“SETI 的历史 - 3”的版本间差异
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Morrison and Cocconi's short article became the blueprint for most of the SETI projects conducted in the past 40 years. The suggestion that electromagnetic signals were the most promising means for interstellar communications became the underlying assumption of all the searches, including the optical ones. The assumption that any alien signal would exhibit a Doppler drift has also been incorporated into all subsequent SETI projects, which invariably check for signals at drifting frequencies. But most important of all was their suggestion of a "universal" frequency that the aliens would most likely use for their transmissions. 1420 MHz has remained the most popular frequency used by SETI projects to this day. | Morrison and Cocconi's short article became the blueprint for most of the SETI projects conducted in the past 40 years. The suggestion that electromagnetic signals were the most promising means for interstellar communications became the underlying assumption of all the searches, including the optical ones. The assumption that any alien signal would exhibit a Doppler drift has also been incorporated into all subsequent SETI projects, which invariably check for signals at drifting frequencies. But most important of all was their suggestion of a "universal" frequency that the aliens would most likely use for their transmissions. 1420 MHz has remained the most popular frequency used by SETI projects to this day. | ||
| + | Morrison 和 Cocconi 的短文成为了过去40年来大多数 [[SETI]] 项目的蓝图。电磁信号作为最有希望的手段的建议成为了所有搜寻星际通讯的基本假设，包括了光学的。来自外星文明的信号将发生多普勒漂移的假设也被采纳到后来所有的 SETI 项目中，这些项目都无一例外的检查信号的频率漂移。但文中最重要的建议是外星文明最有可能使用的“通用”传输频率。1420Mhz 到今日仍然是 SETI 项目中最流行的搜寻频率。 | ||
| − | [[Image:Water_hole.jpg|350px|right|thumb|''' | + | |
| − | + | [[Image:Water_hole.jpg|350px|right|thumb|'''水洞''<br> | |
| + | "水洞" - 这个神奇的频率介于 1420Mhz 和 1660Mhz，许多SETI科学家相信这是最有希望的SETI搜寻。] | ||
In later years another SETI pioneer, Hewlett Packard Vice President Bernard Oliver, added another magic frequency, 1662 KHz, the emission frequency of another very common molecule - OH, or hydroxyl. Hydrogen and hydroxyl combine to form H2O - water - the basic component of life, as we know it. Since 1662 KHz shares the advantages of 1420 MHz in being in a relatively "quiet" region of the spectrum, Oliver came to believe that the band between them held some unique promise for detecting an alien signal: "Surely the band lying between the resonances of the disassociation products of water is ideally situated and an uncannily poetic place for water-based life to seek its kind," Oliver wrote in 1971. "Where shall we meet? At the water-hole, of course!" Since then, the term "water hole" has been used to refer to searches at or around the hydrogen emission frequency. | In later years another SETI pioneer, Hewlett Packard Vice President Bernard Oliver, added another magic frequency, 1662 KHz, the emission frequency of another very common molecule - OH, or hydroxyl. Hydrogen and hydroxyl combine to form H2O - water - the basic component of life, as we know it. Since 1662 KHz shares the advantages of 1420 MHz in being in a relatively "quiet" region of the spectrum, Oliver came to believe that the band between them held some unique promise for detecting an alien signal: "Surely the band lying between the resonances of the disassociation products of water is ideally situated and an uncannily poetic place for water-based life to seek its kind," Oliver wrote in 1971. "Where shall we meet? At the water-hole, of course!" Since then, the term "water hole" has been used to refer to searches at or around the hydrogen emission frequency. | ||
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[[SETI的历史:2 - SETI成立的瞬间|'''第2章：SETI成立的瞬间 ←''']] | [[SETI的历史:4 - Ozma项目的起源|'''→ 第4章：Ozma项目的起源''']] | [[SETI的历史:2 - SETI成立的瞬间|'''第2章：SETI成立的瞬间 ←''']] | [[SETI的历史:4 - Ozma项目的起源|'''→ 第4章：Ozma项目的起源''']] | ||
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==相关链接== | ==相关链接== | ||
2009年6月6日 (六) 08:43的版本
<资料来源：The Planetary Society>
第3章：SETI的蓝图
Morrison and Cocconi's short article became the blueprint for most of the SETI projects conducted in the past 40 years. The suggestion that electromagnetic signals were the most promising means for interstellar communications became the underlying assumption of all the searches, including the optical ones. The assumption that any alien signal would exhibit a Doppler drift has also been incorporated into all subsequent SETI projects, which invariably check for signals at drifting frequencies. But most important of all was their suggestion of a "universal" frequency that the aliens would most likely use for their transmissions. 1420 MHz has remained the most popular frequency used by SETI projects to this day.
Morrison 和 Cocconi 的短文成为了过去40年来大多数 SETI 项目的蓝图。电磁信号作为最有希望的手段的建议成为了所有搜寻星际通讯的基本假设，包括了光学的。来自外星文明的信号将发生多普勒漂移的假设也被采纳到后来所有的 SETI 项目中，这些项目都无一例外的检查信号的频率漂移。但文中最重要的建议是外星文明最有可能使用的“通用”传输频率。1420Mhz 到今日仍然是 SETI 项目中最流行的搜寻频率。
[[Image:Water_hole.jpg|350px|right|thumb|'水洞
"水洞" - 这个神奇的频率介于 1420Mhz 和 1660Mhz，许多SETI科学家相信这是最有希望的SETI搜寻。]
In later years another SETI pioneer, Hewlett Packard Vice President Bernard Oliver, added another magic frequency, 1662 KHz, the emission frequency of another very common molecule - OH, or hydroxyl. Hydrogen and hydroxyl combine to form H2O - water - the basic component of life, as we know it. Since 1662 KHz shares the advantages of 1420 MHz in being in a relatively "quiet" region of the spectrum, Oliver came to believe that the band between them held some unique promise for detecting an alien signal: "Surely the band lying between the resonances of the disassociation products of water is ideally situated and an uncannily poetic place for water-based life to seek its kind," Oliver wrote in 1971. "Where shall we meet? At the water-hole, of course!" Since then, the term "water hole" has been used to refer to searches at or around the hydrogen emission frequency.
Morrison and Cocconi's article was a call for action, and they hoped to put their theory to the test. Cocconi contacted Sir Bernard Lovell at the Jodrell Bank radio observatory, the largest dish in the world at the time, and suggested devoting telescope time to search for an extraterrestrial signal. Sir Bernard was, however, skeptical, and nothing came of the venture. The launch of the first radio search for an alien signal was left to others.
第2章：SETI成立的瞬间 ← | → 第4章：Ozma项目的起源