George Basalla
- Published in print:
- 2006
- Published Online:
- September 2007
- ISBN:
- 9780195171815
- eISBN:
- 9780199786862
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195171815.003.0008
- Subject:
- Physics, History of Physics
In the 1930s, astronomer Edwin P. Hubble and others claimed that we lived in an expanding universe filled with galaxies containing billion of stars. At about the same time, Karl G. Jansky invented ...
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In the 1930s, astronomer Edwin P. Hubble and others claimed that we lived in an expanding universe filled with galaxies containing billion of stars. At about the same time, Karl G. Jansky invented the radio telescope that detected radio waves naturally emitted by astronomical bodies. Pioneer radio astronomer Frank Drake realized that radio telescopes could also be used to search for radio messages transmitted by distant, advanced civilizations. He then proposed Drake’s equation for calculating the number of civilizations in our galaxy able to transmit and receive radio signals. These developments raised questions about the proper radio frequencies to use in searching for extraterrestrial messages (Giuseppe Cocconi, Philip Morrison), the identification of astroengineering projects of alien civilizations (Freeman Dyson), and the ranking of extraterrestrial civilizations according to the amount of energy they controlled (Nicolai S. Kardashev).Less
In the 1930s, astronomer Edwin P. Hubble and others claimed that we lived in an expanding universe filled with galaxies containing billion of stars. At about the same time, Karl G. Jansky invented the radio telescope that detected radio waves naturally emitted by astronomical bodies. Pioneer radio astronomer Frank Drake realized that radio telescopes could also be used to search for radio messages transmitted by distant, advanced civilizations. He then proposed Drake’s equation for calculating the number of civilizations in our galaxy able to transmit and receive radio signals. These developments raised questions about the proper radio frequencies to use in searching for extraterrestrial messages (Giuseppe Cocconi, Philip Morrison), the identification of astroengineering projects of alien civilizations (Freeman Dyson), and the ranking of extraterrestrial civilizations according to the amount of energy they controlled (Nicolai S. Kardashev).