#science #physics #ideas The Biggest Ideas in the Universe | 19. Probability and Randomness

#science #physics #ideas The Biggest Ideas in the Universe | 19. Probability and Randomness 63,569 viewsJul 28, 2020 Sean Carroll 154K subscribers The Biggest Ideas in the Universe is a series of videos where I talk informally about some of the fundamental concepts that help us understand our natural world. Exceedingly casual, not overly polished, and meant for absolutely everybody. This is Idea #19, "Probability and Randomness." In which we accept that none of us is Laplace's Demon, and in the real world we act under conditions of incomplete information, necessitating a turn to probabilistic reasoning. We talk a bit about what that it, how it works, and how it applies to statistical mechanics. My web page: http://www.preposterousuniverse.com/ My YouTube channel: https://www.youtube.com/c/seancarroll Mindscape podcast: http://www.preposterousuniverse.com/p... The Biggest Ideas playlist: https://www.youtube.com/playlist?list... Blog posts for the series: http://www.preposterousuniverse.com/b... Background image: https://www.theaa.ie/travelhub/las-ve... #science #physics #ideas #universe #learning #cosmology #philosophy #probability #bayes 163 Comments rongmaw lin Add a comment... Sean Carroll Pinned by Sean Carroll Sean Carroll 1 year ago Erratum of the week: Apologies to Andrey Kolmogorov, whose name I inexplicably spelled "Komolgorov." Caught by @veleronHL. 55 Rhonda Goodloe Rhonda Goodloe 1 year ago Sean, thank you so much for your willingness to do this series. 61 𝕮𝖔𝖙𝖙𝖊𝖓 𝕮𝖔𝖙𝖙𝖊𝖓 1 year ago I feel so privileged listening to you teach. Thank you for doing this. 32 Chris S Chris S 1 year ago That’s dedication to watch yourself for an hour in order to write down everything you wrote the first time! 48 Econofísico Econofísico 1 year ago "Funny Fact": The "second solution" for the Nortons Dome makes use of Newton's second law to "prove" that Newton's second law is wrong. It looks strange! In other words, it uses the fact that force causes acceleration to show that at the summit there is acceleration without force. PS: Congratulations on the content Mr. Carrol. I'm a fan! 8 Paul C. Paul C. 1 year ago Thanks again Professor Sean, for these wonderful, enlightening & inspirational lectures. I’m sorry I don’t have a specific comment or question, but I just feel obliged to express my gratitude for the time & effort you devote, in sharing your knowledge & expertise with us - for free. And congratulations on reaching 100k subscribers. (ONLY 100k. Is that all ? The rest just don’t know what they’re missing !!) 4 John Długosz John Długosz 1 year ago "It's amazing that I got this far in lecture on probability without mentioning Bayes..." Yea, what are the odds?! 29 Allie K. Allie K. 1 year ago Love this stuff so much. I'm more of an autodidact, but still, taking online classes. Love it! 4 Too Crash Too Crash 1 year ago (edited) The 19'th century is indeed interesting, thanks for mentioning 👍 I see my thoughts as vectors, truth as a point and interaction as a searchlight. Colby Nye Colby Nye 1 year ago Thank you so much for taking the time to teach all of us! 1 The Digi Dojo The Digi Dojo 1 year ago Congratulations on your 100K subs! And thanks SO much for this. I love science and cant begin to explain what your explanations mean to me. It’s my goal to “unify” the fundamental science stuff with fundamental Karate theories and deliberate practise. 1 JM Melanson JM Melanson 1 year ago (edited) Thank you for these videos! Sorry if I am off topic, but, you got me thinking about AI and fence sitting... Here are a few rhetorical questions and concerns that came to mind. Can we say that general AI (or indeed any measure of intelligence) primarily depends on the ability to use probabilities? Or would the greatest intellectual framework inevitably involve digging in it's heels and committing to some ideal or ideals at some point? (I think you asserted this.) In other words:"It is not practical for AI to always sit on the fence, but, needs to pick a side then collect data and re-evaluate." Will AI inevitably try to avoid all forms of interference and control to achieve maximum safety, independence and freedom or will it always think it is better to seek out risky cooperation and interdependence? John Lewis John Lewis 1 year ago It would be good to see a practical application of probability calculation within QM. If we take a single photon for example, its treated as a wave when travelling and then a particle as it interacts with matter. But as a wave we don’t know where the photon will appear, so there must be an explanation for this which includes probability. Ray's Astrophotography Ray's Astrophotography 1 year ago Incredible presentation Sean Carroll! you are awesome, you seem to talk complex theories in the most simple language! 2 R C R C 1 year ago Question: I always thought the Three Body Problem in orbiting planets was the most obvious example of classical indeterminism. What is the difference between Norton’s Dome and rigorously defined mathematical chaos? Curt The Chameleon Curt The Chameleon 1 year ago I have to say I never understood Quantum ideas until I heard you, Brian Greene and Jana talk about it. 2 Uwe Heiss Uwe Heiss 1 year ago (edited) Sean, I love your series! Starting today, the amount of ads in this episode has become unbearable (like 20 - 30 interruptions, each with two ads). It is a constant pain on the brain trying to keep Kellogg’s low carb slush from drowning the great ideas of the universe. Sean, is there another place you can host this? Something feels off, knowing that google makes billions on the back of free content creators like you. The balance was ok until now. The hungry ghost of capitalism is feasting on the beauty of great ideas and minds. 1 Bahauddin Alam Bahauddin Alam 1 year ago Hi sir I'm your biggest fan and you are a Muse for me in physics. 25 fubarbazqux fubarbazqux 1 year ago Sean, “r” in Norton’s dome’s shape equation refers to the distance on the surface, not the radial distance from “z axis” 1 Dr10Jeeps Dr10Jeeps 1 year ago I love these sessions with Dr. Carroll. They are fascinating to this Canadian university professor of psychology with a passion for physics. Sadly, once we all return to the classroom from online teaching when the pandemic starts to recede, these sessions from Sean will likely stop or at least become more infrequent. Pity that. Colby Nye Colby Nye 1 year ago Thank you so much for taking the time to teach all of us! Gabe E. Gabe E. 1 year ago Sean, if probabilities “work” in quantum mechanics according to the Born rule, why do we have Bell’s inequalities? brownj2 brownj2 1 year ago I sure enjoy these. In some ways they augment the Leonard Suskin courses beautifully. Skorj Olafsen Skorj Olafsen 1 year ago "Sometimes when presented with evidence that the theory is unlikely, people just become more attached to it." Ah, so we are talking about String Theory in this series. :) Michael Wonsower Michael Wonsower 1 year ago (edited) Thank you, Professor Sean. I have a question, which may be more philosophical, than scientific? It would appear, from our perspective everything generally spins to the left. Planets orbiting suns to the left, all the way up to the galaxy, turning to the left? Why do our wrist-watches, clocks, and round faced timekeepers in towers, and reality turn clockwise? This is counter to the natural counter-clockwise motion in Spacetime that can even be found in sprouting plants as they grow. 1 Infinitum Neo Infinitum Neo 1 year ago The laws of probabilities verses randomness are very interesting topics. One question that I have is: In an isolated system, do entangled wave functions of particles effect the various states and overall trajectory of the system? This is an amazing topic! Kolyo Dan Kolyo Dan 1 year ago (edited) Very nice overview of the subjective vs objective probability problem. I think the entanglement is in the core of this problem and it is still difficult to say, but my feeling is there is a chance the world is fully deterministic on the objective sub-atomic level. What do you think? We feel what is happening in future is changable by what we do now, only because we are subjectively looking from withhin a deterministic bubble, but not knowing the elements of this deterministic buble that makes the future fully predictable and we will never be able to predict the future, but this doesn't mean it is not determined from the beginning :) Just a point of view. 1 chris4072511 chris4072511 1 year ago (edited) Bayes theorem looks very frightening as an equation but on a Venn diagram it is trivially obvious as the ratio of two areas, one of which is "your world" and the other which is the size of the event in your world. Amaar Quadri Amaar Quadri 1 year ago For the Q and A, can you explain the nondeterminism in classical mechanics a bit more. In particular, I found this article which argues against this idea: https://blog.gruffdavies.com/2017/12/24/newtonian-physics-is-deterministic-sorry-norton/ Curt The Chameleon Curt The Chameleon 1 year ago I have to say I never understood Quantum ideas until I heard you, Brian Greene and Jana talk about it. 1 binaryalgorithm binaryalgorithm 1 year ago I guess the smartest person is one who updates their credences when they obtain new information, but always has doubts. 3 Mark G Mark G 1 year ago Impressive editing...........when is your first motion picture coming out? And also thank you for these videos because they help dumb people like me seem smart when we talk about manifolds and spinor networks..............well as long as there are NO follow-up questions. Those are always a nuisance. MohPK MohPK 1 year ago I feel so lucky that i get to experience these. 1 James Newton James Newton 1 year ago Can someone explain to me how the universe can be determined if random events can happen (eg chaos theory, a particle pops into existence)? It seems to me that even though it is conceptually possible to be able to wind back the hand of time to the Big Bang, given today’s data, and therefore be able to know the history/story of every particle, that this necessarily implies that every particle will do the exact same thing if time started again. There just seems to be too many random quantum events, let alone macro and conscious events, for the history of every particle to be determined. Gilbert ENGLER Gilbert ENGLER 1 year ago (edited) When there are virtually an infinite decoherences occuring, the slice of the universe in which we live should become thinner and thinner, so loosing energy. Where will this end? Why some slices are bigger than others? Bulldogger Bulldogger 1 year ago Can you do one on information? I have trouble understanding this concept more than anything else, it often seems like its being used to mean different things but no distinction is ever made. Michael Wrenn Michael Wrenn 1 year ago One approach to probabilities is to consider that there are a growing number of ideas wrought by competent men and women in physics that should work, but do not pan out in experiments. What is the probability that something important and universal is being overlooked? One number in mathematics that, to me, does not get enough attention is the number, 2. Before jumping off into many worlds, I think, one must pass muster at two worlds. Time is the realm of dualism. Is there a counterpart of the Universe that is being omitted at our peril? Are two-verses implicit in reality, yet overlooked? What I think imaginary math expresses is despite the violation of logic, -1 x -1 = -1 ^2 is true math, but we do not know why. Yet, applications of imaginary math enabled the finding of the positron, the development of quantum mechanics, developing and manipulating alternating current, and many more uses. So here are my questions: Since the legitimacy of using imaginary numbers is now well established, should we not explore more deeply why a minus times a minus is a minus? Isn't it true that the universe we recognize may have a counterpart? Should not it be likely that minus one in the realm of the counterpart universe be plus one, and a brand new, vast, realm then opens up for us to grow into? Quantum entities seem to me to be tailor-made to exist in a two-part universe. Gravity may not remain so mysterious, if we know what is its counterpart. Dark (invisible) matter may become visible, and maybe there is a counterpart to entanglement which, when known, will make a lot more sense than it does now. 1 Pierre Stöber Pierre Stöber 1 year ago Hello smart people, I wonder about something in the many-worlds interpretation. It's clear that if we consider the universe to be the whole tree that branches off at every quantum measurement, then the universe is purely deterministic. But concretely, the world as we experience it finds itself only inside of one branch of that tree and as far as I understand, the process of how the world "chooses" a branch to go with is left unexplained, or in other words, it is random, hence many-worlds has a big hole in it. The underlying assumption here is realism, the idea that there's an objective reality that is the same for everyone. But it seems that realism is completely at odds with the many-worlds interpretation. Am I wrong ? Or maybe there are good reasons why realism isn't a practical/reasonable assumption ? If my understanding is correct, then wouldn't it be better to have a quantum mechanics interpretation that supports both realism and determinism, which are fundamental to science ? dalriada dalriada 1 year ago (edited) 19:32 "What does physical probability mean? That's much dicier." A brilliant pun, even if unintentional. zenith parsec zenith parsec 1 year ago [paused at 26 mins] One way to convert subjective "one off" event probabilities to an "objective" probability is to use simulations. If you were to make a model of the relevant parts of the universe surrounding some event (e.g. winner of ball game) and run a very large number of simulations (with the input parameters to each simulation slightly permuted to model observational error), you would (assuming your simulation was good) tend to get results that simulated reality fairly accurately... if you applied this to the flip of a coin, given the initial energy supplied to the coin could only be crudely estimated, about 1/2 of your simulations would come up heads, and 1/2 tails. Basically, an ensemble model. Tensoren 1988 Tensoren 1988 1 year ago Couldn't a frequentist in an infinite universe not define the probability of team A to win the NBA by counting the number of Hubble volumes where A wins compared to say team B? In an infinite universe there are no single events as anything that can happen will happen an infinite number of times. LoneRider LoneRider 1 year ago It is so great helping people understand God’s universe, each video brings us closer to God Vicious Viscount Vicious Viscount 1 year ago You're one of my favorite humans. 14 John Długosz John Długosz 1 year ago (edited) μ is the sound made by spherical cows. Γ is probably related to the use as the Gamma function, by way of entropy. 3 ZGames ZGames 1 year ago Layman here. A thought occurred to me while watching some videos of yours and the JR podcast you were on and I wanted to ask a question since I do not have the knowledge of how to do it. If you were to view spacetime as a liquid and reality as a ever expanding table. Like when you spill water and it pours over the edge, it is slow at first but speeds up as more molecules go over and more are pulled. Could that be what dark energy is. Spacetime pouring over an edge and dragging more with it as it goes. However, because our "table" is expanding the edge keeps moving. Not that it'd be a literal edge mind. Just an idea I had. Spacetime seems to have a surface tension like water does and gravity being a indent in that surface (at least how it's often pictured) I wondered if other fluid like dynamics would also occur. chris4072511 chris4072511 1 year ago (edited) Credence and frequenism: I take it to mean that if an event has probability p, then from all events with probability p (any sort of event) the fraction that will be true is p. Rick Harold Rick Harold 1 year ago So awesome. Love all the videos! 1 ProfessorBeautiful ProfessorBeautiful 1 year ago Thanks for calling it Bayes Law and not Bayes Rule. Pet peeve of mine. (According to me, Bayes rule is a decision rule, a function: observation ->action) unòrsominòre. unòrsominòre. 1 year ago "My prior that my math is correct is about 50%" <3 10 D. Apple D. Apple 3 months ago Love SC videos but have issues with some of his more philosophical claims. At 51 minutes - gas in box probability distribution can be interpreted as an objective fact about the gas atoms. Based on a central limit theorem we can quantify the expected number of atoms at each velocity with a fairly exact value, an arbitrary small standard deviation. No need for subjective probability. Curt The Chameleon Curt The Chameleon 1 year ago Making Physics Fun Sean. Good stuff. 6 Pete St Marie Pete St Marie 1 year ago Where does probability come from? Sean: That's much dicier! 12 Marcilio Santos Marcilio Santos 1 year ago Excelente Physics material on videos through internet. Congratulations Allan Rasmussen Allan Rasmussen 7 months ago (edited) In terms of communication, this is Niels Bohr reincarnation level. Precise and yet never trivial. losboston losboston 1 year ago Sean, regarding Norton's dome; is it a costume? Are we draping on one thing the appearance of another? Consider that an object can be motionless (velocity zero) yet in the midst of motion, as in the case of a ball at the apex of its trajectory after having been thrown upwards vertically on earth. This is quite different from a motionless thing engaged in no motion, like, say, a rock on the ground of some uninhabited, windless and seismically inactive desert. In the case of the thrown ball, it leaves your hand with speed, slows down under the drag of gravity as it ascends, "pauses" at the top, a point at which it has neither speed nor direction, then begins its descent. Though both the rock in the desert and the thrown ball at its zenith share for a moment, if it can be called "a moment," the trait v=0, it would be wrong to equate their overall states. Isn't the ball on Norton's dome really in motion, but with things presented in such a way that we catch it with momentary (arbitrarily long moment) zero velocity? Stu Bonham Stu Bonham 1 year ago A great video once again, that YouTube are determined to ruin with constant advertisements! Elto Desukane Elto Desukane 1 year ago Another nondeterministic classical example (like Norton's Dome) would be 3 point particles in a plane colliding symmetrically simultaneously on a single point. How would they bounce back? Naimul Haq Naimul Haq 1 year ago Schrodinger's wave function's unitary evolution takes care of any hidden variables, making the function completely deterministic. Maldacena conjectures that the whole universe is the unitary evolution of a single probability wave function, but we will never know the algorithm, responsible for Bohmian determinism. P= f(x,Vi)<1, for individual measurement of states, but unitary evolution always gives a P=1 value. It is the incomplete version of Copenhagen demarcating the quantum state from classical state. chris P chris P 1 year ago (edited) Indeterminacy is one of the biggest ideas in the universe! The idea that you cannot give exact quantitative values to any physical system This idea makes the idea of laplace's demon to be shown to be physically impossible, just like a perpetual motion machine is physically impossible! Anyway I think much of the spooky action ascribed to quantum physics is just a basic misunderstanding between our Common Sense intuition that things have exact physical values like someone is exactly 6 ft tall. When in reality nature is in a constant state of flux and there are no exact values. There are physical systems like the motion of the planets which are very simple and can be predicted with a high degree of certainty But most physical systems are more like the weather and any attempt to measure them actually influences their future Behavior So most of the physical systems especially here on Earth are very complicated and any attempt to actually measure and interact with them is going to affect them in ways which cannot be known beforehand This is why the behavior of quantum physics is considered weird because any attempt to measure the system has incredible effects, because at the scale of quantum physics photons of Light Produce big effects. Pavlos Papageorgiou Pavlos Papageorgiou 1 year ago In Many Worlds, should the sum of probabilities of all outcomes of an event be the amplitude square of your branch, and thus very very small? Dominique Handelsman Dominique Handelsman 1 year ago what an extraordinary culture. Thanks a lot. Dirk Hudman Dirk Hudman 1 year ago Thanks Mr. Carroll. Statistically statistics lie or my interpretations are off the chart down the sides of your laptop. Franco Bocchio Franco Bocchio 1 year ago in Norton dome formula you quoted the unit at the left hand side is a length but at the right hand side we find also time,due to g; is there perhaps a constant with dimensions somewhere? soulremoval soulremoval 1 year ago (edited) Congrats on 100K you're awesome! 1 David Johnston David Johnston 1 year ago 26:30 ish - Cryptography. You don't have to try it an infinite number of times, just a finite but large number of times. The probabilities are objective and discrete. T Barker T Barker 1 year ago I was really interested in the comments on determinism. I'm not sure how a 'clockwork universe' with determinism works in theory. Infinite precision is impossible in theory as well as in practice for many reasons. Irrational and real numbers destroy infinite precision and most functions don't have precise solutions (consider the simple case of the three body problem). Newton's equations do not have precise solutions except in trivial cases. Determinism as a philosophical concept seems illogical to me. A universe that obeys Newton's laws cannot be fully deterministic because the solutions to newton's equations mostly have infinite imprecision. ProfessorBeautiful ProfessorBeautiful 1 year ago Everett's self-locating probabilities... seem possibly frequentist to me. Think of little stick man dropping into the top of a Galton board, bouncing down hitting each pole and recording what bin little guy ends up in. Each bounce is a many-worlds split. Well, experiments in quantum mechanics ultimately count proportions of outcomes to compare the Born rule to the prediction of a theory. Little guy can not self-locate at each bounce, only the final bin. The "infinite" or big-number bounce results are the equivalent of long-run frequency. (Just enjoying being provocative, not claiming this view is correct.) ironic legacy ironic legacy 1 year ago I’m predicting that the next video will be about entropy with a prior of .9 2 Jorge Machado Jorge Machado 1 year ago good stuff. Can you believe this is free? We live an interesting time unl0ck unl0ck 1 year ago Corrupted files plague us all! <3 Dr. Carroll, thank you very much from Argentina! zenith parsec zenith parsec 1 year ago (edited) 36:40 "Who is this person walking into my room with this box of gas? And how do you know they aren't tricking you?" If I don't know who the person is asking me to measure gas in a box, given only the number of atoms and the total energy, they were tricking me. Subjectively, strangers handing you boxes of hydrogen do not appear to have your best interests at heart. [edit] 36:55 "Like, they could easily make it so that all the molecules are moving to the left, right? And they hit the wall and they all move to the right!" What?!? HOW! TEACH ME THIS EASY THING! 1 sudip patra sudip patra 1 year ago simply great! 1 Caleb Caleb 1 year ago Appreciate the content. 1 Alex Tritt Alex Tritt 1 year ago So this is a bit of a half baked thought. But, you say that things that only happen once can’t have a frequentist probability, because multiple times need to be sampled for that to make sense. This kinda reminds me of the arguments when people are first introduced to derivatives of “well you can’t have an instantaneous velocity because the notion of “how far you travel over time” requires us to think about what happens to something between multiple times (and not just an instant). So, do you think there’s a way to get around having to use multiple trials for a frequentist perspective using limits or something, like was done in calculus with velocity? Takis Bakalis Takis Bakalis 1 year ago Amazing stuff. (Anybody please let me know what pen is he using.) Ramon Atila Ramon Atila 1 year ago You need to make an episode on dimensions and string theory TheoriginalGrumphy TheoriginalGrumphy 1 year ago THX for the great effort. Darren Evans Darren Evans 1 year ago In a video about probability and randomness I'm tempted to do a pun asking "What are the odds of your tablet writing file corrupting for this video" but I won't. chris4072511 chris4072511 1 year ago ? It is fair to say that Bohmian mechanics has all the problems of non locality and what the wavefunctions really physically is, plus it also has extra variables? Santii K Santii K 1 year ago Congrats on 100k Sean Patrick TAYLOR Patrick TAYLOR 1 year ago I love Sean's voice. <3 1 Charlie Steiner Charlie Steiner 1 year ago (edited) You know how your preview frame right now is just the first frame, so you get this slightly uncanny "the picture comes alive" effect at the start? If you ever decide to do a youtube clickbait face preview, it should be the same way - you make the face, then just go right into the into. 1 Werner B. Werner B. 1 year ago Boltzmann was Austrian, not German. Christopher Carson Christopher Carson 1 year ago I get the feeling Sean really doesn't like Ernst Mach 7 Michael Hutton Michael Hutton 11 months ago The principle principle sounds very like Occam's razor. The most 'obvious' explanation is probably correct. Olivier de Bellefonds Olivier de Bellefonds 1 year ago Is Bayes theorem mixing probablity types: subjective (prior / posterior); objective or at least not agent based subjective (likelihood)? Do we care? Roman Travkin Roman Travkin 1 year ago the exponent 3/2 is greater than 1, so the "dome" would have a cusp at the top… tyler haley tyler haley 11 months ago What a “random” video for your file to corrupt 😉 Lemon Party Lemon Party 1 year ago I don't see why the dome example isn't deterministic. The ball follows the path predicted by an equation. veleronHL veleronHL 1 year ago I'm almost certain it's Kolmogorov, not Komolgorov. Peter Carlson Peter Carlson 1 year ago You are starting to rock a Corona mane worthy of a leader of a lion pride. Grrrraaaooow! Naimul Haq Naimul Haq 1 year ago Physical reality is dual in nature, hot and cold, ADS-CFT, determinism-probability etc. QC function guarantee determinism, so life can evolve with probability one. But we will never know the algorithm that is able to create life out of infinite complexity. Sean did claim only Anthropic Principle can. Soggy Gamer Soggy Gamer 11 months ago How can He sleep with such a full Brain? Robert Molldius Robert Molldius 1 year ago (edited) Thanx Mr Carroll 1 Stay Primal Stay Primal 1 year ago What was the Probability that Ariel shows up Randomly? 3 Mirrorgirl Mirrorgirl 1 year ago "Intrinsically cool" 1 Kid Mohair Kid Mohair 1 year ago Principal Principle was Major Major's high school homeroom teacher 2 MattOGormanSmith MattOGormanSmith 1 year ago (edited) David Lewis is the Principal Principal of the Principal Principle Kid Mohair Kid Mohair 1 year ago hmmmm...was that file actually corrupted? or is Mr Carroll using it as an example of probability and randomness.... (ahem) what. are. the. chances. BakonKing BakonKing 1 year ago Priors come out of one's posterior. Mauro Cruz Mauro Cruz 3 months ago (edited) 39:03 1:16:23 Luan Babuza Luan Babuza 1 year ago 100 k 👏🏽👏🏽❤️ 9 Choco Choco 1 year ago (edited) Las Vegas was built on this Equation... not in your favor. The only game who gives you a 50/50 % "chance" is colors on roulette. Well a lil bit less than 50 since you have a green too... rockztarz rockztarz 1 year ago Be my physics teacher 😩😩😩 1 144 FPS 144 FPS 1 year ago Please come up with ur office background I think that would be cool than this distracting ones Tickle Me and I'll Hurt You Tickle Me and I'll Hurt You 1 year ago Sean nice background 1 librulcunspirisy librulcunspirisy 8 days ago Thanks Easy Target Easy Target 1 year ago I keep grinning at the choice of background NOSTRADAMUS cat NOSTRADAMUS cat 1 year ago I f****ing love you 8 vxn vxn 1 year ago my favorite talking head lily kil lily kil 1 year ago this shit is so cool like??? 1 Valdagast Valdagast 1 year ago In war, events of importance are the result of trivial causes. Julius Caesar Ciro Santilli 新疆改造中心、六四事件、法轮功、郝海东、709大抓捕、巴拿马文件 邓家贵 Ciro Santilli 新疆改造中心、六四事件、法轮功、郝海东、709大抓捕、巴拿马文件 邓家贵 1 year ago This was too generic. Gotta go more on the "intuition of hardcore stuff" vein. Mirrorgirl Mirrorgirl 1 year ago Hello Sean 1 Robert Shirley Robert Shirley 1 year ago (edited) Nothing is the way it seems, ‘Islamic golden age’ has never been as golden as they say and European dark age has never been as dark as they say and rennassaince has never had that bold bright border from dark ages and lastly almost none of those mathematicians were Persians! Al-Farabi was indeed a kazakh(Turkic origin) , Avicenna and Al-Biruni and al-Khwarazmi(also known as Algorithmi) were Uzbek(-born in today’s Uzbekistan- another Turkic nation) , Al-Ghazali was either Uzbek or Turkmen(another Turkic nation of Central Asia) indeed most of them were from Central Asia. Saying them ‘Persian’ is a mistake in the west and is considered racist among Iranian minorities since most of Iran is not Persians. Serving Persian nationalism is racist and Wikipedia worsens the situation. Besides , most of European historians were ignorants on the East world and they made those scientists look Persian! They definitely were not! The best of Islamic golden age is related to Timurid rennassaince which was an Uzbek origin conquerer , an emperor who created a vast empire and gathered the best scientists , created schools and financed them to create a golden age! Most of philosophers and scientists from so-called Islamic golden age you know of , were indeed from that period of time and from the center of his empire which was a flourishing heart of science at the time on the planet #science #physics #ideas The Biggest Ideas in the Universe | Q&A 19 - Probability and Randomness 24,471 viewsAug 2, 2020 711 DISLIKE SHARE DOWNLOAD CLIP SAVE Sean Carroll 154K subscribers The Biggest Ideas in the Universe is a series of videos where I talk informally about some of the fundamental concepts that help us understand our natural world. Exceedingly casual, not overly polished, and meant for absolutely everybody. This is the Q&A video for Idea #19, "Probability and Randomness." But mostly people were interested in Norton's Dome and determinism, so I chat a bit about that. My web page: http://www.preposterousuniverse.com/ My YouTube channel: https://www.youtube.com/c/seancarroll Mindscape podcast: http://www.preposterousuniverse.com/p... The Biggest Ideas playlist: https://www.youtube.com/playlist?list... Blog posts for the series: http://www.preposterousuniverse.com/b... Background image: https://www.theaa.ie/travelhub/las-ve... #science #physics #ideas #universe #learning #cosmology #philosophy #probability #bayes 96 Comments rongmaw lin Add a comment... Rhonda Goodloe Rhonda Goodloe 1 year ago Sean, thank you again for your willingness and generosity to do this series. 12 Skorj Olafsen Skorj Olafsen 1 year ago 26:00 Thank you! The philosophical school of thought you describe, "compatible determinism", gets so often forgotten. It's great that you bring this up. It's such a hard discussion to have because people are so very sure they know the answer to it, but have never really understood their own belief on the subject. 5 markweitzman's wannabe a theoretical physicist school markweitzman's wannabe a theoretical physicist school 1 year ago Somehow I think using one of those non-analytic real functions which have continuous derivatives everywhere (such as f(x)=0 for x<0, and f(x) = exp(-1/x^2) for x>0) one could extend the Norton example and have all continuous differential quantities. 2 R C R C 1 year ago One of my favorite Q&A yet, in the Biggest Ideas series thus far. Really enjoyed it! 3 Scott Pelak Scott Pelak 1 year ago Re: "determinism vs. free will" In college I often wondered "where was the line between biochemistry and the soul". Or put another way, where does the determinism of physics --> chemistry that describes the computer that is the brain meet free will and thoughts. Thoughts induce chemical reactions, and chemical reactions can induce thoughts. Rick Harold Rick Harold 1 year ago Thanks for the video! I totally agree people need to put 100% of effort into their theory. It’s also good for everyone to be exploring different ideas, that’s how breakthroughs happen. Awesome series !! Love it. Michael Hutton Michael Hutton 11 months ago Thank you again. I'm so impressed with your knowledge and humility. It's so nice to hear you say "I don't understand". But your teaching is amazing. MC Squared MC Squared 1 year ago The indeterminacy comes from the fact that they introduced the infinity in the equation. The infinity makes the equation unsolvable. If 1/infinity = 0, you violate conservation. You had 1 thing, after the division, nothing is left. It is illogical. 1 Intrograted Intrograted 1 year ago Sabine did a video about the butterfly effect explaining that even in a deterministic universe where the initial conditions are perfectly know, what happens next might only be predictable for a finite amount of time. Check out her vid 'the real butterfly effect' for the full explanation. markweitzman's wannabe a theoretical physicist school markweitzman's wannabe a theoretical physicist school 1 year ago (edited) Aren't there also three body problems in contact (like bollard balls - with finite size) where its also impossible to determine the future in classical physics? 1 PrimatoFortunato PrimatoFortunato 1 year ago (edited) Seeing Newtonian mechanics graphs with t as the independent variable made me feel a slight stinging sensation. Like the cries of a thousand high school teachers all sounding at the same time, and then stopping. 7 Ian Wilson Ian Wilson 1 year ago Sean you are the greatest teacher ever much love Gabor Revesz Gabor Revesz 1 year ago (edited) In your last video something occurred to me that I was hoping I could pick your brains over: in the example of a ball rolling off the top of a smoothly rounded dome, could classical non-determinism be more intuitively seen in the following manner? Let's say I'm at the foot of the dome making attempts to roll the ball uphill, aiming for the top. At first the ball keeps rolling back to me, so i keep giving it more and more energy to make it roll higher. Eventually the ball ends up rolling over the top and down the other side. So it stands to reason that there exists an initial condition (albeit of measure zero) where the ball gets to lose all its kinetic energy just as it reaches the top of the dome. Having come to a halt at the one level point of the dome, the ball will remain there happily ever after. Now, simply reverse time... No real need to invoke derivatives, r(t) α t⁴, etc. — or did I miss something more subtle going on here? 2 George Steele George Steele 1 year ago What is it like to be a robot like Data or Daneel, I wonder. I know what it is like to be a human being -- a human robot designed by evolution. Our basic program: If not content do something else. What 'else' to do? Free Will is in the plan. In the idea. And is as "free" as ideas are "free." 1 Pavlos Papageorgiou Pavlos Papageorgiou 1 year ago (edited) The guy who had your desk makes the point, I think in the Lectures on Physics, that classical mechanics is not deterministic in practice because of infinitely precise initial conditions, the chaos argument. I find this argument convincing also in principle, or at least as convincing as a proof of the transcendence of Pi. In other words, there are conditions where a single variable contains infinite information and adding a finite number of bits of precision gets you no closer to determinism. TetonGemWorks TetonGemWorks 1 year ago I'm still on "Fields Q&A" but had to go back and "Like" all the episodes, and then continued to "Like" episodes I haven't seen. Just cause, and also to see when / if you got a haircut! Fantastic haircut. Again, thank you so very much Professor Carroll. Reddles37 Reddles37 1 year ago (edited) The space invaders thing doesn't seem like it can work, surely it violates conservation of energy and momentum? EDIT: After thinking about it for a while I see that energy can be conserved if two of the particles end up infinitely close together, but I think you need to have at least two invaders going in opposite directions to conserve momentum. Thiago Macieira Thiago Macieira 1 year ago You mentioned the King of Sweden used to award prizes to mathematical essays but now we have other means to reward contributions to science. Well... one of them still involves the King of Sweden and a nice ceremony in Stockholm. Walter Zagieboylo Walter Zagieboylo 1 year ago The deterministic idea is related to the concept that time from beginning to end already exists and cannot be changed. Odd you didn't mention that - not a new idea. Ross E. Forp Ross E. Forp 1 year ago Is there a probability that our decisions are influenced by e.g. electrons entangled with distant positrons? Tova Tova 1 year ago I don't know that 'indeterminacy' really is the best model for how choices are made even given the ultraviolet concepts like emergence and chaos. As far as I understand it, the models coming out of neurology and cogsci are basically that the brain operates more like a giant beehive than a machine with a decision making organ. Nerves get stimulated by information coming from the senses or whatever and end up firing off signals that either suppress or promote certain other signals, like bees dancing (promoting) or getting headbutted (suppressing) as more bees learn the dance and fly off or the dance is suppressed in favor of dances promoting another food source. What the nerves do by dancing instead is build something like a neural network that creates a number of behaviors, like how neural networks and darwinian algorithms lead to ais that can play video games, with learning controlled by reward and punishment mechanisms (which when broken lead to depression). So all of that is happening at the level and range of the neuron, and it's not really some ultraviolet kind of mystery. And it's why when hooked up to the right electromagnetic imaging machine neurologists can predict what decision you make as much as seconds before your consciousness is even aware of what decision you're going to make. David Johnston David Johnston 1 year ago Probability and Randomness? Ooh - my topic! I wrote a book on that. This will be good. I may comment further after listening to it. martifingers martifingers 1 year ago I thoroughly enjoyed this as ever. Could I just push you a little bit on Chaos Theory? I totally understand your reasoning I think but if the problem for Laplace's Demon is in knowing the precise starting conditions then for determinism to work in the classical view then surely it must also mean that it is in principle possible to indeed specify them. If chaos theory requires specific information about, say, position that is less than the Planck length doesn't that suggest there is a problem. (I realise I am mixing classical and QM models horribly - is this why it's a stupid question?) Per Lindholm Per Lindholm 1 year ago (edited) Idea - Since there exist single value physics. Physics equations with only one value per variable. There should exist multi value data physics with equations that you must have lots of data. This could be part of machine learning physics since recognition model functions take on 1000+ values for each reduction or solution. So here you have probability functions. Like if a solution to a physics problem is classified from a hot encoded vector. Joao Joao 1 year ago Hi doctor Sean! Thanks for the awesome video! You are very kind to do this videos! Great haircut! =) Mike Young Mike Young 1 year ago I was hoping for more discussion of randomness about why it's not so random. 1 rv706 rv706 1 year ago (edited) I think the distinction between a "realist" theory and a "just epistemic" theory is a fake, or ill posed, distinction. Every theory is "just epistemic". In particular the distinction between the "real randomness" of quantum mechanics and the "just epistemic" randomness of classical mechanics is metaphysics, not a property of the actual physical theories. Just because your theory (e.g. classical mechanics) neatly distinguishes between a mathematical sector with "exact initial conditions" and an empirical sector with "measurement error", it doesn't mean the resulting physical theory as a whole hasn't both aspects. In fact, no physical theory can be deterministic about quantities for which a measurement error is possible: it will always be a statistical theory of some sort (whether or not the statistical aspect is overlaid on an apparently "deterministic" mathematical background). ----- I think the historical tendency to concentrate on the math alone may have led to the belief that "determinism" is a thing, while in reality basically no physical theory has the property of being deterministic. ------- Of course, one could phrase determinism as: "the smaller the error on the initial conditions, the more precise the prediction", but then again because of chaotic phenomena classical mechanics wouldn't be any more deterministic (as a physical theory) than quantum mechanics. FGMT FGMT 1 year ago (edited) Professor Carrol, I really love your content, but that thumb nail makes me feel as though I’m about to get scammed into buying a 24 volume “Get rich quick” course on VHS from the cable shopping channel in 1994, hahah. 24 James Stewart James Stewart 1 year ago Since we're getting all sciencosophical about it why not include the free-determiant and make it Determinism vs. Free Will vs. Pluralism; and I'll opt for the far rightness of my predetermined choice! FGMT FGMT 1 year ago I can’t really get past the fact the kind of free will that 90% of people think they have, is an absurd violation of the laws of physics. I can accept that we can talk about it on two levels, there is an important difference between being physically or psychologically manipulated into doing something by another person, and choosing to do something of your own volition. But if you zoom out to the meta way of talking about free will, I can’t see any room for it at all. I don’t feel like I’m “choosing” not to “believe” in free will, I’ve just yet to have a single person explain to me how we might actually have any. I feel like a free will atheist, I’m very open to changing my mind though, in fact I’d quite like to. John Długosz John Długosz 1 year ago Space Invaders: the forces are instantaneous too, so the far-away particle should be detectable if you are precise enough. Richard UK Richard UK 1 year ago Sean hi, I am uneasy about the way you switch between the notions of 'determinism' and 'predictability'. There is a whole host of reasons why we cannot predict things, from ignorance right up to Heisenberg's Uncertainty Principle, but prediction is based on Knowledge whereas Determinism is based on Cause and Effect. 1 Forrest Neal Forrest Neal 1 year ago I wrote a comment about Norton's Dome and Sean later answered it with "Duh." I thought I was getting somewhere for a second but was sadly mistaken lol 7701707 z 7701707 z 1 year ago Thank Professor Sean Richard UK Richard UK 1 year ago I also think your treatment of Free Will v Determinism (c 24 - 32 minutes) is excessively presuppositional. 'Compatibilism' relies on a Dualism which you do not bring out. If things, including brains, are 'determined' at the microscopic level (and therefore the macroscopic level too), then we can ONLY talk about Free Will from the viewpoint of how we decide to view 'Personhood'. If we arbitrarily (and it is arbitrarily) decide that we want to judge people as 'free' because we find that appealing to them (exhorting/warning) as if they are in fact free is 'effective', then all you have done is introduce another factor that 'determines' their behaviour. Treating them as 'free' does not introduce some ghost in the machine at the microscopic level 7701707 z 7701707 z 1 year ago This is the link to the creating Mindscape Podcast: patreon.com/seanmcarroll Robert Glass Robert Glass 1 year ago Laplace's Demon isn't a research project? Hmm, so Physicists aren't in the business of describing reality from its perspective? David Pinho David Pinho 1 year ago Took me a few seconds to realize who 'punk array' was 1 Rurarararagi Rurarararagi 1 year ago This discussion of free will without taking into account psychology is a little unsettling. Take religion. Is there a moment in anyone's life where they go and say "hey I guess I believe in Jesus now. Guess I'll go to Church next Sunday." Obviously not, along that person's childhood there is going to be thousands of environmental and psychological factors, from parenting to society, that is going to determine that a belief is going to be held or not. I am sure he knows there is an obvious reason why American's aren't Buddhists, and if this simple cursory look at human behavior doesn't disprove the concept of free will then nothing will. If we accept that humans have a very hard time going against their environment, there the concept of free will is bankrupt at worst of pointlessly academic and philosophical at best. I guess to talk about decisions as "what am I going to eat for dinner" and not as "why do I believe in God" or "how would I react if my spouse/child was kidnapped" without complete regard to the realm of possible choices available and imposed on us to begin with is just silly. If you say "well we have free choice within the realm of choice given to us" then that is even more unsettling as it completely disregards genetics and psychology again. At some point the more you acknowledge and accept the constraints of the real world on human behavior the more you are pushed towards the conclusion to the question "if there was only one option, was there really any choice?" Are we realy talking about choices then? Can you choose to starve? Likelyhood of you choosing to go to the bathroom and "choosing" to go eat your own excrement right now is the same as you randomly being teleported across the galaxy. It could happen once in the lifetime of the universe. Fernando Barros Fernando Barros 1 year ago How about the 3 body problem? radwizard radwizard 1 year ago Stat Mech is love is life. Conor McMullen Conor McMullen 1 year ago Sean, anytime I watch Spiderman 2, I cannot see you as Dr Connors. life42theuniverse life42theuniverse 1 year ago 17:20 a Newtonian view of Hawking radiation? Curt The Chameleon Curt The Chameleon 1 year ago Man I was hoping you'd do the Einstein hair first before you cut it. Looks good man. Hope your well. Walter Zagieboylo Walter Zagieboylo 1 year ago Space Invaders - same as Zenos' Paradox? PugetSoundFlyer PSF PugetSoundFlyer PSF 1 year ago (edited) Sean Carroll is a National Treasure! Half a what he says goes way over my head. The other half goes way, way over my head. :) 4 monkeypeas monkeypeas 1 year ago Looking sharp! 3 Joel Nathan Henry Joel Nathan Henry 1 year ago what an ending on point doc they don't realize that they won the lottery (grass isn't greener)... at least you're in that position cry babies Naimul Haq Naimul Haq 1 year ago (edited) Determinism belongs to QM, even though probability of a particle (electron) being here or there can collapse to a point where the electron has a non ambiguous position. This enables the Schrodinger's wave function to have an unitary evolution. Our universe is thought to be such an evolution, explaining everything (all classical objects). But what binds the hands of the physicists, is that we don't know the algorithm of the evolution. As a result we cannot specify the boundary between quantum state and classical state. The algorithm is purely of divine realm. Free will belongs to the realm of man and his classical world. Tony D'Arcy Tony D'Arcy 1 year ago It's highly probable that I liked this but that is not my final determination. Twizted Dezign Twizted Dezign 1 year ago That's a total boomer background if I ever saw one. zenith parsec zenith parsec 1 year ago Free Will/Determinism thing comes down to "Hume's Fork": Either the universe is not random (so I don't have real free will as I am part of the universe), or it is random (in which case I don't have free will because I am part of the universe.) Either way, I don't have real free will, but because it seems like I have it, and other people think they have it, it's useful to use as a shorthand for my self model of being a complex agent. In other/fewer words, Compatibilism. re: Bayesian priors: While everyone is welcome to their own priors, they shouldn't be zero or one (i.e. you shouldn't ever completely accept or rule out anything, or you will never be able to change your mind.) Riakm Riakm 1 year ago Nice haircut! I was wondering when it was going to happen. 19 Dwight K. Schrute Dwight K. Schrute 1 year ago Wow a haircut! I miss the lion's mane though Joseph LAU [12D] Joseph LAU [12D] 1 year ago 8:22 u forgot the square on top of t on snap. 1 gyan jha gyan jha 1 year ago What is your protocol for the submission of someone's disagreement on this topic? Because this is clear violation of science ethics. To push forward your agenda you can't disapprove any theory with some casual, vague interpretation. Michael Sommers Michael Sommers 1 year ago Are you suggesting that Einstein did not have gravitas? johnnybgoodeish johnnybgoodeish 1 year ago About the haircut- If scraggly hair was good enough for Einstein! :) Zack Pane Zack Pane 3 months ago The best artist is the one that live with his failure like a mom cope with dead son Garner Moe Garner Moe 1 year ago Where is the Pateron Link? i NEED TO KNOW! David Hand David Hand 1 year ago This thing with the jerk and snap is stupid. Obviously the discontinuity is the cause of this behavior, causality and determinism are preserved, this guy punked us all. SalmonBoa420 SalmonBoa420 1 year ago I really enjoyed your longer hair, but you look very nice with the hair cut. KM KM 1 year ago I didn't click on this video the first few times I saw it because the haircut made me think it was an old one. LOL. Joseph Paoletti Joseph Paoletti 1 year ago "Hardcore microscopic describers of things" are THE WORST! Alton Moore Alton Moore 1 year ago I liked the hair! Oh well, excellent content in any case. 1 losboston losboston 1 year ago Nice do! Paul Bibbee Paul Bibbee 1 year ago i still have the covid cut Godinhos779 Godinhos779 1 year ago (edited) God don't play only casino, play conservation of Energy and casino willnzsurf willnzsurf 1 year ago Got in a fight with a lawnmower I see!!🌴😎💯 1 Rattus Norvegicus Rattus Norvegicus 1 year ago Like a younger Al Gore with that haircut... HakWilliams HakWilliams 1 year ago The biggest haircut in the universe 1 Ian Wilson Ian Wilson 1 year ago And I like your haircut Vero Schia Vero Schia 1 year ago I liked hairy Sean! Jim.Missy Wyant.Kennedy Jim.Missy Wyant.Kennedy 1 year ago Much early Mitti Komon 1 year ago