Ep 10. Optical Telescopes

Introduction to Astrophysics season 1 episode 10, titled “Optical Telescopes,” explores the world of telescopes that use visible light to study the Universe. This episode delves into the history of optical telescopes and their evolution to modern-day instruments used in astronomy.

The episode begins by introducing the concept of refracting telescopes, the earliest form of optical telescopes. Viewers learn that the first refracting telescope was built by Hans Lippershey, a Dutch lens maker, in 1608. This invention led to the discoveries of Galileo Galilei, who used a refracting telescope to observe the moons of Jupiter in 1610.

The episode then moves on to the development of reflecting telescopes. It explores the work of Sir Isaac Newton, who used a concave mirror in a reflecting telescope to observe the sky. Viewers also learn about the work of William Herschel, who built the largest reflecting telescope of his time, known as the Great 40-foot telescope.

The episode then discusses the modern-day optical telescopes used in astronomy. The most well-known of these is the Hubble Space Telescope, which has revolutionized our understanding of the Universe. Viewers learn about the development of the Hubble telescope, the challenges it faced in its early years, and the groundbreaking discoveries it has made over the past few decades.

The episode also discusses ground-based optical telescopes, which are used to observe the night sky from Earth. Viewers learn about different types of ground-based telescopes, including the largest optical telescope in the world - the Gran Telescopio Canarias. This telescope, located on the island of La Palma in the Canary Islands, boasts a primary mirror of 10.4 meters in diameter.

Another major aspect of the episode is the discussion of adaptive optics - a technology used in ground-based telescopes to overcome the blurring effects of Earth's atmosphere. Viewers learn about the principles behind adaptive optics and how they are used to obtain clearer images of the night sky.

Towards the end of the episode, viewers are introduced to the concept of interferometry - a technique used to combine signals from multiple telescopes to create a larger virtual telescope. This technology has revolutionized the study of astronomy and has led to the discovery of exoplanets, galaxies, and other celestial objects.

Overall, Introduction to Astrophysics season 1 episode 10, “Optical Telescopes,” is an informative and engaging look at the history and modern uses of optical telescopes in astronomy. Viewers will come away with a better understanding of the technology behind telescopes and the incredible discoveries they have enabled.