Just because our universe reaches this high entropy state it would mean the totality of everything is over. And maybe we could defy entropy… that’s an interesting theoretical idea
Happy New Year Sean. Been a fan since I picked up your book 'The Particle at the End of the Universe' when I was just embarking on my PhD back in 2013. Your podcast is a gift to humanity.
At 65 years old- time has a different emphasis that what it use to. Long ago it was watching the clock at elementary school waiting to get outside to play- now- how much time do I have left. You know time goes faster when you get older. You know why? ...Because it's downhill.
I’ve successfully internalized the basic question! Before Sean said it, I was thinking of the only way I have come up with to describe the world without time. It’s the observation that Things. Change. Now, even this seems to have “time” hidden in the statement. If things didn’t change there would not even be a way to conceive that concept. Nothing would happen. Everything would be frozen like a picture, with no one to even observe the picture. You have to give some dimension to reality to be able to observe change. That thing is time. You can’t have change without this thing we call time, whatever it ultimately is. It seems essential to the functioning of our universe, even if it might not be fundamental.
My favorites are the hard science interviews... That's where Sean excels. The "soft science" (psych, sociology, philosophy, etc.) ones have much vaguer subject matter and are often fluff. I no longer listen to the AMAs. I was one of the people he first answered in AMA but after answering 3 of my questions he stopped answering any more from me, despite the fact that some listeners get their questions answered every time.
A surprisingly clear discussion of a topic that threatens to dissolve into obscurity. Oddly, the talk has an arc that corresponds to the theory of emergent time having a beginning and an end even when we don't know what the end will be.
Sean thank you for this solo episode // the more, the merrier // also getting a kick out of the "cosmic timepiece" video thumbnail with A.I.-drawn wobbly gears 😅
A happy and productive year for you and your family! I wish you would consider getting an electronic blackboard for the solo episodes. You don’t have to appear on camera but it would be helpful to get the graphs and equations pictured to make understanding easier. I realize it is easier to edit a podcast with an static image but I think the effort of adding a few graphs or equations would be not much effort and it would be a great service to us. May we be able to listen to you for a long time!
I’m only 9 minutes in, but it seems like the fact that time dilation has been observed is really the only nail you need for this coffin. But more than that, at its most fundamental, time is simply the property of the universe that allows for things to change, and things change. The fact that we are able to measure different rates of change for different observers is astonishing, and icing on the cake. This post has been brought to you by idiomatic expressions. Speaking of time, do you like saving time? Try an idiomatic expression! Idioms can cut down the time it takes for you to explain what you’re trying to say by 33%!! So use an idiom today. They’re FREE!!!
More fidelity in Page, Wootters and Albrecht kind of time evolution, than the relationist Connes, Rovelli evolution imo. I'm very intrigued by this talk, gonna research their papers! Thanks Sean!
A thought experiment relative to the Wheeler - Dewitt equation: Suppose that two black holes of equal mass are stabily orbiting each other 1000 light years apart. Do the respective bodies "feel" their partners where they were 1000 years ago? In theory nothing can move faster than the speed of light, including the respective space-time distortions surrounding the bodies. Does Wheeler-Dewitt propose that the time between them essentially does not exist? That is, their gravity waves may propagate at the speed of light, but their spoace-time distortions communicate with no delay? This would then add another layer to the dark matter or MOND question.
The problem with science today is we've adopted this position of "as below, so above", having rejected "as above, so below". There is no 'scalar primacy', they all affect each other. I'd like to see more discussion about scalar phase transitions and the qualities that lead to them.
Time is the existence of change. > Time = Change > Change = Existence > Existence = Time... Thus stating that: "Time does NOT exist." ... Seems like saying that 'Time does NOT Time' ... Or maybe rather 'Time is not Time'... Which seems somewhat meaningless 😛 - Thanks for all your great content Sean! You truly are a very gifted communicator... Clear, concise, articulate... and entertaining 😀 - Happy times in 2025!
I like to picture time as the block universe undergoing a phase transition in which it coalesces on a string of quantum events. Like a bolt of lightning going from a branching sea of possibilities to a single bolt on the ground.
But to say that entropy is increasing is to say that it is increasing across time, so how can something that is said to have a temporal direction while also being said to cause that temporal direction? I also question that one can speak of time without it having a direction, as this would be saying that change does not necessarily have a direction.
25:21 In order for some sort of pendulum to oscillate the universe would need to have gravity and that would result in the energy of the pendulum diffusing through space in the form of gravitational waves. That’s an increase in entropy, so this example doesn’t work. Is there *any* example that works?
I fell asleep to this and had a vivid dream Sean and I were discussing it. I periodically tried to interrupt him to say I wouldn't understand any of it, but he wouldn't let me! Generous but at the same time kinda rude. Lol
I think the time is an side effect of entanglement, more fields, particles and interactions, more entropy, faster time "speed" and vice versa If it's true in the cosmic voids time "speed" would be different from time in the regular spacetime
This was a brilliant episode. Incredible food for thought. Demanding at times but phenomenal. Sean I fall on the opposite side of belief to you regarding the "everything is happening everywhere all the time" argument where you say civilisations are popping into existence and falling constantly. Essentially (layman's take but I hope this is interesting), only histories that add up to 0 are able to exist. The existence of anything must be propelled by some process and the more I think about these things the more I feel it is just this pure mathematical driver persistently changing parameters and mathematical relationships of the forces of nature, dimensions, etc - time is a requirement for any universe that can exist, as these are the ones which have histories that "add up to static" effectively. The reason I believe this is because of the nothingness principle - why is there something instead of nothing? If the quantum state of a universe is the mathematically consistent part, only those universes that satisfy the Schrodinger equation and add up to static can ever exist. Otherwise youd have to have a system that can create something out of nothing. It seems like reality is specifically mathematics. The anthropic principle explains why we find ourselves in these ones, as usual.
I am confused about how you get to every state being visited. If we consider the phase space as a directed graph, then we should expect that the solution with a single cycle would be extraordinarily rare. Most cycles in a random direct graph would NOT visit all states. And of course, once a cycle is encountered, then the universe will visit no more new states. What is it that ensures that every single state is visited?
21:45 Is this seriously a big claim? I was asking this some years ago, and even said that "Space-Time" should really be called "Space-Dynamics" if people want to insist on keeping the 'time' element into the naming. It is pretty obvious that different stages of entropy can exist in the overall universe, we see it all the time, things get made and things get destroyed, birth/death etc., am i missing the point here? Entropy and thermodynamics are the descriptions we use for the process of change, Time as in seconds and hours is only relative to us, we use it to differentiate between periods or phases of the observed matter, through means of a set start and ending of the observation, a snapshot or interval, but the process of change is still there for observers no matter what name you give to it. Time is like degrees centigrade, whereas one effect of thermodynamics can be measured in temperatures, and another effect in hours and seconds. Without thermodynamics there would be no change, and without change there would be no time to make distinctive snapshot intervals. I am really confused why this claim would need a "huuuuge amount of work", i am more confused as to why this isn't common knowledge, or even common sense.
I do see how having a finite phase space and an infinite amount of time implies that you will visit states more than once (an infinite amount of times, in fact) but I don't see how it implies that you will visit all the states. How do you know that there can't be two states such that there is no way for the laws of physics to evolve one into the other?
Time is the label we put on the ever changing and evolution of the universe. But there's no clock, there is just the constant change of the state of the universe from its current state, to the next. And we always experience the current state.
Why combine space and time to form spacetime? The answer, I fairly believe, hides in plain sight. The word "time" closely approximates TIE + ME. In other words, time = ti + me, which implies "tie together". Pronunciation is an interpretation. Further, time spelled backward is emit.
Hi Sean Carroll, would it be possible to activate the automatic youtube audio transcription to spanish or another language, the whole world will thank you for it.
we need time for making measurements, collecting the results and for their further statistical analysis - which is the basics for the universe to appear out from the observations at the sight of the observer. therefore time is fundamental for us as observers and for our obsevable universe which is one thing with us.
Sean, isn't the measurement problem all about bringing the system to the 'now' moment? While you haven't measure the system it's state is in the future, when you do a measuremente you collapse the system into some kind of 'now'. I know that defining this now moment is a problem in itself, but think about this, the probabilistic state is always in the future, when you do a mesure, you mesure the present, and it's not probabilistic anymore..
is the clock ambiguity a problem? just because there could be other valid ways to formulate a time-like subsystem, we don't have to care about how the universe evolves from the perspective of any such subsystem except the one we are situated in, no?
On the intro and i agree that it is becoming popular to call potentially emergent properties as illusions and i find that wrong as well BUT i do hold the view that consciousness IS an emergent property of the biological supercomputer that we call the brain in a body in the world and not an illusion (as you said) but when it comes to free will there s evidence to suggest it is an illusion and the brain just interacts with the world, processes and reacts to stimuli all the time so fast before we re even conscious of it (if at all in a lot of cases) and that makes free will an illusion in that sense but i dont think you can call free will an emergent property in the physics sense of the term anyway.
*Time is the only resource.* 🐲✨🐲✨🐲✨ "Before I start, I must see my end. Destination known, my mind's journey now begins. Upon my chariot, heart and soul's fate revealed. In time, all points converge; hope's strength resteeled. But to earn final peace at the universe's endless refrain, we must see all in nothingness... before we start again." 🐲✨🐲✨🐲✨ --Diamond Dragons (series)
Hello Sean first of all my best wishes for you and your loved one . I have an important question that afflict my mind : According Schrodinger equation Time is absolute like in Newtonian physics , how do you reconcile this with the time dependence of the observer of relativity ?
If we make the square root of negative one or i, the imaginary unit, the field that represents the reference frame taking the measurement and place it above the stress energy tensor in Einstein’s field equations (Ruv - 1/2Rguv = 8piG) instead of an expectation value (^) of a probability distribution (from quantum mechanics), doesn’t that solve the measurement problem and quantize the time? The field (of the complex plane), which could be called the time, measurement, conscious, or tachyonic field interchangeably is quantized by the reference frame taking the measurement and consciousness and those that have it becomes the metric the universe uses to measure or experience the time. Consciousness is the non-local universe and also the non-local hidden variable or “spooky action at a distance” that is collapsing the wave function of the energy system it is observing. Is this not the only way Einstein’s theories of relativity, quantum field theory based on the standard model of particle physics, evolution by natural selection, and Gödel’s incompleteness theorem can work and be compatible with each other? It is not a theory of everything but a step that has to be taken to understand ourselves better. The act of measurement is the same thing as the universe measuring itself. The tachyon, consciousness, and the imaginary unit all appear to have the same characteristics and relativity becomes the fundamental piece of quantum field theory being the quantization of this field, or time. The reference frame taking the measurement is simultaneously in the past, can anticipate the future, and take measurements in the present to take the time. It is not only there simultaneously but before anything that is moving through spacetime, including photons, making it faster than the speed of light. If you also look at the ‘beginning’ when all of the energy and time in the universe was condensed to a single reference frame, that is where the entanglement of all things happen, and this non-local reference frame (before time) measures itself to create the time. For a tachyon to measure itself or slow down to the speed of light, it would require an infinite amount of energy to do so, creating conditions similar to what we think of as the Big Bang. If this was the case, then everything (all energy) would fall under one wavefunction. Perhaps Euler’s Identity represents a moment in time (e^ipi + 1 =0) that can be derived from Einstein’s field equations through the imaginary unit i. Consciousness would then be something that does not emerge from spacetime but fundamental to it. Gravity becomes the curvature of this particle or energy, which we will call the tachyon, measuring itself and consciousness (the reference frames that have it) becomes the metric that the universe uses to measure or perceive the time. Simply there is no time without consciousness. Even if consciousness was emergent from spacetime, what configuration of particles, made of unconscious ingredients, creates a conscious one? Even if you figured out that a specific configuration of particles creates a conscious experience, how would you be able to verify that? You would have to be the experience itself, no? This relates to Gödel’s incompleteness theorem in which the fundamental truth can only be experienced not described by words or numbers. That which cannot be described by words or numbers is fundamental, it is assumed. Consciousness is fundamental. If consciousness is emergent, how did the universe know to assemble itself together in a specific structure that would inevitably lead to a conscious experience? What is the probability of that? That has to be zero, correct? How can the universe and spacetime work any other way if these theories are correct? Relativity is the quantization of time disguised as the square root of negative one or i. The imaginary unit, the square root of negative one or i, is the energy or field that relativity theory is describing. We are the reference frames of the nonlocal universe (i) experiencing itself and collapsing the wave function of time once we make a measurement. Our consciousness is the metric the universe uses to measure or experience the time, we are the reference frames or quanta of this fundamental field.
Time and space are the result of moving slower than causality. Photons don’t experience time passing. We should consider this, the true reality. What photons experience. Over as soon as it began. Blip. That is time. That is space. That is the entire big bang beginning to end. Blip. Fermions, as opposed to bosons (photons, gluons) experience mass, and with it, the effects of velocity as well when accelerating. So time then can be said to be this experience, for fermions, slow motion blip. Key phrase ‘slow motion’ as causality to a fermion is slow enough to observe. This is in alignment with the notion of time being relative to the observer. The ‘observer’ is the fermionic system. Waddling through causality with its chunky mass having self. Creating a relational network and accruing like the state puff marshmallow man as it goes along, eventually falling through the very wake of causality through the density of its heft. Symmetric reunification with informational infinity. And on it goes. As nothing does not exist. Empirically. Objectively. In accordance with known physics. Ergo, the closest thing to it, must be considered a strong candidate for the most fundamental quanta, something. Something but only just. As wheeler put it, it from bit. Spacetime, our universe, is the or a, collapse of infinite causal information.
What if there is an underlying reality below the quantum. If so its not that nothing happens at equilibrium or that everything is happening, but simple something, perhaps a nothing sort of something, is happening but we don't have the ability to know what that something is. From our perspective, a rock seems like an object in an equilibrium state, but at a different level of representation than our perceptual level it is actually doing stuff. Ancient people may have assumed that the rock was static, but it's not.
If you have a podcast 1189 I want to be invited to speak then or 1681 either one of those. Thanks for an enjoyable evening listening to ideas about time. I really got to check out the Wheeler De Witt equation...
Yeah tgere is a spectrum of ways to have an infinite recurrance time or no recurrance time. From fundamentally dissipative physics, to an infinite set of false vacuas on top of each other, which would entail no recurrance time at all, nor well defined proper ground states and so on, and no min or max entropy for the fundamental mechanics.
If ya think eternity ain't 'bout endless time but more 'bout chillin' in the now, then livin' forever is for those who ride the present vibe. Ludwig Wittgenstein - probably
I don’t think present or eternal truly doesn’t matter to things like us, conscious beings, in the universe. Whatever the answer, we wouldn’t expect to see or experience anything different than we already do, either way.
Rather than thinking that the universe unfolds in time we can say that time unfolds because motion and things moving with a necessary orientation to their motion are fundamental. Entropy on this account is not related to time but to motion instead.
re: The Big Bang, the multiverse, and fizz-ics In the beginning, a young god punctures a can of Coca-Cola Classic and begins to pour. The soft drink expands outward from the center of a SOLO cup until it reaches the inner wall. A frothy, foamy sea of bubbles has formed atop the drink: a multiverse. Short-lived, the bubbles start to dissipate and collapse upon one another. The Coca-Cola goes flat. The multiverse falls lifeless.
Time emerges from space. If all the particles in the universe were so tightly packed together that they couldn't move, time would stop. Introduce space and the particles begin to move. Time starts to flow again.
Your efforts to sit down and record these lectures are greatly appreciated.
I have to admit, I love the solo and AMA episodes the most!! 💯
"Time is an illusion, Lunchtime doubly so" - Douglas Adams. Happy new year Sean, thanks for all of the amazing work and entertainment you provide.
Survival, Enquiry, and Civilisation: How can we eat? Why do we eat? Where shall we have lunch?
If you explain the joke...
They say nothing lasts forever, but I hope Sean Carroll's podcasts defy entropy.
Just because our universe reaches this high entropy state it would mean the totality of everything is over. And maybe we could defy entropy… that’s an interesting theoretical idea
Happy New Year Sean. Been a fan since I picked up your book 'The Particle at the End of the Universe' when I was just embarking on my PhD back in 2013. Your podcast is a gift to humanity.
Quite an excellent presentation, especially for your contrast and comparison of how the same phenomena are treated in GR versus quantum mechanics.
Congratulations Sean, may this continue to grow long into the future!
At 65 years old- time has a different emphasis that what it use to. Long ago it was watching the clock at elementary school waiting to get outside to play- now- how much time do I have left. You know time goes faster when you get older. You know why? ...Because it's downhill.
At 65 a yr is one 65th if your life at ten yrs old it's a 10th,hence the speed it goes by
Happy New Year and thanks for the continued delivery of excellent and thought-provoking content.
For me the solo episodes have always been my favorites :)
Hi Sean, I'm really enjoying your audiobooks. The many hidden worlds was fab. Looking forward to future releases :)
I’ve successfully internalized the basic question! Before Sean said it, I was thinking of the only way I have come up with to describe the world without time. It’s the observation that Things. Change. Now, even this seems to have “time” hidden in the statement. If things didn’t change there would not even be a way to conceive that concept. Nothing would happen. Everything would be frozen like a picture, with no one to even observe the picture. You have to give some dimension to reality to be able to observe change. That thing is time. You can’t have change without this thing we call time, whatever it ultimately is. It seems essential to the functioning of our universe, even if it might not be fundamental.
Hello everyone welcome to the mindscape podcast! ❤
I like this intro
Happy New Year to you, Jennifer, and the cats!
I love solo episodes like this! Thank you!
He Sean! Solo and AMA episodes are my favourite. thinking about time is unsettling
My favorites are the hard science interviews... That's where Sean excels. The "soft science" (psych, sociology, philosophy, etc.) ones have much vaguer subject matter and are often fluff. I no longer listen to the AMAs. I was one of the people he first answered in AMA but after answering 3 of my questions he stopped answering any more from me, despite the fact that some listeners get their questions answered every time.
Wish you a happy and great new year ahead, Dr. Carroll!! ❤🎉🙏🙌🙏🎉❤
Happy New Year! Happy 300!
A surprisingly clear discussion of a topic that threatens to dissolve into obscurity. Oddly, the talk has an arc that corresponds to the theory of emergent time having a beginning and an end even when we don't know what the end will be.
I learn so much and there's always at least a couple of laugh-out-louds. You teach with great humanity.
A good year this one is going to be indeed! May we all be healthy and well ☀
Sean thank you for this solo episode // the more, the merrier // also getting a kick out of the "cosmic timepiece" video thumbnail with A.I.-drawn wobbly gears 😅
Happy new year. I am trying to wake up and time keeps moving despite me not waking up.
Time is relative, especially wake up time!
Have been waiting for this for more than a year. ❤
What a gift to be able to listen to this.
A happy and productive year for you and your family!
I wish you would consider getting an electronic blackboard for the solo episodes. You don’t have to appear on camera but it would be helpful to get the graphs and equations pictured to make understanding easier. I realize it is easier to edit a podcast with an static image but I think the effort of adding a few graphs or equations would be not much effort and it would be a great service to us.
May we be able to listen to you for a long time!
Go watch his "Biggest Ideas" series.
39:53 Sean famously does not like to kill imaginary quantum cats but is happy to step on imaginary chaotic butterflies :(
Solo and AMA is best. Happy new year!
Happy new year Prof SC ! My favorite topic Time !!!
Happy new year Sean m Carroll .
I’m only 9 minutes in, but it seems like the fact that time dilation has been observed is really the only nail you need for this coffin. But more than that, at its most fundamental, time is simply the property of the universe that allows for things to change, and things change. The fact that we are able to measure different rates of change for different observers is astonishing, and icing on the cake. This post has been brought to you by idiomatic expressions. Speaking of time, do you like saving time? Try an idiomatic expression! Idioms can cut down the time it takes for you to explain what you’re trying to say by 33%!! So use an idiom today. They’re FREE!!!
Happy New year,,well done on the 300.
❤
I've been waiting for this 🎉
Congratulation, I've liked probably 300 of them so thank you for it.
Thank you so much. My happiness is emergent.
More fidelity in Page, Wootters and Albrecht kind of time evolution, than the relationist Connes, Rovelli evolution imo. I'm very intrigued by this talk, gonna research their papers! Thanks Sean!
A thought experiment relative to the Wheeler - Dewitt equation: Suppose that two black holes of equal mass are stabily orbiting each other 1000 light years apart. Do the respective bodies "feel" their partners where they were 1000 years ago? In theory nothing can move faster than the speed of light, including the respective space-time distortions surrounding the bodies. Does Wheeler-Dewitt propose that the time between them essentially does not exist? That is, their gravity waves may propagate at the speed of light, but their spoace-time distortions communicate with no delay? This would then add another layer to the dark matter or MOND question.
26:20 i have a question about the arrow of time: if you reverse the movie about the pendulum, wouldn't the forces applied to the pendulum be opposite?
The problem with science today is we've adopted this position of "as below, so above", having rejected "as above, so below". There is no 'scalar primacy', they all affect each other. I'd like to see more discussion about scalar phase transitions and the qualities that lead to them.
"There's a finite number of states, effectively"
You are technically correct, the best kind of correct
I enjoy the AMA solo episodes very much !
Time is the existence of change. > Time = Change > Change = Existence > Existence = Time... Thus stating that: "Time does NOT exist." ... Seems like saying that 'Time does NOT Time' ... Or maybe rather 'Time is not Time'... Which seems somewhat meaningless 😛
- Thanks for all your great content Sean! You truly are a very gifted communicator... Clear, concise, articulate... and entertaining 😀 - Happy times in 2025!
But try to find anything in existence equaling zero and it’s a fun part of math a social construct. Very real though.
I like to picture time as the block universe undergoing a phase transition in which it coalesces on a string of quantum events. Like a bolt of lightning going from a branching sea of possibilities to a single bolt on the ground.
Thanks Dr. Carroll! You rock!
But to say that entropy is increasing is to say that it is increasing across time, so how can something that is said to have a temporal direction while also being said to cause that temporal direction? I also question that one can speak of time without it having a direction, as this would be saying that change does not necessarily have a direction.
25:21 In order for some sort of pendulum to oscillate the universe would need to have gravity and that would result in the energy of the pendulum diffusing through space in the form of gravitational waves. That’s an increase in entropy, so this example doesn’t work. Is there *any* example that works?
Well done, Sean. Peace ✌️ 😎.
I fell asleep to this and had a vivid dream Sean and I were discussing it. I periodically tried to interrupt him to say I wouldn't understand any of it, but he wouldn't let me! Generous but at the same time kinda rude. Lol
Frickin magnets, how do they work? Love your presentations Dr. Carroll.....even if your are just an amalgamation of vibrating fields.
I think the time is an side effect of entanglement, more fields, particles and interactions, more entropy, faster time "speed" and vice versa
If it's true in the cosmic voids time "speed" would be different from time in the regular spacetime
This was a brilliant episode. Incredible food for thought. Demanding at times but phenomenal.
Sean I fall on the opposite side of belief to you regarding the "everything is happening everywhere all the time" argument where you say civilisations are popping into existence and falling constantly.
Essentially (layman's take but I hope this is interesting), only histories that add up to 0 are able to exist. The existence of anything must be propelled by some process and the more I think about these things the more I feel it is just this pure mathematical driver persistently changing parameters and mathematical relationships of the forces of nature, dimensions, etc - time is a requirement for any universe that can exist, as these are the ones which have histories that "add up to static" effectively.
The reason I believe this is because of the nothingness principle - why is there something instead of nothing? If the quantum state of a universe is the mathematically consistent part, only those universes that satisfy the Schrodinger equation and add up to static can ever exist. Otherwise youd have to have a system that can create something out of nothing.
It seems like reality is specifically mathematics. The anthropic principle explains why we find ourselves in these ones, as usual.
I am confused about how you get to every state being visited. If we consider the phase space as a directed graph, then we should expect that the solution with a single cycle would be extraordinarily rare. Most cycles in a random direct graph would NOT visit all states. And of course, once a cycle is encountered, then the universe will visit no more new states. What is it that ensures that every single state is visited?
21:45 Is this seriously a big claim? I was asking this some years ago, and even said that "Space-Time" should really be called "Space-Dynamics" if people want to insist on keeping the 'time' element into the naming.
It is pretty obvious that different stages of entropy can exist in the overall universe, we see it all the time, things get made and things get destroyed, birth/death etc., am i missing the point here?
Entropy and thermodynamics are the descriptions we use for the process of change, Time as in seconds and hours is only relative to us, we use it to differentiate between periods or phases of the observed matter, through means of a set start and ending of the observation, a snapshot or interval, but the process of change is still there for observers no matter what name you give to it.
Time is like degrees centigrade, whereas one effect of thermodynamics can be measured in temperatures, and another effect in hours and seconds.
Without thermodynamics there would be no change, and without change there would be no time to make distinctive snapshot intervals.
I am really confused why this claim would need a "huuuuge amount of work", i am more confused as to why this isn't common knowledge, or even common sense.
Thanks for the false vacuum. Just when I was coming to terms with a super volcano and nearby gamma ray burst, I have to add this to the list.
I do see how having a finite phase space and an infinite amount of time implies that you will visit states more than once (an infinite amount of times, in fact) but I don't see how it implies that you will visit all the states. How do you know that there can't be two states such that there is no way for the laws of physics to evolve one into the other?
A discussion on this topic with David Albert would be incredible please 🙏
Yeah but all David would say is "Ok--Good"...lol..jk...but factual...love David too though.
Thank you Dr. Carroll,
A chemistry student majoring in organic chemistry wants to study quantum mechanics. Where should they start? Can you recommend some books?
Time is the label we put on the ever changing and evolution of the universe. But there's no clock, there is just the constant change of the state of the universe from its current state, to the next. And we always experience the current state.
Why combine space and time to form spacetime? The answer, I fairly believe, hides in plain sight. The word "time" closely approximates TIE + ME. In other words, time = ti + me, which implies "tie together". Pronunciation is an interpretation. Further, time spelled backward is emit.
The entropy increases from past to future, but that is not the cause of so-called arrow of time, even the thermodynamics arrow of time.
Hi Sean Carroll, would it be possible to activate the automatic youtube audio transcription to spanish or another language, the whole world will thank you for it.
More technical the future of this podcast the better!!
we need time for making measurements, collecting the results and for their further statistical analysis - which is the basics for the universe to appear out from the observations at the sight of the observer. therefore time is fundamental for us as observers and for our obsevable universe which is one thing with us.
you know I can't resist that title.
Thanks for the podcast, Dr. Carroll. Can you tell me whether ENERGY really exists? 🤔
I get the impression some scientists use terms (like time being "illusory") because they think it sounds cool. It's almost like click-bait.
People have a habit of parroting the arguments word for word while pretending that they came up with the idea.
1 step away from flat earth.
Sean, isn't the measurement problem all about bringing the system to the 'now' moment? While you haven't measure the system it's state is in the future, when you do a measuremente you collapse the system into some kind of 'now'. I know that defining this now moment is a problem in itself, but think about this, the probabilistic state is always in the future, when you do a mesure, you mesure the present, and it's not probabilistic anymore..
the Definition of what a universe is looks like it needs to be defined, it seams like the ambiguity of words drives science more that results
is the clock ambiguity a problem? just because there could be other valid ways to formulate a time-like subsystem, we don't have to care about how the universe evolves from the perspective of any such subsystem except the one we are situated in, no?
This is fine. I didn't need to sleep ever again.
On the intro and i agree that it is becoming popular to call potentially emergent properties as illusions and i find that wrong as well BUT i do hold the view that consciousness IS an emergent property of the biological supercomputer that we call the brain in a body in the world and not an illusion (as you said) but when it comes to free will there s evidence to suggest it is an illusion and the brain just interacts with the world, processes and reacts to stimuli all the time so fast before we re even conscious of it (if at all in a lot of cases) and that makes free will an illusion in that sense but i dont think you can call free will an emergent property in the physics sense of the term anyway.
2:09:35 What would be of physics without spheric cows! xD
*Time is the only resource.*
🐲✨🐲✨🐲✨
"Before I start, I must see my end. Destination known, my mind's journey now begins. Upon my chariot, heart and soul's fate revealed. In time, all points converge; hope's strength resteeled. But to earn final peace at the universe's endless refrain, we must see all in nothingness... before we start again."
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--Diamond Dragons (series)
Hello Sean first of all my best wishes for you and your loved one .
I have an important question that afflict my mind :
According Schrodinger equation Time is absolute like in Newtonian physics , how do you reconcile this with the time dependence of the observer of relativity ?
Just in time!
in my calculations, i had to stop time in order to have a residue that would collapse dimensionally, for pendulums to start ticking.
Is an interval of time; a time of time?
Babe wake up a new Sean Carroll solo just dropped
If we make the square root of negative one or i, the imaginary unit, the field that represents the reference frame taking the measurement and place it above the stress energy tensor in Einstein’s field equations (Ruv - 1/2Rguv = 8piG) instead of an expectation value (^) of a probability distribution (from quantum mechanics), doesn’t that solve the measurement problem and quantize the time? The field (of the complex plane), which could be called the time, measurement, conscious, or tachyonic field interchangeably is quantized by the reference frame taking the measurement and consciousness and those that have it becomes the metric the universe uses to measure or experience the time. Consciousness is the non-local universe and also the non-local hidden variable or “spooky action at a distance” that is collapsing the wave function of the energy system it is observing. Is this not the only way Einstein’s theories of relativity, quantum field theory based on the standard model of particle physics, evolution by natural selection, and Gödel’s incompleteness theorem can work and be compatible with each other? It is not a theory of everything but a step that has to be taken to understand ourselves better. The act of measurement is the same thing as the universe measuring itself. The tachyon, consciousness, and the imaginary unit all appear to have the same characteristics and relativity becomes the fundamental piece of quantum field theory being the quantization of this field, or time. The reference frame taking the measurement is simultaneously in the past, can anticipate the future, and take measurements in the present to take the time. It is not only there simultaneously but before anything that is moving through spacetime, including photons, making it faster than the speed of light. If you also look at the ‘beginning’ when all of the energy and time in the universe was condensed to a single reference frame, that is where the entanglement of all things happen, and this non-local reference frame (before time) measures itself to create the time. For a tachyon to measure itself or slow down to the speed of light, it would require an infinite amount of energy to do so, creating conditions similar to what we think of as the Big Bang. If this was the case, then everything (all energy) would fall under one wavefunction. Perhaps Euler’s Identity represents a moment in time (e^ipi + 1 =0) that can be derived from Einstein’s field equations through the imaginary unit i. Consciousness would then be something that does not emerge from spacetime but fundamental to it. Gravity becomes the curvature of this particle or energy, which we will call the tachyon, measuring itself and consciousness (the reference frames that have it) becomes the metric that the universe uses to measure or perceive the time. Simply there is no time without consciousness. Even if consciousness was emergent from spacetime, what configuration of particles, made of unconscious ingredients, creates a conscious one? Even if you figured out that a specific configuration of particles creates a conscious experience, how would you be able to verify that? You would have to be the experience itself, no? This relates to Gödel’s incompleteness theorem in which the fundamental truth can only be experienced not described by words or numbers. That which cannot be described by words or numbers is fundamental, it is assumed. Consciousness is fundamental. If consciousness is emergent, how did the universe know to assemble itself together in a specific structure that would inevitably lead to a conscious experience? What is the probability of that? That has to be zero, correct? How can the universe and spacetime work any other way if these theories are correct? Relativity is the quantization of time disguised as the square root of negative one or i. The imaginary unit, the square root of negative one or i, is the energy or field that relativity theory is describing. We are the reference frames of the nonlocal universe (i) experiencing itself and collapsing the wave function of time once we make a measurement. Our consciousness is the metric the universe uses to measure or experience the time, we are the reference frames or quanta of this fundamental field.
Time and space are the result of moving slower than causality. Photons don’t experience time passing. We should consider this, the true reality. What photons experience. Over as soon as it began. Blip. That is time. That is space. That is the entire big bang beginning to end. Blip. Fermions, as opposed to bosons (photons, gluons) experience mass, and with it, the effects of velocity as well when accelerating. So time then can be said to be this experience, for fermions, slow motion blip. Key phrase ‘slow motion’ as causality to a fermion is slow enough to observe. This is in alignment with the notion of time being relative to the observer. The ‘observer’ is the fermionic system. Waddling through causality with its chunky mass having self. Creating a relational network and accruing like the state puff marshmallow man as it goes along, eventually falling through the very wake of causality through the density of its heft. Symmetric reunification with informational infinity. And on it goes. As nothing does not exist. Empirically. Objectively. In accordance with known physics. Ergo, the closest thing to it, must be considered a strong candidate for the most fundamental quanta, something. Something but only just. As wheeler put it, it from bit. Spacetime, our universe, is the or a, collapse of infinite causal information.
Can someone answer the question please.
What if there is an underlying reality below the quantum. If so its not that nothing happens at equilibrium or that everything is happening, but simple something, perhaps a nothing sort of something, is happening but we don't have the ability to know what that something is. From our perspective, a rock seems like an object in an equilibrium state, but at a different level of representation than our perceptual level it is actually doing stuff. Ancient people may have assumed that the rock was static, but it's not.
If you have a podcast 1189 I want to be invited to speak then or 1681 either one of those. Thanks for an enjoyable evening listening to ideas about time. I really got to check out the Wheeler De Witt equation...
Happy New Year and thanks for the upload!
Yeah tgere is a spectrum of ways to have an infinite recurrance time or no recurrance time. From fundamentally dissipative physics, to an infinite set of false vacuas on top of each other, which would entail no recurrance time at all, nor well defined proper ground states and so on, and no min or max entropy for the fundamental mechanics.
If ya think eternity ain't 'bout endless time but more 'bout chillin' in the now, then livin' forever is for those who ride the present vibe. Ludwig Wittgenstein - probably
I don’t think present or eternal truly doesn’t matter to things like us, conscious beings, in the universe. Whatever the answer, we wouldn’t expect to see or experience anything different than we already do, either way.
Solo podcasts 4 lyfee!!!!
Rather than thinking that the universe unfolds in time we can say that time unfolds because motion and things moving with a necessary orientation to their motion are fundamental. Entropy on this account is not related to time but to motion instead.
Cool. Thank you.
re: The Big Bang, the multiverse, and fizz-ics
In the beginning, a young god punctures a can of Coca-Cola Classic and begins to pour. The soft drink expands outward from the center of a SOLO cup until it reaches the inner wall. A frothy, foamy sea of bubbles has formed atop the drink: a multiverse. Short-lived, the bubbles start to dissipate and collapse upon one another. The Coca-Cola goes flat. The multiverse falls lifeless.
Weeeeeeeee........................d?
Sounds like a scene from "Allegro Non Troppo"
2:05:33 "...sounds more sciencey"
Why does emergent equal not real? I am emergent from my parents. Hello!
What happens in to time in universe that is indifferent to time? The universe is mass and energy and particles all of which are cannot be destroyed.
Time emerges from space. If all the particles in the universe were so tightly packed together that they couldn't move, time would stop. Introduce space and the particles begin to move. Time starts to flow again.
Kinda sucks that the state of the universe is static but we're still all gonna die someday
If the universe was static, would we be here? How could anything grow?
From the past to the future.
Not to the past, cant go back there, since you would need a universe at hand to reverse it, and you are in it.
I wish time was fundamental. I wish there was matter that wasn’t invisible to perception, but I might be wrong.
300 even numbered episodes hmmmmm, have you got 300 odd numbered episodes too?
And they gave him a PhD....lol...jk