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The Mystery of Dark Energy

   2016    Science
Dark energy - the mysterious force that is unexpectedly causing the universe's expansion to speed up. The effects of dark energy were discovered in 1998 but physicists still don't know what it is. Worse, its very existence calls into question Albert Einstein's general theory of relativity - the cornerstone of modern physics. The hunt for the identity of dark energy is on". Experiments on earth and in space generate data that might provide a clue, but there are also hopes that another Einstein might emerge - someone who can write a new theory explaining the mystery of the dark energy.

Journeys in Space and Time

   1980    Science
Ideas about time and space are explored in the changes that constellations undergo over time, the redshift and blue shift measured in interstellar objects, time dilation in Albert Einstein's theory of relativity, the designs of both Leonardo da Vinci and spacecraft that could travel near light speed, time travel and its hypothetical effects on human history, the origins of the Solar System, the history of life, and the immensity of space. In Cosmos Update, the idea of faster-than-light travel by wormholes (researched by Kip Thorne and shown in Sagan’s novel Contact) is discussed.
Series: Cosmos

Einsteins Nightmare

   2014    Science
Professor Jim Al-Khalili investigates the most accurate and yet perplexing scientific theory ever - quantum physics. At the beginning of the 20th century scientists were led into the hidden workings of matter, into the sub-atomic building blocks of the world around us. They discovered phenomena unlike any encountered before - 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 we observe it. Albert Einstein hated the idea that nature, at its most fundamental level, is governed by chance. Jim reveals how, in the 1930s, Einstein thought he'd found a fatal flaw in quantum physics because it implies that sub-atomic particles can communicate faster than light in defiance of the theory of relativity. In the 1960s the scientist John Bell showed there was a way to test if Einstein was right and quantum mechanics was actually mistaken. Jim repeats this critical experiment - with shocking results.
Series: The Secrets of Quantum Physics

Unexplained Mysteries

   2008    Science
Explore the myths, misconceptions, truths & amazing mysteries of our unique universe. Could life exist on Mars? Is time travel possible & does Einstein's theory of relativity support it?
Series: The Universe

Is Time Travel Possible

   2011    Science
Einstein's world-shaking Theory of Relativity says that time travel is perfectly possible -- if you're going forward in time. Finding a way to travel backwards requires breaking the speed of light, which so far seems impossible. But now, strange-but-true phenomena such as quantum nonlocality (where particles instantly teleport across vast distances) may give us a way to make the dream of traveling back and forth through time a reality. Step into a time machine and rewrite history, bring loved ones back to life, control our destinies. But if succeed, what are the consequences of such freedom? Will we get trapped in a plethora of paradoxes and multiple universes that will destroy the fabric of the universe?
Series: Through the Wormhole
The Human Body
The Human Body

   1998    Medicine
Stephen Hawking's Favorite Places
Stephen Hawking's Favorite Places

   2016    Science
Frozen Planet
Frozen Planet

   2011    Nature
Triumph of Life
Triumph of Life

   2006    Nature
The Wehrmacht
The Wehrmacht

   2007    History
Seven Ages of Rock
Seven Ages of Rock

   2007    Art
Galapagos with David Attenborough
Galapagos with David Attenborough

   2013    Nature
The Germanic Tribes
The Germanic Tribes

   2007    History