Ep 7. How Does Gravity Affect Light?

PBS Space Time season 2021 episode 7, titled "How Does Gravity Affect Light?" is a fascinating exploration into how gravity affects the movement of light throughout the universe. In this episode, the hosts delve into the complex interplay between these fundamental forces, examining the ways that gravity can bend, warp, and distort the paths of light rays as they travel through space.

The episode begins by introducing viewers to the concept of gravitational lensing, which occurs when a massive object such as a star or black hole bends the path of nearby light rays. Using sophisticated computer simulations and breathtaking visualizations, the hosts explain how scientists are able to detect these lensing effects and use them to map the distribution of matter in distant galaxies.

From there, the episode dives into even more mind-bending concepts, such as the way that gravity can actually slow down the passage of time itself. Viewers will learn about the concept of time dilation, which occurs when the intense gravitational fields near massive objects like black holes cause time to pass more slowly. As the episode explains, this effect has been confirmed by real-world experiments and is a key prediction of Albert Einstein's theory of general relativity.

The hosts also explore the fascinating phenomenon of redshift, which occurs when the wavelength of light is stretched as it passes through a gravitational field. This effect can be used to study the properties of distant galaxies and explore the history of the universe itself.

As the episode progresses, viewers will learn about the groundbreaking experiments and observations that have helped scientists to unlock the secrets of gravity and light. From early astronomers like Isaac Newton and Galileo Galilei to modern-day space probes like the Hubble Space Telescope, the hosts trace the history of humanity's fascination with these fundamental forces.

Throughout the episode, the hosts emphasize the importance of science and curiosity in unraveling the mysteries of the universe. They demonstrate how advances in technology and knowledge have allowed us to see deeper into space and further back in time, revealing the awe-inspiring complexity and beauty of the cosmos.

In the end, "How Does Gravity Affect Light?" is a captivating journey through some of the most awe-inspiring and mind-bending concepts in physics. With stunning visuals and expert insights, this episode of PBS Space Time is an invitation to explore the universe and expand our understanding of this remarkable universe in which we live.