Speed of light the fundamental excitations (or quanta) of the electromagnetic field, called photons. In QED, photons are massless particles and thus, according to special relativity, they travel at the speed of light in vacuum. Extensions of QED in which the photon has a mass have been considered. In such a theory, its speed would depend on its frequency, and the invariant speed "c" of special relativity would then be the upper limit of the speed of light in vacuum. No variation of the speed of light with frequency has been observed in rigorous testing, putting stringent limits on the mass of the
In the Light of What We Know shortlisted for the Goldsmiths Prize 2014 and nominated for the Folio Prize 2015. The author was shortlisted for New Writer of the Year award at the National Book Awards (UK) 2014. In the Light of What We Know In the Light of What We Know is the debut novel of Zia Haider Rahman. First published by Farrar, Straus and Giroux, the novel was released in the spring of 2014 to international critical acclaim and earned its author the James Tait Black Memorial Prize, Britain's oldest literary prize. and the inaugural International Ranald McDonald prize 2016. The novel has already been