Fermi paradox
Michael H. Hart published in 1975 a detailed examination of the paradox, which has since become a theoretical reference point for much of the research into what is now sometimes known as the Fermi–Hart paradox. Geoffrey A. Landis prefers that name on the grounds that "while Fermi is credited with first asking the question, Hart was the first to do a rigorous analysis showing that the problem is not trivial, and also the first to publish his results". Robert H. Gray argues that the term "Fermi paradox" is a misnomer, since in his view it is neither a paradox nor due to Fermi; he instead prefers the name Hart–Tipler argument, acknowledging Michael Hart as its originator, but also the substantial contribution of Frank J. Tipler in extending Hart's arguments.
Fermi paradox
Although astronomers do not usually search for extraterrestrials, they have observed phenomena that they could not immediately explain without positing an intelligent civilization as the source. For example, pulsars, when first discovered in 1967, were called little green men (LGM) because of the precise repetition of their pulses. In all cases, explanations with no need for intelligent life have been found for such observations, but the possibility of discovery remains. Proposed examples include asteroid mining that would change the appearance of debris disks around stars, or spectral lines from nuclear waste disposal in stars. An ongoing example is the unusual transit light curves of star KIC 8462852, where natural interpretations are not fully convincing. Although most likely a natural explanation will emerge, some scientists are investigating the remote possibility that it could be a sign of alien technology, such as a Dyson swarm.