Last Watched

"Joseph von Fraunhofer"  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
A Traveler Guide to the Planets
A Traveler Guide to the Planets

   2010    Science
Chased by Sea Monsters
Chased by Sea Monsters

   2003    Science
Wild Russia
Wild Russia

   2009    Nature
Enemies of Reason
Enemies of Reason

      Medicine
Clash of the Gods
Clash of the Gods

   2009    History
Through the Wormhole Season 5
Through the Wormhole Season 5

   2014    Nature
The Making of the Mob
The Making of the Mob

   2016    History
Woody Allen A Documentary
Woody Allen A Documentary

   2011    History