. (Apologies if my question is pointless.)

[@stephenhawdon2208]

I love watching your videos. Always eloquently explained!

[@meesalikeu]

there is nothing more clear and straight forward than a doc sabine video.

[@francescos7361]

Thanks prof.Hossenfelder for sharing your knowledge

[@dewiz9596]

There are an infinite number of Brooklyn Bridges waiting to be sold. . .

[@TheoWerewolf]

Dr. Hossenfelder, I most enjoy your presentations when you're focused on core science and this is very core. But the two issues that most resonate with me are "the untestable 'science'" problem and "scientists who confuse the model with reality" problem. I run into both of these so often with otherwise well qualified and highly intelligent scientists who should know better. The latter case is even weirder because it works both ways: "extend a model outside its range of application and define it as reality" and "selectively limit a model to avoid hitting an unwanted outcome where the model and reality just don't line up". The one that drives me spare is "if you go faster than light, you go backwards in time." Well, no, because you can't go faster than light. This is a case where there are multiple models that say different things (which should be a huge clue that ALL the models are incomplete), but Einstein's equations (by way of Lorentzian math) say that any object with rest mass cannot go AT the speed of light, let alone faster. Moreover, if you go faster, you require imaginary numbers to represent time, length and mass/energy, which makes no sense. That's not how the real world works. The thing about Lorentz equations is that they work VERY well (it's why the GPS system works, for example), but clearly at the speed of light or past it, they break down. In fact, ALL similar equations break down when an object with rest mass hits or exceeds the speed of light. So making statements like "if you go faster than light you go back in time" are not science. They also ignore the entire question of "Is there an extant past and future?" (if not, there there is no 'past' to go back to), "Is the universe absolutely deterministic?" (if so, then the question is meaningless since you already ARE in the past, you're just describing the worldlines more completely - you didn't 'travel'), "Is there a second (or more) t-axis?" (which you'd need if you can consciously choose to 'move" back in time, since moving is a change in location over time and now you're treating TIME as location) and so on, all of which fall into the "untestable science" domain, for now. It's perfectly OK to say "we don't know" or " we don't know how to model that yet," but I often see scientists try to fix a problem with a model by layering even more model on top or by willfully ignoring other models that don't mesh with theirs (see: Einstein and quantum mechanics...). When done for the right reasons, this is actually good - it forces scientists to refine and test their models rigorously - but at its worse (Fred Hoyle's staunch refusal to accept the big bang mainly because a Jesuit priest figured it out - even though that priest was a world class physicist) it just slows everything down and confuses and misleads people (anti-vaxxers, anyone?).

[@DragNetJoe]

Interesting choice to close with anti-vaxers. That term itself now has wildly different meaning depending on what case you are trying to make. Although the anit-vax movement is at least 100 years old, for most just a couple years ago "anti-vaxer" was fairly well confined to people like Jenny McCarthy making unfounded claims tying vaccines to autism. Now, people wishing do discuss completely rational risk decisions are dubbed "anti-vax". If the risk of negative outcome from a disease is very low, the risk of the vaccine must be even lower. That isn't anti-vax, it's basic risk management.

[@Dragrath1]

@@DragNetJoe Risk analysis is important but if anything that only greatly invalidates the stance of antivaxxers because the risk of comparing severe disease to possible vaccine side effects is so extremely unequal that no logical argument is really favorable towards everyone capable of getting vaccinated. The relative sample sizes of those vaccinated with vaccine side effects and those infected with severe symptoms in the case for covid influenza measles and polio to name a few is absurdly different in relative orders of magnitude. All these disease carry a significant risk of debilitating long term health effects even if one recovers and the fact that viruses evolve and not necessarily to lower virulence means that stopping transmission is the only effective way to stop the threat. Its ultimately a civilization scale threat and thus concepts like short term personal privacy and rights make as much sense as allowing someone to help out a foreign state in war even indirectly. It is in terms of impact severely detrimental effectively infringing on the rights of everyone ultimately which exposes the fallacy behind negative freedom. Antivaxxers and other "negative freedom" movements are an enemy of civilization as negative freedom the removal of all restrictions to what a person can do means in effect that there can be no rules or social norms and thus they are fundamentally anarchists. As such I'm curious what rational risk management strategy related to vaccines can be considered valid enough to not be classified with antivaxxers? I do know of several historical examples particularly the early Dengue vaccines which rushed ahead of the science and failed to account for warnings that severe disease is usually associated with poor cross compatibility of antibodies of one strain on the others meaning that such a vaccine that doesn't vaccinate for all 7 family strains is likely to do more harm than good but to my knowledge that is an outlier. Is this something related to the whole poorly named "monkey pox"? I admit that the decision to dilute the vaccine (technically actually the smallpox vaccine given the close evolutionary relation of the two viruses) was a questionable political move not really based on science but in principal there is good reason to be concerned with the virus spreading even with a small community subset of humans as that is a prerequisite for establishing new better adapted variants to humans. In particular the much more virulent west African strain was a branch offshoot of the more "mild" version which has jumped abroad globally so we know that this virus can and has in the past caused more severe viral strains. There was work which predicted and warned this virus would likely be able to jump out into the larger population as smallpox vaccination ceased. Moreover the vaccination against pox viruses should become all that more imperative in light of recent work in Alzheimer's showing a scarily strong association of the condition with reservoirs of latent (Nucleocytoplasmic Large DNA Viruses)NCLDV based viruses (mainly the pox and herpes simplex viruses ) which typically permanently set up shop within Neurons abusing the cells immunoprivileged essential status to remain within the host permanently lying in wait for an opportunity to reemerge. Autopsies have found that in all cases sampled for these viral DNA one or more of these viruses has been found in the associated brain region. Of course correlation is not causation but with the amyloid hypothesis having failed to produce results and the foundational papers under scrutiny for widespread data manipulation its time to look elsewhere. Notably there is some hints that amyloid plays a role in the immune system responses within the brain so it may very well be that reemergence of these viruses within nervous tissue or something similar is the root cause for this horrifying disease. If true exterminating these viruses may be the ultimate cure to the disease. NCLDV as their name suggests are not simple viruses once they enter a cell they set up a complex viral replication factory which is functionally analogous to the nucleolus with phylogenetic evidence finding strong evidence for a shared evolutionary origin between the Eukaryotic nucleolus and the conserved core nuclear genome with the NCLDV. (I.e. this family of viruses most likely shares a common ancestor with Eukaryotes, plus there is also some evidence building a case that the NCLDV may share strong links to the recently identified and sequenced archaeal viruses. As a consequence treating these viruses with antivirals is unlikely to be promising as from a biomolecular perspective Eukaryotes are functionally indistinguishable from NCLDV to the point where it may be better to say Eukaryotes potentially descend from a population of NCLDV clade viruses which adapted a way to replicate with their host. Point of this is vaccination is quite likely the only way we will ever beat these viruses as weapons that will work effectively against this viral family will also be highly effective at killing our cells. With "monkey pox" being a close relative and or possibly even the potential reservoir population from which the ancestor of small pox splintered off from just because the current virus is relatively "mild" doesn't mean we should expect it to remain that way as at least twice in adapting to spread among humans this virus has developed far higher virulence making it extremely deadly. Even a strain with a small fraction of the mortality rate of small pox would still be a horrifying disease we need to stop this monster and exterminate its reservoirs else in the long run the reemergence of a smallpox analog is highly probable. This is an existential battle.

[@DragNetJoe]

@@Dragrath1 Sorry, not going to read that wall of text. The risk of severe negative outcomes to COVID19 to a healthy child (under 12) is virtually zero. A parent that choses to take that infinitesimal known risk of infection rather than take the significantly less known risk of the vaccine are behaving completely rationally. Not all vaccines are created equal, therefore being "anti-vax" in a specific case (COVID 19 and small children) is a completely different case than being something like anti-smallpox vaccine (which had a fatality rate around 30%).

[@Dragrath1]

@@DragNetJoe If you read my comment you would know that the claim you made has been falsified the risks of the vaccines are extremely minimal less than 1 in a million odds while the risk for long covid is about 1/5 odds. Yes the fatality risk is lower than smallpox but it is more deadly than influenza. Notably there is still a relatively high number of deaths among children compared to influenza or a typical cold.

[@yueelson]

@@Dragrath1 Tell that to someone whose lung fibrosis got activated as a result of vaccination, and their life got cut short for a few years... And no - I'm not anti-vaxxer - got all the way through booster. As to Dr H opinion on multiverse - it should be expressed in peer review publication and be part of scientific debate. This is not a matter of public opinion... And yes - the fate of multiverse/eternal inflation theory is still up in the air (or false vacuum? ;-) ).

[@thakursn]

Honesty in science is the need of the hour, and I thank you!

[@fpostgate]

Thanks again Sabine, you keep me watching. Thanks for the comments about people extrapolating their math models!

[@janee11able]

Amazing ! Thank you for clarifying why it is not science. Keep up the good work ;)

[@Tacopi3]

I feel like this addresses many worlds theories unfairly by claiming it "Postulate[s] the existence of unobservable entities". It postulates that to observers, these many universes are all observable. It's not fair to say that this has no testable experimental significance to us if it is the true rationale behind Bell's theorem.

[@Tacopi3]

@Evi1 M4chine First of all, please get off your high horse. That second paragraph is unnecessary. You misunderstand my position as I do not believe that observers are ever in an 'absolute' universe. We are always experiencing many worlds at a time and the observations/measurements we take define the common characteristics of those worlds; limiting their differences. The consequences of all observers to be observing multiple worlds simultaneously can elegantly explain quantum mechanical weirdness without stripping particles of their discreet positions in their respective universes. But we as observers can never collect enough information to define ourselves to a single universe and must live in many worlds. She even admits that these theories can explain all the same observations in 14:36 but claims that it means nothing if the theory mechanisms parallel those of the Copenhagen interpretation albeit with different assumptions. She views it as more complicated so it is 'pseudoscience' now? This is wielding Occam's razor as a club in the exact way she criticized.

[@ibperth]

Outstanding! As a professional theoretical physicist who has used his mathematics to occasionally show experiment to be wrong (via subsequent experiments agreeing with our calculations and not previous experiments), I tell students that the domain of mathematical validity is always limited. Mathematics is not the reality, but a phenomenally useful tool on certain occasions. The challenge is to know when and where. While I love existential problems, I subscribe to: "Don't worry, just calculate!". Utility trumps all.

[@noirekuroraigami2270]

The problem is to say that the Big Bang exists but say it only could happen once is statistically crazy when coupled to infinity. Like a fish in the sea debating if space is real

[@jonathansachs1979]

Thanks for this. as a curious layperson I thoroughly enjoyed both the content and the delivery.

[@russswanson3820]

Both the science and the humour are well done. Thanks!

[@daddyleon]

Yeah, she’s a true star at it: clear, concise, convincing, quite witty!

[@tomschmidt381]

Another great episode exercising my brain cells. I'm multiverse agnostic. As our knowledge expands our notion of being in the center of things has been diminished so I don't find the notion of multiple universes untenable but as you mentioned if they are impossible to observe there is no way to know if they exist or not so not scientific.

[@Achrononmaster]

She did point out @11:50 published papers of tests for multiverse hypotheses using the CMBR.

[@joansparky4439]

@@Achrononmaster for some of them, not all..

[@joansparky4439]

@Evi1 M4chine _"research grant money being spent on them, leaving juust that one bit too little for research for that thing that ultimately caused your child to die from something totally preventable"_ That argument is based on research grant money being distributed/allocated on merit instead of need.. which is a broken/inefficient system to begin with. Markets are very good at distributing/allocating scarce resources based on need instead of merit, while commissions and other such processes/constructs/frameworks are usually being run by a "select" few who NATURALLY optimize locally for their own benefit. Markets are global optimizers IF every market participant has the same rights.. this is then also what differentiates free markets from unfree markets, where the former are as equal as possible the latter enforce rules that create a select view - which is what leads to the suboptimal local optimization instead of the gloabl optimization.

[@peterbaxter8151]

Thank you for your criticism of multiverses Sabine. Great work.

[@sharonminsuk]

The first of your videos that I have watched. I love that you are opinionated! I'm no physicist, but sometimes some aspects of modern physics seem insane to me. It is refreshing to hear "there may actually not be anything to this".

[@joelwexler]

This always seemed like such mathematical hand waving, but as a physics dropout (quantum was the end for me), I never felt my opinion worthy, But when they talk about multiple, infinite universes for every particle's slightest movement, specific copies of us as individuals - it's sounds nuts to me. If you like debunking, check out Sabine's friend Dr, Unzicker: www.youtube.com/@TheMachian

[@nightmareTomek]

That multiverse thing sounds like some scientists have no idea what to do.

[@sharonminsuk]

I don't want to go overboard on condemnation. I'm actually a scientist myself (biology, not physics), and I think that proposing and considering novel ideas is useful and important. As long as somebody knowledgeable can bring a critical eye to it, which is why I appreciated this video. And if nothing else, such ideas can make for some AWESOME science fiction stories! Also, some of the "crazy" ideas will turn out to be true, and you just never know in advance, which ones they will be. Everything we now take as established and solid, once sounded crazy to most people.

[@utubekullanicisi]

Well, existence is still insane and complicated.

[@joeltunnah]

​@sharonminsuk very little in modern physics is "established". It changes at least every generation, if not sooner.

[@DJ_Force]

Sabine is great at pointing out how scientists are not immune from wanting the universe to "make sense" and have explanations that are emotionally satisfying. This is something that people ridicule religious people for. Maybe we're all the same.

[@alasdairwhyte6616]

quite right we scientists gather easch week in celebration of the multiverse 🤣

[@pansepot1490]

I don’t know which scientists Sabine refers to as actually “believing” in the multiverse. The ones I have listened to, however convinced of the validity of the idea, always admit that it’s just hypothesis and there’s no way of testing. I don’t see problems, as Sabine seems to, in writing speculative papers, after all “If we knew what it is we were doing, it would not be called research. Would it?” (Albert Einstein) Unless of course people lose sight of the fact that is speculation and believe it’s reality.

[@Achrononmaster]

@@pansepot1490 She did point out @11:50 published papers of tests for multiverse hypotheses using the CMBR.

[@alexandretorres5087]

@@pansepot1490 I think this may be a problem if you think in terms of financing such research instead of serious science. Then, there is the misinterpretation problem of our "show the paper" culture. Being published is not a guarantee of being right.

[@squarerootof2]

​@@alasdairwhyte6616 Not each week, pretty much every day is a mass prayer day for the average preacher/scientist.

[@ronigbzjr]

When I was younger and more into physics, I took a few university courses on quantum mechanics. One of them was called Quantum Mechanics Interpretations, a course supposedly about physics, however took place in the building that was used for philosophy and social studies and such. The course was probably one of the things that made me give up on physics altogether. The professor, an avid believer of the many worlds interpretation btw, was the single most boring lecturer I have ever had a class with. His tone never changed as he droned on and on about what seemed like completely unscientific ideas, some somewhat plausible and others completely absurd. If this is supposed to be the cutting edge of physics, I said to myself, what's the point? It all sounds a little harsh, and I don't mean to shit all over the work of very important and intelligent human beings. They deserve their funding and noble prizes, no doubt. But I think what Sabine is saying should be a wake up call both for scientists and for the public to stop treating science like the new religion. Science is only concerned with explaining observation, belief has nothing to do with it. Human beings will keep exploring the cosmos and discover many new things but we may never know the answers to the so called "fundamental questions" and that's alright. Science doesn't have to explain everything and we're frequently chasing our own tail with this race towards a magical "one theory to rule them all". It's just an unnecessary burden on science to force it to bend to our human need of finding meaning in everything. That's what we have belief for, and to each their own. Thank you for another great video from the realest science communicator on youtube.

[@DoctorBiobrain]

I think the issue is people wanting to prove how smart they are by using their imagination to get ahead of science and pretend it makes them cutting edge. The further ahead their theory gets and more confusing it sounds, the smarter they must be because other people don’t understand what they’re talking about and you end up with followers saying how beautiful the emperor’s clothes are to prove they’re one of the smart ones who totally understood the gobbledygook. But if you don’t have evidence then you’ve got nothing and life doesn’t reward guesses. Thus said, I think this would be best defined as science as philosophy, not religion. Religion includes rituals and philosophies usually change to adapt to new knowledge while religion usually denies new knowledge if it conflicts with established beliefs. Scientific Philosophers love grabbing the latest research to build their imaginary theories on because it keeps them ahead of everyone else.

[@theultimatereductionist7592]

Why not make your list: Entertainment, Science, Politics, Capitalism, Communism, Religion, Pseudoscience, Engineering, Coding, Law Enforcement, Medicine, Mathematics? There exist many many many different categories of human activity. What is this narrow-minded closed-minded obsession with having to compare the human activity of science with the (utterly useless unimportant unnecessary garbage) activity of religion?

[@Steiwerd]

Do calculations. Never think about anything. Based.

[@maalikserebryakov]

@@theultimatereductionist7592 Why do you hate God

[@maalikserebryakov]

@@Steiwerd lol

[@justsomeguy4260]

Countries together form a continent, continents together form a planet, planets together form a solar system, many solar systems together form a galaxy and it keeps going on. Once we thought milky Way was all there is until it was proven wrong, I'm sure it's the same case with multiverse as well.

[@Jacob_A_OBrien]

Beautiful... When did so many people start to believe their models as reality, as what is "real"? I'm not sure if there is any branch of science that does not have people who fall into this category. It is just so important to work within the framework of models. After all, our models can only exist insofar as we can experience them. If we can't think of them, how could we generate them? This begs the question, is it possible to think up a model that accurately represents some aspects of the world around us or not? It'd be nice to know. Perhaps we are not capable of generating thoughts consistent with an accurate model of reality.

[@mattpotter8725]

From what I take from this is that the Copenhagen interpretation of Quantum Mechanics is fully alligned with the Multiverse hypothesis it's just because at the point the wave function collapses and the measurement is made and the probability is gone it deals with our reality because any other probabilities don't exist and is there are other universes where something else has happened they can't be evidentially measured because there is no way of observing them, not that we know of currently. I think that's what you're saying and I'd never thought of it that way. You then seem to suggest that because we can't observe it it isn't scientific to try and see if there is any way of observing or measuring it? But isn't this what science does? It is about forming hypothesise, postulating (of even better actually creating) an experiment, and either confirming your hypothesis, adapting it and doing another experiment, or throwing it out of the window? I'm a little confused because if Einstein (and I know you hate to mention him) when he came up with new interpretations on how reality worked, sometimes which in the end he didn't like, his thought experiments, at the time there weren't ways to measure them (there were with some of his theories, but not all, and not at that time), then you're saying we should just not purpose these theories because they are pseudoscience? It is only science to propose what we can prove with an experiment? That does make sense, but it doesn't mean that we as humans shouldn't put theories out there as someone may come along to prove of disprove the theory with more advanced technology or equipment. It might not be science but isn't it theoretical physics, is that not what theoretical physics is all about? Maybe some things that people come up with is rubbish, sometimes it just can't be proven (and shouldn't be believed), but isn't it a worthwhile endeavour in itself, because of we don't do this we would just discard a lot of opportunities that may help us explain the universe? Lastly, doesn't the Copenhagen interpretation of Quantum Mechanics make an assumption about the collapse of the wave function? Of course it does, it fits with the results we see in our universe, but it doesn't explain what actually happens at that point as far as I know, it just says the other probabilities disappear (maybe it does, but if people cleverer then me are looking into possibile explanations as to why there are probabilities in the first place and what happens to the other possibilities, which is one thing even Einstein, yes him again, wanted to know, and doesn't fit well with our experience of everyday life, then I doubt it does). You are basically saying don't even hypothesise because you can't observe or make it currently, and other proposed theories have found nothing, which I find highly unscientific, so I'm torn here. Many may lap this up because you present your thoughts very well (even if at times you throw in the absurd to convince the viewers it's a good technique for that), and I don't disagree with what you say, I just like to question everything, accept what has been proven by experiment, accept refinements when problems in theories are found (under certain conditions), and more forward building on what went before. Those scientists who don't accept your position of just accept the assumptions made and move on, and would like answers, may be wasting their time, they may be wasting money doing so, in your opinion, but it doesn't make it any less worthwhile.

[@agimasoschandir]

"It is only science to propose what we can prove with an experiment?" True. But... if multiverse exist, is it possible to have the impossible? Just because we can postulate a frammin' flibbertigibbets does not mean it has to exist

[@Vexas345]

There's a difference between saying "Oh, this theory might be true. Let's test it." And "This theory is true. Let's prove it." Believing comes afterwards, not before. You can do thought experiments all you want. But if you start arguing your thought experiments are true with no real evidence to back it up, it's pseudoscience.

[@joansparky4439]

_"You then seem to suggest that because we can't observe it it isn't scientific to try and see if there is any way of observing or measuring it? But isn't this what science does? It is about forming hypothesise, postulating (of even better actually creating) an experiment, and either confirming your hypothesis, adapting it and doing another experiment, or throwing it out of the window?"_ That's what science does, yes. But a lot of those theories have no ways to confirm or deny the hypothesis therein which turns them into a scientifically unverifiable theory.. i.e. pseudoscience or religion.

[@mensaswede4028]

One of the problems nowadays is that the leading edge of true science in physics is unrelatable to the average layperson. So if you want to publish popular books on physics that the average person will buy and enjoy, you have to resort to talking about things that are highly speculative.

[@arctic_haze]

When was the last time the leading edge of physics was relatable to the general public? Certainly not since the relativity and quantum mechanics. In other words, no one alive remembers times when it was relatable

[@garycarter6773]

I love you in every multiverse. Thank you!!! Great video! :)

[@tb1974]

Hey Sabine, thanks for another good video. The more I hear "scientists" wax poetic about the origin of the universe, multiverses, et al, the more I fear that Hoyle was on the right track.

[@briansmith3791]

I remember a time when scientists would not entertain any talk of there being anything outside of this universe. "Don't bring in stuff from outside the universe, we'll explain the universe by examining the universe itself." Then the Cosmological Constants were discovered.

[@TheSwiftFalcon]

"It's not that I think science is the only thing that matters" And this, I think, is a big part of why I respect Sabine so much. I have encountered too many people who seem to despise things like religion and other non-science...while not realising that their own relationship with science is not all that different from religious worship. Sabine meanwhile, has an excellent understanding of science, while at the same time understanding that it may not be unlimited in what it can answer, and also that it is not everything. Excellent video as usual, clear minded, rational and interesting.

[@TheSwiftFalcon]

@@schmetterling4477 Okay, I'll bite, I'm curious. :) How did you come to that conclusion?

[@TheSwiftFalcon]

@@schmetterling4477 Still not quite clear on what you're trying to say here. To whom or what doesn't it matter? And what was it that was taught in science class which you think I missed?

[@TheSwiftFalcon]

@@schmetterling4477 Ah, I do love the suggestion that I have less than half a mind, served up together with a smiley. :D Look, my science classes, high school or otherwise, just taught me science, not what to care about or what I should think of other people. I was originally curious about what you thought I missed, as my original comment was just a personal opinion, and not really something which would be covered in a science class. But now I'm starting to think that there might have been something in there which struck a nerve. Was something I wrote offensive to you?

[@TheSwiftFalcon]

@@schmetterling4477 What did I write which contradicts that?

[@TheSwiftFalcon]

@@schmetterling4477 Well, then you should easily be able to give a concrete example.

[@timoluetk]

Thank you so much far making this Sabine. This is one of the big theories in public perception and someone needed to call it out!

[@mickmiah7605]

Thank You for this presentation. I saw you being polite to Michio Kaku, along with Roger Penrose, so TY for discussing this tired issue. I was hugely happy to hear Roger talk about the failing of QM and the need for a "Gravitised Quantum Mechanics". Is there any chance you could explain what he meant by this or your thoughts regarding this? Thank You Sabine for all these vids, I really appreciate them.

[@user-jk1tw2qf1i]

I second this post. My thesis is on this topic, so I would love to hear an opinion.

[@kiyoaki1985]

I tried to watch that video but just couldn't. Michio Kaku irritates me to no end with his speculative pandering.

[@user-jk1tw2qf1i]

@@kiyoaki1985 lol. me too. i think penrose is similarly speculative, but i like his originality. string theory might play some role in understanding quantum gravity in the future, but without confirmation of it experimentally (not for many years i might add) making crazy untestable claims is the goofiest thing you could do. you'd think that a physicist would have a stronger logical compass than that

[@kiyoaki1985]

@@user-jk1tw2qf1i I really don't get the appeal of speculative theories about multiverses and the fermi paradox and interstellar travel, it all just seems so infantile and uninteresting. I liked Kaku when I was 12 and didn't know better but kind of hate him now.

[@edwardorr9439]

Whenever Sabine shot down a tenet of string theory, I'd hear "Michio Kaku" in my head. Luckly, I didn't make that a drinking game. I would have been unable to write these comments.

[@brasiljan1]

You're the best Sabine!!!! love your content

[@samuelpoche-mercedes2352]

I agree with everything in this video, You're not questioning the validity of the multiverse but rather questioning its scientific aplications.

[@barakeel]

"Shut up and calculate" approach, I guess.

[@MarceloTrindade1]

That's another great video, as always, but not because Sabine questions the multiverse(s). It is great because she condemns those physicists that, instead of using Mathematics as a Science translation tool, use Mathematics to "create" science.

[@jensphiliphohmann1876]

She doesn't even condemn them but just says what they're actually doing and, by doing so, they're not doing natural science.

[@melgross]

@@jensphiliphohmann1876 there is nothing “natural” about science. It’s purely a methodology that was invented by humans as a way to find out how things work, and why.

[@martifingers]

A counter example possibly though: Dirac's prediction (using only mathematics) of the positron. Sabine is formidable but I feel there is a slight tension here with here previously stated notion that you cannot really understand basic physics through analogies - the maths is essential. I hope I am not misrepresenting her but I come away from this feeling I need to really think this through. Her characterisation of the scope of science may be open to challenge.

[@jcolvin2]

In her other videos she contradicts herself tho. She says that the essential mathematical parts of our theories should be considered to exist. She can't make up her mind on this, and contradicts herself.

[@MarceloTrindade1]

@@jcolvin2 Really? I don't remember any of her videos saying this. Do you have a link? Anyways, I just bought her book "Lost in Math" that I hope will bring more information about her thoughts on this topic

[@pratoarancione7646]

Very well done and said, Sabine!!!

[@holeshothunter5544]

10:30 I agree completely. Too many think that mathematics IS something. I say it describes something with an unknown degree of accuracy. Thank you,. Sabine

[@a156a2]

For sure, "too many think that mathematics IS something" -> too many think that physical theory=mathematical model of physics IS something

[@ivanelrino]

Sabine, I'd really love it if you reviewed the sci-fi physics written about in The Three-Body Problem series, especially the third book.

[@DanielECulbertson]

That would be an amazing video. 👍

[@ASLUHLUHCE]

You know somethings wrong when Many Worlds is the least controversial one

[@mk1st]

It’s fascinating how new mathematical techniques are invented / discovered to probe all sorts of “problems” but just because “answers” are spat out does not automatically mean it is “real”. Papers published = employment = wages (and perhaps fame)

[@vladpetric7493]

Dr Hossenfelder, I'd like to respectfully object to your characterization of the Flying Spaghetti Monster. There are multiple aspects of the FSM that one could technically observe in the current universe. For instance, while we haven't directly observed spaghettification, I don't think anyone would argue that it doesn't happen near black holes. Similarly, the pasta-like layers in a neutron star have been hypothesized as well. There are other references, but perhaps less testable.

[@ikarienator]

Afaik, the many-worlds interpretation does postulate the existence of "many worlds". It's a prediction not a postulation. It also doesn't suggest the universe "split" because of the behavior of some particles either. It suggests the wave function gets more and more complex and the macroscopic objects get entangled with the microscopic particles. The reason it's "better" is because it doesn't treat "observation" as if it's not a quantum process. It also predicts the Born rule through decoherence.

[@KirkpatrickSounds]

Fantastic as always. Would love to see Sabine discuss the MWI on the Mindscape podcast one day.

[@bjorsam6979]

Yes! Both have taught me much. Carroll is just mindboggingly clever and having someone challenge some of his proposals would be great.

[@fullyawakened]

Yes I think everything in this video is very well debunked even just in reading Carrol's book "something deeply hidden". It's almost like she hasn't heard of this stuff before even though it's her profession. She didn't address a single argument the multiverse theory stands on, just kept calling it silly.

[@Bookah88]

The invisible elephant and I are pretty happy together. Thanks for introducing us. Sometimes the right person for you is right in front of you all along. And an elephant.

[@erichstocker8358]

I think this was a very good explanation of the issues.

[@marcelob.5300]

There exists a universe where Sabine supports the multiverse interpretation 😀

[@SimonBrisbane]

Only on your fantasy KZbin channel

[@not2busy]

🤣🤣 Good one! 😂

[@CAThompson]

🤯

[@Achrononmaster]

@Marcelo B you wonderful lunatic! You've lampooned the entire serious point of Sabine's commentary: to assert *_there is_* is precisely the anti-scientific point of view she was trying to de-promote. What is the case is that Many Worlders *_think there is_* a universe where Sabina supports MWI. "Thinking there is" is totally different to "there is" --- this was the entire point of the video.

[@CAThompson]

@@Achrononmaster I'm pretty sure that the grinning smiley-face indicates Marcelo B. was joking.

[@brucehoward8767]

Hooray for Sabine, a delightful blend of high IQ, cynicism, sarcasm, hot pepper and humor. Perhaps she’s the science gadfly. She not only rips apart theories but bloods the noses of those that promote them.

[@henrythegreatamerican8136]

I thought this was going to be a video about the multiverse being nothing more than an endless amount of simulated universes

[@storksforever2000]

The problem Sabine has is that she calls anything currently untestable as “not science”. People thought that proving gravity waves or determining whether a hidden variable theory could exist were impossible. Those weren’t testable for decades. Until they were. Things evolve, it’s not static.

[@brucehoward8767]

@@storksforever2000 Good point but I don’t think that it is applicable in this case.

[@storksforever2000]

@@brucehoward8767 Could’ve said the same thing about hidden variable theory. They literally thought it was intrinsically philosophical in nature for decades. Then someone came along and made it not. Same thing here. You can’t assume things will remain the same into the infinite future.

[@reasonerenlightened2456]

Why is she constantly insisting that the measurer must have consciousness in order to have determinism of the measured?

[@johnminehan1148]

These are interesting: well explained and dryly humorous.

[@solarwinds3311]

One of my favourite books, Quarantine by Greg Egan is all about multiverses and collapsing waves. I recommend this "sci-fi apocalyptic" novel.

[@zyansheep]

Here so early, this video isn't even in the videos tab yet!

[@suan22]

I think if we stick to the generally accepted theories then science would stop making progress. So i think it worth thinking about new ideas. Who knows maybe at some point someone will find a way to test those theories and they will be upgraded form pseudoscience to real science.

[@tonybiddle6668]

Exactly. The genuine SCIENTIST does like Darwin and follows the evidence wherever it leads him, regardless of whether it demolishes his previously held hypotheses. The PSEUDO-scientist hangs onto his preconceived notions and rejects all the evidence (drawn from all over the world since anything began to be recorded) that proves them wrong as so much superstitious nonsense. Therefore some of our leading Atheists forfeit all credibility to be considered scientists - they are just using PARTS of science (scientia =knowledge) to push their own agenda.

[@leslielandberg5620]

I love your videos and I'm a big fan of science and I have a question. Might there be, at some point in the near or distant future, a discovery at the quantic level so anomalous that is necessarily leads us back around to reviving this the multiverse theory? Just because it doesn't fit with the body of knowledge we have now and the methods that we now employ, certainly to my mind anyway, that not preclude that there will be a time, perhaps an inevitable moment, when everything that we thought we knew is up-ended. In defense of my proposition, I wish to point out that this has happened inumerable times in the history of scientific thought and discovery. Thank you very much and I look forward to your reply.

[@waltergith6535]

As you pointed out correctly, it is a "multiverse theory". And as a theory it can be revived. But lets never forget not to mix theory with reality. The reality will always be something else then the theory. That is the observer problem. Fortunately this "problem" is being rediscovered by quite some physicists recently.

[@aidanblah9646]

Loved it! Thanks you. It needed to be said.

[@glasses685]

Great video. Some people would say the multiverse idea is currently the only way to explain why the physical constants happen to be in the narrow range that permits life (and observers). In the same way that, if we assumed Earth was the only planet, we'd want some sort of explanation as to why it happens to have conditions that allow life. But if we assume there are trillions of other planets then it's much less surprising that some of them would have the right conditions for life. I'm not claiming it's scientific though, since other planets can be observed and other universes can't. Still, in the absence of any scientific theory explaining why the values of the constants are what they are, from a philosophical standpoint it seems as good as explanation as any.

[@joansparky4439]

That still doesn't help explaining why something (obviously) is - it just throws a statistical cape over it. You can do that when you philosophize, but don't call it science.

[@annamyob4624]

"the only way to explain" ... balderdash. The existence of other "earths" doesn't explain a single thing about our Earth. "oh, there's a trillion of 'em, so there's bound to be one that has the particulars that ours has" doesn't explain a thing. yet another logical fallacy masquerading as science.

[@davegold]

The 'narrow range that permits life' is a totally unproven conjecture.

[@annamyob4624]

@@davegold that too. :)

[@M200Sniping]

The book was fantastic! THe audio book reader was also excellent and captured your tone and speaking style well.

[@SabineHossenfelder]

I'm happy to hear! 😊

[@_John_P]

@@SabineHossenfelder Please talk about rotating wormholes, thanks.

[@AquarianSoulTimeTraveler]

@@SabineHossenfelder Well if we take all the space between all the atoms and electrons and close the gap we could fit all of reality everything in the entire universe down as the size of a grain of rice. Ultimately everything is subjective so there is no truth but all we can do is try to come up with the most simplistic Solutions like you always say. Each universe's version has its own frequency and they all share the same so-called Mass or fundamental building block for creating everything we see. But it's hard for people to comprehend is how a change in the frequency can allow you to Only See what is part of your reality and I hypothesize that accelerating expansion of the universe could be caused by dark matter and I have a couple different reasons on what could be causing this dark matter to grow exponentially. On one hand I think that the dark matter does interact with regular matter and if we were to not slap the mainstream narrative then you could easily say that dark matter is all of the other Universe versions and the more time travel you have in a particular time the more differentiation you have and therefore you have more increase density of dark matter because dark matter is these other Universe versions bleeding through we could see it there we could so-called measure it but we just can't actually see it. Increasing the number of soul Time Travelers in a area of operation like on this planet will create a rise in the density of Dark Matter creating an illusion of accelerating expansion this is one of the theories but just know everything is a theory and it's all a waste of time...

[@AquarianSoulTimeTraveler]

@@SabineHossenfelder that's a good thing about philosophy it can easily destroy "science" if a tree falls in the woods and no one is around to hear it does it make a sound... like I always say in order to have objectivity you need to have an observer that exists from the very beginning of time and will exist all the way to the end of time and even if we have an observer that existed from the very beginning of time the end of time is not now and therefore there is no objectivity only subjectivity so yes if no one is around to hear the tree fall could it possibly make a sound??! And also called objects in our universe are also subjects because No Object existed from the beginning of time and will exist all the way to the end of time and if even if it does the end of time has not came yet so there is no objectivity! All this does is creates a hierarchy of bullshit people wanting to sound Superior when they are absolutely not! Therefore all science is pseudoscience! Plain and simple! I guess we need something to waste our time on though I enjoy our interactions here and I like your little winks you do...

[@AquarianSoulTimeTraveler]

@@SabineHossenfelder all I know is that the fact that 'science' has claimed that our universe is expanding faster than the speed of light just slaps itself in the face. You could say it's relative and all the other bullshit but ultimately it is all bullshit! The fact that scientists or so-called scientists would accept this as so-called science it's just mind-boggling how so many people could be so stupid... it's a lot easier than having to rethink our entire scientific method though because all of our instrumentation and all of our measurements would be considered completely inaccurate and unmeasurable which they are. Like I say one of the biggest problems is thinking that we can observe from our singular point in space and time even if we've napped our entire galaxy there's nothing but a singular point in space and time with physical ships mapping our entire galaxy it would still be nothing and therefore to think that we can map accurately our entire universe from our singular point in space and time using telescopes that cost billions of dollars it would ultimately lead to all of the measurements being wrong and that we can't map from our singular point in space and time if we were logical we would come to this conclusion but it's not about logic it's about getting funding and if there is no logic to anything then why would we fund the work... if we know the objects in the mirror may be closer than they appear due to this exponential growth of dark matter which is everywhere our measurement ability would be completely knocked so it's easier to say that we can measure the dark matter and our universe is accelerating and expansion past the speed of light which is totally insane instead of saying that the dark matter is exponentially growing creating an illusion of accelerating expansion pass the speed of light! I stand for a lot of things but without what I will not stand for is our universe accelerating faster than the speed of light it's just not true and if science was honest with itself it would know that there was no way to physically prove it from our singular point in space and time. we would need to map the entire universe with physical ships... Anyways i bit your head off enough for this abomination of a video... Lu ttyl

[@waltergith6535]

Great, it is so important to state what science can and can't do and how it is supposed to work. Thank you Sabine.

[@leonard3826]

A marvelous demonstration of "how to call out Michio Kaku, without calling out Michio Kaku".

[@andygoldensixties4201]

I like this video and I agree totally with the conclusions (I mean I do so in this universe, I cannot exclude that in some other universes another "me" does not)

[@etakarinae248]

But the other 'you' is therefore not you. Simply because you cannot tell if there is another 'you'. I there was one 'you' , you (now the real you - here) would know. You=You, me=me. BUT you != 'you' --> there are no parallel yous, you are always unique

[@MaryAnnNytowl]

Thanks for the gobbledygook-free interpretation. I appreciate what you do, Sabine. ❤️❤️ As for the hypothesis? One would hope that, in at least one of those other potential universes, my life didn't fall apart 22 months (and 28 days, but who's counting?) ago. I'd hope at least somewhere I'm still happy. 😔

[@srobertweiser]

Roughly 23 months? You should be thanking your lucky stars. My life didn't fall apart, it was ripped away from me 31 years ago when I was dx'd with multiple sclerosis before I was 17 years old. And I wasn't even lucky enough to get the part-time type [relapsing/remitting], I was chronic, on duty 24/7/365. MS strikes men only 25% of the time, PPMS [primary/progressive] in only 10%, and it rarely occurs in children as young as 13 [when my symptoms first reared their ugly ufcking head]. So the planets were in perfect alignment against me in the darkest hours on the fifth of November, in the year Our Lord Nineteen Hundred and Seventy-Four. I'm sure there's a universe somewhere where I don't have MS, but I'm stuck in this one. Maybe we'll meet up in one of the better universes in the Multiverse. BTW, I think Nytowl was one of the drugs my doctor rx'd to combat insomnia.

[@peacesound1101]

For some of us it's not a hypothesis, but what is experienced

[@BartvandenDonk]

"Curiousity killed the cat" not humans, so stay curious. 😏🕊️

[@alexsanchez98]

@@srobertweiser I'm really sorry that happened/is happening to you, hope you ever get to experience the better paths that you had in the multiverse

[@scene2much]

Loss happens, and can suck in all 216000 space-time degrees ( 60 ^ (dimensions-1)), Sorry for your losses, and I wish you a meaning & joy-restoring grieving.

[@TheSulross]

the principal value for what the Multiverse theory is actually good for is inspiring fun Sci-fi plots - oh, and we get the endlesly fun Mandella Effect to play with in social media

[@rickwyant]

To think that our universe is the only one is like the time when some people thought the world was all that they could see, or that our planet was the only one, our galaxy the only one. Whatever the conditions were that created this universe must surely be occuring over and over again.

[@carmenmccauley585]

No guarantees on that.

[@macsnafu]

Thank you for this video. A lot of new age types have tried to use multiverse theories as justification for their wacky ideas. I enjoyed the multiverse DC Comics created in the 60s and 70s, but retroactively ruined in the 80s, but even as a teenager, I knew the multiverse was as fictional as the super-powered beings that populated it.

[@HW-sw5gb]

She’s not saying the multiverse is fictional, she’s just saying it’s philosophical, not scientific. The exact same way the question of the size of the universe is. Science can’t tell us anything because we can’t observe outside our bubble. So any speculation on what’s past the observable universe will be unscientific. Philosophically, an infinite universe is the most popular answer since it makes the least assumptions. But there’s absolutely no proof of it. The multiverse is the same way (except for the Many Worlds one). The amount of variables at the moment of the Big Bang that allow for life to exist objectively means that either we’re very lucky, something (God/a computer) planned the universe, or an infinite amount of universe are created with all these variables and so the odds aren’t a problem anymore. Science can’t tell us which of these is correct. Philosophy prefers the multiverse, but only for the same reason it prefers the “infinite universe”. It makes the least assumptions.

[@macsnafu]

@@HW-sw5gb Sorry for the mis-implication of my statement. DC's multiverse is fictional.

[@HW-sw5gb]

@@macsnafu My bad as well, I get what you meant in your original comment now 🙏 You’re 100% correct.

[@redshiftdrift]

Wonderful, thanks for showing what the limits of science are!

[@dialatedmcd]

Well the limits are that it's uncreative, it's already set.

[@lawrencium2626]

thank you for an honest and skeptical pitch, I got fed up of 'science media' glossing over these topics with a little too much permissive ease.

[@justlive1651]

What got me as a kid and still gets me today at 65 is the single direction we take in every micro second as apart from the billions of others that we could have made. I'm not just talking decisions we make but every single thing we do - relative to what we think is our own decisions. Intuitively I remain of the opinion all our actions are a result of bumps and vibrations at the quantum level. In other words I think (like the cats in a box) something at the very lowest level nudges an outcome. Our brains catch that outcome at the very point we choose but ultimately, the outcome could keep going like a ball in a pin ball machine. In summing up I'm just really happy I'm in a Universe where I can hear Sabine pronounce Einstein the way she does.