What Is Time? | Professor Sean Carroll explains

#whatistime #seancarroll #physics What Is Time? | Professor Sean Carroll explains the theories of Presentism and Eternalism 1,894,565 viewsAug 7, 2018 23K DISLIKE SHARE DOWNLOAD CLIP SAVE Wondrium 428K subscribers It's said that the clock is always ticking, but there's a chance that it isn't. The theory of "presentism" states that the current moment is the only thing that's real, while "eternalism" is the belief that all existence in time is equally real. Find out if the future is really out there and predictable—just don't tell us who wins the big game next year. This video is episode two from the series "Mysteries of Modern Physics: Time", Presented by Sean Carroll Learn more about the physics of time at https://www.wondrium.com/YouTube 00:00 Science and Philosophy Combine When Studying Time 2:30 Experiments Prove Continuity of Time 6:47 Time Is Somewhat Predictable 8:10 Why We Think of Time Differently 8:49 Our Perception of Time Leads to Spacetime 11:54 We Dissect Presentism vs Eternalism 15:43 Memories and Items From the Past Make it More Real 17:47 Galileo Discovers Pendulum Speeds Are Identical 25:00 Thought Experiment: “What if Time Stopped?” 29:07 Time Connects Us With the Outside World ------------------------------------------- Welcome to Wondrium on YouTube. Here, you can enjoy a carefully curated selection of the history, science, and math videos you’ve come to know and love from brands like The Great Courses, and more. 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Your brain is going to love this place! ------------------------------------------- You can also read thousands of articles from the smartest experts in their fields at The Great Courses Daily: https://www.Thegreatcoursesdaily.com And, of course, check us out on all of our social channels: -Facebook: https://www.facebook.com/wondrium -Twitter: http://twitter.com/wondrium -Instagram: https://www.instagram.com/wondrium ------------------------------------------- #whatistime #seancarroll #physics Chapters Science and Philosophy Combine When Studying Time 0:00 Experiments Prove Continuity of Time 2:30 Time Is Somewhat Predictable 6:47 Why We Think of Time Differently 8:10 Our Perception of Time Leads to Spacetime 8:49 We Dissect Presentism vs Eternalism 11:54 3,378 Comments rongmaw lin Add a comment... John Roberts John Roberts 1 month ago What an incredible documentary! I enjoyed it so much I’m going to watch it again yesterday. 20 Sardarzada Mohammad Yunus Sahir Sardarzada Mohammad Yunus Sahir 5 months ago After watching the lecture, I began to read comments and was so surprised that the large majority of commentators had a great understanding of the subject discussed and made more easy for me to get my concepts more clearer than ever.....keep on spreading the light of knowledge with a logical approach....my heartfelt thanks to the entire team who made this happened... 44 Feynman Schwinger E_MC2 Feynman Schwinger E_MC2 10 months ago Sean Carroll is a freaking genius. He has a brilliant mind: the ability to COMMUNICATE this eloquently about a subject matter this complex is a sign of deep, deep intelligence. Verbal IQ is just as important as Mathematical IQ, alas without philosophy there is no physics. This is why, for centuries the field of physics was called "Natural Philosophy," and also why so many of histories most brilliant minds were philosophical inclined - Plato, Socrates, Aristole, Descartes, Leibniz, Newton, EINSTEIN, Goethe, Wittgenstein, Godel, Soyinka, Chomsky etc. Bravo Sean Carroll. I look forward to watching more of your lectures. Astounding video! I learned a lot. 4 spyros spyrou spyros spyrou 2 years ago This was a truly great lecture, which certainly opened my eyes to a few aspects about time which I was wrong about. The only thing is that time is always described as something that passes us by at a particular rate which depends on where you are and how fast you are travelling. The reality is that time itself does not 'flow'. Moreover, it is like space in that we travel through it. The difference is that we can travel through space in any direction but we can only travel through time in one direction, albeit at different speeds. What the human mind finds hard to accept is that time is not a fundamental unit of the universe but speed is. We see speed as a construct of distance divided by time but the truth is that time is a construct of distance divided by speed, where distance and speed are the fundamental units, not time. 27 Wondrium Carlos Lember Carlos Lember 1 year ago Mind bending concept explained so eloquently and made so easy for a little brain like me to completely get it. LOVE YOU Sean Carroll 32 Wondrium Jean-Pierre De Vent Jean-Pierre De Vent 1 year ago I can't follow the other physics or science channels but professor Carroll is able to put himself in the shoes of people with mathematical talent. It's possible certain topics are so much only math that you can't explain them any simpler without getting very vague. 2 Room 111 Photography Room 111 Photography 3 years ago Carroll is awesome. He is able to distill scientific concepts to a level understandable by a common person. I saw him on Joe Rogan. The way he was able to explain heavy concepts...unbelievable. 175 Wondrium Pines Pines 3 weeks ago I've been struggeling a bit lately with the sudden realization that what we experience are only moments in time. What we did 5 minutes ago is essentially gone forever, all because of how time works. This did help me sort my thoughts a little, but I'm sad that I most likely won't live to see the physics of time (and space for that matter) completely cracked. Bruce Ma Bruce Ma 2 months ago I often consider the movement of time is related to a “time field” which matters that have time sensitivity, such as consciousness, move through it according to the field guide direction. The speed the consciousness move through time depends on the contents of the matters. Similar to mass moving through space according to gravitational field. Of course this may only belong to science fiction. Even though we now consider space-time together, certain field could have effect only on part of the property of space-time. To the Trees! A family of climbers 🌳🎄 To the Trees! A family of climbers 🌳🎄 3 months ago Yes! He is fast becoming my favorite physics teacher. I actually had come up with the analogy of meeting somewhere in time in space as a way of explaining before. It’s cool to hear him use the same analogy 1 Wondrium aalever aalever 1 year ago (edited) I'm sure I read somewhere once that time is effectively another manifestation of the force of gravity. Moving forward in time is traveling along the curvature of space-time effectively propelled by that same force. The constant which governs the predictable speed at which we do that is the same constant which governs the speed of light - meaning if you were to simulate our universe and only change that one constant, you would also change the speed of time. Does that ring any bells for anyone else? 5 Ted Bates Ted Bates 1 year ago Thank you Sean. Some people who think about such things go nuts like me. It's really nice to hear someone talk on these things who has an excellent mind and a noble character. 40 Wondrium Kali Gold Kali Gold 3 years ago Love this format. No audience. No overuse of special effects. No host trying to be overly entertaining and funny like some of today's documentaries. 295 Wondrium Jonathan Dobson Jonathan Dobson 1 month ago "There is nothing different about the past, or future from the present except we are consciously experiencing it." If eternalism is real, could it possible to experience ALL of time at once? Would we really call this “experiencing” since experience requires time to flow? Let's call it “knowledge of all time”. How could a single mind hold so much knowledge? Could it be recalled with perfect accuracy and at any time, or would this knowledge fade over time, as our mind ages? What if a mind could be engineered or altered in some way to enable it to retain all knowledge of experiences and recall them accurately and precisely without fading or forgetting? Is time real? What if time is not real, but rather a condition of consciousness? Such a condition that is unable to perceive the true reality which is not time. The “not time” would be the real. The “block universe”. Maybe TIME is blindness, and NON-TIME is sight. Could a blind person experience color? or the clouds in the sky? or the moon, or stars? With only smell, taste, touch, and sound as his only means of perception. Certainly a sort of “reality” could be formed in his mind that could represent these things through his limited senses, however without the sense of vision, the true reality will always remain elusive. What happens if we lose this consciousness or we die? Would we also be freed from this blindness of time? What is consciousness and how does it work? 1 n1ck n1ck 1 year ago Here's my take on it- We know that everything in the universe moves from low to high entropy(that's just how it works). Time is just the measure of the rate at which this happens and since we are all subject to it, we accept it as time. This predicts that time may have never existed before the bigbang because there probably was nothing to move from low to high entropy. 10 david tomlinson david tomlinson 1 month ago This chap explains things brilliantly , well interesting , fascinating , great stuff 🙂 1 Wondrium einsteindrieu einsteindrieu 2 years ago I know the energy source of time and gravity and how it works.I've study this for 40 years.Dr.Sean Carroll is correct what he says good teacher this is Einsteins stuff. 1 Demetrio Pina Demetrio Pina 6 months ago (edited) Wow! Great! well explained! Congratulations and my respect to Professor Sean Carroll. 3 Inhuman0 Inhuman0 2 years ago Truly one of the best science communicator out there. 237 Wondrium Elvis Sibilia Elvis Sibilia 1 year ago (edited) Excellent video. And besides Philochrony is the theory that describes the nature of time and demonstrates its existence. Time is magnitive: objective, Imperceptible (intervals) and measurable (duration). 1 Antonio Calhau Antonio Calhau 3 years ago One of the great things about most of The Great Courses (TGC) lectures that I have seen so far, like this one, is that professors, like Dr. Sean Caroll here, bind all the concepts involved together in great talks, you get to see the whole picture, the tree and the forest. When I was in college, we did the calculations, I took tests, exams, finals, but never really had the chance to see things like this, in a holistic way. And TGC do all this in all its courses consistently. I would say that all universities should have this for people to be able to follow up, and to be more connected! Not to mention that we can always revisit these lectures over and over again, for example in search of inspiration, to research any particular topic. They help us to go from the tree to the forest back and forth all the time consistently! 8 Wondrium heavy meddle heavy meddle 1 year ago I first heard about Sean when I watched Joe Rogan. He's amazingly good at explaining very complex stuff for dummies like me 22 Wondrium GC J GC J 6 months ago Professor Carrol shows how time does so many things, and explains in a clear way why we can't live if time were to stop. Paul T Paul T 6 months ago Thank you. Decent lecture. What was not addressed was the connection between time and consciousness. When can only perceive things within a stream. Your lecture for example. If we had a more expensive consciousness and a more efficient language we could perceive all of your lecture in a shorter time. So time and consciousness are directly connected. Eternalism is not feasible given our current state of consciousness. 4 Man In The Hills Man In The Hills 1 year ago One thing I've always found fascinating is the notion that there are no events, just arbitrary points of perception labeling a this versus a that, or a now versus a then. 4 eesa ahmad eesa ahmad 4 months ago (edited) Oooops! I have been following and watching Sean Carrol videos for at least 7 years by now and always admiring his knowledge and ability to simplify complex subjects, But around the five minutes mark, and further on, into this video he is talking about the ability of science to predict the future if what all is happening in the universe is known! I am sure he knows that's a false statement to make and very far from the current state of scientific knowledge and quantum theory if there is a "real" one, pun intended, that is! Quantum mechanics, which is one of Sean's expertise areas, tell us we can not know for certain the reality of the physical universe around us, it's hidden from us by the Heisenberg principle of uncertainty. All we can know is the state that it collapse into forced by the action of measurement by the observer which is only one special state it Can be in. This means science can not predict the future, with certainty, till it actually happens! So much for prediction! Sergey Novikov Sergey Novikov 3 years ago i admire Sean's ability to speak so simple and clear about most fundamental and complex things. 20 Wondrium Tony Gonzalez Tony Gonzalez 5 months ago First time seeing this video, and I got to say, I’m not very smart like college level or anything like that, but I always been a sucker for un-answered questioning and you just made my brain do BAM! This explains a lot 4 Kd Ud Kd Ud 1 year ago Considering how we perceive and measure time, I think time is an intelligent or systematic measure of energy expenditure, transformation or expression within space. We can only move forward because we can only flow with the new transformed energy, going back in time would require the retrieval of the transformed energy in its holistic/universal form within space... If we still use the same technique to measure time in days on mercury or jupiter, I don't think they would have the same 24hours as earth, because their energy expenditure within the space they rotate round the sun is different from earth. Just my thoughts though! Gökhan Bozkurt Gökhan Bozkurt 1 year ago Beautifully explained. Wondrium Matko Smat Matko Smat 2 years ago Thank you, Professor! I just don't see why anyone would waste the time to dislike this. Mohamed Selim Mohamed Selim 1 year ago (edited) Time is life This is the introduction The videos are really great, Thank you for sharing let me prove that time is life now...... we can't know what time is unless we are alive/ being aware of the surroundings/ consuming time.... otherwise, it's a state in time now is a state in time now is another state in time by a state of time, I mean anything is in a "Stop" state otherwise, it's growing/diminishing/living ... doing something during a period of time this is why there is the so called "progress"; which has different stages/states And it is the default, since it's alive Anything has a time to end, all tangibles but it's relative to tell anything is "old" we should have a benchmark to relate to, then to be said older .... "than" or just "old" we can relate to what time is, by having a general/common/agreed upon benchmark, though we created the benchmark; keeping the sun (day/night) as the benchmark Then we have a year... month, day, hour, minute, second.. we should keep in mind that there is something wrong with this scheme, since there is a leap year! What's it meant by being old, but to compare it to something else. This is not physics, though it is. if time was taken as life, now to make life is not possible but to create living creatures is possible but we don't know how yet Thanks again for the knowledge introduced. Brian Freeman Brian Freeman 3 years ago Gosh. Sean Carroll you are such a smart man. You say things in what seem like to be the best possible ways to explain them. Such a great communicator. Intelligence is less valuable without good communication. Good communication is less valuable without good intelligence. You sir are what happens what you have both. TY for your hard work. 86 Wondrium Clarence Wooten Clarence Wooten 2 years ago If everything is happening at once then "reality" is the point where consciousness is focused. As consciousness evolves the meaning taken from the past may change, changing in turn, the future. It seems to revolve around an expanding consciousness. Phiz Ix Phiz Ix 2 years ago It would be interesting to discover that moments could be compared to a strobe light so fast that it appears to be smooth; much like a sound frequency that oscillates quickly enough to sound like a continuous, and different, sound frequency. Just a thought. Donna Hughs Donna Hughs 1 year ago I think time is not "straight" but curved relative to the spatial dimensions, and only intersects with them at one point--the present--like a circle rolling along a line. I do like his description of what it would be like if time stopped--except for a few feet around us: how everything would be dark because light rays would not be moving towards us so we would see nothing, and how we couldn't move through it because stopped air particles would be like a wall stopping us. Horrific, but makes sense. C C 1 year ago Wow, what a great lecture. 3 Wondrium Muffin man Muffin man 6 months ago As a non physicists(like myself), I really enjoyed this. 9 Insidious Vidz Insidious Vidz 3 years ago Dr. Carroll has that rare Professor Carl Sagan ability. The gift to know what he is talking about combined with the ability to dumb it down for the layman to understand. Many professors are genius academics inn their given field of expertise, but few possess the unique ability to share this knowledge with their audience without having a bunch of eyes glazing over. 7 Wondrium Looptap Vishal Looptap Vishal 9 months ago This is a masterpiece, Greatly done, Sir 1 Wondrium برسات لفظوں کی BLK برسات لفظوں کی BLK 2 years ago (edited) Dr. Carroll very correctly and nicely explain the time. I am grateful of him for such a wonderful presentation 4 Drew Shourd Drew Shourd 1 year ago Dr. Carroll is such a pleasure to listen to. I have seen him on many documentaries. Did you guys see that all 13 different time pieces on the set were set at different times?? 3 Christian Faust Christian Faust 1 year ago Very nice presentation about the philosophical aspects of time. I am currently reading Einstein's book: "Über die spezielle und allgemeine Relativitätstheorie" which is for me as a German a very precious book because Einstein's carefully chosen words about time and space are of course a German that does not exist anymore. It's unbelievable how precisely Einstein can describe his thought experiments only by words with very few sketches. This approach is totally different to the visual world of today. Professor Caroll has the same talent to illustrate very abstract but "real" aspects of life only by his very well chosen English words and statements that only a native speaker can achieve. But I am very grateful as after war generationperson who raised up in an English affine environment that listening to him is like as if he spoke in German to me. Danke! roy roy 9 months ago It seems to me that time is tied to movement. I like to think of space as a motionless medium with no beginning or end because it is static. Everything in this media that moves is on its own time scale that begins at the very moment it moves.. if things come to a rest then time does too. The ultimate clock is our universe expanding at the speed of light, all other measurements of motion in contrast to the original movement of our universe explains time dilation and differences in time. Basically everything in movement has its own time and all things in motion can be compared to each other describing its own time. MrRozsta MrRozsta 1 year ago (edited) I’ve been thinking, and I came to the conclusion that in fact the term “time” is confusing. We think about what “time” is, but in fact there is no time, only “time-flow”. Time is not a thing, but rather a process. I think helps understanding things by using this terminology, helps us asking the right questions. Space is the water, and time-flow is the flow of the water. 12 Guillaume Maurice Guillaume Maurice 9 months ago Thank you for sharing this that was a very interesting topic. Very well presented. I enjoyed it. Wondrium Lorne Melin Lorne Melin 3 years ago (edited) Thanks to prof Carroll for yet another very interesting lecture. 7 Wondrium UNSTOPPABLE-AR UNSTOPPABLE-AR 1 year ago Sean Carroll is just too intellectual and interesting. Thank you professor Chris Jager Chris Jager 1 year ago Time is unique because you can be two different times at the same place, but only one place at any given time. Plus, entropy increases over time but space has no equivalent. Sid Masey Sid Masey 1 year ago Great host, made it all very interesting and understandable Wondrium Ogye Danjuma Ogye Danjuma 2 years ago Wonderful lecture I must say! 5 Wondrium aeomaster32 aeomaster32 1 month ago Time is (measured in) events; it is the measurement of motion. Time is measured by comparing events using a regular standard event, such as a watch, or the orbit of a planet or the vibration of a crystal or speed of light. (When there are no events, time is said to have stood still). The past refers to a certain previous state of events that existed. Going back in time is the imaginary retracing a sequence of events, depending how far you want to go. The future, tries to predict what unfolding events will end up looking like, based on our knowledge of past event history. CorwynGC CorwynGC 3 years ago A great thought experiment might be, what we would understand about time, if the speed of light was closer to everyday speeds (say 200 mph). Would you be able to meet someone at a given time, if they drove faster than you? Would we think of time as constant and reliable? How would our intuitions work? 6 Wondrium Mein Deutschkurs mit Johannes Mein Deutschkurs mit Johannes 5 months ago (edited) My individual experience of spacetime is sometimes way to fast, so it seems to be that the measurement by my mind is not detailed enough and not fast enough to expire it slower. I assume, that the clock speed is the same for all of us while watching the video. I wish it could be possible to expand the individual experience of time, without losing any real second. Or while "pending"/waiting for something, to skip real seconds. Dee Morris Dee Morris 9 months ago What a wonderful teacher. Wondrium Venkatesh Babu Venkatesh Babu 1 year ago (edited) Time is the number distribution in a specific sequence. Distribution is related to energy. Energy is related to waves and matter forms. If you are good at distribution sequel and matrix forms you can capture time. Usually time is embedded in recursive log sequel of numbers of various forms. Functions are relational data base of number piles. Cosmic theories are interpretation of the various forms of energy distribution. Energy can be positive or negative in curled up space. Negativity is always related to zero and positivity never. Only few irrational negativity surds is related to positivity. Bruno Manoel Bruno Manoel 3 weeks ago (edited) I never heard a very good explanation about the relation beetwen space and the time , and how these caracteristics behave itself one to another , i am impressive , pretty good job teacher Sean carroll !! Wondrium vinm300 vinm300 6 months ago 17:17 Imagine 2 billiard balls colliding in empty space. The scene looks the same forwards and backwards. Until you zoom in : then you see a hot-spot on each ball. The hot-spot is a record (memory) of the collision. That is what distinguishes past from future. (As Sean Carroll just said) If you run the film backwards, the heat in the balls would migrate to a spot then vanish after the collision. This is an extremely unlikely scenario. But not impossible. However, the chances would be 2 to the power a trillion trillion. 8 Polymorphic Doombooger Polymorphic Doombooger 2 years ago "It always is good to go back to what clocks do." -Professor Sean Carroll 2018 6 berner berner 1 year ago I'm warming up to the idea that in terms of linear time, there's no one single timeline that we're all on but instead we just exist in this reality/dimension on our own timelines and because of that, right at this moment as I type it, it's happening "now" for me, but to you the reader, you may be existing on your timeline 20 years from where I am right now which in essence would mean that I'm basically part of your history and vice versa. Rock Brentwood Rock Brentwood 2 years ago (edited) Consider the possibility that both senses of time have physicality as independent though related phenomena! An eternal coordinate time (t), and a presentalist moving time (s). The former goes with General Relativity and the Heisenberg Picture of Quantum Theory, while the latter goes with the Schroedinger Picture of Quantum Theory, the "equivalence" of the two pictures being a mere appearance, not a fact on the ground - especially not for Quantum Field Theory (QFT)! (and especially not for QFT on curved space-times!! (and especially! not for QFT on globally non-hyperbolic space-times!!!)). In a special relativistic setting, s would be tied to proper time; and the Minkowski metric - rendered as ds² = dt² - (dx² + dy² + dz²)/c² - would be re-rendered as a constraint ds² - dt² + (dx² + dy² + dz²)/c² = 0 ... or defining the difference du ≡ c² (ds - dt) ... as a quadratic constraint dx² + dy² + dz² + 2dtdu + du²/c² = 0 and linear constraint ds = dt + du/c². Notably, this has a non-relativistic limit as the constraints: dx² + dy² + dz² + 2dtdu = 0 and ds = dt (the two senses of time, in non-relativistic theory, now merging as one). The bifurcation of the two senses of time may then be seen as a relativistic effect, even though a vestige of it lives on (as du) in the non-relativistic limit. The geometry (in both the relativistic or non-relativistic cases) has a 4+1 signature; except now that the (s) coordinate is treated as process time - the arena of presentalism - not as eternal time. In effect, it is a geometry in which the entire 4D space-time continuum, itself, flows in time! 4 Ogye Danjuma Ogye Danjuma 2 years ago If time is a projection of 3D space in continuous “frames”, how then is the idea of time travel possible? Since the the future (new frame hasn’t yet come into existence) I love this topic dearly, and I’m just in search of answers like everyone else. 1 Jonathan Graef Jonathan Graef 6 months ago While this is an interesting discussion of the physical processes that are associated with time, I would just like to point out that the universe, being a brick of events, does not actually have a notion of time itself beyond preserving the relationship between objects in time and space. To actually have time, that is, the thing that passes and makes us experience life at different moments, you need a life form. Basically, time is a property of the soul, inexorably linked to the causes and effects in the universe. If anyone is looking for evidence of god, possibly our benevolent machine overlords come back in time to fix history, our perception of time as moving forward, so that we remember the past and plan for the future, is most certainly a gift that could not have arisen by random chance, as our brains could easily have done this for us with us perceiving time as backwards, random, or being a soul embedded in a rock somewhere with no clue what is going on. ars khan ars khan 1 year ago (edited) What I understood about time , it is a relative term. The time scale that we apply is linked with earth spin and it's rotation in the space. The time clock click started for us at big bang i.e at the event of this universe birth and time will stop at the event of this universe extinction (i. e death). The concept of birth and death also applies on this universe as well on us. Bognostrokulum Bognostrokulum 2 years ago I often wondered how did the ancients were sure that every year , month and day actually have the same lenght? How were they sure that tomorrow would be the same lenght as today? According to modern history people started measuring periods of time before they actually knew the Earth is revolving around the sun. So what was their measure for a period of time they called "one year" ? Sure enough the very seasons vary in terms of temperature? Marcus Erectus Marcus Erectus 1 year ago Time is a psychological construct of movement from one snapshot to the next. The snapshot represents a moment in time, but it's always now continuously. 1 Hammer Chen Hammer Chen 3 years ago Thank you Professor! 3 Wondrium Time is a path Walking to understand Time is a path Walking to understand 7 months ago Thank you for the video. Here in New York City 7:38 a.m. Wednesday October 6th watching again, and I love the background cool pictures. So many philosophical answers about "what is time." 1 Yasha Kami Yasha Kami 1 month ago (edited) If I had 2 specific objects right next to each other I could predict how they're interacting. Space is also easily imposed by the laws of physics. A simple example, a cotton ball on Earth would look much different to a cotton ball on Jupiter. Gerry K Gerry K 1 year ago Time is the amount of conscious awareness one experience while one is alive on this planet . 1 babyrazor babyrazor 8 months ago Time and space can be used separately, you can accelerate your own "personal" time so that while you can move freely about and manipulate objects the world/space around you appears frozen motionless to you. While the speed of light might appear insurmountable in space, it is easy conquered by moving in time. Χαραλαμπος Στρογγυλος Χαραλαμπος Στρογγυλος 1 year ago He said it very well. The laws of modern physics are controversial to reality as we have a sense of it. So, the reality is real, also our senses are mostly real. Then what is wrong? Our math and the laws of physics when they don't describe real things and couldn't be observed with en experiment. Also, somebody could tell that everybody could have e different approach and interpretation of the result of the experiment, yes but then you have to create en experimental equipment to do e different experiment to see that your theory is correct. So 50 years of string theories not even one proof not even one experiment. This makes the hall thing e joke, disinformation, lays in science, bla bla bla. Hasitha Warusawitharana Hasitha Warusawitharana 9 months ago (edited) Interesting! I was amaze with the fact that more than 2500 years old philosophy can be prove with these theories. If prof Sean Carroll can go through with Buddhism he could complete the theory of time and space. 3 මලින්ද සමරසිංහ මලින්ද සමරසිංහ 9 months ago I refered to Buddihist philosophy Sir.It really was helpful not only to map out the Universe but find your own self within. Boris Nahalka Boris Nahalka 9 months ago the problem with physics is that it confuses space with distance. the common notion is more distance more space. and the same applies with time. more distance between one moment and the next moment doesn't mean more time. another problem is that for physics it is up to now impossible to go beyond spacetime and beyond creation itself. RSD B RSD B 2 years ago I just love Carroll! Brilliant communicator ! 1 Wondrium Damian Weiss Damian Weiss 7 months ago Time,(movement), creates space and space creates time. Thus dark energy being injected into the universe to expand the universe is also creating more time,(spacetime). The bigger the universe gets the more space created and more time needed to travel through the universe; thus time is created. You could say dark energy is time. Shah Nawaz Shah Nawaz 9 months ago (edited) in my opinion time is being controlled by a force for every string if it is the unit of universe so in other words every string has a specific start and end time and can be stopped for particular object if the controlling force wishes to. Barry Zeeberg Barry Zeeberg 7 months ago question about "presentism": what is the duration of the "current moment" - does it have a finite duration, or is it a point source, so to speak? either view seems to lead to philosophical and physical contradictions and paradoxes. 8 gerry williams gerry williams 10 months ago What I find odd is I am watching this ( from Sean's perspective ) in the future . He is now in the past , and may have changed hid mind. Yet this exists. 2 sabesh bala sabesh bala 1 year ago Great Theory about time and he is able to explain it using simple examples. 6 Wondrium Moronic Pest Moronic Pest 2 years ago Sometimes I think of time as concentric shells or bubbles with discrete energies upon which information of past, present, and future states of existence reside. With each tiny passage of time there is a slightly larger bubble of information produced with higher entropy, and the preceding bubble contains information in the immediate past with lower entropy. We only reside in the present bubble though at any particular instant. Then I get stuck. ;) Robert Müller Robert Müller 1 month ago The way Sean Carroll explains things sometimes reminds me of Richard Feynman's way of explaining things. Tim Macpherson Tim Macpherson 1 year ago Very clear until the end. A clear exposition about time speeding up when travelling near the speed of light would've helped 1 Cap Compass Cap Compass 4 months ago (edited) I was taught that the shortest "moment" is 10 to the minus 43 seconds; the time it takes for light to cross an electron. (Presentism is therefore, pretty short. Mr Danger Mr Danger 8 months ago I experience time in Quanta! Not kidding. I never knew that was a "thing" but all my life I've experienced time as glitchy and jumping from one period to the next. Mystic Flyer Mystic Flyer 2 years ago To me, time is simply the change in the state of the universe. 5 Amyth Dutta Amyth Dutta 1 year ago 30:07 - "We should be grateful that we live in a world that lets us coordinate time and be social creatures " Sean Carroll. Well Professor, how "social" can we really be in these current "times" 1 Forevers12 Forevers12 1 year ago The explanation of time-stopping being impossible is such a buzzkill Stavros Burke Stavros Burke 1 month ago Fantastic lecture! 1 Wondrium Brian Tubbs Brian Tubbs 3 months ago (edited) Causality moves at the same speed as light (=4 velocity). The time it takes light to travel 1 Planck is a discreet packet of space. Therefore, couldn't you say that causality has the same discreet packet in spacetime? Dondatta Ford Dondatta Ford 2 years ago Time is something we made to describe passing moments each passing moment is different which is similar to multiverses 1 thegreatreverendx thegreatreverendx 2 years ago Eternalism - Where you know that all of your most embarrassing events in life are preserved forever. 74 John Dude John Dude 7 months ago Really easy to understand something so complex thanks to the one explaining it much appreciated sir Prem Kumar Prem Kumar 9 months ago Fantastic explanation 👏.....its very simple and understandable... Great work . jack russell jack russell 5 months ago If the universe, for some unknowable reason, were to stop expanding, what do you think will happen? Would it explode? Would it instantly cease to exist? Would it freeze where it is forever? Would it collapse in on itself and disappear into a black hole? And what would happen to time? Would it still have an independent existence? Or is time nothing more than motion, which we measure by comparing a standard (commonly accepted) kind of motion that is cyclical and perfectly consistent (called a clock) that we compare all other motion to? Is the universe then definable as space motion rather than space time? 1 Aryal Gajbhiye Aryal Gajbhiye 1 year ago apart from being really really smart , he is an incredible speaker 2 Wondrium MikesAvenger MikesAvenger 1 year ago Well presented. Very concise. 1 Wondrium Frank Ciborski Frank Ciborski 2 years ago I agree with those commenters who say he communicates well. Easy to listen to. 11 Wondrium Kidz Bop 38 is Straight FIRE!! Kidz Bop 38 is Straight FIRE!! 5 months ago Sean is an awesome teacher and a brilliant mind...just wish he would get a competent sound guy lol Jeff Farris Jeff Farris 1 year ago I don't know how Sean even sleeps at night. His brain never stops 7 Josh Shailes Josh Shailes 4 weeks ago I'll admit that I found the 'sesame Street' level set design a bit of a distraction. But I honestly loved that they took the time and effort with it. An awesome vid. 😊♥️ john john john john 1 year ago I am surprised time is taken so seriously when we know time is virtual and only exists in our heads You can only go back in time IN YOUR MEMORIES Algorithms is a way of 'seeing' the future for forecasts like futures and weather Robert Early Robert Early 1 month ago Great subject and great presentation. However, having studied this topic for over fifty years, I don't entirely agree. I began my study of time with the question, Where is life? Say all you wish to say about the past. There is no life there. Whether it is a recorded event of 200 years ago, or a personal experience of one mili-second ago, it is still the past which is subject to only the experience of recall and its many imperfections. There is no life in the future. The future is nothing more than imagination, expectation, and hope. We never experience the future, because there is no life there. That tiny gap between the past and future is what we experience as the present moment. Can we give it a name? How about Eternity? Vinay Seth Vinay Seth 2 years ago 28:10 I think he's wrong there. With everything else stopping, the reflected light rays would stop where they were before that instant, and so would be the case with the air molecules. But with everything in the tie-stopper's body still moving, the protagonist in question would be able to pierce their way through their surrounding space(time). So the fictional plot holds. Javier Pena Javier Pena 4 months ago When the word " space" is used, is it meant in reference to distances at all? So, if there was a way to make the Earth's rotation reverse, would time reverse? And if so, would time reverse on earth only but no where else? Bassotronics Bassotronics 1 year ago Here is what puzzles me about present time and how Time “flows”. What is so special that I’m sensing present time right now? Is it like I’m alive and flowing on a Big Bang wave that is heading into the future with everybody else around me riding on it and experiencing? But what about before I was even born?; “present time” was still there and existed for everyone else prior. A person from the 1970s for example was in the “present time” the same way as I am now writing this. It makes me want to think that time does not “flow” but everything that will happen is already written and the people who are alive right now are just experiencing it which in turn is relative to each person. Are we riding in the Big Bang wave of time? I’m not sure about that since time is distorted with gravitational forces everywhere in the universe and where there’s a lot of gravitational force time can distort. What about planets or objects that are really close to a black hole of which distorts the fabric of spacetime? Probably for them, we are in the year 5061 while for us, we’re still in the year 2020. The notion of time as well as consciousness is very confusing and hard to grasp from many point of views. 6 Sazib Bhuiyan Sazib Bhuiyan 1 year ago Time is an illusion created by change. When we are close to strong gravity e.g. a blackhole, change slows down. Also, when we are travelling at close to the speed of light, change slows down for the traveller. Both effects create the illusion that time has slown down. George Andrews George Andrews 2 years ago "Time" is a unit of measurement that measures perceived rate of change. Just like mile, foot, meter and kilometer. There is no past or future except in our own minds. 1 Juan Perez Juan Perez 1 month ago The issue is that the "laws of physics" that we know are an approximation, a modeled way or mechanism that just works (inside some constraints), but not the ultimate or "real" or true laws of physics of nature. Those laws are unknown, and most probably impossible to know. So, Universe of four dimensions, deterministic... yeah, that sort of work for most simple cases. Is the truth? Of course not. Or just apply some simple rule: if an idea is depressing (about the "design" of the Universe), it cannot be true. On the other hand, if one wants to be really scientific, nobody proved so far that the past or the future truly exist. So... that's not scientific to affirm that IMO. And if we want to get more picky, we can't prove that the past ever existed either. It is easier to prove that the future will exist, you only have to wait. The four dimensional space-time is a belief, and something that for practical purposes works, but not a truth. In fact, science do not provide any truth, just theories that work (again, with some constraints). As anyone can see, I have a strong belief in presentism, and I reject eternalism (and determinism). Trevor Taylor Trevor Taylor 5 months ago Time is equivalent to a specific related moment of travelling moments in a element of matter relegated to memory satisfied by curiosity. Retro Gamer Retro Gamer 10 months ago "Time is the only true unit of measure. It gives proof to the existence of matter. Without time, we don't exist. Humans consider themselves unique so they've rooted their whole theory of existence on their uniqueness. One is their unit of measure, but it's not. All social systems we've put into place are a mere sketch." - Scarlet Johannssen, 'Lucy' Mats Borgkvist Mats Borgkvist 7 months ago Mats Borgkvist says: It only applies to those who have such a notion of what time is. For my part, I mean that Professor Sean Carroll has confused the word time with the word duration and aging. Because I have no problem with time, as it is 'up to me' to choose which times I want to travel in, because it is I who chooses the time form I want to be in, which everyone can do and has done since time immemorial by choosing which verb form we should add our verb to the event in our languages ​​that indicates in what time we want to be in. It is thus easier to determine the time to travel to than to get to places. I have a hard time keeping up with the professor because I can go as fast and far as I like without any problems. The problem is that knowledge as a sect has kidnapped the word time from our human languages ​​and given the word a completely different meaning than the original, the one who does things and according to our intellectual property can not make clocks, namely measure time and own it with a stolen word that we humans exclusively already own by tradition but Galileo and Newton and Einstein have managed to push away with their original meaning when they together committed the copyright infringement in Pisa in 1610 and the rest of us let it be accepted by church opponents who should have known better than that be seduced by a Protestant mob. This in respond to the professor Sean Carroll's statement: ”We move through space as we like, we can choose to go to some other location in space, we can’t choose to go to some other location in time, we inevitably move through time at the rate of one second per second. Time is relentless whereas space is sort of ’up to us’ how to move in it. That gives us a certain perspective on what the world is.” 4 chaosenergy1990 chaosenergy1990 2 years ago How can one make a model of "the state of the entire universe right now to predict the future" if 'now' is different depending on your frame of reference. Also how can we make a perfect model of a system that isn't closed and things are 'happening' outside the observer's light-cone? Brainstorming & sharing Brainstorming & sharing 1 year ago Absolutely well done and definitely keep it up!!! 👍👍👍👍👍 1 Wondrium Ben Tomlinson Ben Tomlinson 1 year ago Rest in piece to Professor Steven Hawkins, the master of space and time x 2 Carl Kerstann Carl Kerstann 11 months ago "Time is what clocks measure" But we know that the clock i carry in my hat measures time differently than the clock I carry in my boot. So are they actually measuring time or some aspect of time? If a time traveler wanted to come back to a specific instant in the past they would need to not only know the exact instant but the exact point they must reach traveling at the correct velocity relative to everything else in the universe or they might be out of place relative to the event they intended to return to. My mind is scalded now. Time to shut it down. 1 wesinat0r wesinat0r 8 months ago