Mysteries of Modern Physics: Time

Course No. 1257
Professor Sean Carroll, Ph.D.
California Institute of Technology
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Course No. 1257
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Course Overview

Time rules our lives. From the rising and setting of the sun to the cycles of nature, the thought processes in our brains, and the biorhythms in our day, nothing so pervades our existence and yet is so difficult to explain. Time seems to be woven into the very fabric of the universe. But why?

Consider these contrasting views of time:

  • A movie of a person diving into a pool has an obvious arrow of time. When the movie is played backward, everyone recognizes that it shows an event that would never occur in the real world.
  • But zoom in on any part of this scene at the atomic scale and the movie can be run backward or forward and be indistinguishable. Either way, the particle interactions are consistent with the laws of physics.

Why does one movie have an arrow of time moving in only one direction and the other does not? Surprisingly, the search for an answer leads through some of the most pioneering fields of physics, including thermodynamics, relativity, quantum theory, and cosmology.

The key concept is called “entropy,” which is related to the second law of thermodynamics, considered by many scientists to be the most secure law in all of physics. The second law has even been compared to Shakespeare’s plays in its importance to the education of a culturally informed person.

But that’s only the beginning, since the quest for the ultimate theory of time draws on such exciting ideas as black holes, cosmic inflation, and dark energy, before closing in on a momentous question that until recently was considered unanswerable: What happened before the big bang?

In 24 riveting half-hour lectures, Mysteries of Modern Physics: Time takes you on a mind-expanding journey through the past, present, and future, guided by Professor Sean Carroll, noted author and Senior Research Associate in Physics at the California Institute of Technology.

Designed for nonscientists as well as those with a background in physics, Mysteries of Modern Physics: Time shows how a feature of the world that we all experience connects us to the instant of the formation of the universe—and possibly to a multiverse that is unimaginably larger and more varied than the known cosmos.

While focusing on physics, Professor Carroll also examines philosophical views on time, how we perceive and misperceive time, the workings of memory, and serious proposals for time travel, as well as imaginative ways that time has been disrupted in fiction.

Clues to the Origin of Time

Break an egg. Melt an ice cube. Mix coffee and cream. Each starts with an ordered state and ends with one that is much more disorderly. Each is an example of an increase in entropy, which is a measure of the degree of disorder in a closed system. The entropy of the universe was lower in the past; it will be higher in the future. Increasing entropy defines the arrow of time, implying that at the beginning of the universe entropy must have been extraordinarily low. This course seeks to understand why.

Professor Carroll begins like a detective by gathering the facts. What do we know about time, what characterizes it, and how do we measure it? Then he combs the universe for clues, from the contrasting views on time of Isaac Newton and Albert Einstein, to Rudolf Clausius’s invention of the concept of entropy and Ludwig Boltzmann’s brilliant insight about why entropy increases and therefore why time proceeds from past to future.

You explore Boltzmann’s statistical explanation for the nature of time, and you see how, carried to its logical conclusion, it leads to a bizarre scenario called Boltzmann brains. You look at another curious thought experiment, called Maxwell’s demon, which helps explain the presence of order and life in a universe of relentlessly increasing disorder.

In the course of these inquiries, you consider time from many perspectives, including these:

  • A dimension with a difference: Time is the fourth dimension. But unlike the three dimensions that constitute space, time can’t be explored randomly from point to point. You just experience it sequentially second after second. This continuous flow from past to future is the arrow of time.
  • The view from “nowhen”: The present moment seems real in a way that the past and future do not. But to better understand why time and the universe are the way they are, it’s useful to view all moments—past, present, and future—as equally real. This is the view from “nowhen.”
  • Quantum time: Some phenomena at the quantum scale are not reversible with respect to time—unlike all other processes in fundamental physics. Could these events be the origin of the arrow of time? Could they explain why we remember the past but not the future?

You also investigate the past hypothesis, which assumes that atomic theory and fundamental physics cannot account for the difference between the past and the future by themselves. Instead, the arrow of time can only be explained by the initial conditions that gave birth to the universe itself. Which brings you to the big bang, one of the major focuses of this course.

Time to Get This Course

Your time-traveling adventures also include excursions into fiction and film, which Professor Carroll engages with characteristic enthusiasm and wit. While storytellers are seldom concerned with getting the physics right, it’s instructive how they usually get it very wrong:

  • Stopping time: Stories that stop time as the hero moves through a stationary world fail to consider that no one could function in such an environment. Air would be as immovable as a brick wall. Light and sound would stop. No plot would be possible!
  • Time going backward: A character who experiences the arrow of time in reverse faces grave difficulties relating to another character going through time the normal way. They would be like travelers on the highway going in opposite directions.
  • Time travel: Fictional time travelers typically dematerialize and then rematerialize at a different point in time. But real time travel, if it were possible, could not skip over the intervening part of spacetime. Real time travel would be a journey through spacetime.

In the time that has passed since you started reading this, the entropy of the universe has increased. The future of a few moments ago is now the present. You are at a different point in spacetime, even if you haven’t moved from your chair. “What is time?” asked Saint Augustine 1,600 years ago. “If no one asks me, I know. But if I wish to explain it to someone who asks, I know not.” With Mysteries of Modern Physics: Time, you will be much closer to an answer.

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24 lectures
 |  Average 30 minutes each
  • 1
    Why Time Is a Mystery
    Begin your study of the physics of time with these questions: What is a clock? What does it mean to say that “time passes”? What is the “arrow of time”? Then look at the concept of entropy and how it holds the key to the one-way direction of time in our universe. x
  • 2
    What Is Time?
    Approach time from a philosophical perspective. “Presentism” holds that the past and future are not real; only the present moment is real. However, the laws of physics appear to support “eternalism”—the view that all of the moments in the history of the universe are equally real. x
  • 3
    Keeping Time
    How do we measure the passage of time? Discover that practical concerns have driven the search for more and more accurate clocks. In the 18th century, the problem of determining longitude was solved with a timepiece of unprecedented accuracy. Today’s GPS navigation units rely on clocks accurate to a billionth of a second. x
  • 4
    Time’s Arrow
    Embark on the quest that will occupy the rest of the course: Why is there an arrow of time? Explore how memory and aging orient us in time. Then look at irreversible processes, such as an egg breaking or ice melting. These capture the essence of the one-way direction of time. x
  • 5
    The Second Law of Thermodynamics
    Trace the history of the second law of thermodynamics, considered by many physicists to be the one law of physics most likely to survive unaltered for the next thousand years. The second law says that entropy—the degree of disorder in a closed system—only increases or stays the same. x
  • 6
    Reversibility and the Laws of Physics
    Isaac Newton’s laws of physics are fully reversible; particles can move forward or backward in time without any inconsistency. But this is not our experience in the world, where the arrow of time is fundamentally connected to irreversible processes and the increase in entropy. x
  • 7
    Time Reversal in Particle Physics
    Explore advances in physics since Newton’s time that reveal exceptions to the rule that interactions between moving particles are fully reversible. Could irreversible reactions between elementary particles explain the arrow of time? Weigh the evidence for and against this view. x
  • 8
    Time in Quantum Mechanics
    Quantum mechanics is the most precise theory ever invented, yet it leads to startling interpretations of the nature of reality. Probe a quantum state called the collapse of the wave function that may underlie the arrow of time. Are the indications that it shows irreversibility real or only illusory? x
  • 9
    Entropy and Counting
    After establishing in previous lectures that the arrow of time must be due to entropy, begin a deep exploration of this phenomenon. In the 1870s, physicist Ludwig Boltzmann proposed a definition of entropy that explains why it increases toward the future. Analyze this idea in detail. x
  • 10
    Playing with Entropy
    Sharpen your understanding of entropy by examining different macroscopic systems and asking, which has higher entropy and which has lower entropy? Also evaluate James Clerk Maxwell’s famous thought experiment about a demon who seemingly defies the principle that entropy always increases. x
  • 11
    The Past Hypothesis
    Boltzmann explains why entropy will be larger in the future, but he doesn’t show why it was smaller in the past. Learn that physics can’t account for this difference except by assuming that the universe started in a state of very low entropy. This assumption is called the past hypothesis. x
  • 12
    Memory, Causality, and Action
    Can physics shed light on human aspects of the arrow of time such as memory, cause and effect, and free will? Learn that everyday features of experience that you take for granted trace back to the low entropy state of the universe at the big bang, 13.7 billion years ago. x
  • 13
    Boltzmann Brains
    One possible explanation for order in the universe is that it is a random fluctuation from a disordered state. Could the entire universe be one such fluctuation, now in the process of returning to disorder? Investigate a scenario called “Boltzmann brains” that suggests not. x
  • 14
    Complexity and Life
    Discover that Maxwell’s demon from lecture 10 provides the key to understanding how complexity and life can exist in a universe in which entropy is increasing. Consider how life is not only compatible with, but is an outgrowth of, the second law of thermodynamics and the arrow of time. x
  • 15
    The Perception of Time
    Turn to the way humans perceive time, which can vary greatly from clock time. In particular, focus on experiments that shed light on our time sense. For example, tests show that even though we think we perceive the present moment, we actually live 80 milliseconds in the past. x
  • 16
    Memory and Consciousness
    Remembering the past and projecting into the future are crucial for human consciousness, as shown by cases where these faculties are impaired. Investigate what happens in the brain when we remember, exploring different kinds of memory and the phenomena of false memories and false forgetting. x
  • 17
    Time and Relativity
    According to Einstein’s special theory of relativity, there is no such thing as a moment in time spread throughout the universe. Instead, time is one of four dimensions in spacetime. Learn how this “relative” view of time is usefully diagramed with light cones, representing the past and future. x
  • 18
    Curved Spacetime and Black Holes
    By developing a general theory of relativity incorporating gravity, Einstein launched a revolution in our understanding of the universe. Trace how his idea that gravity results from the warping of spacetime led to the discovery of black holes and the big bang. x
  • 19
    Time Travel
    Use a simple analogy to understand how a time machine might work. Unlike movie scenarios featuring dematerializing and rematerializing, a real time machine would be a spaceship that moves through all the intervening points between two locations in spacetime. Also explore paradoxes of time travel. x
  • 20
    Black Hole Entropy
    Stephen Hawking showed that black holes emit radiation and therefore have entropy. Since the entropy in the universe today is overwhelmingly in the form of black holes and there were no black holes in the early universe, entropy must have been much lower in the deep past. x
  • 21
    Evolution of the Universe
    Follow the history of the universe from just after the big bang to the far future, when the universe will consist of virtually empty space at maximum entropy. Learn what is well founded and what is less certain about this picture of a universe winding down. x
  • 22
    The Big Bang
    Explore three different ways of thinking about the big bang—as the actual beginning of the universe; as a “bounce” from a symmetric version of the universe on the other side of the big bang; and as a region that underwent inflationary expansion in a much larger multiverse. x
  • 23
    The Multiverse
    Dig deeper into the possibility that the big bang originated in a multiverse, which provides a plausible explanation for why entropy was low at the big bang, giving rise to the arrow of time. But is this theory and the related idea of an anthropic principle legitimate science or science fiction? x
  • 24
    Approaches to the Arrow of Time
    Use what you have learned in the course to investigate a range of different possibilities that explain the origin of time in the universe. Professor Carroll closes by presenting one of his favorite theories and noting how much remains to be done before conclusively solving the mystery of time. x

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Your professor

Sean Carroll

About Your Professor

Sean Carroll, Ph.D.
California Institute of Technology
Professor Sean Carroll is a Senior Research Associate in Physics at the California Institute of Technology. He earned his undergraduate degree from Villanova University and his Ph.D. in Astrophysics from Harvard in 1993. Before arriving at Caltech, Professor Carroll taught in the Physics Department and the Enrico Fermi Institute at the University of Chicago, and did postdoctoral research at the Massachusetts Institute of...
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Mysteries of Modern Physics: Time is rated 4.1 out of 5 by 123.
Rated 4 out of 5 by from Is relevant to the title. I recomend to translate in spanish. Should be more blackboard graphics and demostrations as in classroom.
Date published: 2019-07-29
Rated 5 out of 5 by from This is the third teaching company course I have had with Professor Carrol. It was excellent
Date published: 2019-07-27
Rated 5 out of 5 by from This is an appropriate title for this course. I've read several books and watched other presentations about this topic, but kudos to Sean Carroll for giving us one of the best explanations I've heard. Taking an arcane subject like the physics of time and trying to explain it in a popular fashion is no easy task, but he choses appropriate examples and keeps focused and on topic. His careful editing and selective repetition of the material helps you stay on track. While I wouldn't recommend this to someone who is very unfamiliar with this topic, those who have an interest and who put the effort in, will be well rewarded. I also appreciate that he does add some equations to help support the material. I am ranking this course a five. It is one of the best ones I've bought.
Date published: 2019-06-14
Rated 5 out of 5 by from Masterful Teacher The professor teaches without reliance on visible notes. He has a great grasp of the subject and presents it in a manner that holds your attention. I am truly enjoying his lectures.
Date published: 2019-05-30
Rated 3 out of 5 by from Format problem I purchased this item reluctantly because I prefer to listen to the courses while driving. Although, in this case, I was so interested in learning more about “time” at additional expense, I bought the visual format. However, when playing course, I saw no reason for that format! Very disappointed.
Date published: 2019-04-14
Rated 5 out of 5 by from Mind Stretching This course is based on physics, philosophy, mathematics, cosmology, astronomy, and enhanced self awareness. I have gone through all twenty four lessons and am now starting over. The content is so extensive that I think it will take another pass to begin to remember everything and that might not be adequate. The characteristic of the course is that there are many difficult topics treated fairly comprehensively but the range of topics is equivalent to more than a few college courses.
Date published: 2019-04-07
Rated 5 out of 5 by from Stimulating With and academic background in history and political science, I want to explore disciplines beyond my comfort zone. I found this series by Dr. Carroll fascinating. While I don't pretend to understand all that was presented, I thoroughly enjoyed the intellectual stimulation and piqued my interest for further courses in physics and cosmology
Date published: 2019-04-02
Rated 5 out of 5 by from Great Course in Demystifying the Mystery of Time Initially mundane with discussions of the engineering aspects of thermal energy, focusing on19th Century steam engine technology, and smattering of History topics, Professor Carroll delved into various modern topics in Physics such as Thermodynamics, Quantum Mechanics, Elementary Particles, Relativity, etc., and the lectures became considerably more stimulating and interesting. Professor Carroll has the unusual ability to explain difficult Physics concepts with clarity, organization and insight, but would not "talk above the heads of the audience". The caveat for some viewing the course lectures without basic understanding of college science is that one should have some basic requisite scientific knowledge to be capable of understanding Professor Carroll's lectures, i.e., preferably college-level Physics but not anything more advanced such as upper-division or graduate studies. Courses in Chemistry or Engineering involving Heat, Thermodynamics, Classical Mechanics (Dynamics, etc.), Molecular Science/Modern Physics and Electrical Energy/Electricity would be extremely helpful. All in all, this is an excellent course taught by an outstanding Caltech faculty member - an advanced and abstract subject such as Time would require a brilliant mind to deliver the lectures and offer explanations accessible to those who are not research physicists. BTW, Professor Carroll's lecture style enabled me to complete viewing of all of the lectures on the DVD disks on "Time", a matter I admit I have yet to follow through with many other DVD ones I purchased from Great Courses! How about a follow-on course based on more advanced concepts on related Physics taught by Professor Carroll?
Date published: 2019-02-24
Rated 4 out of 5 by from Time, Is There a Question? This course spends a great deal of time answering the question of why there is an arrow of time. The course tries to answer this using the second law of thermodynamics. In fact, half the course wanders around the discovery of the second law. This course was interesting and it did hold my attention although I don't think I actually learned anything I didn't know.
Date published: 2019-02-05
Rated 4 out of 5 by from Time: Still a Mystery Professor Carrol is a great mind and the concept of time is really difficult. If the question is "Why is there and arrow of time?", that implies looking for a cause. I think spending so much effort on the second law of thermodynamics showed a correlation, but not a cause. That key question wasn't answered. Having said that, I learned a great deal in the course and was pleased by the information. It's not his shortcoming that we haven't yet figured out what time actually is. My own uneducated idea is that time has more to do with the fact that the speed of light is not infinite. Light takes time.
Date published: 2019-01-02
Rated 5 out of 5 by from Mysteries of Modern Physics: Time A great course, easy to understand, interesting topics, well prepared and professional presentation. Highly recommend to those who are interested in Science and Physics but without in-depth knowledge of these subjects. You will learn a lot from this course, good value (knowledge) for money.
Date published: 2018-12-14
Rated 5 out of 5 by from Brilliant Attempt to Understand the Arrow of Time! Mysteries of Modern Physics: Time presented by Dr. Sean Carroll is OUTSTANDING! Sean is unleashed at the start of each lecture and never misses a beat. It is obvious he is sharing his lifetime work in physics and cosmology and there is no script. I had purchased the lecture set to casually review and gain some insights into the arrow of time, but was I wrong! Dr. Carroll is mesmerizing and eventually found myself wanting to become a cosmologist. He is brilliant in a matter of fact way as he discusses entropy and it relationship to the arrow of time. I have now purchased over 300 lecture sets and this is in the top 5! I highly recommend this lecture set and especially Dr. Sean Carroll. I am going to purchase every other set he had produced!!
Date published: 2018-12-07
Rated 5 out of 5 by from Time An excellent explanation of time, mostly from the viewpoint of physics, especially the notion of entropy. It did make me realize the full impact of Newton, wherein the philosophers thought they had beat the arrow of time with the advent of a fully mechanistic and hence predictable universe. That euphoria is long gone.
Date published: 2018-12-01
Rated 5 out of 5 by from Mysteries of Modern Physics: Time One of the best of the Great Courses, and I have quite a few. Sean Carroll is an excellent teacher. He does not talk down to the viewer but at the same time uses language that non-physicists can understand. An exceptional course.
Date published: 2018-11-28
Rated 5 out of 5 by from Mysteries of Modern Physics : Time Sean Carroll is a gifted lecturer and writer. All of his Great Courses projects are first-class.
Date published: 2018-10-22
Rated 5 out of 5 by from My BA is in general education and MA in educational counseling (background) and other than "general" science courses I have little background in advanced physics nor concepts of relativity. Having stated this I was quite pleased with this course (although there was more than one "rewind" to review/understand certain concepts and ideas) and tout the gateway foundation to delve deeper into quantum physics (now that I've retired I plan on eventually attempting to truly understand Rodger Penrose's writings) and how the universe actually functions on all levels. I have already ordered and received the course on Chaos, partly due to the way the present course was setup and presented. HIGHLY recommend this course to anyone not already versed in the space/time aspects of quantum physics.
Date published: 2018-09-22
Rated 5 out of 5 by from Lifes big questions I've just finished watching this for the second time. I have many of these courses and all of the professors are excellent. Professor Carroll is probably my favorite. He has a way of discussing the most complex subjects in a way I can understand even though I have virtually no formal education in physics, cosmology, and the rest. I also have the other two courses of his which I plan on watching multiple times. My fervent hope is The Great Courses will bring him back for more courses in the future.
Date published: 2018-08-26
Rated 1 out of 5 by from Repatative course, I didn't learn much This is my first review. I think it only fitting that I warn others that this course, unfortunately is a dud. Professor Carrol does not just physics in this course. He tries to take journeys in the history of clocks, and other non-physics disciplines - which in my opinion makes the title of the course inaccurate. It should be re titled. A better presenter, I think would be Dean Buonomano the author of the recent book "Your Brain is a Time Machine" - or even better MULTIPLE presenters with fields in philosophy, neuroscience and physics... All I learnt was that entropy is correlated with the passage of time, that the past has less entropy, (the past hypothesis) and that the 2nd law of thermodynamics is correct in predicting more entropy. We don't know why the early universe had less entropy, because we do not know how the big bang happened. I was thrilled in the first 3 lectures or so because I thought I was going to get some sort of physics of time, but what I got was a lot of waffling on the point. Professor Carrol should review his remarks and make them concise and to the point, with better titles for the sections. I would like to see a purely physics presentation with a more concise structure next time in a second edition, which I would consider purchasing.
Date published: 2018-08-25
Rated 2 out of 5 by from tries to cover too much and can't pull it off I was expecting this to deal with time primarily from the perspective of science but obviously science is not clear on this topic and/or the presenter seems not to be. So rather than focus down on maybe the history of our scientifically evolving understanding of the phenomenon we call time he unfortunately jumps from philosophy to psychology and literature to science and back in what seems to be a haphazard manner. I plowed through but found it generally unsatisfying and did not feel at all enlightened about time.
Date published: 2018-06-23
Rated 1 out of 5 by from don't buy it I have bought 74 courses through "great courses." I've generally liked them. Some have been too basic. "Time" was a total waste of my time and money. With each lecture, I thought...what did I learn from this? Very little.
Date published: 2018-06-21
Rated 1 out of 5 by from mysteries of modern physics:time Too simplistic,shies away from math too much to give good context. Too repetitve-it seems like he thinks I do not hear what he has already said.
Date published: 2018-06-16
Rated 4 out of 5 by from Somewhat disappointed Some portions were interesting but entropy discussion ignore current approach to describing entropy with less emphasis on Boltzman
Date published: 2018-05-24
Rated 5 out of 5 by from Excelent course Very interesting and well presented. Both people with some background in physics and those who lack the basic knowledge but are interested in the subject can benefit from the course.
Date published: 2018-04-14
Rated 5 out of 5 by from Interesting and addictive Of all the Courses I have bought from the Great Courses, this is the first CD (audio only) one I have bought. I thought I was getting the DVD and was somewhat disappointed. However, the CD forces me to pay more attention to the course material and I find myself imagining what the DVD would be like at that time. Not sorry at all.
Date published: 2018-04-06
Rated 1 out of 5 by from Too Speculative The lecturer is trying to deal with a difficult subject, and I give him great credit forthis. However, the style at times appears ad lib or more like a rant than a carefully reasoned thesis. The only solid point he appears to make- and he does this over and over again- is that entropy increases with time and the changes cannot be readily reversed. The remainder of the course, through no real fault of his own, is speculation. Hence, the amount of solid information you will garner from this course is not great.
Date published: 2018-03-19
Rated 5 out of 5 by from The best Great Course I've ever experienced. Outstanding. The focus on "time" may mislead people into believing this is a narrow topic. Instead, time is used as a framework for an expansive tour of modern physics, from entropy to Einstein, from the big bang to black holes, from quantum mechanics to the multiverse. The result is an informative and entertaining tour de force. Sean Carroll is not only a genius physicist, he's also a genius communicator. He has a remarkable ability to distill subjects in a manner that is constantly and surprisingly entertaining. With extremely well-written and well-organized sessions, Dr. Carroll leads the viewer through historical, physical, and even mechanical concepts of time, along the way introducing viewers to thermodynamics, relativity, particle physics, cosmology, and much more. That makes this course not only a fascinating introduction to time as a concept of physics but also a solid primer for anyone desiring an overview of the state of physics today. It's also a fascinating study in how physics works. Dr. Carroll reveals the scientists behind the development of time as a concept and relates their work to steam engines, railroad schedules, and fire. He discusses how and why theories evolved and urges views to consider not just which questions physicists were trying to answer, but to ask themselves "what would be a reasonable question to ask"? The result is fascinating and delightful. You will watch it once to be informed and enlightened, but you will watch it again as sheer entertainment. Highly recommended.
Date published: 2018-03-16
Rated 1 out of 5 by from One of My Best Investments Great content presented in an interesting, understandable way. I plan to view this video repeatedly for its educational AND entertainment value.
Date published: 2018-03-12
Rated 5 out of 5 by from An Outstanding Lecturer I am neither a scientist nor a science college graduate, but I've had a lifelong interest in science, particularly cosmology and time (what exactly is time?), and so I was eager to purchase this course, and I was not disappointed. Professor Carroll turned out to be such an articulate and insightful lecturer, that I intend to explore his other courses on TGC as well as his books. I initially thought this course would focus on Einstein notions of time, the paradoxes of time, and time travel, but the emphasis is on entropy, and how with changes in entropy we can reveal the arrow of time, i.e., that there's a past, present, and future. I had always understood the increase in entropy in the universe, as embodied in the 2nd Law of Thermodynamics, as a movement from order to disorder, but I now understand entropy more clearly from Prof. Carroll's lucid presentation (per Boltzmann: the higher the entropy, the higher the number of "microstates" for a given "macrostate", or stated another way, there are many different ways to arrange the atoms, and all of them look alike). But don't let this formalized phrasing intimidate you, this lecturer explains everything multiple times and in a clear and accessible manner. One of the key issues this course explores is the seeming conflict between: (1) the notion that the laws of physics, in principle, are time reversible, and more specifically (2) that in the quantum realm time reversibility can occur; each of these appears to conflict with the arrow of time we presume as time moves in our world and in our personal experience from the past to the future. Newton's chain of causality suggests the laws of physics do not select a direction of time; they can go forward or backward. Entropy can help explain this inconsistency. Be prepared to stretch your mind, but again with material made very accessible by a clear and cogent "explainer."
Date published: 2018-03-01
Rated 5 out of 5 by from Outstanding material and presenter! Dr. Carroll is a "rock star" among intellectuals with his presentation about Time. I am always impressed with the skill in which the teaching Co. assembles these presentations, and presenters. I am a regular customer of this company and this is a good example of why I keep coming back for more. This is the type of experience that keeps me thinking about the material long after I am done with the course. I look forward to letting it all "sink in" and revisiting the material again to see what I missed the first time around. This made my brain hurt in a good way!
Date published: 2018-01-03
Rated 5 out of 5 by from Surprisingly Good Even Without Heavy Mathematics I bought this set of DVDs last year but only managed to view the lectures through the first DVD. It starts off with lots of historical background, which can be interesting but may also be viewed as a "bore", depending on how one feels. But as the lectures progress onwards, Prof. Sean Carroll delves deeper into the subject with far more profound and advanced ideas drawn from Heat and Thermodynamics, including relevant Engineering ideas, and moves onto Modern Physics, typically Quantum Mechanics. At every step in all the lectures, historical roots and foundational ideas from Engineering and Classical Physics, are not neglected but carefully woven in. What is amazing is that Prof. Carroll manages to explain deep and profound concepts in such simple ways so that someone like I myself can understand, all without invoking Mathematics, not even simple Calculus, save for some very simply algebraic expressions. Yes, it is true I did Engineering in school and was trained in applications of Mathematics, particularly mathematical methods that apply. So Mathematics treated with respect does not scare or deter me. But Prof. Carroll understands the need to keep the analytical intensity of the lectures to a minimum so that the partially informed layman can benefit. The layman who has a inkling of what the mysteries underlying the questions of Time and its passage, so-called the "Arrow of Time" (going "forwards" in a single, prescribed direction) can effectively appreciate the research conducted up to now on the topic of Time and pertinent issues that were uncovered through Physics research over the years. All in all, it is a very educational experience based on what I have viewed so far. So I would highly recommend the set of DVDs here because merely reading books on the topic will simply confuse and confound the layman rather than educate, let alone enlighten (there are some which are deep, intensive and profound, one of the classics being Prof. Hans Reichenbach's "Direction of Time" and in a way another is Dr. Michael Mackey's "Time's Arrow", Dover Publications, to name but a few here). The only reservation I have is if the viewer happens to be very lacking in terms of a scientific background and in addition has no a priori concept of the issues underlying the topic of Time and its passage, he or she may not stand to benefit from Prof. Carroll's lectures; even a strong intuition without the proper scientific foundation can help the person develop some understanding or feeling for the subject matter.
Date published: 2017-09-22
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