PBS Space Time Season 2018 Episode 5 What is Energy?

PBS Space Time season 2018 episode 5 titled "What is Energy?" explores the fundamental concept of energy that powers everything in the universe. This episode begins by introducing the concept of energy and how it is a measure of the ability to do work, such as moving objects or heating them up. It poses some important fundamental questions about energy, such as where it comes from, how it is transferred between systems, and how it is conserved over time.

The episode then dives deeper into the nature of energy by exploring the different forms it can take, from mechanical energy to thermal energy, electrical energy, and more exotic forms such as dark energy and dark matter. It discusses the relationship between energy and matter and how they are fundamentally related through the iconic equation E=mc², which states that energy and mass are interchangeable. The episode also touches upon the concept of entropy, which is a measure of the disorder or randomness in a system, and how it is related to energy.

The host of the show, Gabe Perez-Giz, then takes viewers on a journey through the history of energy, discussing how humans have harnessed different forms of energy throughout history, from the harnessing of fire to power steam engines during the industrial revolution, to the development of fossil fuels and nuclear energy in the modern age. However, he also discusses the negative impact that our dependence on fossil fuels is having on the environment, and the urgent need to transition to cleaner, renewable sources of energy.

The episode also explores the role that energy plays in the functioning of the universe, from the fusion reactions that power stars to the mysterious dark energy that is believed to be accelerating the expansion of the universe. It discusses how the total amount of energy in the universe is always conserved, and how it is constantly being transformed and transferred between different systems.

Ultimately, "What is Energy?" is a fascinating exploration of one of the most fundamental concepts in physics and how it plays a vital role in shaping our world and the universe at large. It provides viewers with a thorough understanding of energy, from its origins to its many forms and applications, and leaves them with a greater appreciation for the fundamental forces that drive our world.