Today on Far Future Horizons we present the fifth episode of Cosmos: A Spacetime Odyssey ~ “Hiding in the Light” hosted by Dr. Neil deGrasse Tyson.
The exciting installment explores properties of light, cameras, the scientific method, and the composition of the universe.
The episode includes a look at the contributions of the 10th century physicist Ibn al-Haytham, described as the “father of the modern scientific method.”
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| Ibn al-Haytham |
This episode also 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.
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| Mozi |
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 19thcentury 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.
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| William Herschel |
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| Joseph von Fraunhofer |
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.
If you want to learn more about the scientists mentioned in this and other episodes in the series here is a very good reference page ~ The Scientists of Cosmos: A Spacetime Odyssey.
Cosmos: A Spacetime Odyssey ~ Hiding in the Light
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