Professor Jim Al-Khalili investigates the amazing science of gravity. A fundamental force of nature, gravity shapes our entire universe. It sculpts galaxies and warps space and time. But gravity’s strange powers also affect our daily lives in the most unexpected ways. This is a story with surprises in store for Jim himself. In telling the story of gravity, his own understanding of the nature of reality comes to be challenged. Finally, Jim discovers that, despite incredible progress, gravity still has many secrets to unveil.

Sodom and Gomorrah, a tale of two cities incinerated by a hail of fire and brimstone. Is this a fantastic fable, or could it be a near apocalyptic disaster from space? In this episode, we will check into the mysteries relating to the destruction of both cities. Were they astronomical events?
Newly discovered evidence might hold the secrets to one of the Bible's greatest mysteries.

Helvetica is a feature-length independent film about typography, graphic design and global visual culture. It looks at the proliferation of one typeface (which celebrated its 50th birthday in 2007) as part of a larger conversation about the way type affects our lives. The film is an exploration of urban spaces in major cities and the type that inhabits them, and a fluid discussion with renowned designers about their work, the creative process, and the choices and aesthetics behind their use of type.
The film encompasses the worlds of design, advertising, psychology, and communication, and invites us to take a second look at the thousands of words we see every day.
Interviewees in Helvetica include some of the most illustrious and innovative names in the design world, including Erik Spiekermann, Matthew Carter, Massimo Vignelli, Wim Crouwel, Hermann Zapf, Neville Brody, Stefan Sagmeister, Michael Bierut, David Carson, Paula Scher, Jonathan Hoefler, Tobias Frere-Jones, Experimental Jetset, Michael C. Place, Norm, Alfred Hoffmann, Mike Parker, Bruno Steinert, Otmar Hoefer, Leslie Savan, Rick Poynor, and Lars Müller.

This episode explores the wave theory of light as studied by mankind, noting that light has played an important role in scientific progress, with such early experiments from over 2000 years ago involving the camera obscura by the Chinese philosopher Mozi. Tyson describes the work of the 11th century Arabic scientist Ibn al-Haytham, considered to be one of the first to postulate on the nature of light and optics leading to the concept of the telescope, as well as one of the first researchers to use the scientific method. Tyson proceeds to discuss the nature of light as discovered by mankind. Work by Isaac Newton using diffraction through prisms demonstrated that light was composed of the visible spectrum, while findings of William Herschel in the 19th century showed that light also consisted of infrared rays. Joseph von Fraunhofer would later come to discover that by magnifying the spectrum of visible light, gaps in the spectrum would be observed. These Fraunhofer lines would later be determined to be caused by the absorption of light by electrons in moving between atomic orbitals when it passed through atoms, with each atom having a characteristic signature due to the quantum nature of these orbitals. This since has led to the core of astronomical spectroscopy, allowing astronomers to make observations about the composition of stars, planets, and other stellar features through the spectral lines, as well as observing the motion and expansion of the universe, and the existence of dark matter.

Can skyscrapers be made safer, more efficient, and livable in our rapidly growing cities? Skyscrapers are gleaming symbols of prestige, and an ingenious way to save space in dense urban areas. But as buildings rise ever higher, what are the risks of these architectural behemoths?
Do we truly know how they will hold up in earthquakes, fires and wind? What have--or haven’t—we learned from past tragedies? But even as we devise ways to defend them against potential disasters, can we also make them more livable, interactive, and eco-friendly?

This is our home, the earth it's, it's the only place we've got. It is one strange rock because it's ours and we are here and we don't know if any other place in the universe, yet, that can support life. We're very lucky to have it as our home.
Astronauts including the legendary Peggy Whitson, who spent 665 days in space, speak about how their concepts of home have changed since their experience.