Faster than light

In the sky this week…

  • Jupiter rises about 6 p.m, and for most of the night is an incredibly bright object in the southern sky. If you have a telescope or binoculars, get them out. The opportunities for looking at the giant planet, its cloud belts and four largest moons don’t get much better than this.
  • Mars comes up around 1 a.m.
  • The Moon will be Full on November 10.

Ken Tapping, November 02, 2011

At the end of the 19th Century, it looked as though physics was near complete, and all that needed to be done was to measure a few things with greater accuracy. Isaac Newton had come up with the mathematics and physics needed to explain the motions of the planets. His calculations are what we still use today for space missions and exploring the Solar System. His work was based on a fundamental assumption, that space and time are exactly the same everywhere in the universe. However, from time to time we have come up with things that just don’t add up with this approach.

These inconsistencies led people like Albert Einstein to come up with a very different view of the universe. This picture is described in what has become known as the “Theory of Relativity,” the main points of which are that space and time are distorted by large masses and by moving very quickly, and that the speed of light is the same to everyone, no matter how quickly or in which direction they are moving. Finally, any object cannot be accelerated to the speed of light, and definitely cannot exceed it. The speed of light, just under 300,000 km/sec, is the cosmic speed limit.

Overall view of the Large Hadron Collider at the CERN laboratory in Geneva Switzerland. Credit CERN

Overall view of the Large Hadron Collider at the CERN laboratory in Geneva Switzerland. Credit CERN

Understandably, over the 100-plus years since the Theory of Relativity was published, this intriguing description of the universe has attracted a lot of attention. It has been tested over and over again. One experiment involved comparing the passage of time on satellites orbiting the Earth at 30,000 km/h, with the passage of time on the ground. In these experiments, the predictions made using the Theory of Relativity have been proved correct, and it is now used as a basic tool in understanding the workings of the universe; that is, until recently.

A portion of the accelerator tunnel in the Large Hadron Collider. Credit CERN

A portion of the accelerator tunnel in the Large Hadron Collider. Credit CERN

Scientists at the CERN laboratory near Geneva, Switzerland were doing an experiment to study neutrinos. These are rather weird particles that are produced in high-energy particle accelerators and as a by-product of energy production in stars. In this experiment, a beam of neutrinos was generated at CERN and squirted in the direction of another laboratory at Gran Sasso, in Italy, some 730 km away. It would take light 2.5 thousandths of a second (milliseconds) to travel that distance. Over three years, about 15,000 neutrinos made the trip. The result was more than surprising. They were making the trip in less than 2.5 milliseconds, which meant they were travelling faster than light.

There are three possibilities. Firstly there could problems with the Theory of Relativity. Secondly, maybe we don’t understand neutrinos. Thirdly, there could have been something wrong with the experiment. Having used the Theory of Relativity effectively for so long, most scientists question the experiment. New experiments are in progress to check the results. 

Ken Tapping is an astronomer with the National Research Council's Dominion Radio Astrophysical Observatory, Penticton, BC, V2A 6J9.

Telephone: 250-497-2300
Fax: 250-497-2355
E-mail: ken.tapping@nrc-cnrc.gc.ca

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