Thoughts & Insights
When Time Stands Still
OUBEY called his computer-based “painting with light”, created between 1988 and 1993, “PhotonPainting”. For him it was less a technique than an idea, a philosophy: the idea of painting with light.
“Perhaps it is also a reminiscence of the borderline character, the universal constant of the speed of light, which separates us human beings from the universe. This constant keeps us in a kind of quarantine, the boundaries of which can only be overcome with the help of imagination”, he once said about this himself.
How these boundaries can be overcome with the help of imagination is demonstrated by science fiction. Yet even Wernher von Braun reflected on the reachability of the stars more than forty years ago. His ideas went far beyond the limitations of what is technically feasible into the regions of what we call fantasy. At the time, he spoke of a “photon rocket”, with which one could travel – if it existed – at the speed of light through outer space to reach a fixed star a thousand light years away within the span of a human life. “It would be necessary to come up with a rocket that could transform the entire mass M of the fuel supply into radiation energy according to Einstein’s famous relation of E = M·C². The emission product of such a ‘photon rocket’ would be a beam, and the emission speed would naturally correspond to light speed C.” This sounds quite plausible, but “the problem is that no one knows how to build a photon rocket.”
A further problem arises in terms of the consequences that traveling at the speed of light would have for the life of the traveler. Since the passage of time for an object approaching the speed of life increasingly decelerates in comparison with the passage of time for a stationary observer (e.g. on earth), until it comes to a complete standstill upon reaching the speed of light, time would never pass for a person traveling at the speed of light through space. This effect would make it possible for an astronaut traveling from earth to reach a fixed star one thousand light years away within a period of time that he would experience as 13.2 years. Including the return then, he would be traveling for a total of 26.4 years – if he does not make any stops. This expedition could therefore certainly be carried out within the span of a human life. “The only problem then,” writes von Braun, “is that more than 2000 years would pass on earth during his absence. So it could happen that he might end up in a zoo upon his return.”
Neutrinos presumably have no problems of this kind. As was measured with experiments in the CERN particle accelerator in Geneva three weeks ago, neutrinos move slightly faster than light. Who knows, maybe a hundred years from now there will be these super fast rockets – driven by neutrinos …?