This conclusion: neutrinos are 60 nanoseconds faster than photons (1 nanosecond equals one billionth of a second).
It has been proved that it is an experimental error, which is caused by the loose optical cable connection between the computer and GPS equipment.
The researchers of Opera project in Gransasso National Laboratory used a set of devices to receive the neutrino beam emitted by CERN 730 kilometers away, and found that neutrinos reached 60 nanoseconds earlier than photons (1 nanosecond equals one billionth of a second), that is, they "ran" 6 kilometers more per second. "We were shocked," said Antonio Iratitato, a physicist at the University of Bern and a spokesman for the Opera project. 20 1 1 The website of the British magazine Nature reported this discovery on September 22nd. The researchers plan to submit a report to CERN on 23rd. (According to the website of Science magazine, the discovery that neutrinos run faster than the speed of light shocked the scientific community last year, but the experimental result was actually due to an operation error and the loose optical cable connection between the computer and the global positioning system (GPS) equipment. )
Challenge the classics
Relativity is one of the basic theories of modern physics, which holds that the speed of any substance in vacuum cannot exceed the speed of light. This latest discovery may overturn Einstein's classical theory. John Ellis, a theoretical physicist at CERN, commented: "If this result is true, it is really extraordinary." Pierre Binet.Alfred Lu, a French physicist, told the French media that this is a "revolutionary" discovery. Once confirmed, "both general relativity and special relativity will be questioned". He didn't take part in the project, but he checked the experimental data. Binet.Alfred Lu said that in this experiment, neutrinos pass through various substances, including the earth's crust. "This may slow them down, but it will never increase their speed and make them exceed the speed of light." .
acceptance testing
This is not the first time that Einstein's theory of light speed has been challenged. In 2007, researchers at Fermi National Laboratory in the United States obtained similar experimental results, but they doubted the accuracy of the experiment.
Iratitato, a spokesperson for the Opera project, said that the project team fully believed the experimental results and then published them publicly. "We are very confident about the experimental results. We repeatedly checked all possible mistakes in the measurement, but found nothing. We want to ask our colleagues to check independently. "
This project uses a complex set of electronic and photographic equipment, weighing 1 1,800 tons, and is located at the underground of Gransaso National Laboratory 1 1,400 meters deep. The researchers of the project said that the distance between the receiver and CERN is within 20 cm, and the speed measurement accuracy is within 10 nanosecond. In the past two years, they have observed more than 16000 "superluminal" phenomena. Based on these data, they judged that the experimental results reached six sigma or six standard deviation, that is, the judgment was correct.
Ellis, a physicist at CERN, still has doubts about this result. Scientists have previously studied neutrino pulses emitted by supernova 1987a. If the latest observations are applicable to all neutrinos, then the neutrinos emitted by this supernova should reach the earth several years earlier than the light it emits. However, observations show that these neutrinos arrive only a few hours in advance. "This is hardly consistent with the observation of the Oprah project," Ellis said.
Alfons Weber, a neutrino project expert at Fermilab in the United States, believes that the Oprah experiment "still has the possibility of measurement error". Jenny Thomas, a spokeswoman for Fermilab, said that until the results of the Oprah project are announced, Fermilab researchers plan to continue to do more accurate experiments, which may start in the next year or two.
Iratitato welcomes colleagues to question the experimental data and is equally cautious. "This discovery is so surprising that everyone needs to be very cautious at present," he told Reuters.
As far as Weber is concerned, even if the experimental results are confirmed, the theory of relativity is "still an excellent theory", but "it needs to be expanded or revised". He said that isaac newton's theory of gravity is not perfect, but it does not prevent people from flying into space with it. In September, the agencies that released the news of "neutrino superluminal" were CERN and the project team of large-scale neutrino oscillation experiment (OPERA). Experiments show that the neutrino beam emitted by CERN on the border of Geneva "goes over mountains and mountains" and reaches Italy 732 kilometers away. Under the condition that the experimental error does not exceed 10 nanosecond, the speed of neutrinos is 58 nanoseconds faster than that of light. This result, which may subvert the current foundation of physics research, shocked the whole academic community and attracted the collective questioning of most physicists in the world. In the original question, scientists specifically pointed out that it takes much longer for the proton beam to produce neutrinos at the beginning of the whole experiment than after completing the experimental distance. In view of this, CERN changed its equipment in June+10, 5438, and shortened the neutrino generation time to 3 nanoseconds, so as to better compare with the neutrinos arriving in Gransaso, Italy. The results of the second repeated experiment show that neutrinos still arrive 62 nanoseconds earlier than light. This is completely consistent with the conclusion of the first experiment, and it also denies the speculation that the persistence of neutrino pulses is related to the experimental results.
165438+1October17th, the research team released a report again, saying that it had passed the second test and obtained the same results as the first experiment, thus eliminating the possibility of errors in the experiment. A spokesman for the experiment, Dr Antonio Erititatou of the University of Berne, Switzerland, said that the result was "slightly better". Other researchers also believe that this experiment has been improved in many aspects, such as accuracy and statistical analysis. Although all of them are from OPERA, different groups have completed repeated experiments.
According to the news of The New York Times Online Edition and Washington post Online Edition1October 20th, 165438+, the researchers from OPERA released the newly generated experimental data on June 7th, local time, reconfirming the previous sensational experimental results of "neutrino superluminal", and this is the experimental conclusion again after modifying the equipment in response to some previous doubts. However, in view of the fact that the "original" maker and revalidator of the experiment are both from the same institution, scientists everywhere generally hope to have an independent experiment to copy and analyze it, otherwise, the questioning of the theory is another matter, because the questioning of the experiment itself cannot be calmed down.
This result has brought great confusion to the scientific community because it violates Einstein's theory that the speed of light is the limit of the speed of the universe, and nothing can exceed the speed of light.
In June+10, 5438, CERN optimized the experimental scheme and began to review the neutrino superluminal experiment. Finally, "the new measurement method has not changed the original conclusion". But CERN also said that more experimental observations and independent tests are needed before the conclusion that neutrinos are faster than the speed of light is refuted or confirmed. Beijing time1June18th news, the existence of superluminal neutrinos means that Einstein's speculation is wrong. At least since the researchers proposed that neutrinos arrived 60 nanoseconds earlier than we thought through the OPERA experiment in Italy, it has been a topic that some very popular news media like to talk about. Scientists who were very interested in this unusual result began to look for a more accurate answer. Three weeks after the news was announced, more than 80 explanations were posted on the preprint of arxiv website. Although some people have put forward the possibility of new physics, such as neutrinos traveling in extra dimensions, or neutrinos with specific energy running faster than light, many people have put forward less innovative explanations for this experiment.
One of the earliest objections to the explanation of superluminal came from an astrophysical study. 1987, a powerful supernova produced a large amount of light and neutrinos that flocked to the earth. Although the neutrino detector observed that this particle arrived about 3 hours earlier than light, it is very likely that this ultra-light particle first started to fly to the earth. Neutrinos are difficult to interact with matter, and it is relatively easy to escape from the exploded star nucleus, while photons will be absorbed by many elements and re-emitted, and it takes longer for them to escape from the star nucleus. If the result of OPERA experiment is the same as the observation result, scientists believe that neutrinos should arrive more than four years earlier than light.
Other scientists have applied this superluminal result to tasks using standard physical models, which describe all subatomic particles and their interactions. According to the standard physical model, high-energy neutrinos should be able to generate virtual electron pairs through a process called Cohen-glashow ejection. As the Nobel Prize winner glashow and his colleagues explained in a paper, these ejecta will gradually exhaust the energy generated by superluminal neutrinos, thus slowing down their running speed.
Matt Strasler, a theoretical physicist, also said on his blog that the characteristics of the standard physical model show that in order for neutrinos to run faster than light, electrons should also run faster. But if electron neutrinos run at the speed proposed in the OPERA experiment, then electrons should be at least one billionth faster than the speed of light. Many experiments have determined the theoretical limit of electrons, which well excludes the above assumptions. OPERA's research team used GPS satellites to accurately measure the distance of 730 kilometers between the detector and the particle beam of CERN, which produces neutrinos. However, according to the special theory of relativity, if two observers are close to each other, they will come to a slightly different conclusion.
Because satellites orbit the earth, the positions of neutrino sources and detectors will change constantly. According to the paper, the satellite motion will lead to an error of 64 nanoseconds, which is almost close to the observation results of OPERA's research team. In the end, the physics community still needs to spend a lot of time and acquire a lot of academic knowledge in order to provide a true explanation for the results obtained by this research group. Until then, the heated debate may continue. After the release of the experimental results of OPERA, in addition to the opinions expressed orally by scientists, dozens of papers appeared in a few days to discuss the experimental results. Many famous scientists, including Nobel Prize winners, said categorically that OPERA's experiment must be wrong.
In terms of probability, the biggest possibility is that there are loopholes in the experiment itself, but it has not yet been discovered. It has been pointed out that some measurement links in the experiment may go wrong. Glashow, a Nobel Prize winner, published a paper explaining that if the speed of light really exceeds, neutrino energy will be lost in underground flight, and the experimental results will be contradictory. Therefore, it is imperative to repeat the experimental results. Nobel Prize winner Lu Biya said that two other Italian neutrino experiments, BOREXINO and ICARUS, can be used for verification. The MINOS experiment in the United States also indicated that they would immediately analyze the data and give preliminary results, and then improve the measuring equipment to verify the results of the OPERA experiment.
The second possibility is that neutrinos have special properties, so the theory of relativity is also right, and the experimental results are also right. For example, the neutrino emitted by CERN may oscillate into an inert neutrino, which can "cut corners" in multi-dimensional space and then oscillate back to ordinary neutrinos, so it seems that neutrinos run faster than light. Some people think that the mass of neutrinos is not fixed, which is related to dark energy and will change with the change of environment, so it looks faster than the speed of light during flight. There are many such theories, but these theories themselves need a lot of experiments to confirm.
The third possibility is that relativity is wrong, and the speed of light can be surpassed. The papers containing the specific contents of the two experiments have been published online for public inspection and submitted to the magazine High Energy Physics. Compared with the situation that some OPERA members are unwilling to sign the draft report after the experiment in September and hope to have more time for testing, Erititatou told the press that people will see the signatures of all the research members in the second experiment report.
After the paper was published, opposition physicists pointed out that despite answering some questions about the experiment, OPERA's report still avoided the following information: How do Geneva and Gran Sasso keep pace? How to accurately measure the distance between two places? John Leonard, a neutrino physicist at Mano University in Hawaii, said that although the researchers' ideas and efforts are innovative, there are still deep systematic errors in time difference measurement. Like many other physicists, Leonard admits that absolutely credible theories don't actually exist. But they saw the other side of this event-because of the profound and extensive influence that neutrinos may bring, the study of neutrinos is becoming more and more attractive. Back to the theory of physics, even if the experimental conclusion is finally confirmed, it will be "very interesting".
Alvaro Rugula, a theoretical physicist at the European Nuclear Center, believes that the results of neutrino experiments can only be explained in two ways: first, although the experimenter accidentally made a revolutionary great discovery; Secondly, he chose to believe that there were the same mistakes in the two experiments but they were not recognized.
20111/2 Wen Wei Po reported "superluminal shock" with a full page.
At present, most other physicists still have doubts and reservations about the conclusion of this subversive law.
However, The New York Times's report pointed out at the beginning of the full text: Although a small number of pediatricians have begun to dare to question Einstein's classical theory, OPERA's "magic particle" still lacks explanation. According to the website of Science, a famous American magazine, a source close to CERN experimenters revealed that the result of neutrino speed exceeding the speed of light made by Italian laboratory in September last year was finally explained: the system error caused by the poor connection of optical cable between GPS signal receiver and PC caused this illusion.
Previously, more researchers have come forward to say that this contradictory experimental result is caused by some undiscovered systematic error, and the theory of relativity has been confirmed by many experiments in the nearly one hundred years after it was discovered. This is exactly the case: after examining the optical cable connecting the GPS signal receiver used to correct the flight time of neutrinos and the PC, the researchers found that the experimental results of neutrinos traveling 60ns faster than the speed of light can be explained. The specific progress needs to be further confirmed and announced after the official document is issued.
Of course, it is not so easy to be recognized by the mainstream scientific community. At the same time, it also illustrates the importance of wiring again. It's time to tidy up the computer room. ...
The latest progress of neutrino superluminal experiment-"There is no superluminal effect" According to the report of the famous American magazine Science 20 12 on March 23rd, the experimenter re-measured the neutrino velocity from GERN with Icarus receiver in Gransaso, and found that the neutrino velocity is just the speed of light, and there is no superluminal effect. Carlo rubbia of GERN (the spokesman of Icarus team) said: What can I say without the superluminal effect? A spokesman for OPERA said: "The experimental results from Icarus are consistent with our recent experimental results." 、
20 12 On June 8th, at the International Conference on Neutrino Physics and Astrophysics held in Kyoto, Japan, researchers reported the latest progress of this research to the international scientific community. Physicists announced that previous experiments that challenged the limit theory of light speed (the basis of Einstein's theory of relativity) were proved wrong. Subsequent verification experiments conducted by many independent research groups in the world have proved that neutrinos, like all other things, follow Einstein's law of cosmic speed limit. At the same time, CERN scientists have clarified that the previous experimental results are wrong, and there is a problem with the cable interface of the experimental equipment, which leads to the error.