Editing General relativity (section)

== Current status ==
General relativity has emerged as a highly successful model of gravitation and cosmology, which has so far passed many unambiguous observational and experimental tests. However, there are strong indications that the theory is incomplete.<ref>{{Harvnb|Maddox|1998|pp=52–59, 98–122}}; {{Harvnb|Penrose|2004|loc=sec. 34.1, ch. 30}}</ref> The problem of quantum gravity and the question of the reality of spacetime singularities remain open.<ref>section [[#Quantum gravity|Quantum gravity]], above</ref> Observational data that is taken as evidence for dark energy and dark matter could indicate the need for new physics.<ref>section [[#Cosmology|Cosmology]], above</ref>

Even taken as is, general relativity is rich with possibilities for further exploration. Mathematical relativists seek to understand the nature of singularities and the fundamental properties of Einstein's equations,<ref>{{Harvnb|Friedrich|2005}}</ref> while numerical relativists run increasingly powerful computer simulations (such as those describing merging black holes).<ref>A review of the various problems and the techniques being developed to overcome them, see {{Harvnb|Lehner|2002}}</ref> In February 2016, it was announced that the existence of gravitational waves was directly detected by the Advanced LIGO team on 14 September 2015.<ref name="NSF" /><ref>See {{Harvnb|Bartusiak|2000}} for an account up to that year; up-to-date news can be found on the websites of major detector collaborations such as [[GEO600]] and [[LIGO]]</ref><ref>For the most recent papers on gravitational wave polarizations of inspiralling compact binaries, see {{Harvnb|Blanchet|Faye|Iyer|Sinha|2008}}, and {{Harvnb|Arun|Blanchet|Iyer|Qusailah|2008}}; for a review of work on compact binaries, see {{Harvnb|Blanchet|2006}} and {{Harvnb|Futamase|Itoh|2006}}; for a general review of experimental tests of general relativity, see {{Harvnb|Will|2006}}</ref> A century after its introduction, general relativity remains a highly active area of research.<ref>See, e.g., the ''[[Living Reviews in Relativity]]'' journal.</ref>
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