Le 01.03.2013 23:08, Pentcho Valev a écrit : > http://cfile205.uf.daum.net/attach/141EBD484EE5A30219CDD4 > The Elegant Universe, Brian Greene, p. 19: "If she fires the laser toward you - and if you had the appropriate measuring equipment - you would find that the speed of approach of the photons in the beam is 670 million miles per hour. But what if you run away, as you did when faced with the prospect of playing catch with a hand grenade? What speed will you now measure for the approaching photons? To make things more compelling, imagine that you can hitch a ride on the starship Enterprise and zip away from your friend at, say, 100 million miles per hour. Following the reasoning based on the traditional Newtonian worldview, since you are now speeding away, you would expect to measure a slower speed for the oncoming photons. Specifically, you would expect to find them approaching you at (670 million miles per hour - 100 million miles per hour =) 570 million miles per hour. Mounting evidence from a variety of experiments dating back as far as the 1880s, as well as careful analysis and int erpretation of Maxwell's electromagnetic theory of light, slowly convinced the scientific community that, in fact, this is not what you will see. Even though you are retreating, you will still measure the speed of the approaching photons as 670 million miles per hour, not a bit less. Although at first it sounds completely ridiculous, unlike what happens if one runs from an oncoming baseball, grenade, or avalanche, the speed of approaching photons is always 670 million miles per hour. The same is true if you run toward oncoming photons or chase after them - their speed of approach or recession is completely unchanged; they still appear to travel at 670 million miles per hour. Regardless of relative motion between the source of photons and the observer, the speed of light is always the same." > > Brian Greene is lying about the "variety of experiments dating back as far as the 1880s"