The finding by an 11-nation research group, including Nagoya University, that neutrinos may travel faster than light has astonished physicists in Japan and around the world.
Confirmation of the discovery would overturn Albert Einstein's theory of special relativity, which asserts that the speed of light can never be exceeded.
Modern physics has been built on the basis of Einstein's theory, and the impact of the startling data announced Thursday in Europe on neutrino studies alone would be immeasurable, according to experts.
"This challenges a fundamental principle universally accepted in today's physics," said Prof. Yoichiro Suzuki at the University of Tokyo's Institute for Cosmic Ray Research, who expressed surprise Friday at the news that one type of neutrino--muon neutrinos--was found to exceed the speed of light.
Muon neutrinos are one of the three known types of nerutrinos.
The astonishing finding announced Thursday was made by researchers working on a research project called OPERA. As part of the project, neutrinos emitted from a research center in suburban Geneva arrived at the Gran Sasso National Laboratory in central Italy faster than the speed of light.
The Swiss research center is operated by the European Organization for Nuclear Research, known as CERN.
The Italian facility has the world's largest underground laboratory for experiments in particle physics.
Einstein's theory of special relativity was published in 1905 and has since been the foundation of major strides in modern physics.
The theory says nothing that has a mass can travel faster than light. According to the theory, when the speed of an object approaches the speed of light, its mass increases so much that it cannot accelerate any further.
Since muon neutrinos, like the other two other kinds of neutrinos, have a mass, they should not be able to exceed the speed of light, according to Einstein's theory.
The theory explains a number of other strange things that happen when an object approaches the speed of light.
For example, time slows down for an object traveling at that speed, and space shrinks.
The notion that time can slow and space can shrink has had an enormous impact on a large number of fields beyond physics.
The late Alfred North Whitehead, considered one of the greatest philosophers of the 20th century, established a unique view of space based mainly on Einstein's theory.
The most recent finding may lead to a revolutionary change in not only the basic principles of physics but also in our concepts of space and time.
Masanori Yamauchi, deputy director of the High Energy Accelerator Research Organization's Institute of Particle and Nuclear Studies, said: "If independent studies by a plural number of experimental facilities confirm the same finding, the theory of special relativity will have to be modified for the first time in 100 years. But I have no idea how it will have to be modified."
Hitoshi Murayama, director general of the University of Tokyo's Institute for Physics and Mathematics, said confirmation of the European discovery could mean that strange phenomena only considered possible in the world of science fiction may become possible in reality. For example, time machines could allow us to travel back in time and change events.
If the CERN-Gran Sasso finding is confirmed, the neutrinos in the experiment arrived at the Gran Sasso Laboratory "earlier" than when they were emitted from CERN, 730 kilometers away, Murayama said.
(Sep. 25, 2011)