当前位置:文档之家› 2012年北航SDLTRADOS杯研究生科技英语翻译比赛原文

2012年北航SDLTRADOS杯研究生科技英语翻译比赛原文

2012年北航SDL TRADOS杯研究生科技英语翻译比赛原文
The Fermi–Hart Paradox: Where are the Aliens?
Fermi is reported to have mused over lunch that there could not beintelligent lifeforms elsewhere than Earth because they would havecolonized space and already be here. Conversely, the presence of lifeon the Earth implies its presence elsewhere. This problem, though itoriginated with Fermi, has been worked on by many people, mostnotably Hart. Over the years, the absence of evidence for aliens hasemerged as one of the few solid data in the field of exobiology. In thissection, we therefore confine our attention to the Fermi–Hart paradoxand how it may be resolved.
Drake’s formula is the traditional way to quantify the frequencyof extraterrestrial civilizations. Itinvolves a product of probabilities,ranging from the astrophysical (e.g. the fraction of stars which havehabitable planets) to the sociological (e.g. the relative timescale forthe development of technology). However, each of the componentprobabilities is poorly known, so the result has a high degree ofuncertainty. The nearest tecபைடு நூலகம்nological civilization to us may bearound a nearby star, or in one of the most remote galaxies.
It is important to realize in the application of Drake’s formula thatthere is a continuum of systems to which it can be applied: the stars ofthe Milky Way, the local group of galaxies, or all of the objects in thevisible universe. To order of magnitude, there are as many galaxies inthat part of the universe accessible to observation as there are stars inthe Milky Way. Signals from extraterrestrial civilizations involve, fortheir detection, a balance between the number of sources (which goesup approximately as the cube of the distance) and the signal strength(which goes down for electromagnetic radiation as the square ofthe distance). This is like the situation we encountered before inregard to Olbers’ paradox. The American program on the Search forExtraterrestrial Intelligence has concentrated on nearby stars, butprevious Russian surveys focused on distant galaxies. The fact thatno signals have been detected from either class of objects brings usback to the Fermi–Hart paradox.
An immediate suggestion for a resolution is, of course, that aliencivilizations are sparse in the universe.Indeed, Tipler and others haveargued that human civilization may be unique and that we are trulyalone. This view is distasteful to many, and some researchers such asClarke and Sagan have reached theopposite conclusion, that life(and by implication civilization) is common. The reason for thisdivergence of opinion lies simply in a lack of data.
相关主题