For the triumphant final video in the Biggest Ideas series, we look at a big idea indeed: Science. What is science, and why is it so great? And I also take the opportunity to dip a toe into the current state of fundamental physics — are predictions that unobservable universes exist really science? What if we never discover another particle? Is it worth building giant expensive experiments? Tune in to find out.
The Biggest Ideas in the Universe | 24. Science
Thanks to everyone who has watched along the way. It’s been quite a ride.
Please continue your lectures!!!!
😎😇
Thank you so much for sharing your time and knowledge in these videos! I have enjoyed them immensely.
Science is a big idea. And, along with other ideas, big and small, it evolved. The notions of Galileo would not have occurred to earlier thinkers. Those of Einstein, for similar reason, could not have entered the mind of Copernicus—or did they? As I’m sure you know, Matt Ridley has addressed this. He is probably not the only one but my reading time is limited, for several reasons. And due to insurmountable constraints.
Waiting to receive two works by Donald Davidson. Truth is in both titles. Philosophy claims to pursue truth. I am waiting…thanks for making your site readable…
@Sean: Do you think this “dig deeply” strategy also involves rethinking assumptions underlying mathematical models for these theories, or rethinking which mathematical model to use in the first place (admittedly way too ambitious)? e.g. in GR, differential geometry is used – what’s been your personal experience in trying to use non-standard assumptions, etc.?
Thank you so much for this wonderful video series, Professor Carroll. It certainly bares re-watching. I appreciated both the clear presentation of difficult ideas and the inclusion of your own work/thinking.
With regard to doing science, I heard Richard Feynman say in his lectures that it wasn’t just about the obvious ability to make accurate predictions (epicycles were quite good at that). Rather, if a theory suggests an attitude that creates a new, productive approach, it is a valuable thing, even if it’s not quite “right.”
Best of success in the future to you and the cats.
All good. I am philosopher—much more than scientist. Lack the math and physics background. Am reminded of Feynman’s assessment of quantum mechanics ( or was that, physics?) He said, roughly, anyone who says they understand quantum——, probably does not understand quantum—–. Inasmuch as my knowledge does not encompass these concepts and their foundations, I cannot say much more than what was previously offered. I will, however, stand by my original remarks. Thanks for allowing me to comment.
Thanks very much for this excellent series Sean. So much to get through! I am still at number 10 but will get there.
Many thanks again for this series of talks. It was very inspiring to me, although I was not able to follow each and every detail. I think I will have to dive quite a lot deeper into mathematics to get a detailed understanding of all the theories and models you presented. You should have mentioned one aspect in your last video, though: science is fun!
Just so you know where this comment is coming from: I’m no scientist or mathematician but I love both and try to learn from pop science books and various You Tube channels.
I found The Biggest Ideas series particularly fascinating and entertaining because rather than putting the emphasis on simple analogies that a non-expert could digest more easily you gave us the explanations for grown-ups and I always felt that I was accompanied on the journey by a candid and good-humoured friend.
Many thanks Sean.
Hi! Love your “Ideas”! It was a great joy to learn from these informal lectures. I feel enthusiastic to start some more advanced course on e. g. QM.
And looking forward to seeing your new blog projects!
I just want to add my thank you for the time and effort you took, to put on this series. I have enjoyed every minute of them, and will be re-watching them for sure. I find I pick up on things i missed, or didn’t quite understand, the first time through by watching again. I’ve done the same with your courses you did for The Great Courses, and of course your books. I wish it could go on, but I can only imagine the time it took out of your life to do this. I just hope you realize how many people you have helped and added something to their lives through your effort.
Watching these videos has been a weekly treat during the past 24 weeks, especially for those of us staying home right now. Thanks for these Biggest Ideas, your books, and The Great Courses series. I hope you enjoyed the process as much as we did.
Seems to be a lot of response to your blog. I have not been able to navigate it well. Item: your narrative concerning complexity and the other notion seems counterintuitive to me. My own notion of the opposite of complexity is simplicity . Every yin has a yang. Not a contretemps. So, Professor Carrolll, how would you have it—now? Sure, I have announced my ignorance of those disciplines over which you have command. I have also stated my appreciation for your previous books about eternity and a big picture. These are large achievements for you. As they should be. So, what have we, in common? I’m not sure. Continued good luck.
Amendment:
After some reflection,( I still think, rather than ‘process’) I think Ridley was on the right track, but, perhaps, emergence is a better description than evolution?
Many thanks Professor Carroll. I’ve looked forward to Sunday and Tuesday nights for the next instalments. Thanks for pointing out some of the areas where the answers are unknown. Maybe 4000 people will be giving them some thought which wouldn’t have happened otherwise. You’ve given me encouragement to continue reading science books in my retirement – its vastly better than learning a foreign language, doing crosswords, Suduko etc.
Thank you for giving up your time and sharing your knowledge about the only thing we have left as compass for guiding us through fact and fiction. Your ability to communicate is beyond reproach.
Yes. Pretty much. I had thought about sharing something with you. From my youth. My family was from ‘Appalachia ‘. When my brother and I were young, we explored the hills behind our home in southern Ohio. There were piles of rock, sedimentary stone to be exact. We called this an Indian burial ground. And so it is. Modern paleontology says so. History requires attendance. Thanks again. Waking Up was not revelation to me. Yeah, I said I had read your work. Wonder who stole what from the site. We can never know.
PS: our parents scoffed at us then. It does not matter, now….
I keep wondering. Your blog page invites comments. All good. However, there appears to be no interaction—only: let us know something. We will get back to you, or not…I get that you are probably overwhelmed with inquiries.. So, why deal with any of them
at all? Accesibility is only a word, nowadays. Tell me, if it is not too much trouble,,what you think about my revelation on southern Ohio paleontology. Not important enough? It is all connected, Pretty sure.
I will support you and your work. As I have supported Dawkins; Dennett; Hitchens and others.
Good night, and, PSPD ( providence smiles on purpos and determination.)
I am starting to have a problem with the word “Universe.” The universe is so very big, and growing all the time (both much larger and much smaller) that a single word like universe cannot suffice to even begin to be applicable to the universe. Consider the word “atom” which when I was much younger was considered the smallest thing to be discussed. As science has grown and or understanding increased we now have particles, sub particles, muons, electrons, and more. A person can sort of grasp what any of them means and can find ways to relate them to other things. In space we have stars, planets, solar systems, galaxies, clusters, and all other kinds of descriptive words. Yet, the only word to describe everything is universe so I have to wonder if better words can be used In the universe humans on planet earth are on the very, very, small end of the spectrum, there is a universe much smaller than us, and the grander universe outside of planet earth so how can we continue to use just one word (universe) to describe it all? I think this is a topic worth consideration and discussion.
Bernie has a point. For everything impossibly vast, there seem to be as many things, sub microscopically small. Some philosophers have posited that there are no paradoxes, only ironies. Maybe this is true or maybe it is not. But, your preposterous universe certainly ‘feels like’ a paradox,hmmm? I don’t know, however, how might either prove or disprove it.
Could you express Many Worlds more humbly without the words? You could say there’s the wave function, it evolves according to the Schrödinger equation, and there’s a phenomenon called decoherence where long vectors containing macroscopic parts of the universe become orthogonal to one another. Globally the wave function is a sum of these vectors whose amplitudes are small, but from the point of view of structures inside each vector (or branch) the amplitude of that vector is 1 and all others are 0. At any time we’re in one of these vectors or branches and that’s the reality that we perceive. Are there people in the other branches? We don’t know. It’s a very strong implication but not testable, so metaphysics.
In fact I think you said all these things. It took me years of following the topic to realize that vectors of (gas, cat, environment) which become orthogonal is literally what happens except with 10^something quantum degrees of freedom as elements. The physics community should have no trouble grasping that, but they still seem to recoil at the many worlds. Is it the difficulty of expressing “from the point of view of structures inside one of the terms” in math? People could find it obvious to normalize amplitudes to 1 and 0, but others would say there’s no operator for that. In math you typically solve for x but maybe its unusual to ask from the point of view of x what does reality look like?
Or maybe its the consciousness that bothers them. Are all these other people in the other branches experiencing and feeling things? Should we count them as a multitude? I don’t know. For now the fact that a neural network in our heads experiences and feels things is a brute fact, and we can extrapolate that other people’s heads do the same and to a greater or lesser extent other creatures. With other terms of the wave function that intuition is a stretch. I understand we can freely choose basis vectors so one or another term, or the superposition appears dominant and that shouldn’t change what is real. If we’re agnostic about other worlds as we are about other consciousness, putting all the metaphysics to one side so to speak, will people object less?
Enjoyed these lectures! But for old fogies like me, I needed more time to process some of the abstract and mathy parts; I could have taken notes but that takes so much time; SO PLEASE MAKE THESE LECTURES INTO A BOOK! I think it would be a wonderful book! Then I could read it more slowly and really have time to better understand the concepts; what I didn’t understand I could research until I did; then, I could move to next page. Thanks for making this critical physics and science more understandable to the public!
Thank you for the 24 “biggest ideas in the universe” (+ QA). I really enjoyed them.
I’ll second the mention of you turning this series into a book. I’m another “old fogie” who needs time to digest it, and it would also allow us to repay you for the time you took to help all of us.
The book notion sounds doable. Not sure how it would be structured. Had tried to send thoughts on the emergence aspect mentioned in an earlier comment,but hit an unintended command and the whole thing evaporated. I’ll not try to reconstruct it here. Let’s try this, as an intuition pump:
If science becomes deeper and more complex, as humans get smarter, then it comes to us as a function of our ability to understand it. That might be a foundation or premise for the book, should you decide to write one.