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Plunge into the exciting quest to investigate everything beyond Earth through the laws of physics. Introduction to Astrophysics takes you step by step through the calculations that show how planets, stars, and galaxies work. In 24 episodes by noted astrophysicist Professor Joshua Winn, you’ll tour a universe of exploding stars, colliding black holes, dark matter, and other wonders.

Introduction to Astrophysics is a series that is currently running and has 1 seasons (24 episodes). The series first aired on November 30, 2018.

Introduction to Astrophysics is available for streaming on the website, both individual episodes and full seasons. You can also watch Introduction to Astrophysics on demand atAmazon Prime, Amazon online.

The Great Courses Signature Collection
1 Season, 24 Episodes
November 30, 2018
Cast: Joshua N. Winn
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Introduction to Astrophysics Full Episode Guide

  • In this last episode, follow the trail of the greatest unsolved problem in astrophysics. Along the way, get a grip on the past, present, and future of the universe. Discovered in the 1990s, the problem is "dark energy," which is causing the expansion of the universe to accelerate. Trace this mysterious force to the lambda term in the celebrated Friedmann equation, proposed in the 1920s.

  • Begin with active galaxies that have supermassive black holes gobbling up nearby stars. Then consider clusters of galaxies and the clues they give for missing mass - dubbed "dark matter." Chart the distribution of dark matter around galaxies and speculate what it might be. Close with the Big Bang, deduced from evidence that most galaxies are speeding away from us; the farther away, the faster.

  • Investigate the physics of gravitational waves, a phenomenon predicted by Einstein and long thought to be undetectable. It took colliding black holes to generate gravitational waves that could be picked up by an experiment called LIGO on Earth, a billion light years away. This remarkable achievement won LIGO scientists the 2017 Nobel Prize in Physics.

  • Look inside a star that weighs several solar masses to chart its demise after fusing all possible nuclear fuel. Such stars end in a gigantic explosion called a supernova, blowing off outer material and producing a super-compact neutron star, a billion times denser than a white dwarf. Study the rapid spin of neutron stars and the energy they send beaming across the cosmos.

  • Trace stellar evolution from two points of view. First, dive into a protostar and witness events unfold as the star begins to contract and fuse hydrogen. Exhausting that, it fuses heavier elements and eventually collapses into a white dwarf - or something even denser. Next, view this story from the outside, seeing how stellar evolution looks to observers studying stars with telescopes.

  • Discover the fate of solar mass stars after they exhaust their nuclear fuel. The galaxies are teeming with these dim "white dwarfs" that pack the mass of the Sun into a sphere roughly the size of Earth. Venture into quantum theory to understand what keeps these exotic stars from collapsing into black holes, and learn about the Chandrasekhar limit, which determines a white dwarf's maximum mass.

  • Learn how stars work by delving into stellar structure, using the Sun as a model. Relying on several physical principles and sticking to order-of-magnitude calculations, determine the pressure and temperature at the center of the Sun, and the time it takes for energy generated in the interior to reach the surface, which amounts to thousands of years. Apply your conclusions to other stars.

  • Get a crash course in nuclear physics as you explore what makes stars shine. Zero in on the Sun, working out the mass it has consumed through nuclear fusion during its 4.5-billion-year history. While it's natural to picture the Sun as a giant furnace of nuclear bombs going off non-stop, calculations show it's more like a collection of toasters; the Sun is luminous simply because it's so big.

  • Consider the problem of gleaning information from the severely limited number of optical photons originating from astronomical sources. Our eyes can only do it so well, and telescopes have several major advantages: increased light-gathering power, greater sensitivity of telescopic cameras and sensors such as charge-coupled devices (CCDs), and enhanced angular and spectral resolution.

  • Survey representative planets in our solar system with an astrophysicist's eyes, asking what makes Mercury, Venus, Earth, and Jupiter so different. Why doesn't Mercury have an atmosphere? Why is Venus so much hotter than Earth? Why is Jupiter so huge? Analyze these and other riddles with the help of physical principles such as the Stefan-Boltzmann law.

  • Investigate our prime source of information about the universe: electromagnetic waves, which consist of photons from gamma ray to radio wavelengths. Discover that a dense collection of photons is comparable to a gas obeying the ideal gas law. This law, together with the Stefan-Boltzmann law, Wien's law, and Kepler's third law, help you make sense of the cosmos as the course proceeds.

  • Use your analytical skill and knowledge of gravity to probe the strange properties of black holes. Learn to calculate the Schwarzschild radius (also known as the event horizon), which is the boundary beyond which no light can escape. Determine the size of the giant black hole at the center of our galaxy and learn about an effort to image its event horizon with a network of radio telescopes.

  • Why are the rings around Saturn and the much fainter rings around Jupiter, Uranus, and Neptune at roughly the same relative distances from the planet? Why are large moons spherical? And why are large moons only found in wide orbits? These problems lead to an analysis of tidal forces and the Roche limit. Close by calculating the density of the Sun based on Earth's ocean tides.

  • Continue your exploration of motion by discovering the law of gravity just as Newton might have - by analyzing Kepler's laws with the aid of calculus (which Newton invented for the purpose). Look at a graphical method for understanding orbits, and consider the conservation laws of angular momentum and energy in light of Emmy Noether's theory that links conservation laws and symmetry.

  • In the first of two episodes on motion in the heavens, investigate the connection between Isaac Newton's laws of motion and the earlier laws of planetary motion discovered empirically by Johannes Kepler. Find that Kepler's third law is the ideal method for measuring the mass of practically any phenomenon in astrophysics. Also, study the mathematics behind Kepler's second law.

  • Discover how astrophysicists map the universe. Focus on the tricky problem of calculating distances, seeing how a collection of overlapping techniques provide a "cosmic distance ladder" that works from nearby planets (by means of radar) to stars and galaxies (using parallax and Cepheid variable stars) to far distant galaxies (by observing a type of supernova with a standard intrinsic brightness).

  • After touring the universe on a macro scale in the previous episode, now zoom in on the microcosmos - advancing by powers of ten into the realm of molecules, atoms, and nuclei. Learn why elementary particles are just as central to astrophysics as stars and galaxies. Then review the four fundamental forces of nature and perform a calculation that explains why atoms have to be the size they are.

  • Define the difference between astrophysics and astronomy. Then study the vast range of scales in astrophysics - from nanometers to gigaparsecs, from individual photons to the radiation of suns. Get the big picture in a breathtaking series of exponential jumps - zooming from Earth, past the planets, stars, galaxies, and finally taking in countless clusters of galaxies. #Science & Mathematics