The Biggest Ideas in the Universe | 5. Time

[@CoreyChambersLA]

Sean Carroll is among the greatest teachers of all time.

[@deez9588]

Its amazing how he introduces such difficult topics without blantly providing facts. He asks questions, makes predictions, gives room to interpret. And all that comes with enthusiasm and general curiosity about the topic. Thank you Sean!

[@fatihokhider]

most near death experiance candidates agree that there is no time when we die ...this mean that entropy will stop with time and both are related to the process of living not the cosmose...Allah knows best.

[@jeannieh3661]

Clearly... He has the "Spherical Cow" Award. 🐄 ↔🔵 = 😇 Much love Sean

[@FigmentHF]

Thank you for all your time and effort. I left school with no real education, but I find all this stuff fascinating. It always felt academically impenetrable to me, and while I do occasionally get a bit lost, I can actually follow along with most of it. You’re a great communicator and teacher, you can convey complex ideas without being too esoteric, and yet you don’t tend to over simplify difficult concepts. It feels very genuine, honest and accessible. Thanks again!

[@kostanchik10074]

Please, don’t stop these videos. This format is awesome!

[@James-fe7wd]

You sir have an incredible gift as an educator

[@cambriolage778]

Had to pause at 48:21 "the size of the macrostate is entropy" 𝖒𝖎𝖓𝖉 𝖇𝖑𝖔𝖜𝖓! A true moment of wow for me! Thank you, Sean for this work, it's a crucial part of my life!

[@wagfinpis]

I can not get enough of Sean's awesome consideration's. Great sense of humor, I love this guy every time I tune in! Only way to keep the appreciation short is to not even begin to mention it.

[@brankooffice]

For some reason, I find you the most eloquent professor while also being the most informative in the whole field of science popularization. I watch all of your videos and read all of your books for years now and you always seem to give the most understandable definitions for science readers while not making a lot of compromises and avoiding bad analogies. Sometimes I wonder if science popularization would benefit more if you gave talks to your colleagues about how to explain things and how to structure talks then just educating the public directly. But please don't stop :) These are great.

[@curtthechameleon]

I feel the same, Brian Greene and Neil Tyson are also favorites.

[@mariapawlowski8078]

I agree with Goat boy. Carroll communicates for the edification of his audience.

[@mariapawlowski8078]

@@curtthechameleon Greene and Tyson are two of my favorites also. Brilliant communicators, something I'd enjoy seeing in more scientists.

[@Corvaire]

Ditto ;O)-

[@mgenthbjpafa6413]

Sean has become, over the last decade, my most admired personality in terms of pedagogy inspiration on top of his explicit expertise on QM, we feel the joy of acquiring knew skills, confronting the edge of Human Knowledge. This may be a truism, but it must be acknowledged...Congrats, once more.

[@733eel]

I use to watch you back in the day i think it was the Universe or some series. You have always been able to talk to me as the years go on. I have no background in physics/maths but after a few years of watching your lectures and the many others like you it starts to make sense. Anyhows I guess all I wanted to say was thank you for being here all these years. Cheers

[@gkelly34]

Wish I had a physics teacher like this at school. Fascinating stuff

[@russxdxdxd4675]

he is a PHD wasting time in school is a waste of knowledge.. people like him deserve more which is university and science college

[@gkelly34]

chillz :D just someone qualified to teach the curriculum, and passionate about their subject. Think you missed the point

[@robbyjohnson6531]

@@gkelly34 Haha, great response

[@richardofoz2167]

Your description of psychological time at around 39-40 minutes is fascinating. Many years ago, when I was young and embarked on open-ended travel for the first time, I found that writing at intervals to my family at home was a weird experience for me. Reviewing my diary for news to send home, I found myself amazed that so much had happened in the previous week or fortnight. ("Was that just last week? It feels like 6 weeks ago!) Somehow, time had been "stretched" to a significant degree, and it struck me how differently time is experienced while traveling than while working. I attributed this to the fact that in a work routine, experiences are, to a high degree, predictable. Most people can anticipate reasonably well what they will be doing next Thursday morning or the Thursday morning after that. Consequently, little seems to happen. I frequently had the experience of talking to someone after a break of some weeks and finding I had no news to report to them. I think this is quite common. ("What's news?" "Oh, nothing.") When travelling, however, the reverse was true. Upon waking each morning, we generally had no idea where we would spend the night or who we might have met and what we might have done during the day. So looking back on my recent experiences, I would be amazed at how "full" life had been. For a long time I attributed this richer experience to travel itself, and work itself. But of course, it's due not to travelling or working as such, but to the lack or abundance of new memories, which is how we experience time. You have finally made clear to me - 50 years after the fact - what this experience of mine was all about.

[@stewarthayne8304]

I did a masters degree in physics 25 years ago and then became a lawyer. All forgotten until now. This is so amazing to watch. So well presented. Thank you!

[@sbassett5572]

I've spent 20 years in disaster zones.. 100% my mental clock speeds up in an emergency situation, but its not because I'm "falling" or my physical movement. Its the same if you're walking and spot a snake 1m ahead and you're stood still. You just "switch on". I'd say it's more a response to danger and an awareness we need full processing power than a physical reaction to a fall or similar though. We call it part of RPD, recognition primed decision making and it takes time in those extreme environments to develop (10 years typically) but then you can "think" "see" "analyse" etc everything much better and several times faster. Hope there's more done on this, its fascinating. Also there seems to have been an assumption that heart rate increases in these situations to get blood pumping and to extremities which would make sense but it appears (more weirdly) its actually to increase the likelihood our heart beats at the same moment as others, because this (weirdly) makes us much more cooperative, and this is the real key to surviving a sudden threat above how your muscles react.. Will my friends jump to my aid. It was taught to us for the job so I don't know enough but alot of interesting points in this area.

[@fekeetsa]

Its learning to not respond to the fight or flight response. Being this is an autonomic response, it takes many, many many (10years mol) times to condition your brain to Not automatically trigger FiOFl. Different factors can speed up or slow down the time it takes an individual to condition themselves to respond calmly and correctly in dangerous situations.

[@fekeetsa]

Btw... thank you for your service 🙏

[@williamhogancamp7716]

I love it that you need a haircut like the rest of us. I hadn't been much of a fan previously due to your atheistic entrancement, considered that close minded. After I subscribed to The Great Courses Plus and watched some of your courses, I realized you are a very good educator. That you are spending your time educating us for free on KZbin is magnanimous and very much appreciated. Just a reminder that first impressions are often wrong and one aspect of a person does not indicate all of that person. Thank you Dr. Carroll.

[@992turbos]

Do you still consider atheism to be close minded?

[@pierfrancescopeperoni]

Seeing these concepts finally popularized on KZbin always fills me of joy: I had the intuition about eternalism and the block universe at age 15 without knowing about Einstein's theory of relativity, and since then I started studying physics. I also had an intuition about identity, deriving naturally from the eternalism, which fits perfectly the many world interpretation (though I haven't taken yet a position on interpretations of quantum mechanics): I think that we all are one conscious being, which is the only existing "whole thing" in the universe, or even better, which is the universe itself as one conscious being, and the only one being at all. I'll explain my intuitions and mental experiments in the answer to this comment, since it will take some lines.

[@pierfrancescopeperoni]

Time doesn't flow at all. You can order the events a priori in relation to the increase of entropy. Accumulation of memory goes together with the increase of entropy, and this gives, at any instant, the illusion of time flowing to the increase of entropy. Mental experiment. The following events are ordered from what happens first to what happens after: 1-Albert wonders if it is possible to reverse the time flow. 2-Albert starts building a reversing time flow machine. 3-Somehow Albert just built a reversing time flow machine. 4-Albert activates the reversing time flow machine. 3-Somehow Albert just built a reversing time flow machine. 2-Albert starts building a reversing time flow machine. 1-Albert wonders if it is possible to reverse the time flow. Observation 1: Albert always perceives gaining information even when Albert's mind loses information (when time is reversed): if time flows backwards, then everything, even memory and thought, flow backwards. Observation 2: however you arrange the order of the events, Albert will always perceive exactly the same in any given event. Intuition: Albert's perception is confined to the events themselves, and any way of ordering them is just abstraction: what if there isn't any real order, and all the events occur simultaneously and will last forever, i.e. time doesn't flow? At least Occam's razor would be sharp. So, assuming that time is flowing, it is not possible to know the direction of flowing, and the perceived direction is always pointing to the increase of memory in our brain, regardless to the real succession of the events. Now I'll define SIMOULTANEOUS INSTANTS OF TIME We've seen, that we can reasonably assume that time doesn't flow. So I'm perceiving all my life, past and future, in this moment, though in different simultaneous instants: note that there are not contradictions since we are considering time as a mere coordinate (since it doesn't flow), so past and future are not "what has happened" and "what will happen", but rather different "positions" all existing now and standing still: this is the meaning of simultaneous instants of time. PERCEIVING THE DIFFERENT INSTANTS SIMULTANEOUSLY SEPARATELY I perceive all the moments in my life simultaneously, though separately, with no interference from each other: though in this instant I have memory of other events, the perception I have of them here is different from the perception I have of them in the past (we assume for simplicity that our memory is not such a mess, and it relates to real events, though the discussion of this assumption is interesting and could eventually be done separately). Let capital letters denote events, and numbers denote different perceptions of them. The sequence of their presence in our mind, to the increase of memory (as the illusory flow of time is perceived), is: (A1)->(A2,B1)->(A3,B2,C1), and so on. So, though I perceive A at any instant, I perceive it differently at any different instant. I'll say two events are perceived separately whenever I consider their perception in different instants: A3,B2,C1 are NOT perceived separately, while A1,A2,A3 are. I can consider sets of events, like entire instants: any instant is perceived simultaneously but separated from each other, while the events from a same instant are not perceived as separated. We see that the word separation now is used where one uses to use simultaneity: saying that time doesn't flow we emphasize that EVERYTHING is simultaneous, though separation in those sets of perceptions is maintained. MY (YOUR) IDENTITY We notice that not only any two different instants are perceived separately by the same person, but also the same instant is perceived separately between different persons. There is not substantial difference between [different instants in the same people] and [different people in the same instant], but matters of similarities in the content of perceptions. If I perceive myself in each simultaneous instant separately, this is equivalent to as I perceive different persons simultaneously. I can actually say I am different persons simultaneously, one for each instant of time, who share in common similarities in the information in the memory, arrangeable as a continuous flow of perceptions to the accumulation of information. And I can even say I am all the people, not only this one writing, i.e. I'm ALL the separate instants, regardless to the similarities between them. So we also eliminated possible assumptions about the disposition of identities (there is only one identity), and Occam's razor is even sharper than before. I recently found a similar intuition in Andy Weir's short story "the Egg", which I suggest you to read if these things are still not clear to you. After eliminating the assumptions about time and the identity, we can easily eliminate any other assumption about reality, like any possible disposition or order of perceptions. I am in fact convinced that all the existence is structureless. Intuitively I like to think of it as a point with no space around it. Any structure we can think of is purely abstract.

[@cmacmenow]

Just like to give a huge thanks to Sean for putting together these incredibly illuminating and engaging Y.T talks /presentations. Green screen,apps and real time iPad usage works beautifully.

[@rc5989]

I enjoy when Professor Carroll covers the bases in philosophy including the original Greek philosophers. I find that it enriches my understanding and familiarity with science.

[@kidzbop38isstraightfire92]

Your ability to comprehend complex ideas and explain it to us laypeople is, in my opinion, as good as Feynman's. Well done.

[@byronwatkins2565]

It is true that times t>t0 cannot become tx0 on a line also cannot become x

[@icesrd]

Dr Carroll... I hope you enjoy making these lectures as much as we do listening to them. Please keep up the good work. Can't wait for the next installment.

[@pranaysheshak5931]

Watching this at 1.5x speed and thinking "I live life faster than 1 second/second"

[@SirThorp]

Quality content right here.

[@tanishqgandas2633]

you my friend deserve everything

[@jharris7]

🤣🤣🤣👏

[@bkbland1626]

Why? That serves no purpose.

[@positron5687]

Dito

[@ASLUHLUHC3]

Wish you talked about time itself, and how it (& mass) are emergent properties of timeless & massless particles bumping around fields, resisting acceleration.

[@ibmor7674]

This guy is too dope, useful yet not boring.

[@bruinflight]

Sean Carroll is my favorite science guy (along with Dr Lincoln at Fermi Lab) and I just heard him utter what is now my favorite Sean Carroll quote (19:11), "That's crazy talk!" Love ya Sean!!! Thanks for all of your great, great internet chats, buddy! Be well!

[@tonycotto8073]

This is simply the best explanation of time I've ever heard.

[@badron88]

These talks right here, and others like it, are the reason I'm planning to study physics. I'm coming up with some great ideas but don't know enough yet to answer them. Mr Carroll, thank you.

[@AndrewCMumm-sf2yo]

Sean, without knowing it, you kept me in the game when I was a grad student studying general relativity. I was lucky to come across the early .pdf notes of your general relativity book (you were offering them for free online) and it was such a relief to finally read a book that explained things clearly. I ended up writing my masters thesis on the Kerr metric and your book helped so much in that respect. You're an outstanding educator and I'm really enjoying some of you mindscape podcasts and youtube videos. If you ever come to Hong Kong (in a post-corona world), then please come give a talk to the awesome physics students at my school - we would even love to host you as a resident scholar for a short while if that could interest you. My school is an outstanding place that wants to push the boundaries of what's possible in high-school (we've hosted an AI researcher who spoke about entanglement, another Caltech quantum-professor who is an alumnus of our school, Jerry Coyne from Chicago U. on evolution - you would fit right in!). Take care.

[@NicleT]

Thank you for these video courses. They’re very important! I want also to share that I had myself a big accident when I was a teen that let me saw time slowing down significantly. This is what I felt while it was happening. My mind was “ultra aware” of each details that was unrolling from the accident but also I was struck to realize that at the same time, my perception of time was different. So I’m not saying time was running slower with my physical movements, but more that my perception of it let me feel it slower. It’s also important to say it was not a souvenir aftermath, but really while it was happening.

[@daverei1211]

My favourite topic by my favourite speaker - thank you Sean

[@pedromalafayabaptista3655]

The strange thing is that time has a speed, being speed a derivative of length in order to time. The clocks beat is slowed down with the growth of velocity, so t=f(v) and v=dx/dt - too circular for my taste.

[@ag-bf3ty]

That part about novelty adjusting your perception of time makes sooooooo much sense. If I watch a movie for the first time, and then watch it again, it seems to always go by quicker the second time. Which is kind of odd and counterintuitive, since you'd think it would be more boring (and "time flies when you're having fun" as they say.) I think that maybe in the moment, it feels like it drags more slowly, but in retrospect you don't remember much and so it feels like it passed more quickly.

[@GodlessPhilosopher]

These lectures are incredible and Sean is a genius. Highly recommend his new book defending the many-worlds "interpretation" of QM.

[@qingyangzhang887]

"Something deeply hidden". I just read it. It's amazing.

[@avrenna]

It is amazing! And his book The Big Picture is a multidisciplinary masterpiece. I very, very highly recommend that one especially.

[@chrstfer2452]

How formal is it? Is there any exploration of the equations?

[@endrawes0]

@@chrstfer2452 informal for sure.

[@David-qv9yy]

how would dark matter affect quantum entanglement specifically near a black holes event horizon?

[@alexpotts6520]

48:30 that equation (written S = k log W) is written on Boltzmann's gravestone

[@User-jr7vf]

And the grave in turn is featured at the top of Sean's blog.

[@robbyjohnson6531]

Been looking for something like this for years. The equations in the last episode went way the hell over my head, and I got quite seriously lost. This one, though, I was able to follow the entire time. Blew my mind multiple times. Thanks for this.

[@maddmann]

My brain hurts thanks keep this up I like it. Do not dumb it down

[@beeble2003]

"Clock: changes reliably & predictably with respect to other clocks." Here, I like the parallel with something that came up a couple of talks ago, where you said that one solution to a set of conservation of energy equations is that a ball on a slope stays exactly where it is. Similarly, one solution to this system of "clock equations" is that a rock is a clock, because it changed reliably and predictably (i.e., not at all) with respect to other rocks.

[@seionne85]

This is great 😂😂

[@alikarimi76]

I'm a big fan of the time topic. Thanks Sean for starting this. I'm looking forward to next videos about time 🙌

[@JacobCanote]

We love you Sean! Best of luck! You are a rebel and I know it. Your role just changed. You do a wonderful job of opening up people for different ways to frame things. Theoretical physics and allowing liberties to probe different depths are a priceless tools for discovery and understanding... too drunk. To drunk

[@anm3037]

I just met this channel today 26/09/2023 and am already at part 5. It’s amazing how you explain these physics. Now I wonder if you are a university teacher …? If yes then your students are very lucky 🍀

[@kenwalter3892]

Been waiting for this one.

[@iruleandyoudont9]

you're a brilliant man Sean. thanks once again for making these vids. much respect.

[@tigertiger1699]

Man .. I really appreciate the effort you put in here…, I get to come n go on this.., but to look at it for an hour .. hurts the head

[@pizzacrusher4632]

These are so excellent! Thank you very much for doing this!!!! I wish everyone was as generous with their knowledge & expertise. Thanks again!

[@willjeremijenko4633]

Wow! Shaun has incredible communication skills and is very pioneering in his work

[@scowell]

Very much like the new background... much easier on the eyes. Thanks for listening! Love the content.

[@dvoss7680]

Sean, I really enjoy your work and your lectures. I bought a few of your books and just wanted to say I really appreciate you. Thank you!

[@DoleoSeorsum]

Sean Carroll is not afraid to address subjects that are at the forefront of research. Too many other speakers gloss over what is unknown and only repeat what is proven and already known.

[@NoFunNoMoshNoCoreNoTrends]

Sean, this is absolutely fantastic content. Holy cow man.

[@The1belal]

Such a convenient way to speak and illustrate...very cool !...Thank you Sean, you have a very pleasant voice for explaining things.

[@BitwiseMobile]

This guy reminds me of my Calculus professor. He makes complex things seem simple and easy to understand.

[@ericladror14]

Hey, I am 67 years old. Over the past year I have aged 10 years, even ask my wife. When I was 17 it took 10 years to finish that year. So time has sped up 100 fold in 50 years, that's 2 years/year. And you say we live 1 sec/sec? :-) I love your videos, THANK YOU!

[@KamranRazvan]

You have a great course on "Great Courses" about the arrow of time. I "think" I finally grasped, in that course, what entropy is!

[@jcf20010]

I have that course too and have watched a couple of times. It's very good.

[@richardschuerger3214]

Love this series - Ty for doing this. If we were to exist at an event horizon while time flows past us, we would be able to "see" one direction (the past) but not the other (future). Essentially time is flowing past us at the speed of causality and our perception of present time emerges from that

[@TheHalothane]

In Forward's Dragon's Egg, a species lives on a neutron star. Gravity is so warped that time travels differently for them. They travel quicker through time than beings in another frame of reference. Granted, everyone in their frame of reference travels at the same time.

[@jimwolfgang9433]

Thanks Sean, I've watched and listened to so many of your lectures and podcasts; but I think this format is the best yet imho. 👍

[@jessicaphillips763]

It must be so cool to be extra smart! This guy seems like such a good person on top of it all. 👏 ☺️

[@IarctusI]

For QA: 1) Is it valid to say that time is a part of space-time conceptual model because it is impossible to measure time without space being involved (changes in time are tracked through space)? 2) What is the smallest measurable unit of time we can measure? Meaning, what is the smallest unit measurable where we can see a change in space? Thank you!

[@diamon999]

Well, I got plenty of time for this. Thanks

[@Ni999]

I wish this video was longer too.

[@clayz1]

Nodded off, dreamed we were in conversation, I couldn’t break in because Sean just keeps talking. I try to break in, Sean keeps talking! Damn!

[@matthewrichmond4139]

I definitely recommend Carlo Reveli's lecture on the Physics and Phsychology of Time found on YT.

[@manlamb1]

I lent his book to someone before I was able to finish it but what I read was mind blowing.

[@Edwinvangent]

Thanks Sean, your a great communicator, I can listen for hours, to make really difficult stuff easy marks a good teacher, in the movie Lucy at the end she said time is the fundamental unit of measure I kind of agree.

[@party-sy2tk]

Thankyou Sean. Very enjoyable and interesting talk. Glad I took the time to watch it!

[@incoathwetrust4612]

Hey Sean, could you please explain how the spontaneous radio-active decay of an unstable nuclei does not actually violate time-reversal symmetry, contrary to what most people are inclined to believe? Thanks!

[@2ndAmendmentX]

I'd further want to understand why all of the four forces don't violate time-reversal symmetry. Gravity acts one way. If you reverse time, you have to reverse the force of gravity right?

[@MartinWilson1]

Thanks. Hopefully the Tralfamadorians will get a mention in the Q and A. After all Sean, the goal is to be a master of multidisciplinary teaching.

[@ryrez4478]

awesome thank you Sean Carroll! btw i really appreciate that you know so much about philosophy as well. makes these videos even that much more interesting

[@ianmarshall9144]

just like mathematics , its a human abstract concept that helps us to describe the interactions that go on around us , it is a fact that i do not bump into myself , i exist here , the physical reality i accept changes by interactions , those interaction do not require time , it is our ability to remember / perceive that gives us a notion of time .

[@konsamtambradhwaja3870]

Thank you Sean for this lecture.Very interesting and enjoyable talk.

[@charonme]

what is called "the arrow of time" in this video is just time asymmetry: while we know there is a difference between different times, we don't know the direction of time. The apparent "arrow" comes from the direction of our observation: we always observe time from lower to higher entropy

[@ToriKo_]

7:20 “(the Past already happened) the language that we have, that was not invested to talk Scientifically or Philosophically about time [or any concept] - comes from ordinary use - embedded into this language is a very definite notion of how time [that concept] works. [An example of this is the sentence:] The Past is settled but the future is up for grabs.” More broadly this whole section has a lot of really interesting moves surrounding philosophical and language ‘traps’

[@kaaregus]

I just found your channel and love it. I have a few experiences that go with the time in bad situations. I used to ski race, downhill, and had a crash at over 65mph and landed on my back, slid under the safety fence, and wrapping myself around a tree, breaking my femur and major internal injury's, and no, time did not slow down as i was sliding on my back watching the trees's come at me. If anything, it sped up. Another one, was my own fault, but decided to jump off a bridge (for fun not suicide) that was about 90 feet. It, again, sped up for sure. (broke my tailbone and ankle). These things might be different for each person, but for me, things went faster then I could mentally process as they where happening.

[@JiminiCrikkit]

Thanks for another great episode ... this one reminds me of the old Greek god(S!) of time - Chronos and Kairos - where the former is how we think about time nowadays sequential (chronological), but equally back in the day there was Kairos - the god of timeliness, of situation... Love this idea.

[@nuriagiralt617]

I'm so glad I don't have to worry about whether time is real anymore 🤓

[@d3vilm4ster]

OMG!!!!! I didn;t know you had a youtube channel!! I love how you explain things nad i hope you keep posting videos here. You are really brillant!

[@philtrumcorp]

This is brilliant because i think it talks seriously about little metaphysical biscuits we all roll over in our heads in one way or another. Time seems more difficult to extract ones 'sentience' from (or something). We feel distinctly separate from other(inanimate) matter. But time seems like a force that we move along with in concert with the rest of the universe. You have to ask: What is the relationship between time and sentience? Is our perception of time twisted or limited/narrow or just wrong? ...Or is there some part of the experience of time that is emergent from sentience or self-awareness or consciousness. What is time to a rock? I think we'd all agree that time is nothing to a rock. It seems like that has implications for the realness of time?

[@madderhat5852]

Question. 4:30 I thought given that everything in the universe is moving, that cancels out the idea of "choice" in moving through space. Wouldn't the only way not to move through space is not to move through time?

[@bob-c702]

I'm glad I live in the particular world where this video got released..

[@clorofilaazul]

I think that often there is a missconcept between language and reality. The word "cup" isn't a cup, it's a linguistic/abstract representation of a cup. Likewise, the laws of physics are just language trying to explain the world and represent it in equations. Equations are a language with a special property like maths: they can predict, but they are still a language. If some equations seem to represent things that we haven't seen in the world, and now we can see them (like black holes), it doesn't mean they can represent other aspects of reality.

[@clorofilaazul]

@Vendicar Kahn It's not an hypothesis in the sense of a thesis. But I'll try my best. We discovered black holes in the theory. We didn't know they existed. So: theory was correct before we had evidence. But theory also brings us other conclusions (supositions) that aren't real, like "supersymmetry". We now know that there aren't enough particles like supersymmetry predicted. Another example is Shrodinger's cat. It can't be real. We have a living or a non living cat. We don't have what the theory implies. We can't take it literally. Some are real, in the sense that we discover empitric evidence, and some don't. I said in my comment "there is a missconcept between language and reality" because I see it as evidence. We do that mistake with words (language) and we also do it with some equations/scientific hypothesis. That's all I wanted to say. I love science, despite not being a scientist. I'm an artist. I mostly agree with what scientists say. I am just trying to help some people to keep in mind this mistake we often do: a missconcept between language and reality. Thank you for your question. I hope I have answered it.

[@margaritahernandez7459]

Thanks. Very interesting.I am understanding more of the issues presented in your last book. I am not a physicist but I always was amazed about physics and got great grades in math and physics 👌 long time ago.

[@anticaritz]

Thank you for the invaluable information

[@teghem6723]

@seancarroll. There are also plenty of mathematically explainable physical phenomena which are irreversible and which illustrate the AoT. Think about non-commutative operations or transformations and more fundamentally about surjections.

[@sltraian]

Very nice and useful trainings! Thanks for the good usage of your spare time! About "space usage" I have a comment: when you are showing your hands, they look bigger compared to the rest of picture. Probably you are using low res camera and distance to it is too close. Solution could be increase distance to it and zoom in. Laurentiu, Romania

[@astee58]

Life surely exists. Maybe, as a growing life-entity with a mind, my perception just involves "time". And "matter", which gives me "space". Or "space-time". "Reality" is hard to separate from some kind of "experience". So a completely different kind of being probably could have another notion of space-time, like a fly for example. Different "personal", "macro-state" journeys through experiences of space-time? Thank you for these great lectures!

[@dxhelios7902]

@Sean what is the difference between entropy and time? Times defines entropy, entropy allows us to define time.

[@slash196]

Entropy does not allow us to define time. In a local system with decreasing entropy, clocks still run forward.

[@MeissnerEffect]

So, so good. One of the greatest scientists and communicators of our age. Or should that be ‘time’? Thank you Sean for your time, and energy, an amazing mind! 🎋🦋🌿

[@jaschoudhury18]

Space and time definately affect Sean's left arm from time to time because it disappears from space on several occasions during this lecture!!

[@meters_and_madness]

Thank you for doing these videos Sean! The content is fascinating and your delivery is so well articulated. Love it.

[@detsistaaventyret]

Good work man! Best escapism ever :)

[@brunoprates862]

Hi Sean, big fan here! Love you podcast and books. I have a few questions (you can choose any to answer), feel free to reformulate in your own words if you want to make it clearer. Q1 - You defined entropy as a measure (log) of the number of microscopic arrangements that appear indistinguishable from a macroscopic perspective. Isn’t this notion of “appearing indistinguishable” and “macroscopic” pretty ill-defined to be used in calculating a numeric value of a quantity? Suppose a person has a VERY good eyesight, to the point he can distinguish molecules from each other. Even if you changed the position of just a few molecules of milk, this person would be able to tell the difference. Would we measure different values for the entropy? Where is the catch here? (You can go mathematical if needed) --- Q2 - Do you think time is discrete or continuous? Why? Could this be tested someday? --- Q3 - How would you treat past and future equally, if you take into consideration quantum uncertainty? (I can only see MW as a solution here...) Thanks!

[@DomainRider]

The macroscopic perspective is, by definition, sufficiently coarse-grained that you cannot distinguish the individual particles...

[@nathanisbored]

If I'm in a building, there's lots of air particles flying around. I would describe the room as a complex system with high entropy. But a giant standing next to the building would look at it and say it's a very simple system with low entropy: just a small collection of particles that can't get very far. It would take a lot of math to describe what's going on in the building from my perspective, but it would take very little math to describe what's going on in the box from the giant's perspective. It's a bit like studying the behavior of atoms in a system vs studying the behavior of molecules in the same system. It's mathematically more elegant to describe what the molecules are doing than what the atoms are doing. Another way to say that is: chemistry _emerges_ from thermodynamics and in the process, the mathematical theory jumps down in complexity. You could say this jump is also less fundamental and therefore is just an approximation, but then you could use the same argument to say that everything is just an approximation of something at a lower level. *Question:* Is there a sense in which entropy measures the zoom level required for a system to be mathematically elegant? A bit like how a Reynold's Number tell you what equation to use, entropy tells you whether you should be talking in terms of thermodynamics or in terms of chemistry, for example.

[@derricksteed3466]

Perception of time: Cyprus 1974. I was, along with others along the street who were sat on their verandas, watching the Turkish jets paste the hell out of Nicosia airport from the comfort of my chair sat on the veranda of my house on the outskirts of that airport. Then one of those jets, unseen by me lets loose directly over the street. Naturally, I leaped off my chair to crouch down on the floor behind the wall surrounding the veranda. To my perception I seemed to be floating like a feather gently wafting its way as I drifted down to the floor - that seemed, at the time, to be far too long for comfort! And trust me please - what I experienced was in real time! Not retrospective at all! It was what I experienced in the moment.

[@Bestape]

This one was a lot of fun, thanks! I think time is like the color purple. It's the point at which the ouroboros eats itself. The parietal eye. Can you talk about -(entropy) = k log (1/D) described in Schrodinger's "What is Life?" p. 73? What I associate with exergonic process.

[@terryluxton774]

Dear Sean, I’ve loved all your KZbin content during this lockdown here in the uk, fantastic content I’ve really enjoyed it. There is a tv series that’s just aired in the uk called Devs, I won’t give to much away but it’s basically about a tech giant based in Silicon Valley who has developed a program that can see any given point in time. If you can get it in the US it’s worth a watch. Really well done and fun to watch during this lockdown. Once again fantastic work on all your KZbin content. Kind regards From the uk

[@tomlakosh1833]

Dear Doc; Entanglement and time are mutually exclusive where entanglement mandates superposition precluding acceleration and the time function. That's why we need a dual membrane electromagnetic field that produces antimatter strings without a time function on that half of the brane. We're entangled through that brane given that our structure is half antimatter strings. It is the conduction tensor in the 1 to 3 aspect ratio graviton tori and subsequent graviton clusters that keeps the matter and antimatter strings from annihilating and time on our brane renders the antimatter strings recessive on our brane. Gravity is just the electromagnetic processes applied to the flow of graviton and graviton clusters around and through Standard Model particles. The clusters are actually gluons that were formed en mass during the GUT Epoch and are continually formed in SM particle cores. These gluons/clusters act like a dipole gas subject to condensation via Feshbach resonance and BCS field effect, and this condensate is formed in the electromagnetic field of galaxies as dark matter that is scattered by cosmic rays . The dipole gas is spin and charge coupled on the surface of leptons and baryons to form the Higgs field operating as an electromagnetic rectenna generating space-time viscosity as it captures the momentum of gravitons and clusters flying through the field. The gas is also the working fluid for a gravitational propulsion system operating as an “ion thruster” through the core of the leptons and baryons. Dark energy is just the increase in quantum friction of the propulsion system in barren space where the Higgs field drags the particle backwards toward even less dense space. Thanks for employing speculation as it is needed in your profession but please revise your gravity podcasts to comport with a more rational hypothesis.

[@myothersoul1953]

That the laws of physics are reversible with respect to time seems more like an unconfirmed hypothesis than a fact. Yes we can use the laws of physics to retrodict the past but what if time itself were to reverse? Time always moves forward so we can't do any experiment to confirm that hypothese. We do have good reasons to believe it's the case but shouldn't we alway be a be skeptical?

[@timgreenglass]

spice? thyme? time has always seemed (to me) to be connected to consciousness.

[@johntitorii6676]

Sean my new fav universe guy

[@xaviergamer5907]

You are emerging as the early 21st century premier world’s science teacher to the average modern man.

[@yeti9127]

Sean: Great lecture, as usual. The concept of time reminds me of something I read regarding the Mahabharata (Indian epic) story. This epic or the battlefield scenes were recited to a blind king by “time” itself. Interesting! So, the statement that “time travel” or “movement across time” has not been found to be imagined in any ancient culture may not be quite correct. In fact, the Bhagawat Geeta (ancient eastern -Indian- text) seems to have contained some of these time travel ideas. There are plenty of stories about sages moving across space. Schrodinger himself was quite fascinated by these Vedantic texts especially the All in One concept.

[@KungFuKeni]

Perhaps he meant popular stories, ones that were passed on from generation to generation

[@mapeandrews3951]

Loved the last part of the video about how the study of entropy progressed 👏🏻 wish you could have included Complex Systems and Emergence but I know it would have been of topic too much. But one day it would be nice to hear about this part of your own research. A bit hesitant to ask for requests after you mention in one of your podcasts that requests tend to have an adverse effect on you. Thanks for providing necessary food for thought.

[@llaauuddrruupp]

I love these videos, and this was maybe my favorite of them so far.