Lightspeed by John C. H. Spence, Hardcover | Indigo Chapters

This book tells the human story of one of man's greatest intellectual adventures - how it came to be understood that light travels at a finite speed, so that when we look up at the stars, we are looking back in time. From the ancient Greeks measuring the distance to the sun, to today'ssatellite navigation and Einstein's theory of relativity, the book takes the reader on a gripping historical journey. It looks at how Galileo with his new telescope discovered the moons of Jupiter and used their eclipses as a global clock, allowing travellers to find their Longitude. We are alsotold of how Ole Roemer, noticing that the eclipses were a little late, used this to obtain the first measurement of the speed of light, which takes eight minutes to get to us from the sun. We then move from the remarkable international collaborations to observe the Transits of Venus, includingCook's voyage to Australia, to the extraordinary achievements of Young and Fresnel, whose discoveries eventually taught us that light travels as a wave but arrives as a particle, and all the quantum weirdness which follows. In the nineteenth century, we find Faraday and Maxwell , struggling tounderstand how light can propagate through the vacuum of space unless space is filled with a ghostly vortex Aether foam. We follow the brilliantly gifted experimentalists Hertz, discoverer of radio, Michelson with his search for the Aether wind, and Foucault and Fizeau with their spinning mirrorsand lightbeams across the rooftops of Paris. Messaging faster than light using quantum entanglement, and the reality of the quantum world, conclude this saga. | Lightspeed by John C. H. Spence, Hardcover | Indigo Chapters