Cosmologists have known that the universe is expanding in all directions since early in the 1920s. Later in the century, they used new instruments to examine the question again. They assumed that-due to gravity-the rate of expansion of the universe today would be slower than the rate in the past. Instead, measurements showed that the cosmic expansion has been speeding up. The expansion is attributed to "dark energy," a kind of springiness of empty...

Hard as it is to swallow, cutting-edge theories are suggesting that our universe may not be the only universe. Instead, it may be just one of an infinite number of worlds that make up the multiverse. In this show, Brian Greene takes us on a tour of this brave new theory at the frontier of physics, explaining why scientists believe it's true and showing what some of these alternate realities might be like. Some universes may be almost indistinguishable...

"One of the world's most renowned theoretical physicists, Carlo Rovelli has entranced millions of readers with his singular perspective on the cosmos. In Helgoland, Rovelli examines the enduring enigma of quantum theory. The quantum world Rovelli describes is as beautiful as it is unnerving. Helgoland is a treeless island in the North Sea where the 21-year-old Werner Heisenberg first developed quantum theory, setting off a century of scientific revolution....

Professor Jim Al-Khalili traces the story of arguably the most important, accurate and yet perplexing scientific theory ever-quantum physics. Early 20th century scientists trying to understand how light bulbs work journeyed into the sub-atomic building blocks of the world around us. Here they discovered a realm where things can be in many places at once, where chance and probability call the shots, and where reality appears to only truly exist when...

"Whether pondering black holes or predicting discoveries at CERN, physicists believe the best theories are beautiful, natural, and elegant, and this standard separates popular theories from disposable ones. This is why, Sabine Hossenfelder argues, we have not seen a major breakthrough in the foundations of physics for more than four decades. The belief in beauty has become so dogmatic that it now conflicts with scientific objectivity: observation...

The authors-- one a philosopher, the other a physicist-- draw on their training and six years of co-teaching to dramatize the quantum's rocky path from scientific theory to public understanding while also exploring the quantum's manifestations in everything from art and sculpture to the prose of John Updike and David Foster Wallace.

What is reality? What is the universe made of, how does it work? In this Horizon program, Theoretical physicist Leonard Susskind, Nobel Prize winner Frank Wilczek, cosmologist Max Tegmark, quantum mechanic Seth Lloyd, experimental physicist Anton Zeilinger and particle physicist Rob Roser reveal their astonishing visions of reality. It may be vast, beautiful and terrifyingly complex, but understanding the nature of reality is one of the most important...

"Evan Ryder is an extraordinary intelligence field agent now working for the security arm of Parachute, a private company and the world's leader in the application of quantum technology. In the past, Ryder has done lethal battle in the modern global wars of power politics, extremist ideology, corrosive disinformation, and outrageous greed. But now she finds herself in a battle arena whose dangers, while less obvious, are greater than anything the...

In the U.S. alone, tornadoes kill up to 70 people a year and injure as many as 1,500 while causing an estimated 400 million dollars in damage. More than ever before, scientists are determined to unlock the mystery of how tornadoes work, especially close to the ground where they wreak the most havoc. But no one has ever been able to get a view from inside the whirling base of a deadly funnel-until now. This program takes viewers into the vortex of...