Book contents
- Frontmatter
- Contents
- Acknowledgements
- 1 Introduction: The Luminous Pathway
- 2 The Discovery of the Milky Way Galaxy
- 3 The New Physics
- 4 Parting the Veil with Radio Astronomy
- 5 The Violent Universe
- 6 New Windows on the Galactic Center
- 7 The Milky Way as a Barred Spiral Galaxy
- 8 The Evolving View of Active Galactic Nuclei
- 9 The “Paradox of Youth”: Young Stars in the Galactic Center
- 10 Stellar Orbits in the Galactic Center, QED
- 11 Black Holes Here, Black Holes There…
- 12 Traces of Activity: Past, Present, and Future
- 13 After Words: Progress in Astronomy
- References
- Index
5 - The Violent Universe
Published online by Cambridge University Press: 05 December 2013
- Frontmatter
- Contents
- Acknowledgements
- 1 Introduction: The Luminous Pathway
- 2 The Discovery of the Milky Way Galaxy
- 3 The New Physics
- 4 Parting the Veil with Radio Astronomy
- 5 The Violent Universe
- 6 New Windows on the Galactic Center
- 7 The Milky Way as a Barred Spiral Galaxy
- 8 The Evolving View of Active Galactic Nuclei
- 9 The “Paradox of Youth”: Young Stars in the Galactic Center
- 10 Stellar Orbits in the Galactic Center, QED
- 11 Black Holes Here, Black Holes There…
- 12 Traces of Activity: Past, Present, and Future
- 13 After Words: Progress in Astronomy
- References
- Index
Summary
A New Constituent of the Universe
The demands of war lead to technological advances that have consequences for pure research long after. The development of radar during World War II is one such example. The German radar dishes left behind in Holland at the end of the war enabled Oort to make a beginning for Dutch radio astronomy which, as we have seen, led to an understanding of the overall structure and kimenatics of the Milky Way Galaxy. Ewing and Purcell, the discoverers of the 21-cm line of neutral hydrogen, both had strong backgrounds in microwave radar technology, Ewing as a naval radar officer and Purcell as director of the MIT Radiation Laboratory. In the United Kingdom the young radio engineer Martin Ryle made a major contribution to the development of radar and thus to the British defense effort. But after the war, he applied these skills at Cambridge in the development of radio astronomy, in particular, the technique of radio interferometry.
In astronomy whenever a new wavelength window opens, major discoveries follow. This was certainly the case in the early 1950s, when crude radio telescopes began mapping the sky in continuum radiation and, in addition to smooth radiation from the Galaxy, discovered a number discrete sources scattered about the sky. Some were clearly Galactic in origin (they were in the plane of the Galaxy and associated with known objects such as supernova remnants) but others were more uniformly distributed outside of the Galactic plane.
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- Information
- Revealing the Heart of the GalaxyThe Milky Way and its Black Hole, pp. 51 - 68Publisher: Cambridge University PressPrint publication year: 2013