Your Daily Equation #32: Entropy and the Arrow of Time
Episode 32 #YourDailyEquation: Einstein referred to entropy and the second law of thermodynamics as the only insights into the workings of the world that would never be overthrown. Join Brian Greene as he explores how these concepts illuminate the difference between past and future--why glasses break but don't unbreak, why candles burn but don't unburn, why we age but don't un-age. Why, that is, there is an arrow to time. Surprisingly, the discussion brings in the Big Bang itself.
Even if your math is a bit rusty, join Brian Greene for brief and breezy discussions of pivotal equations and exciting stories of nature and numbers that will allow you to see the universe in a new way.
The World Science Festival (WSF) is an innovative multi-media organization that produces original live and digital content straddling the arenas of science, technology, the arts, media, performance and education. With the goal of radically transforming public perceptions of science, WSF creates world-class programming, both live on stage and televised, featuring inspired collaborations, outstanding talent and novel production techniques that bring scientific discovery, insight and perspective to a broad general audience.
Official Site: www.worldsciencefestival.com
Twitter: / worldscifest
Facebook: / worldsciencefestival
Instagram: / worldscifest
Subscribe: / worldsciencefestival
I'm not sure if you read the comments posted following your videos, or would even have the time(!), but I'd like to offer a heartfelt thanks for them, and to remark that I cannot get over how much time you willingly give up to educate, entertain and inspire us. So, so generous. Thank you.
I do look from time to time. Comments like yours are very gratifying. Thanks so much.
Mom: Get your life together. Me: Can't Entropy.
Outstanding comment, will use this in the future.
Some hisrorical events can be seen on a surface if We can collect the wibrations backwards..
Fantastic professor Brian! I think this has been the best explanation I have ever seen about entropy!! I feel happy to say this! Thanks for all you have gave to us!!
Hi Professor, Thanks for Ur lecture Lots of love from India God bless you BG
I love Indian because of their curiosity.
Thank you for these videos! I'm not a student in physics, but I've always had a great interest in it, and I've learned a lot from these sessions. Thank you again and take care, stay well and safe!
Thanks so much for taking this question up that I requested in the second episode. This was a really good refresher! Thanks very much again Prof.
I stood in front of the tombstone of Boltzmann in Vienna on friday 13th on my 50th birthday, just days before the world went corona 'crazy'. The cemetery was almost closed, it was hard to find, but in twilight even more impressive! This is an equation that will last.
its an equation with staying power !
Well, the equation itself is due to Planck, not to Boltzmann.
All the Daily Equations have been perfect. I can't wait for the next one. BUT, This one is so great to get a feel for the laws of thermodynamics. Dr. Brian is brilliant in explaining principles that are challenging to dumb asses like me.
We’re in same level bro😆
Another dumb ass here, from Brazil, checking in 😅
i wish he continued these
This was superbly helpful. Greene made the subject matter interesting throughout! (Thank you!)
Whoa.... great lecture Sir ! Especially tht statement about the anchor/ residual order... of Big bang tht sort of gives order to our current ordered stuff !
All I can say is that my desk has a very high entropy and is extremely unlikely to decrease any time soon!
Truly enjoyed your descriptive explanations. Found it interesting and unusually understanding for the most part. Thank you so much.
From explaining the Big Bang to demonstrating the basics of General Relativity on TV with Stephen Colbert, you have made difficult scientific ideas understandable to us all. Science dorks around the world owe you a huge debt. Thanks a million, Dr. Greene.
My man who’s been in all sorts of amazing documentaries with amazing visuals and broad strokes of theories- literally now has me back in AP Physics just as confused as ever once the X and letters enter the picture lol. Almost had some flashbacks there till I remembered how my teacher taught us how to manipulate the reference sheet ;) but this is what happens when science communicators can backup their statements with the cold math... Thanks as always!!!
I deeply appreciate your videos and the knowledge you are sharing with us. Thank you!
I did appreciate every single minute of of all 32 sessions , i thank you dr.brain green
Leo Tolstoy also observed that there are more disordered states than ordered ones in Anna Karenina: "Happy families are all alike; every unhappy family is unhappy in its own way."
Thank you Prof. Greene! I really appreciate your ability to take complex topics and make them easily digestible for anyone (sign of genius). I especially enjoyed how you maintained your focus and train of thought while the phone was going off. I wish I had that skill - fun! Oh...and is it Ree-dl like needle? Someone please solve that problem too (wink).
i only recently found this channel. most explanations concerning physics blow by me. but i can understand yours to the point i at least know what you are talking about. I'm not educated but i'm life long curious. Thanks. first saw you on star talk, now i am a fan. you do a great job illuminating einstein's work for non physicists.
Your content never fails to amaze me and ignite my hunger for knowledge about the universe. Thank you for sparking my curiosity.
Your explanations of math and physics are awesome. Id like to see a Physics of Music episode sometime.
Yes! Thank you Professor Greene!
Wow, I've never ever learned so much about entropy in such a short time. It would be very interesting to hear more about this from Brian. Too bad it's the last episode ...
Brilliantly explained Prof !
Thank you Prof. Greene; very interesting as usual ! So that's why time travel is forbidden, because it would reverse the tendency of entropy to grow. Regarding the arrow of time, you said that things fall in order to reach a region of spacetime where time is slower. Could it be that "falling" should be a way to escape from a region with high entropy (because time is faster so more configurations happen) to another with potentially less entropy due to a "shorter" arrow of time ? Taking this reasoning to its extreme, it is correct to say that if time stops entropy doesn't grow anymore? Another crazy idea: could it be that traveling through time is much more "expensive" than traveling through space ? (I'm talking about components of spacetime) Because when there is a component along the time axis, things "age" (there are changes of state) and so entropy grows...(maybe the Universe tries to fight entropy with gravity). Sorry, but all these lessons unleash my fantasy :-)
What a surprise! An interesting, informative, and articulate description and explanation from Brian Greene. I love these sometimes daily equation sessions and will sure miss them when Dr. Greene stops giving them.
This is the first time I’m watching the video, and it’s already blew up my mind😱 while watching this video I repeat in many times to understand it again cause I really excited about the topic and how I hypnotized by Prof. Brian words🤔. I truly encourage with this topic and I really really appreciated this one. Thank you so much for sharing. Greetings from Indonesia 🇮🇩
Used to decide whether or not to buy a dictionary on their definition of ‘entropy’, it was surprising but common to find dictionaries with no entry for entropy.
정말 대단한 강의입니다. 책을 통해서는 잘 이해가 되지 않았었는데 이 영상을 보고 완벽한 이해에 도달했습니다. 수학 부분은 빼고..ㅎㅎ 엔트로피, 열역학 제 2 법칙 또는 경향, 시간의 화살 그리고 빅뱅 시점에서의 고도의 엔트로피 질서를 갖고 있었던 이유로....우주가 팽창하면서 질서에서 무질서로 진행하는 과정에서 별과 은하계 행성 지구 그리고 인간과 같은 고도의 질서체계가 발생할 수 있는 원리 등등... 브라이언 그린 교수에게 감사드립니다!!
That is extraordinary! Thanks to Prof Greene! I have learned much today, and also today I have more questions than yesterday. For example: if laws of physics allow reverse entropic "trajectories", what about irreversible chemical reactions, such as combustion?
its the same thing, he mentioned that, all laws of physics (physics involved chemistry) are included, he talked about a candle reforming, the laws of physics allow it, its just very unlikely
Thank you professor... Respect from India ❤
That's the most beautiful explanation of entropy that I have ever heard
What time to be alive having these videos from great minds for free. This is a rare moment in history, our world with Electricity providing the internet is very fragile, maybe in a few centuries all this is lost, cherish and embrace your time alive right now
This lecture is weak on pure meaning or in other way vague or loosely associated or half baked thought delusional and slightly halllucinated. Credit is given for the attempt.
Just came across your videos and love this format. So many others have over the top splashy videos and graphics that usually just distract from the topic at hand. Much prefer your approach. Please keep it up! Love the ringing telephone… real life at its best 😂
Artificial atomic structures created by electrochemical resonance will help us to take the first steps in dealing with this great chapter talking about the reversibility of time. Thank you.
Thank you profesor for a very interesting lecture.
Loved it. Thanks, Brian.
Great explanation 👏👏👏
Fantastically explained 👏🏻👏🏻🙌
my appreciation of Brian Greene grows daily !!
These daily equation is awesome.
Such beautiful, almost poetic explanations. Outstanding. Thank you, Brian.
XRP community?
Thanks again Prof. for another great episode. Have you considered doing an update of "Fabric of the Cosmos" ? I would buy the DVD again !! All the Best, Paul C.
This episode was sponsored by Christopher Nolan, so that you can understand his upcoming movie, TENET. Entropy and arrow of time. The inversion.
I am also here because of TENET 🤣
Im here becauE i have seen tenet
@@vincencohan3626 NFLX?
@@kirstinstrand6292 yes
This is greatness !
Thank you Prof. Greene. Your simplification of Entropy rocks! Q. pls, is it possible to get a copy of the code for the coin simulation by Danny Swift? My 17 year old Nephew loves it.
We are waiting for you sir ... Come soon... U r the best teacher of secrets of this world... Salute to ur genius mind and gentle nature towards giving water to our thirst curiosity. Lots of love and respect from India🙏
We couldn't give anything but a huge thanks
incredible lecture Sir as usual. That provides so many foods for thought, for instance if the condition at the time of big bang was in super order what sort of thing that might have been. If life is the result of residue of that order, what kind of consciousness that actual order would have possessed. Are multiverse and parallel universes not accessible by us since they fall under the category of higher entropy, and so on and so forth
It’s make sense, like professor Greene said that Big Bang is came from the end of infinite high entropy , which Big Bang itself is low entropy high disorderly
I've never been addicted to something like this...this much! Thank you Dr. Greene for your valuable insights and wisdom through this series and thanks a lot WSF!
Beautiful, indeed!!!
2 questions: The arrow of time was wonderfully explained (2nd Law + residual order), thank you for that. 1st QUESTION: does this means that the arrow of time loose any meaning when the maximal entropy was finally reached? 2nd QUESTION: by the used example the motions where equally probable, randômico, like by diffusion. How would entropy evolve if we do have a preferential arrow for motions, when there is a slight higher portability in one specific direction, like by the migration of charged particles in an electric field?
Dear Professor Brian Greene, Hi. I just want to say - thank you for having these videos. Are you familiar with Edgar Cayce?
Prof Greene .my name is Eran Sinbar from Israel . Its a pleasure seeing your inspiring videos and read your books . a major question that bothers me: could it be that our known local fabric of spacetime is divided into Planck length sized spacetime cells and between them there is an extra non local grid shaped dimension (or dimensions) that is responsible for the non local quantum phenomena like for example entanglement? could this extra dimension conceal the non - symmetry in the arrow of time?
Great explanation.
Thanks prof. Greene, nice lesson as usual. Question about the past hyphotesis: how can we considered the big bang an highly ordered state? It was a hot soup of photons and high energy elementary particles chaotically moving. Has that to do with gravity? I believe I heard prof. Penrose discuss this but I'd like to hear your point of view.
Thanks, Brian.
Please make more videos on this
thanks prof GREENE
Hello!I was thinking about the energy conversion points...Could we consider these points as sensing sensors in an electromagnetic band type system?I await your response.Thank you!
You changed my thinking on entropy,😍😍 beautiful explanation
Thank you Doctor. Greetings from Romania.
We love you Sir
nice job Sir !
Beautiful!
Hello! I thought about the Brownian movement that would ensure the formation of other structures, but regarding the broken glass experiment on the frequency line, to ensure reversibility,Before the experiment we have to create a linear transformation system, which restructures my atoms, forming these artificial atomic structures. Thank you!
Wonderful presentation. It made me imagine the "stuff" of the universe in its primitive form smeared out over a spherical de Sitter space fluctuating around maximum entropy until finally enough of that primitive "stuff" converges at a point causing a region of minimal entropy which thereby gives birth to a system similar to the one in which you and I currently exist. Maybe extreme spatial curvature at the convergence point causes an outlying region of repulsive flatness which results in separation from the parent de Sitter universe thereby allowing the system to evolve on its own without influence from the parent de Sitter universe until eventually, when a high enough entropy occurs and/or spatial effects ease, it rejoins the parent de Sitter universe.
Brilliant, TY for not editing out the phone. Now we know your human like everyone else! :)
Great lecture
Prof. Greene please make a video on quantum gravity
Times is so sensitive,and we should liked any second of it , let’s have some rest after few year’s hard work and been refresh for next
By the glass breaking example, not only every motion must be reversed but also the chemical reactions, with the recombination of many Si-O bonds. Overcoming their activation energies is necessary, as well.
i love u brian!!
Dr. Greene What do you think about the idea of, when dealing with a local system (for example 100 pennies on your table), that a person can identify and then flip each individual coin to produce an ordered state. How does this relate to the tendency to disorder? Is this because energy is introduced into the system? Just curious.. thanks!
Hi Professor, thank you again for this incredible display of entropy. I have a question regarding your illustration with the change of trajectory of each and every piece of the wine glas in order for the glas to reassemble - would gravity also be required to be at an opposite for this to happen? Wouldn't that break newtons second law?
I think, when you are changing the direction of the smashed glass, you are essentially applying a force which if overall summed will make a negative of Gravity.
@Darshana AmbulkarI thought it was dark energy...? Wait..what's gravity?...we don't know...???...*explodes, leaving a wine glass*
Terrific!
Nice video. Although I think what we lost was the actual equation! It's the equation of the day and he didn't unpack S = k log w and put it back together at the end. What did the k term represent, for example?
Uhh, amazing again. Thank you!
To reverse the broken glass, would you also need to somehow supply (or remove) heat to cause the bonds to re-form to convert it from a bunch of silicon shards into a smooth glass?
Reverse not just the shards as objects, but the atoms making them up, along with the air (which he did mention), as well as the atoms of the floor. Heat is just motion you're not tracking in detail; sound is motion of the air and atoms too. Think about how a cat jumps up to the top of the refrigerator: there is no extra energy so he just eerily comes to rest at the top of the arc. It very much looks like a reversal of something falling. The atoms on either end of the break will come together with exactly enough remaining energy so that the bonds form as they approach and then the bond draws them together further accelerating the velocities towards each other; but finally the energy transferred through the bonds across the face will be in phase to carry on as a compression wave, that meets a similar wave coming up from the ground and they cause the floor's vibrations to cancel out and become still, while the now-unbroken glass is launched upwards.
Dear Dr. Greene, can you please help me understand something i never could find in any of the programs about double slit experiment. Every program says interference pattern breaks down to definite particle state once measurement is done by detector but nobody says how the detector actually measures the "which way" path. Is the detector some kind of a passive screen or does it shoot a beam of laser to measure the path or something else? Some scientists says that interaction with another particle breaks the interference pattern- in that case there are already so many particles moving around in space like photons bouncing off the walls of the lab, or cosmic rays or background microwave radiation. Why that does not interact with the electron wave and break the interference? Does that mean the double slit experiment is done in complete darkness and shielded from all outside interaction?
Hello! Thinking about the reversibility of time, it is possible to form artificial atomic structures. Thank you!
sir brian, your explanation of the entropy is brilliant, but it still only explain the process or the process reverse of the nature, not exactly why the time move forward. For example, the explanation of the broken glass, the way I see it is, even when we try to reverse the process, like you said have to run to each shattered glass molecules and change all its directions, the time itself still move towards one direction, and not back in time.
Hi. Why some things that break you can sometime put together again (like when you break clay dough) but some you can't (like wood, or the wine glass etc)? About the glass, even if you apply force to each of the piece in a such an exact reversed way when it hit the floor, the glass won't become whole again right because you must melt glass for it to be seamlessly joined so the piece will remain in pieces? Since a child I have always wondered how come I can rip a piece of paper in two but I can't put it together again. They won't stick with each other. What happened at molecular level when I rear it? Why won't the molecule join back? I found out it's when the object is mallable or easily separated, that it can be easily joined again. Why?
Interestingly, this explains why the Moonwalk is such a sensation! MJ and the others reversed a natural phenomenon: WALKING. Thank you Prof. Greene for a very easy to digest method of explaining Entropy.
Great lecture! One question though: Might it not be an error to equate the thermodynamic arrow of time with the true arrow of time. As you note, entropy can decrease although it becomes fantastically unlikely as the system grows. Time, however, is not a statistical phenomenon like entropy: it cannot even in theory spontaneously go backward (to our knowledge). Furthermore, suppose the universe reaches its maximum entropy; as far as we know time will still move forward then. It's not like the diagrams you showed stopped progressing once maximum entropy was reached. Yes, perhaps it is practically impossible to distinguish the past from the future in a system of maximum entropy, but that doesn't mean that a past and a future don't exist in that system. Maybe we should simply consider entropy a natural phenomenon that occurs in temporal systems and the direction of entropy is only determined by the arrow of time of the temporal system. In other words, our existence does very much depend on the statistical phenomenon of entropy, but time itself (and the arrow of time) is what enables entropy to function in the first place.
Declare professor Greene the rockstar of science world 🤟🏼
If you wonder how to go from time flowing ahead to time flowing inverted, just take a look to the symbol "i" (aka imaginary unit) which appairs in some physic formulae.
Honest Question I would love an answer to: To Preface it, I will start with - Since we understand entropy by virtue of witnessing and experiencing it, then we see that time moves forward.... and that is based on the information we receive. When people talk about going backwards in time, the assumption they make is that they will carry... some sort of information with them that will be the catalyst for change, leading to a different future outcome. ....seems to me, however, that if we reverse time, we lose information. If I didn't know what the word "photosynthesis" meant and you explained it to me, I would learn. going backwards in time means returning to before I knew what the word meant. If I am returning to a point where I didn't know the meaning of the word.....I lost information. so, my question is the following: If we went backwards in time suddenly.... how would we even know? What test could be done where entropy is measured, then time is reversed and no information is lost? If I see a glass of milk and think "I will trip and spill this if I don't watch out for the cat" ....then the cat runs in my way, but I don't spill any milk..... obviously, that doesn't mean I tripped over the cat, spilled the milk, went back in time and 'intuitively knew' to avoid the approaching cat. So, is it possible that time, say... oscillates and we are unaware? if so, how could we tell either way? I've asked this before and the only answer I got was "we wouldn't survive such an experince"..... which makes no sense. You would be returning to a previous point in time..... where you were alive. if you survived making it through time the first time, you would go through the same stream of events you just went through. you survived it once....why would you die the next time? ......just curious. I'm probably not intelligent enough to get why this is a silly question but, I'm fine making an ass of myself... so, learning in the process isn't going to do me any harm 🙃
Can energy change entropy? If so, is there an equation that links energy and entropy?
Please make more videos on time and Quantum consciousness
In the coin example, all heads or all tails are just particular configurations of the coins, with equal probability than the other ones. We just define "all heads" or "all tails" as "ordered". So it's time just a concept? The likelihood of the unbroken glass of wine is the same of any individual configuration of the broken one. The only difference is that an unbroken glass of wine can be easily drank whereas the others don't. So we define that the unbroken configuration is the ordered one.
will the reverse procces will occur in the time moving forward or time moving backward??????? please give answer
Might Heisenberg's uncertainty principle be the reason the arrow of time cannot be used to restore, for example, the broken wine glass? Let's say that in the instant the glass hits the floor I measure several subatomic particles in the wine glass, and determine their specific position. Upon the restoration of the object, in the instant it begins to "unbreak" I measure the same particles to determine their momentum, since I already recorded my measurement of their location, I now know both, which Heisenberg doesn't allow.
I don’t understand how entropy increasing leads to me remembering the past and not the future. When we deviate and there is a rare fluctuation that reduces S, does that mean time has moved backwards?
Brian, how could the glass shards 'mend' together in reality? Wouldn't some kind of "melting of the glass shards" process(es) have to take place to mend the glass back together?
".....it is so unlikely that it will never happen in the real world...." Another word: IMPOSSIBLE. If the equation does not fit reality we are not changing reality. The equation has to be changed. Let's work on it Prof. Greene.
Dear Prof. Greene, What is your opinion about this Wikipedia entry (Entropy (arrow of time) 6.3 Cosmology): The universe was in a uniform, high density state at its very early stages, shortly after the Big Bang. The hot gas in the early universe was near thermodynamic equilibrium (...) and hence in a state of maximum entropy, given its volume. Expansion of a gas increases its entropy, however, and expansion of the universe has therefore enabled an ongoing increase in entropy. *Viewed* *from* *later* *eras,* *the* *early* *universe* *can* *thus* *be* *considered* *to* *be* *highly* *ordered* . The uniformity of this early near-equilibrium state has been explained by the theory of *cosmic* *inflation* .
Enjoyed it very much! I am thinking about the chemical reactions or crystallization, seems to be contrary to the second thermodynamic law but I know that the enthalpy and the heat released both increase the entropy for the whole system finally. But locally there is a transformation to a lower entropy still ... but as a whole it doesn't count. And how about if we look to a variable other than time, according to which the system entropy changes, such as space dimension? I understand that this is already in the system because it determines the probability of equivalent states or the no. of degrees of freedom. My question here, may be silly, would be: is there only the time that we think of when the entropy changes?
Entropy can certainly change with respect to any quantity other than time. But when you talk of entropy change with respect to space, time is implicitly a part of it. Space and time are one and inseparable.
Dear Prof Greene, what about causality principle that enforce time arrow? As said by Prof Hawking Universe seems to have chronology agency that forbid time travel to past...
Around 3 minutes in, I started to think about entropy in a different way. Those 3 examples were very good for building up the concept