Speed limit still enforced

Turns out the universe’s accelerator very likely has a governor on it after all.

The revelation last year that researchers may have observed particles traveling faster than the speed of light was startling in a number of respects, not the least of which was the apparent violation of the ultimate speed barrier. In his special theory of relativity in 1905, Albert Einstein stated that the speed of light — 186,282 miles per second — is a constant, something that cannot be exceeded. To be moving faster than the speed of light would be to look backward in time.

That, of course, has been the basis of numerous science fiction stories, films and TV shows in which characters have traveled back and forth in time and covered the incredible distances between Earth and the stars in single chapters and episodes, feats that could only be accomplished by traveling faster than light. The universal speed limit forced writers to come up with conventions such as warp engines, hyperspace and wormhole travel to get around the tricky plot-killer of interstellar space travel taking thousands of years, quite a while for a protagonist to hang around for the purposes of plot development.

Last fall, it seemed there might be a chance for life to imitate art.

In September, researchers with the Oscillation Project with Emulsion-Racking Apparatus (OPERA) were surprised when they timed neutrinos that they were firing from the European Organization for Nuclear Research (CERN) toward an underground lab at Gran Sasso, Italy — more than 450 miles away from the CERN site at the Swiss-French border.

What surprised the scientists was the neutrinos reached their destination 60 nanoseconds quicker than they could have had they been traveling at the speed of light. The experiment was set up with a margin of error of 10 nanoseconds. There are, by the way, a billion nanoseconds in one second, which means incredibly delicate timing was involved.

But that scant difference in time was enough to get the world buzzing, though even the scientists who reported the finding were cautious, noting that the results would have to be replicated by others independently before they could be declared valid. When you’re suggesting a fundamental rule of physics may be wrong, the smart money’s always on some healthy skepticism.

This week, officials with CERN said they had found a technical flaw in the experiment — a loose fiber optic cable. That cable helps synchronize an external GPS signal to the OPERA experiment master clock. There’s also a chance that the “stopwatches” for the experiment weren’t functioning properly. Either could have thrown off the incredibly accurate timing that’s required to measure billionths of seconds. CERN officials are planning to do some more measurements in May to determine whether either impacted the results, but regardless of what CERN determines independent verification is still needed.

In the meantime, no need to start drawing up plans for those interstellar warp engines just yet. Exceeding the speed of light, for now at least, seems to be running into some technical difficulties.