Tyson begins the episode by explaining the nature of the speed of light and how much of what is seen of the observable universe is from light emanated from billions of years in the past. Tyson further explains how modern astronomy has used such analyzes via deep time to identify the Big Bang event and the age of the universe. Tyson proceeds to describe how the work of Isaac Newton, William Herschel, and James Clerk Maxwell contributed to understanding the nature of electromagnetic waves and gravitational force, and how this work led towards Albert Einstein's Theory of Relativity, that the speed of light is a fundamental constant of the universe and gravity can be seen as distortion of the fabric of space-time. Tyson describes the concept of dark stars as postulated by John Michell which are not visible but detectable by tracking other stars trapped within their gravity wells, an idea Herschel used to discover binary stars. Tyson then describes the nature of black holes, their enormous gravitational forces that can even capture light, and their discovery via X-ray sources such as Cygnus X-1. Tyson uses the Ship of Imagination to provide a postulate of the warping of spacetime and time dilation as one enters the event horizon of the black hole, and the possibility that these may lead to other points within our universe or others, or even time travel. Tyson ends on noting that Herschel's son, John would be inspired by his father to continue to document the known stars as well as contributions towards photography that play on the same nature of deep time used by astronomers.

Various eminent scientists explain the current knowledge of Black Holes and try to answer the question, do they really exist? New discoveries are challenging everything we know about black holes -- astronomers are beginning to question if they even exist. The latest science tries to explain how they work & what they look like, despite the fact we've never actually seen one.
The two great theories of Einstein's General Relativity and Quantum Mechanics don't work together to explain Black Holes which is a big problem. Other theoretical constructs such as Gravastars and Planck stars have been postulated but proving their existence is just as difficult as that of Black Holes. So where next?

Following engineers and scientists on a groundbreaking mission as they build, test and launch the James Webb Space Telescope, the most powerful observatory ever constructed, and discovers the astonishing cosmological enigmas it will investigate. Using the latest CGI animation technology, the film will follow the journey and share the incredible cosmological images and mysteries that scientists believe the telescope will capture.
This super-telescope is the next generation successor to the Hubble Space Telescope, with a mirror 6 times bigger. It will also be able to peer back in time. For the first time in space exploration, scientists will be able to explore the formation of the first stars and galaxies and search for planets that can support life.

We can't compare anything on earth to the biggest things known in space. The Cosmic Web may connect objects in the universe with threads of Dark Matter. The Lyman-alpha blob is a bubble like structure containing countless galaxies--perhaps the biggest object in the entire universe. Regions of radio-emitting gas called "radio lobes" could be even bigger. Then there are super galaxy clusters which are hundreds of galaxies merged together due to cosmic collisions. Discover which is the largest planet, star, star cluster, constellation, black hole, volcano, galaxy, explosions, moon, storm, impact crater and "void" in space.

Supermassive black holes are the engines that power our universe and one of the major players in the evolution of galaxies. They're in fact the driving force at the heart of nearly every galaxy in the cosmos. Now, a new mystery has emerged about the oldest supermassive black holes. We see supermassive black holes in the very early universe. And we don't understand how they grew so large so quickly. We have clues about their formation but, can we solve the mystery of this supermassive growth spurt?

Black holes are the most enigmatic and exotic objects in the universe. They’re also the most powerful; with gravity so strong it can trap light. And they’re destructive, swallowing entire planets, even giant stars. Anything that falls into them vanishes... gone forever. Now, astrophysicists are realizing that black holes may be essential to how our universe evolved—their influence possibly leading to life on Earth and, ultimately, us.
In this series, astrophysicist and author Janna Levin takes viewers on a journey to the frontiers of black hole science. Along the way, we meet leading astronomers and physicists on the verge of finding new answers to provocative questions about these shadowy monsters: Where do they come from? What’s inside? What happens if you fall into one? And what can they tell us about the nature of space, time, and gravity?