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Hiding in the Light

   2014    Science
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.
Series: Cosmos: A Spacetime Odyssey

The Search for a Second Earth

   2014    Science
Is there another Earth out there with liquid oceans, rocky continents and life like us? Astronomers seek the answer with spectroscopy, direct imaging and telescopes. They hope to find evidence of atmospheres, magnetospheres and signs of life.
Series: How the Universe Works

Chemistry: The Order of the Elements

   2010    Science
In part two, Professor Al-Khalili looks at the 19th century chemists who struggled to impose an order on the apparently random world of the elements. From working out how many there were to discovering their unique relationships with each other, the early scientists' bid to decode the hidden order of the elements was driven by false starts and bitter disputes. But ultimately the quest would lead to one of chemistry's most beautiful intellectual creations - the periodic table.
Series: Chemistry

Chemistry: The Power of the Elements

       Science
In the final part, Professor Al-Khalili uncovers tales of success and heartache in the story of chemists' battle to control and combine the elements, and build our modern world. He reveals the dramatic breakthroughs which harnessed their might to release almost unimaginable power, and he journeys to the centre of modern day alchemy, where scientists are attempting to command the extreme forces of nature and create brand new elements.
Series: Chemistry

Wildest Weather in the Cosmos

   2008    Science
Imagine a tornado so powerful, it can form a planet, or winds sweeping across a planet but blowing at 6,000 miles per hour! How about rain....made of iron? Sounds like science fiction, but this type of weather is occurring daily in our solar system. Scientists are just beginning to unlock the secrets of these planets and their atmospheres. Can this research help scientists solve long unanswered questions that we have about Earth? As our own planet churns with the effects of global warming, it's natural to look into the heavens and wonder about the rest of the real estate.
Series: The Universe
Putin: A Russian Spy Story
Putin: A Russian Spy Story

   2020    History
Vietnam in HD
Vietnam in HD

   2011    History
Cooked
Cooked

   2016    Culture
Space Phenomena
Space Phenomena

   2020    Science
Lost Kingdoms of South America
Lost Kingdoms of South America

   2013    History
Senna
Senna

   2010    Culture
Alien Worlds
Alien Worlds

   2020    Science