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Physicists have many theories for the beginning of our universe: A big bang, a big bounce, a black hole, a network, a collision of membranes, a gas of strings, and the list goes on. What does this mean? It means we don't know how the universe began. And the reason isn't just that we're lacking data, the reason is that science is reaching its limits when we try to understand the initial condition of the entire universe.
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The Poplawski paper about how the universe might have been born from a black hole is here: link.springer.com/article/10....
00:00 Intro
00:25 The Big Bang Theory
03:47 Why So Many Other Theories?
04:53 The Problem With Cosmology
07:30 The Importance of Simplicity
10:57 Stories of Creation
15:35 Sponsor Message
"The Big Bang is the simplest explanation to the universe that we know, and it's probably wrong" (I love you Sabine! 😅)
She should have explained why matter induce space expansion, according to Einstein.
It is a dangerous statement, because lot of stupid people will take it out of context and misunderstand it. It doesn’t mean it didn’t happen. It DID happen. It is only “wrong” in a sense that the current theory is likely not 100% accurate. For example the latest headlines, where we found that galaxy formation happened just a bit earlier after big bang than we predicted.
@@laurenth7187 because of lambda, the cosmological constant.
By the virtue of being human, there are things we will never know. There will always be something too small to see, we will never reach the edge of the universe to see if it’s even there, and we can’t know what happened before the Big Bang. Our senses are only so good, our lives too short, and our bodies too fragile, there are actual limits to what we can know.
Big Bang, Big Bounce or Black Hole? Answer, NONE of them are rational science. They are all mathematicians results of equations that have no relationship to reality. And no need to ask Einstein, obviously he was totally wrong about everything he claimed.
I just finished reading your book, and while I can't claim to have understood everything (and at almost 82 I'm probably not quite as sharp as I once was), I can thoroughly recommend it to all the followers of your videos. This was another great video - they are always something to look forward to every Saturday.
Wow much respect
You sound pretty sharp,age is just a number
Rock on Jim!
I am almost 81 and still have a love of learning new things and Sabine has a great way of explaining things. I wonder how many others in our age group are still expanding our knowledge
@@josephalavezzo8232 I am at 48 now and from my "young" age all I can say is that your example is truly an inspiration, as you are ageing with grace while maintaining the spark of a curious child!
I just discovered Dr. Hossenfelder and she is a hilarious buzzkill. Love it!
I thought she was a physicist. I stand corrected.
14:58 "It is a question that we will never be able to answer just like why do women pluck their eyebrows only to paint them back on?" - rofl 😂👏
I have been blessed to live in a spacetime where/when Newton's ideas are still remembered and Einstein's are still playing out. The odds of that happening are as infinitesimally small as being privileged to watch Sabine make frightfully complicated subjects so accessible to a common mind like mine. Now subscribed.
How about your own ideas? Why do you treat Newton and Einstein like Gods?
only if ye don't believe in providence, otherwise the odds are pretty great
@@JohnPretty1 To paraphase Newton- "You can see further when standing on the shoulders of giants" .
Thank you for helping people see that there actually are questions where the correct answer is "We don't know" Understanding what we may not know is a huge foundation of continued learning.
They never knew!!!! They faked it to make it.
Exactly!
the only true answer to everything is we don't know. each one of us develops our own model of how the world works through empirical observation, but not all models are equal some of us have models that describe the phenomena in our universe better than others.
Yes, there are questions which have no answer. Hmm important and absolutely fine if 'we' isn't used and 'i' is. The answer to where universes ultimately emerge from is I have noticed too uncomfortable to those unable to handle the concept of infinity. The old guard says as per Kuhn's the structure of scientific revolution there is no answer for everyone, is why we have all this anti science backlash.
Yes the biggest factor complicating the matter is the many unknowns that are perhaps more than the knowns.
I love how everything in your videos is far from sensationalist and always cold fact. You're my hero, Sabine
her bias isn't much different
@@NuanceOverDogma what is her bias?
@@gonzalobarragan8076 She makes things too complicated. She's part of the problem. Not part of the solution. She's here to make money by her silly german, klaus schwabisch, accent.
You took me back to a lecture hall 64 years ago, when my professor commented "in the end, the only important questions are Boundary Value Questions". You have said what we all know, but do not say. It is one of your best, albeit not pure science, but slipping into philosophy.
All science is philosophy.
@@kensho123456 Sily is fine so long as it is a true opinion.
@@mikemondano3624 yes, and not all philosophy is science.
@@johnlinley2702 whether theology and nihilism can be considered as science is a very difficult question to answer as well. Philosophies were made up to explain why the world is the way it is. Is it because of Christian God or Hindu Gods? Does God exist? And if God doesn't exist, can atheism give us an answer? Can we use science to determine whether god exist or not? And what does science have to say about people leaning towards a wide variety of philosophies? How can we use psychology, a part of science, to explain religions? Oh god, it's like trying to mix water and oil using emulsifiers...
@@mikemondano3624 Properly speaking, science and philosophy are discrete concepts. Science is what can be verified by experiment (the "Scientific Method") while philosophy is what we imagine that is outside science.
I always love your very dry and sort of awkward sense of humor. Also... that many of your jokes are "smart" jokes. You have a good niche here. Thanks for the fun AND informative videos!
The eyebrow joke was superb, always wondered the same!
I wasn't but now I sit here pondering a question I never had. Thank you, Sabine.
You had a good observation available with the stone throwing metaphor that you didn't talk about. When you rewind the equations from the final state, you do not know when the initial state occured. If you rewind the thrown stone, you could conclude that it jumped out of the ground. That is not true, because the initial state was later in time. You can rewind the physical laws beyond the real initial state, but it doesn't give correct account of the past anymore. IMO rewinding the universe's evolution for as far as the laws we know allow, and even beyond that, suffers from the same issue.
That's a good point indeed!
The fact multiple initial states can lead to the same final state is the exact problem in this context, excellent point!
@@Lincoln_Bio No it doesn't. State means position *and* momentum.
brilliant brilliant
@@Lincoln_Bio You could even take that idea one step further and say that every past that is consistent with currently observable state is equally correct. Unless the laws of the universe are perfectly and deterministically reversible, there's many possible pasts for our current present. Does it then even make sense to talk about there being a single "real" past?
Great video, Sabine! Clear and simple, humorous and cutting-edge sharp!
Hi, I'm in the middle of reading your book Lost in Math, it's so good! I just searched your name on youtube and discovered you have an amazing channel too!
this is an honest, and sober walkthough of a really complicated topic (as usual) you rock Sabine!
She rock while the Universe broccoli.
This was a terrific episode. My new favorite! Philosophy of science mixed with astrophysics.
You are absolutely brilliant on both the subject matter, and with respect to your ability to communicate your ideas. I am a huge fan.
"We should not take these ideas seriously..." I agree we should not take the conclusion that they're accurate seriously, but it may be worth _considering_ them seriously to determine if through exploring the ramifications we can come to some new, _verifiable_ understandings.
Odd that Sir Fred Hoyle was responsible for the term 'Big Bang' (he used the phrase during a radio program because he couldn't think of another term that would describe the theory on radio) when he in fact disagreed with that theory.
This happens frequently, especially people wanting to proof something wrong and then just confirming it practically for good. Possibly due to Popperian way of science, people the genuinely wanted to falsify something and fail are the best proof there is.
Well Georges Lemaître originally called it "the hypothesis of the primeval atom".
Yes! This is exactly why I love listening to SH, she tells the dirty truth without fear or favor. She unsnowballs the supposed consensus by delivering facts and reasonable conclusions based solely on the evidence at hand. Take note other scientists, this is how it is done.
I just can't help thinking that she deeply enjoys trolling (some of) her colleagues. She's indeed a fantastic science communicator.
I'd love to have her and other science communicators use this line ... "Look to the science, not the scientist!"
She makes a lot of bad jokes that are somehow funny.
But her proposition made in this video is insane though. We should not consider other theories because we have some faulty ones that work well enough... She also goes on about simplicity despite having a few other videos talking about how beauty should not be a factor in physics. These two things are equal. Her claims now are counter to her claims in the past. Current theories are highly lacking and do not describe reality in the slightest. We need all sorts of singularities and dark objects to make them even functionally close. This does not even get into the facts even on their best days they are incapable of explaining the constants only describing them. A proper theory needs to tell us why they are the values they are, not just what they are and if we were to follow her lead here we should never entertain new theories because, we already have some shitty ones we all use right now. IDK, just rubs me the wrong way I guess because everything said here stands against one of the core tenants of Science, Curiosity.
@@seditt5146 You need to re-watch the video, or at least be honest because she never said that we "should not consider other theories" as you say, instead of getting confused or triggered. If you don't like her videos, or have any evidence that contradicts what she's saying, you should say so, instead of making things up about what she said. Have a little respect and honesty.
Thank you Sabine. I appreciate the raw honesty of your position (or velocity?). Stay well
I love you're videos! I love the honesty! Keep it going. Sending love your way!
Out of all questions we have about the big band, I find Karl Pilkington's the most interesting: "Was it really a big bang or did it just sound louder since there was nothing around to drown it out?"
so it might just been a so so loud old fart...? ;-)
Big Bang is a poor name because there was no sound because there was no medium for sound waves to propagate through. There was expansion but no bang sound.
@@lrvogt1257 That's not true at all. There is a medium in the early universe, the quark gluon plasma and whatever exists before that. That medium is too sparse in the modern universe to conduct much sound.
@@Xeridanus OK... moments after the big bang. I can accept that.
@@Xeridanus yes! They found signatures of the sound waves in the cmb. Somewhere around that time the universe got too sparse to conduct sound. The CMB has circles like the ripples in a pond.
I'm very new to this channel but I really like it! I'm very impressed with how Sabine openly admits that we don't actually know how the universe was formed and that we may never know. She's also very funny!
Once again brilliant to the point explications.Thank you for such great breakdowns on very difficult subjects.
Mindblowing ideas put forward by Sabine. THANK YOU! Sabine, what impact does the observations of the James Webb telescope so far , have on all these theories of the universe?
Love the series you have done and your sense of humor - thank you for making some very complicated things easier to understand for people like me who have no background in these fields :)
Thank you for your honesty, more scientists, physicists, and other professionals should learn when to admit, "they just don't know"
I like the idea you have about the limit of our understanding about how the universe came about. Human understanding and its limitations is a fundamental subject and it deserves perhaps a scientific theory to specifically address this question.
Probably the most thought provoking talk I have seen you do in the 5-6 years that I have been watching your channel. Thank you for translating gobbledygook about why we still have to speculate on how the current state of our universe came to be. I am a 70 year old who only made it as far as High School. I like Stephen Hawking's hypothesis, though. I don't think you can have time without matter.
agreed, time is the advent of matter/energy in motion through space.
Excellent work on this one. Clearly put, and filled with things I needed to hear. Thanks Sabine.
"We don't know" - the one thing we humans hate to admit when it comes to big questions.
Or we love to rule out other people’s conclusions..
And then they postulate hypothesis that cannot be proven true.
We don't know, therefore, God did it.
"We don't know, but we're going to find out." - This is better for me. Don't settle for not knowing.
@@SimonBrisbane If there is no reason provided to accept your conclusion, no sane man should.
I only recently discovered you, Sabine, but you have changed the entire way I have thought about physics and the universe. Seeing you challenge the views that we've been taught to hold as truth has given me as a mathematician a very different view of reality. Thank you. You are truly amazing. Watching you and Michio Kaku - who comes across as so aggressively confident in his faith in supersymmetry / string theory - is such a refreshing breath of fresh air. I seldom read anything other than mathematics books, but I'm looking forward to reading Lost in Math, especially given how easy it is as a PhD mathematician to become so decoupled from reality and live in an internal world of the beauty of mathematics.
Explendid video, one of yours best one! Congratulations!
You are the best science communicator that I have come across! Clear concise honest and humble. Thank you for the education.♥️
It’s really easy to see the appeal of looking for new models when the simplest best current one has features like singularities that we expect not to be real features of reality. Getting justified about any particular model may be beyond our experimental capabilities. Great analysis!
A comment I made previously elsewhere: "Falsifiability. It's the road-block that "scientists" can't get beyond. If they can't see it, they won't consider it. Problem being, the Universe could be infinite, or at least massive beyond our ability comprehend. So which path is more likely to lead to the answer? Theorizing based solely on what we can SEE... which has ALWAYS failed us in the past... or making reasonable extrapolations about what is BEYOND THAT?" CLARIFICATION: When I said "can't see it", I was referring to any portion of the Universe BEYOND our ability to detect, not potential entities WITHIN the range of our instrumentation which we have not yet figured out HOW to detect, e.g., obviously we can't SEE "Dark Energy" or "Dark Matter", but that doesn't stop many scientists considering them.
Brilliant, as usual! And above all, HONEST. The same can be said about economics & economists as about cosmology and some cosmologists. For now at least, there’s only so much we can know and understand, and not more. The rest is either gobbledygook or charlatanism - both of which are taught in standard University economics courses. Econometrics is in theory about fitting models to data but in practice it’s about fitting data to models. Either way, you can achieve consistency but you can do so in many different ways, and choose the battery of statistical tests that works best for your initial assumptions or for your pet theory. The result is not unlike scholasticism or medieaval medicine: to show you can reason (and/or calculate) consistently about anything. And often forget about “reality” altogether. … Fun!
Loved Lost in Math and just picked up Existential Physics as well. Looking forward to diving in.
Sabine, My theory of the expanding universe is that the expansion is actually part of a sinusoidal motion; wherein after a long period of time, the expansion will cease and contraction will begin. I maintain that the universe never had a beginning and has always been there.
Many cosmologists say the same about a cycle of expansions and contractions; the most favoured cycle is not a sinusoids but an epicicloid...
We have to understand and comprehend what "existence" of something really means. We have to understand what "time" really is. We can be the dream of an incomprehensible cosmic being. We can be a "computer game" of a cosmic "game developer" so there was no begging and not end like there is nothing in a "game world" before you run the programme and there is nothing after you turn it off. It exists only when you play. But inside of the game-world it looks like a constant existence of everything in it. (For me video games programming and working explain a lot about our universe). Maybe we are the cosmic beings that are playing "this game" in our virtual reality pods living it as a character of this Universe. Who knows? Everything is possible.
This idea of a cyclical universe goes back many centuries and is a part of a number of Eastern religions
These videos really make my day whenever you release them. I find the topics interesting and your tone of presentation engaging. If more of science communication focused on what we don’t know instead of focusing on new knowledge, there would be a lot less need to embolden claims.
Thanks for this clear explanation - saves me a LOT of time!
love your theories of everything song , it the best
I bought both of Sabine's books, and I heartily recommend both!
Thank you, Sabine. I love your sense of humour, also. Sublimely droll.
Wisdom and wit! Thank you!
Your content is amazing, keep it up.
There's also the funky idea that maybe the rules have changed over time. We can only observe our _current_ set of rules, so we cannot ever rule out that there wasn't a different set of rules at an earlier point in the existence of our universe.
i like the idea that the laws and constants were self-assembled by some process. (heard it from Sheldrake)
This woman is a treasure in my life. Thanks for everything, Sabine and team.
Yes she is great. When I was young, I was a big fan of Mickey Mouse.
@@memyshadow4062 Yes, but Sabine is funnier
Thank you for the different views of the beginning of everything. Penrose's ideas always feel good to me. BTW apropos of nothing, that new hair style is very attractive in my view. Thanks also for your wonderful humor - I always get at least one good laugh from every show!
Hi! Sabine, you are so Cool. I have subscribed recently and learning so much from you
Thanks Sabine! Once again, please make a video on VSL (Variable speed of light)😉
The speed of light is not variable though.
@@unduloid In a vacuum
@@unduloid In a vacuum
@@andrewpaulhart VSL is about the speed of light in a vacuum.
@@unduloid I refer to the precursor of General relativity. Einstein’s paper from 1911
Thanks Sabine, for another great video! This is dovetailing nicely with your book which I'm enjoying very much!
Thanks for an interesting presentation :)
Love your content!
Sabine, great explanation. I learned something and also enjoyed it. Your humor does a great job of making a point in a fun an engaging way. I am sure you are a great professor. BTW, while I was listening to your points, I was also thinking about the singularity at the center of a black hole and your points about singularity at the beginning of the Universe also apply.
Fantastic video -- For me personally, I find the points you made to be profound and have given me a perspective on this that I can buy into, and that will stay with me. Thank you so much, Sabine...
"We don't know" is a great push to "we wish to know" and maybe "we will know if we..."
Nicely explained, thanks.
Great catching your lecture at the Royal Institution last week Sabine!
Happy you liked it!
@@SabineHossenfelder Hope you enjoyed the cheese!
...really hope that is one that the RI uploads to their KZhead channel. The crux of not living in the UK, but definitely something I would love to hear.
@@SabineHossenfelder I love your ultimate Smackdown this is the ultimate Smackdown video and I love how you did a ultraviolet and green background just as a little wink... Simplicity is the key you understand it that's why I watch your videos that's why I'm here communicating with you. I highly appreciate everything that you do walking on coals to show people what the true goals of a true scientist would be and to show the fallacies in the system what we can trust and what we cannot trust... you did all of that in this video without telling people how to think or what to think you are so beautiful💯😍
@@jttcosmos Well, it was certainly recorded, so it seems likely it will be uploaded eventually.
One of my favorite aspects of Sabine's videos are that she can show why some ideas are not good science without being condescending.
She doesn't seem to have any answers and yes she is condescending you just choose not to see it. It's there.
@@bruceh92 She described an infinite space of equally justifiable answers where people pluck their ideas from. So in a way, she has all the answers. At least her condescension is usually directed towards other's arrogance
So clearly explained. Thanks.
Thank you Sabine, you have unscrambled my brain with one simple, honest, straight forward video, which has quietened all of those competing theories with one 'Big Smack'.
4:45 I absolutely love Sabine’s comedic delivery, it’s genuinely very funny
She's very funny. Dry & understated, but truly funny.
Excellent and hilarious Sabine! Thank you for reminding us of what is known/works, what is not known/working and what is pure conjecture
Just found you. Loved it. You won one more subscriber
CAREFULL, the one that commented my message is not Sabine, it is a SCAMMER
Thank you for this video.
You rule girl...keep up the good work ♥️👼
I’m glad Sabine has admitted to not knowing. I thought it was just me
"In der Beschränkung zeigt sich erst der Meister." - Goethe
I love how sabine is so cool about not knowing sth thats the true spirit coz if u pretend to know sth u actually dont it ll keep you from wondering
12:04 Brilliant exposition of the limits of the scientific method.
Imagine being Sabina's kid. "Hey sis, I think she knows about the chocolate again..."
'step-bro, what are you doing...?'
If Sabine didn't already exist someone would have to invent her! Brilliant explanation, as usual .
I'm pretty sure there are some initial conditions and evolution laws that make it inevitable that Sabine had to exist.
She exists because we observe her
"To create a Sabine, first you have to invent the Universe" - Carl Sagan
Considering I haven't met her in person, I didn't rule out the possibility that she's in fact an invention, or a character created by a team of scientists and artists and the image we see of her is computer generated. I mean, did you see those memes where Willian Dafoe's face is in everyone? It looks uncannily real.
Right on, as usual. I’m wary of making the assumption that simpler is better and probably more accurate. Could be wrong. Maybe it’s crazy to even be TRYING to come up with reasonable (consistent with our limited data) theories of the origin of the universe, but I don’t think so. It’s good to explore and sort through the possibilities, keeps our minds exercised - as long as you keep in mind that that’s what you’re doing, just exercising your mind, and almost certainly the theories are wrong (but some might have kernels of truth; you may never know which those are).
Thank you so much Sabine. An honest scientist, who respects both the inherent beauty and practicality of science but also its inherent limits.
15:00 - It's amazing how Sabine can do this with a straight face. 🤣
I wonder how many takes there have been when she cracks up at her own jokes. I've watched her giving talks and sitting on public panels and she'll say something, I'll laugh but nobody in the audience is, and I'll wonder if maybe nobody else got her joke, I'm an idiot, or both.
Besides Einstein and Hubble, also George Lemaître deserves a mention for getting the idea of the 'Big Bang' ("primeval atom").
Lemaître's paper even preceded Hubble's observations, and Einstein initially told Lemaître that his mathematics was correct but his physics horrific. Dr. hossenfelder dropped a stitch here.
@@johancouder8013 "Lemaître christian, so Lemaître wrong"
Greetings... And thanks for the video.
amazing vid. thank you
Always enjoy your videos - thanks from the UK.
Glad you find them useful! 😊
4:09 This is the most honest statement I've ever heard. When I hear someone humble enough to admit they don't know something or admit they were wrong about something I tend to trust them more. Scientist should be the first to admit their fallibility, you're smart and there is a reason why theories are called theories. Even the most scientifically confirmed theories deserve scrutiny and so do the scientists working on them. We know enough to know we don't know everything. If you have all the correct answers to everything then you are exempt from such scrutiny; Right after your peer review, of course.
Ditto. Science is theories at best. I just wish the politicians in their political theories would follow suite.
@@gregmellott5715 Politicians by their very nature are egomaniacs, they think themselves both scientist and artist. The truth is they are closer to alleyway pornographers and snake-oil salesmen.
Please do not confuse the word theory from every day use with the word theory in a scientific sense. The former is equal to a hypothesis in science. Scientific theories (gravitation, evolution, plate tectonics - just to name a few) are well tested and confirmed.
Very well put.
There are many situations in which "I don't know" is the only honest and correct answer. Unfortunately, we have been taught from early in school that it is a dishonest answer that really means "I was too lazy to try to find out." We need to break old habits and learn when "I don't know" is the only correct and honest answer. That may be unsatisfying, but not everything in life is satisfying.
Thank you Sabine. An honest and intelligent answer to the question of all things. "The Big Bang is the simplest explanation we know, and that is probably wrong, and that's it!" Such is the nature of all things we strive to understand. And we march on
+30 points for making Einstein say "Dang!" It's videos like this that keep me coming back. Rational discussions that include the limitations of our understanding, which are so often left out in the mainstream. That and she keeps getting cuter every video I watch. I think it's her sense of humor. The universe started as broccoli. :-D
I agree. Sabine is adorable
Einstein said "Dang!" pretty often. It's just he then went back to the drawing board instead of rageposting on the interwebz. Also, if the universe is broccoli then is it not cannibalistic to eat broccoli? The universe contains everything, most certainly everything defining you. Hmm. Also the universe starting out as Broccoli also makes James Bond movies an inevitable universal constant.
@@oisnowy5368 Well, you know, lots of parts of the universe eat lots of other parts of the universe, so this would be no surprise ... although, if broccoli IS the origin, that does seem to present a special case. Perhaps then each bit of broccoli is the beginning of another universe, thus the multiverse must be true ;-) Sounds like a new religion. I think there's even defining hymn.... kzhead.info/sun/mq2Yk5uIp3uthWw/bejne.html
loved this video, thanks
Brilliant - Thank you!
thanks for this fantastic video
Hi Sabine, can we see some of the evolution of the universe (over the past 13.7 billion years ) since Hubble and JWST are essentially looking back in time? They cannot see the initial state, but the models should have to agree with what we are observing in this evolution.
Yes, testing models with observation is one of the many things astronomers and astrophysicists are doing with these tools.
JWST will be able to see up to 250 Million Years after the big bang.. thats a lot, but thats also far away from the big bang itself. BTW no telescope with our current understanding of physics will be able to look beyond the "particle soup" before the universe became transparent... because there just isn't any light left from before.
Sure, but just like macroscopic observations of water droplets give few constraints on atomic theories, the bare visible universe gives few constraints on what the absolute beginning would have looked like.
Models? The model that JWSP imagine challenges for when the first galaxies took shape, is just that, a model for when the first galaxies took shape. That model was designed as a placeholder in want of observational evidence, rather than a definitive answer that must hold true or we will have to toss not just that model, but every other model too. As for the “Big Bang”? At this point, we are basically waiting for the next Einstein for that, and everyone thinks that they will be.
@@DJWeiWei I was referring to the when and how the first galaxies formed. We just don’t know. But, I suppose that we could apply your analogy to both model about the first galaxies and the Big Bang itself.
Thank you for displacing some of the confusing cosmology with what I perceive as honesty. Nova has had some very interesting videos in the last twenty years. Membrane collision is something that sounds appealing to me. I caught a very good program on this a long time ago. I'd like to hear more. Is there perhaps a solid core in a black hole? Maybe what we perceive as entering a black hole is actually exiting somewhere else in a parallel universe? Perhaps black holes happen when one bubble of space touches another bubble of space in which lies yet another universe like the one we observe. All I know is there are scales of gravity that stagger the human imagination. I'm reminded that knowledge is starting to snowball with all the technology we have today.., I can't imagine what it will be like in the next ten years at the rate we are going. So much for my two cents.
I am beginning to understand these concepts thanks to your videos. So I appreciate them.
I love it! The best explanation is the simplest, and it probably wrong. How cool it must be, to be able to get paid to come up with unprovable theories! Great episode! … are podcasts episodic?
Great video, i do agree. Below a couple of questions/comments on the parts of the video as food for thought for the viewers: Isn't the high energy density equation of state tested somewhat by observing neutron stars etc, at much higher energies than the LHC? We aren't seeing the final state but actually slices of past states when we observe the universe, right? In principle we can look back to quite a long way towards the initial state, with cmb, neutrinos, matter imbalances, etc. This doesn't go all the way back but there is more info out there to probe. On the question of simplicity: Aren't new hypotheses often posed as effective theories, so that they tend to have extra parameters? Isn't there some point in generating many ideas to see if there are ways to test them? As long as you can find a way to falsify it, it would make sense to do that. Of course I agree, in cosmology it has gone quite far, but if you would say to stop working on hypothesis exploration about another field that just got started it wouldn't make much sense. I understand that your point is that cosmology is not like other areas, since we try to describe the universe and a possibly unknowable initial state (though I think there could in principle be observable consequences of the initial state, otherwise we wouldn't be here either), not all effects might be washed out in some theories, just very hard to detect. Just a bit if devil's advocate, maybe. All in all i agree with the video.
as long as we rely on collecting EM radiation for our data, we will not be able to see beyond the CMB. the universe wasnt transparent for EM radiation before it. i guess we need to start scanning gravity itself somehow.
Thanks for the education & entertainment. You are both an informative cosmetologist and an entertaining standup comedian combined. You are the best example of space, time, and matter the big bang has produced yet far.
cosmetologist? Is that due to her eyebrow comment?😂
Sabine, me has volado la cabeza, con muchas menos justificaciones pensaba lo mismo. Decir no lo se requiere mucha sobriedad, algo que no abunda. Durante tu charla me reí a carcajadas varias veces. Creo que te mereces algo mejor que el premio nobel. Tu aporte está a la altura de ese que nombras muy seguido en tus videos. Brillante Sabine Sabine, you've blown my mind, with far fewer justifications I thought the same. To say it does not require a lot of sobriety, something that does not abound. During your talk I laughed out loud several times. I think you deserve better than the Nobel Prize. Your contribution is at the height of the one you name very often in your videos. Brilliant Sabine
I find your Big Broccoli theory intriguing! Entertaining and educational content, as always.
Don’t be ridiculous, everyone knows it was a cauliflower
@@andrewpaulhart They are very closely related. And to be more precise, it was the big bang is like fractal Romanesco broccoli.
@@steffenbendel6031 I have the equations to prove it.
The Brassica Bang theories of the universe are "ascientific", any plant in that genus can be used to offer a vacuous account for the origin of the universe.
The Big Bang produced perfectly cooked broccoli? Amazing. I see exactly where I’m going wrong.
I'm so glad I found Sabine's channel. She's a real peach, and her blunt honesty is a breath of fresh air. I adore this channel 👍🏻
So good to hear you again Dr. Hossenfelder. I am currently sticking to my home made NO bang infinity2 theory of existence which hit me about age 3. But like you I will never be able to explain why some women pluck off their eyebrows and paint them back on. Nor why people like me and your husband have such a high resistance to doing the garden.🙂
I like that someone is actually saying we don’t know. From logic, If P, then Q; does not imply if Q, then P. Let P be oxygen plus hydrogen plus spark and Q be water. You can test this (as long as you don’t use extremes for ratio of oxygen and hydrogen or pressure or temperature) over and over and determine that P ==> Q. That is oxygen plus hydrogen plus a spark produces water. That does not mean if you have water is with produced by igniting a mixture of oxygen and hydrogen. Other possibilities exist, like the combustion of a hydrocarbon or the neutralization of an acid and a base. This is the difference between observational science and historical science. I can observe an event and come up with a law/theory that explains it accurately and can use that law/theory under the same conditions to “know” what will happen. Historical science can’t do that. Even if a set of original conditions and a process explains what we see now, in no way proves that the original condition or the process is correct. It is just an explanation of what might have happened. Another example that is simple to understand is if you find a stadium filled with material with layers starting with large boulders, then rocks, then stones, then gravel, then sand. You could develop a model that shows that a flood could have caused this exact layering. But I may know that I hired a trucking company to haul in loads of this material and dumped it in layers. So your flood explanation, while it may explain the result perfectly, is wrong. Flood implies layering, does not imply layering means flood. So my whole point is that anything relating to the past that was not observed can only be a possible explanation and not necessarily true and we need to accept that in science and not be dogmatic that one explanation is correct. One last point. While we look for simple explanations, the reality may not be simple.
I think Sabine is slighty wrong when she claims we can only observe the final state (the here and now), but cosmological observations also have us look into the past - the more distant an object from us, the earlier in time or the longer ago, so we have some means to view the universe through its intermediate states.
Milky Way is 100,000 ly. across, so it’s observed pretty much as it is now. For comparison, Earth is 4,500,000,000 y. old. Even Leo I (56th closest galaxy) is less than 900,000 ly. away. There is a lot of stuff that is close to “now”
I think that you could consider the "final state" to be how far back we can see. The stuff we can't figure out happened before then.
I think Sabine is using the broccoli initial state as a humorous example. Physicists can’t come up with equations consistent with a broccoli initial state that agree with observations far back in time using HST, JWST, and other astronomy resources. However physicists have come up with equations for the various non-Big Bang conjectures she mentions for the initial state that are consistent with those observations far back in time, so in the end it boils down to the same argument as the broccoli.
She is definitely wrong
0:50 Wait, can you elaborate further on this? It isn't strictly true to say that GR predicts the universe should expand. What GR predicts is that a static universe cannot be stable. It still doesn't explain why the expansion is happening in the first place. Also, isn't this whole simplicity thing very much like the "beauty" thing in the standard model? The SM has A LOT of free parameters that you need to input in the equations, so it's rather far from "simple". And in any case, it doesn't answer any of the fundamental questions like "what are electrons?" or "how does pair production actually happen?", or the best of them all "Why are there so damn many fundamental particles???"
Why did it take so long for me to find this? It is like KZhead does not want someone with a scientific background to be promoted if they are not buying into the social group think. Wish I had found this sooner.
Wow, Sabine is mindblowing. Her book is worth to be read.