As we have known since our schooldays, there are the so-called cosmological constants in physics. The best known of them is the speed of light. The theories of both general and special relativity (GR and SR) claim that nothing can move faster than light in our material world. This is proved by an apparently simple formula that says that when an object reaches the speed of light, its mass becomes infinitely large. And as mass and energy are also linked in Albert Einstein’s well-known formula E=mc2, this kind of mass would need infinitely large energy, which in turn contradicts another fundamental law – that of conservation of energy. And, although the idea of overcoming this limitation has long been warming the hearts of many sci-fi writers and filmmakers, everything was so far confined to books, films, and other products of this kind. All the more so that overcoming the speed of light limitation makes it in principle possible to travel in time – a pet subject of science fiction authors. If this were the case, one could send a terminator to the past to kill the grandfather or grandmother of an Earthman, which would have brought into question the birth of their descendants. On the other hand, you cannot possibly ban such an interesting thing as dreaming and fantasizing.
SR, which postulates the invariance and limitation of the speed of light, has been the object of attempts to deny it as long as it has existed. The main reason is that experiments to find “ether wind” do not seem to have been very convincing, although they are traditionally regarded as by far the only experimental proof of SR’s validity. All this stream of doubts forced the famous Soviet physicist Sergei Vavilov 60 years ago to instruct his fellow researcher Aleksey Bonch-Bruyevich to carry out an experiment to directly check SR’s second postulate. But that-era equipment did not allow gaining a credible result. A similar experiment, recently conducted at the Kurchatov Synchrotron Radiation Center, confirmed the validity of the second SR postulate: the speed of light is a universal limit.
And what has now shaken the academe, especially physicists, is the report of a group of scientists at the Geneva-based European Organization for Nuclear Research (CERN) on the existence of faster-than-light neutrinos. As part of the Oscillation Project with Emulsion-Tracking Apparatus (OPERA) experiment which attracted about 200 physicists from 36 institutes in various countries, they tested the phenomenon of neutrino oscillations by sending high-energy beams of muon neutrinos produced at the CERN Super Proton Synchrotron to the Laboratori Nazionali del Gran Sasso underground laboratory, 733 km away in central Italy. The report says that, over the past three years, neutrinos – unique and hard-to-catch particles, – have been arriving at their destination 60 nanoseconds faster than the speed of light allows. The neutrino is a particle discovered by the Italian Nobel-winning physicist Enrico Fermi in 1933-1934. The name literally means “little neutron” in Italian.
Quite obviously, the first reaction that this shaking of the foundations caused was that a mistake was made. For three years on end, the Gran Sasso researchers have caught about 16,000 neutrinos, each of them arriving at the detector earlier than SR-based calculations would suggest. The speed of light was exceeded by a negligible 24 parts per million. On average, the neutrinos made the 730-kilometer, 2.43-millisecond, trip roughly 60 nanoseconds faster than expected if they were traveling at the speed of light, with a margin of error of ±10 nanoseconds – in other words the result was statistically valid. When the scientists found this discrepancy, they, naturally, began to look for a mistake. But, no matter how hard they tried, they failed to find one.
Incidentally, rejecting the foundations takes a great deal of civic courage on the part of scientists. The king of mathematicians, Karl Gauss, once failed to sufficiently display it and did not publish his findings in non-Euclidean geometry. Moreover, he did not support publicly the Russian mathematician Nikolai Lobachevsky and the Hungarian scientist Janos Bolyai, which caused strong moral anguish in them, although in private correspondence he inquired about and positively assessed their work. Another example is from the domain of physics. In 1929 the Soviet physicist Dmitry Skobeltsyn spotted electrons in cosmic rays. Letting them go through the Wilson cloud chamber and twisting their trajectory by means of a magnetic field, he detected particles that acted like negatively-charged electrons but curved in the opposite direction. He was sure he was dealing with electrons and, hence, did not believe his own instrument. He in fact discovered the positron but did not dare to publicize his discovery which he thought contradicted the unshakable foundations. In 1932 the American physicist Carl Anderson did the same, but he did believe his eyes and devices. He took a resolute step and called a positron a positron. He published the research results and was later awarded the Nobel Prize. Prof. Boris Ioffe from Moscow’s Institute of Theoretical and Experimental Physics believes that if the scientists were sure of the result they had achieved, they were simply obliged to announce and thus introduce into scientific circulation, even if they had to come under a barrage of accusations and attacks. “The scientist must show courage sometimes. It is the human factor. Even if you are wrong but sure that you are right, you will have an incentive to announce your discovery before others do so,” Ioffe emphasizes.
Interestingly, physicists are not exactly in rapture over their discovery. The OPERA project manager Antonio Ereditato from Bern University said at a CERN seminar that OPERA was not claiming that their work had overturned Einstein: “I would never say that…We are forced to say something. We could not sweep it under the carpet, because that would be dishonest.” In his words, their article in the popular online publication Arxiv.org is not so much a statement on the accomplished fact as a request to the academe to confirm or deny his team’s findings and point out where they erred. However, this slightly veiled attempt to cool the passions down did not quell the overall outrage. Physicists took a dim and resentful view of the announcement that the SR second postulate was challenged.
Some are saying statistics was read wrongly. Others were puzzled where the 10-nanosecond margin came from if the distance between the points of departure and arrival was measured with GPS, a system that has an accuracy of several dozens of nanoseconds. And, what the Gran Sasso researchers themselves emphasize, one should not assert anything on the basis of one experiment only – there should be independent confirmations from other sources.
Leonid Bezrukov, deputy director of the Russian Academy of Sciences’ Institute for Nuclear Research, says that his institute is taking rather a skeptical view of this report. There are ample grounds for this: one swallow doesn’t make a summer. The same applies to physics. One, even repeatedly conducted, experiment does not guarantee absence of errors. Besides, the article has no detailed description of the nature of calculations. It seems to be a junior-school problem: given the distance and the time; find the speed; the distance is divided by the time – that’s all arithmetic and physics. But it is simple at first glance only.
One must find the precise time of the start, i.e. the birth, of a neutrino and understand how this information is relayed via a satellite to the detector, for there can be distortions on this way, and, if necessary, take account of the errors. Then one must determine the moment of the finish, when the particle is recorded by the detector, and take into account the delay time and noises caused by electronic instruments, and many other things. The absence of sufficient mathematical calculations and of a detailed description of the instrumentation makes this story all too strange. It is not the way to do things in science. There is nothing to hide: either a discovery has been made and you should submit all the data to repeat the experiment in other laboratories under different conditions, or there is something that has nothing to do with science. In any case, we should wait for an independent confirmation from other laboratories.
At first glance, there is a hard-to-resolve contradiction. We have to choose between the two options: a large group of physicists has either proved what contradicts the fundamentals or made a mistake, failing to solve what seems to be an elementary arithmetic problem and publishing a wrong result. Incidentally, the latter occurs more often than not, and is only natural. Moreover, mistakes in science may be quite useful and fruitful, for analyzing them may result in dramatic discoveries.
Bezrukov does not think that a mistake was totally unlikely. “There are a lot of physicists but not so many specialists in the world now,” he says. “People know how to press computer buttons, but very few of them are experts who know about electronics. They might well have made a mistake and then affixed their signatures to the article without too much looking into it – just trusting their colleagues’ opinion.”
If so, it is the collapse of not just a long-established physical dogma but of trust in the entire modern physics. But if this turns out to be the truth and neutrinos can really move faster than photons (particles that form light), it will mean a revolution in physics, comparable to the one that Einstein performed in the early 20th century. But this is rather an unlikely case. There may have been an error, but it is so difficult to spot that the very detection of it would be a major discovery. For SR has been confirmed in hundreds, if not thousands, of flawless experiments. We have mentioned of them above. The point is physicists are inert and inclined to cling to a long-established theory. The problem is far more important, for it is about fairness in experiments and science as a whole. There are too many of those who, in pursuit of a sensation, tend to sacrifice, voluntarily or not, scientific authenticity and strictness. This in turn undermines confidence in both science and scientists and brings forth a huge number of crooks who are trying, under the guise of pseudo-science, to reach totally unscientific goals.
Reports on tachions, i.e. particles that move faster than light, occur in physics with enviable regularity, only to be denied with equal regularity and sink into oblivion. In this particular case, it is about a concrete particle called neutrino. It has rather unusual properties if this may be said about microcosm inhabitants. Suffice it to say that an enormous number of these particles pierce through us every second, which we do not even suspect in everyday life. Nevertheless, this is not the first time the neutrino becomes an object of close scrutiny for physicists who experiment with the speeds close to that of light. There had been reports on the findings of a Chicago team who studied the oscillation of neutrinos in 2007 and found that they move faster than light. But those data were of no scientific importance because the margin of error in that experiment was much higher than the obtained values of light speed excess.
Let us assume what is so far incredible: the neutrino has reached a faster-than-light speed. This will be a breakthrough in physics, but nothing disastrous will happen. Crises in science, unlike those in the economy and finances, are beneficial in the long run, for they supply humankind with new knowledge. It is for this end that scientists work. Then the new technologies come into our house and our life.
