Unimaginable Speeds

WHEN we build starships, how fast will they travel? If the speed of the fastest sub atomic particle is any guide, they may be able to travel very rapidly indeed. The so-called "Oh my God" particles detected by the University of Utah's cosmic ray detector at Dugway proving ground near Salt Lake City are ten trillion times more energetic than any created in a man-made atomic-smashing machine, and are crashing into the Earth's atmosphere at 99.99999999999999999999951 percent of the speed of light. ``It is hard to know how they could have been accelerated to such terrific speeds, or where they could have come from,"

Blasted by a supernova explosion?

says physicist John Walker, writing in the Newsletter of the Interstellar Propulsion Society. "One possibility is that they were blasted out by the shock wave of a supernova explosion.'' To see what prospect this discovery might have for interstellar travel, imagine that these particles could be somehow enlarged to the size of starships. Using Einstein's prediction that time slows down inside fast moving objects, Mr Walker has calculated the amount of time which astronauts inside such a vehicle would take to reach various cosmic destinations. They would take 4.3 thousandths of a second to reach the nearest star, alpha Centauri, 4.3 light years away; and a journey to the centre of the Milky Way, 30,000 light years distance would take them 3.2 seconds. A voyage to the Andromeda Galaxy, 2.2 million light years away, would take them 3.5 minutes; and to the Virgo Cluster of galaxies, 42 million light years away, 1.5 hours. A trip of 25 hundred million light years to the brightest quasar 3C273, would last three days and they would reach the edge of the visible Universe at an estimated distance of 14 thousand million light years in 19 days. But if the speed of light were ever attainable, astronauts in an enlarged "Oh my God" particle would make all these journeys in zero time. An amazing footnote to these numbers shows the fastest ships in science fiction, the Galaxy Class Starships in Star Trek's 24th Century United Federation of Planets, do not do nearly so well. Quite early in this series the editors decided to abolish Einstein's relativity because of its inconvenient rule, that nothing can exceed the speed of light. They replaced it with a vague theory, "Time Warps", in which ships could travel at a maximum speed of 1,516 times the speed of light, "Warp 9", but unhappily there is no compensating time deletion. By this reckoning it must take the starship Enterprise a full 20 years (30,000 divided by 1,516) to travel from Earth to the centre of the Milky Way Galaxy, (even though by some magic they break their own rules and somehow make the journey in a fortnight). Except for some marvellous physics in which ships "jump" instantaneously through "hyperspace", the real universe promises to be much more fruitful of new technology than any invented fiction.