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Mysteries of Modern Physics: Time
Saison 1
IMDb 6,0201224 épisodes
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Épisodes
- S. 1 ÉP. 1 - Why Time Is a Mystery27 septembre 201233 minBegin 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.#Science & MathematicsDémarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 2 - What Is Time?1 septembre 201230 minApproach 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 3 - Keeping Time1 septembre 201231 minHow 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 4 - Time's Arrow1 septembre 201229 minEmbark 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 5 - The Second Law of Thermodynamics1 septembre 201231 minTrace 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 6 - Reversibility and the Laws of Physics1 septembre 201230 minIsaac 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 7 - Time Reversal in Particle Physics1 septembre 201231 minExplore 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 8 - Time in Quantum Mechanics1 septembre 201231 minQuantum 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?Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 9 - Entropy and Counting1 septembre 201231 minAfter 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 10 - Playing with Entropy1 septembre 201232 minSharpen 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 11 - The Past Hypothesis1 septembre 201229 minBoltzmann 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 12 - Memory, Causality, and Action1 septembre 201230 minCan 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 13 - Boltzmann Brains1 septembre 201231 minOne 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 14 - Complexity and Life1 septembre 201231 minDiscover 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 15 - The Perception of Time1 septembre 201232 minTurn 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 16 - Memory and Consciousness1 septembre 201231 minRemembering 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 17 - Time and Relativity1 septembre 201231 minAccording 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 18 - Curved Spacetime and Black Holes1 septembre 201230 minBy 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 19 - Time Travel1 septembre 201231 minUse 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 20 - Black Hole Entropy1 septembre 201230 minStephen 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 21 - Evolution of the Universe1 septembre 201231 minFollow 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 22 - The Big Bang1 septembre 201230 minExplore 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 23 - The Multiverse1 septembre 201231 minDig 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?Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
- S. 1 ÉP. 24 - Approaches to the Arrow of Time1 septembre 201232 minUse 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.Démarrer un essai gratuit de The Great Courses Signature Collection ou acheter
Détails
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- Audio
- English
- Sous-titres
- English [CC]
- Production
- The Great Courses
- Rôles principaux
- Sean Carroll Ph.D
- Studio
- The Great Courses
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