A Review of the History, Theory and Observations of Gravitational Microlensing up until the Present Day. (2008)
AuthorsMcClelland, Tamsynshow all
Gravitational microlensing has become almost a household term in the world of astronomy and astrophysics. It has derived fame from being the only technique yet developed that is capable of the detection of Earth-sized planets beyond the Solar System, the first of which was confirmed as discovered only as recently as 2004. It is, however, a concept which dates back a lot further than the modern day. Its roots may be found in the writings of Newton in the early 1700's. It was further developed by Michell, Laplace and Soldner, and reintroduced by Einstein who derived the same findings from first principles. After this period, however, the concepts of lensing due to the effect of gravity became almost forgotten, experiencing another awakening during the 1960's, but generally left undeveloped. It was not until the 1990’s that the subject began to grow. After macrolensing events were detected in 1979, it gradually became apparent that microlensing events could be detected as well. Today, various techniques of analyzing microlensing events have been introduced which can reveal, not just the existence of planets, but the shape and atmospheric conditions of individual and binary stars, brown dwarfs, and a variety of other elusive measurements. The history of Gravitational Lensing also serves as a reminder that it is often naive to acclaim a single scientist or researcher as initiating a field of science, but rather the progression and development of concepts is evolutionary, with each step resulting from previous works and influenced by colleagues of the day.