英和和英

語源

Named after American astrophysicist Frank Drake (1930–2022).

固有名詞

the Drake equation

1. A formula for calculating the probability of civilizations existing elsewhere in the Milky Way galaxy and of their ability to communicate with Earth.
   • 2010, Göran Grimvall, “Chapter 1: Numbers”, in Quantify! A Crash Course in Smart Thinking, Johns Hopkins University Press, →ISBN:

     Arguably the most challenging estimation problem is how many planets there could be in the universe with life forms like those on Earth. A conference in 1961 at the National Radio Astronomy Observatory in Green Bank, West Virginia, was the starting point for the search for extraterrestrial intelligence, abbreviated SETI. The conference discussed the famous mathematical expression that is sometimes called the Green Bank equation but is more often referred to as the Drake equation because it was formulated by Frank Drake in preparation for the conference. The equation seeks to quantify the number, N, of civilizations in our galaxy (the Milky Way) whose radio emissions are now detectable on the Earth. […] If technologically advanced civilizations can avoid self-annihilation for a period L_lifetime at least as long as the existence of Homo sapiens (over 100 000 years), the consequences suggested by the Drake equation are enormous for how we view ourselves. But perhaps our solar system is far from typical. Some people would claim that it is unique, in the strongest sense. […] The original suggestion that civilizations may be able to communicate with radio signals for about 10 000 years was considered by many to be far too long a period. Human self-annihilation through nuclear war was being much debated at the time of the Green Bank conference, and there are of course many other scenarios in which a technologically advanced society perishes, due to actions of the inhabitants or to natural disasters. But even if the typical L_lifetime is much shorter than 10 000 years, the Drake equation suggests that the search for extraterrestrial life is worthwhile, and many enthusiasts are engaged in that endeavor.

参考

• exobiology
• Fermi paradox