“The universe will literally have passed in and out of existence in less time than it takes you to take a breath,” he writes. If a photon could think, it would sense that its flight from one end of the cosmos to the other was immediate, but to an outside observer it would take the entire age of the universe.Īt Warp 37 (a fraction of the speed of light of 0.9999… until there are 37 nines after the decimal point), Odenwald calculates that the trip across the universe would last 0.2 seconds. When nearing the limit c, from their perspective the trip would be almost instantaneous. For the crew of a ship travelling at close to light speed, their clocks run much more slowly than for their relatives back on Earth. NASA physicist and science populariser Sten Odenwald explains that the key problem is time dilation, a consequence of special relativity. However, some scientists say that, in fact, a trip at superluminal speed is not only a logical impossibility, but also that it wouldn’t offer the advantages that we think it would. As for Einstein, what he did was postulate in his special relativity theory that the speed of light is a constant, the “c” coined decades earlier by James Clerk Maxwell, and it is independent of the movement of its source for any observer in other words, since there is no ether, there is no fixed reference system in the universe.Įinstein did not forbid an object from moving faster than light, but he estimated that accelerating it to such a rate would require infinite energy. This value is no longer modified, since in 1983 it was used as a constant to define the new value of the metre in the International System of Units. Michelson’s successive measurements were refined by others until, in 1975, a final value was adopted: 299,792.458 km/s. This conclusion arrived along with the discovery of the photon : particles do not need a medium through which to move. The result was that there were no appreciable differences, thus the ether does not exist and light moves at the same speed in all directions. In his most famous experiment, carried out in 1887 along with Edward Morley, Michelson measured the interference of the phases of light waves in two perpendicular directions. Since the Earth must move through this fluid, it was expected that light would have a different speed in the direction of this “ether wind” and in its perpendicular. At that time, scientists believed in the existence of a luminiferous ether that served to support light waves, just as the air propagates sound. Michelson began his work in 1877 while studying at the Naval Academy in Annapolis. The credit for having calculated the speed of light with some precision rests with the American Albert Michelson (19 December 1852 – ), for which he would receive, in 1907, the first Nobel Prize in a science for his country. Michelson, teaching at the University of Chicago. Not so his assistant, the Danish astronomer Ole Rømer, who in 1676 achieved the first rough measurement of the speed of light. After having proclaimed before the French Academy of Sciences that the abnormalities observed in the times of the eclipses of Jupiter’s moons were due to “ the fact that light arrives from the satellites with a delay ,” he abandoned this line of thought. The first hint in modern science that light was not instantaneous, but rather had a finite speed, is found in the work of the Italian Giovanni Cassini however, he had little faith in it. But is this really the case, and does Einstein deserve the reputation of being the spoilsport who shattered one of the most cherished dreams of science fiction? Of course, this is a great disappointment because it ruins the possibility that we might one day have the technology to holiday near other stars and meet the possible local inhabitants. If there is one idea that’s universally known, even among those of us less versed in physics, it’s that there is a universal speed limit that cannot be broken, because Einstein said so. It is forbidden to go faster than the speed of light.
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