Last Watched

"Sspectrum"  Sort by

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 2014
The Normans
The Normans

   2010    History
Blood of the Vikings
Blood of the Vikings

   2001    History
Through the Wormhole Season 5
Through the Wormhole Season 5

   2014    Nature
Japan Earth Enchanted Islands
Japan Earth Enchanted Islands

   2017    Nature
The Real History of Science Fiction
The Real History of Science Fiction

   2014    Technology
Human universe
Human universe

   2014    Technology
The Crusades
The Crusades

   2012    History