Speed of light fibre optic signals which travel 30–40% slower at the speed of light through glass. There are different ways to determine the value of "c". One way is to measure the actual speed at which light waves propagate, which can be done in various astronomical and earth-based setups. However, it is also possible to determine "c" from other physical laws where it appears, for example, by determining the values of the electromagnetic constants "ε" and "μ" and using their relation to "c". Historically, the most accurate results have been obtained by separately determining the frequency and wavelength of a light beam,
In the Light of What We Know when the true pleasure of a work of fiction is its gravitational pull upon us?” In a 4,000-word review for "The New Yorker", the critic James Wood described Rahman as “a deep and subtle storyteller,” and praised the novel as “astonishingly achieved…Isn’t this kind of thinking—worldly and personal, abstract and concrete, essayistic and dramatic—exactly what the novel is for? How it justifies itself as a form?…"In the Light of What We Know" is what Salman Rushdie once called an ‘everything novel.’ It is wide-armed, hospitable, disputatious, worldly, cerebral. Ideas and provocations abound on every page.” Australian literary critic Louise Adler