Einstein’s special theory of relativity rests on two postulates: a) there is a maximum speed at which particles can travel through space and b) this maximum speed is the speed of light. The special theory of relativity becomes important when speed of particles approaches the speed of light. For lower speeds, it gives the same results as the Newtonian mechanics. The general theory of relativity was developed subsequently, to describe the gravity based on relativistic principles. These theories have been verified in a large number of experiments, setting foundations of modern physics.
However, a recent report questions the validity of one of the two postulates of the special theory of relativity. In an experiment called OPERA, elementary particles called neutrinos were produced at CERN and directed towards detectors in an underground Gran Sasso laboratory, 730 km away inItaly. Neutrinos are particles that do not interact with matter almost at all and they were passing almost unobstructed through the rock/soil formations on their way to the detectors. Measuring the time it took to the neutrinos to travel the distance of 730 km, the physicists came to a surprising result: the neutrinos had to travel with the speed 0.0025 % faster than the speed of light. Careful rechecking of the experiments confirmed that the accuracy of their results is better that the obtained difference between the speed of light and the measured speed of neutrinos. While the difference of 0.0025% may be minute, this result is challenging one of the basic pillars of modern physics. This finding is being tested by other groups. If proven correct, it will require modifying the basic theories of physics.
However three points need to be stressed. Firstly, the theory of relativity is a well-proven theory. Accurate measurements of the global position on the Earth’s surface using the GPS system would not be possible without taking into account the relativistic effects, for example. Secondly, the theory of relativity was used in the very design of the experiment that is indicating the neutrinos travel faster than light. Amongst other things, GPS system was an important part of the experiment, enabling the measurement of the distance between the source of neutrinos and detectors with accuracy better than a centimetre. This distance was changing during the experiment due to the continental drifts. Thirdly, neutrinos are found to travel just a little bit faster than light. If there are elementary particles for which the speed of light is not the limiting velocity, it is reasonable to expect they would travel at a substantially higher speed. For such particles, the speed of light would not be a special speed that they would have to travel close to.
The team reporting their surprising finding did not rush into publishing their results. The measurements were performed from 2009-2011. After careful repeated analysis of their data, they decided to make it public in September 2011 (http://arxiv.org/abs/1109.4897) in order to have other physicists verify their experiment. The question that has to be asked is: what happens if their results are confirmed?
One has to bear in mind that the Newton’s mechanics is a well proven theory for velocities we experience in everyday life. It was merely refined by special theory of relativity, for velocities comparable to the speed of light. Again, the concepts of the theory of relativity have been proven in numerous experiments over the last century. One would expect that confirming the speed of neutrinos being higher than speed of light would merely further refine the theory of relativity. It may well happen that the limiting speed for elementary particles is not the speed of light, but some other speed a bit higher than the speed of light. The theory of relativity does not take into account another pillar of modern physics: quantum mechanics. Quantum mechanics describes the processes on very small scales. All efforts to merge the general theory of relativity and quantum mechanics into one comprehensive theory have been so far unsuccessful. A peculiar feature of quantum mechanics is that elementary particles can appear out of nowhere for a very brief time and then disappear. Particles travelling through space can interact with these virtual particles, which may affect their speed. It may be that such effects are responsible for the reported velocity of neutrinos exceeding the speed of light. After all, the sped of light in matter is lower than its speed in vacuum due to its interaction with matter.
If such scenario proves to be the case, one may say all that the neutrino experiment will change is the value of the maximum speed. However, new questions will then have to be answered, too. The exact value of this limiting speed will need to be found. Small corrections will then be needed to the theories incorporating relativistic effects, which in some cases may result in qualitatively different outcomes to these theories. There is also the fundamental question of whether any particle in our universe can travel at this limiting speed at all. All this may help answer the most fundamental question we are facing: what is the “empty space”?
Written by Associate Professor Joseph Horvat from the UOW School of Engineering Physics
Further reading:
Large Hadron Collider and the search for the Higgs boson: the moment of truth approaches
If you’re going to challenge Einstein, you better be right!
CERN makes an interesting discovery
Einstein used the Lorentz Transformation to form his postulate that nothing can travel faster than the speed of light. To me Lorentz describes an optical illusion. In space time I don’t believe any frame of reference can be fixed. Space time is moving forward. So I would love to see if the latest paper to tell us that CERN must have been wrong used Relativistic Velocity instead of Relativistic Mass would come to the same conclusion. e=mrv2
I wish Physicists would go back to what they learned as “Self Evident” and take another look. The most risky thing in life is to not question postulates/axioms. The speed of light is just that the speed of light. Just like the speed of any other wave. In a world without sight they probably would have used the speed of sound. If you agree with me please spread the word. If not I appreciate your point of view and I am not crazy enough to think I am always right. As you can see, I was way off base when I started thinking about this.
But I can’t help but think what I great century this could be if we remove limits and start really pushing the envelope. http://jetsrock.wordpress.com
Before 23 years, I had proved mathematically that relative velocity may be more than light velocity. CERN proved experimentally that velocity of Neutrinos may be more than light, if this news will be confirmed then that will be new beginning of physics.
Please read paper “What is matter & dark matter is made up of?” on my web site http://www.maheshkhati.com. This paper may help to find solution to problems like what is dark matter? & about true relativity. I strongly oppose special theory of relativity.