Faster Than light - A Measurement Error?

For any of you that were interested in the CERN claim last year of something travelling faster than light, there was, apparently, a mistake. Here's an article by Michio Kaku.


No, You Still Can't Go Faster Than Light


A challenge to Einstein and a measurement error.


By Michio Kaku


The case against Einstein is crumbling. A series of new experiment results flatly contradict the sensational announcement last year that something could—and indeed had—traveled faster than light. Physicists around the world are, for reasons I'll explain, breathing a sigh of relief.

Last September a group of physicists fired a beam of subatomic particles called neutrinos from the CERN particle accelerator, near Geneva, to Italy. They were left gasping for breath when the neutrinos apparently outraced a beam of light by a distance of 60 feet over a distance of 454 miles, violating Einstein's famous dictum that nothing can travel faster than light.

Headlines blared that Einstein, an iconic figure in science for a century, was finally proven wrong. The world of physics was thrown into turmoil because the bedrock of modern physics would disintegrate if that were true. My research is in string theory, for example, which extends Einstein's theory of relativity. So if his theory is wrong, my own life's work would go out the window as well.

The first cracks in this claim began to emerge last month, with clear signs that the experimental apparatus at CERN was miscalibrated. In a race, everything depends crucially on measuring two things: knowing the length of the track, and synchronizing two watches at the starting point and finish line. Apparently, there were crucial errors in both measurements.

First, the clocks in Switzerland and Italy were synchronized by comparing them to a third clock, a carefully calibrated oscillator. Now it appears that the oscillator itself may have been miscalibrated, so the two clocks were not beating in step.

Second, the distance between Switzerland and Italy has to be known to incredible precision for the experiment to be accurate. The only device capable of doing this is the global positioning system. But apparently the fiber optic cable that links the GPS satellite to a master clock may have been loose, which could have introduced errors in measurement. These two errors could easily have increased the speed of neutrinos by 20 parts per million, thereby explaining the discrepancy.

But the floodgates finally burst open last week when a second group of physicists announced that they redid the entire experiment and found that Einstein was correct all along: Their neutrinos traveled at precisely the speed of light, not faster or slower.

What makes this second announcement so convincing is that they used much of the same apparatus as the previous group. They used the same particle accelerator at CERN, fired a beam of neutrinos over the same path, and used the same destination, a laboratory in Gran Sasso near Rome. The crucial difference between these two groups was the equipment used to measure the speed of the neutrinos. This gives enormous weight to the idea that the first group did not properly calibrate their instruments.

Last week the director for research at CERN, Sergio Bertolucci, issued a diplomatically worded statement that read, "The evidence is beginning to point towards the [earlier] result being an artifact of the measurement." Nobel Laureate Carlo Rubbia, a spokesman for the second group, was more blunt when he said, "We cannot be both right. One of us is wrong. I know who is right. We are right."

Since there is so much at stake, in the coming months more experiments will be done to verify this new result. But in the minds of most physicists the issue is now settled—Einstein's theory remains undefeated.

Will there be more spectacular errors in the future? Of course. Experiments like this are fiendishly difficult to perform, with scientists pushing the boundaries of particle physics and high-tech measurements.

This is not the first time that tiny flaws have cascaded into horrendous errors. In 1990, for example, NASA launched the Hubble Space Telescope to great fanfare. So it was a colossal disappointment when the telescope only captured blurry, useless images. Later, it was discovered that the device that ground the mirrors was miscalibrated by a mere 1.3 millimeters. So this billion-dollar telescope was reduced to an orbiting piece of space junk. It became the laughing stock of the scientific world, until a second multimillion-dollar mission successfully put corrective glasses in front of the telescope to correct the error.

In 1999, the $125 million Mars Climate Orbiter was a tremendous failure, disintegrating as it hit the atmosphere of Mars. A careful investigation showed that the mission was a total washout because scientists did not properly convert the metric system—i.e., changing meters into feet—which is something that even schoolchildren can do.

Similarly, in 1979 the billion dollar Three Mile Island nuclear power plant partially melted down because a simple valve got stuck open and leaked millions of gallons of radioactive cooling water, causing the superhot core to melt. Thus, a defective part costing just a few dollars derailed a multibillion-dollar industry for three decades.

Unfortunately, in our increasingly technological world we can expect more sensational errors like the one that, however briefly, challenged the foundation of modern science. How does one limit such costly mistakes? Ultimately, the burden of responsibility falls on the scientists and engineers to be more meticulous than ever before making grand claims like they have broken the light barrier.

As scientists continue to examine subatomic particles—the very building blocks of the universe—we would do well to remember the words of the great astrophysicist Carl Sagan, who said time and again, "Remarkable claims require remarkable proof."

Mr. Kaku, a professor of theoretical physics at CUNY, is author of "Physics of the Future: How Science Will Shape Human Destiny and Our Daily Lives by 2100" (Doubleday, 2011).

 

Does that mean that the light at the end of tunnel will be later than we thought

 

The time paradox (that's two doctors, I think ) went into a causitive loop in 1953 when Ray bradbury wrote the book 'Fahrenheit 451' thus creating a parallel universe where The Great Ipod In The Sky (The GIITS) took over all human thought. The Mark 1 version being known as 'The Old GITS'.