Answer to Shocking 'Faster-Than-Light' Particles Expected Soon
Clara Moskowitz, LiveScience Senior
Writer
18 February 2012
Einstein's theory of special relativity sets of the speed of
light, 186,000 miles per second (300 million meters per second),
as a cosmic speed limit. Some researchers think they may have
broken this limit, and the implications are mind bending.
VANCOUVER, British Columbia — Physicists stunned the world last
year by announcing they'd seen signs that particles called
neutrinos were traveling faster than light — a feat thought to
be proven impossible by Einstein. Ever since, other researchers
have been racing to try the experiment on their own to see if
the findings hold up.
Some results of these tests should be announced this spring,
scientists said Friday (Feb. 17) here at the annual meeting of
the American Association for the Advancement of Science.
"It's very hard to find an error by reading a paper," said
particle physicist Rob Roser of the Fermi National Accelerator
Laboratory (Fermilab) in Batavia, Ill., who was not involved inthe
original experiment. "What you need is for someone else to
make the measurement. We'll see what happens."
Shocking finding
The bizarre finding was first reported in September 2011, when
physicists at the CERN laboratory in Geneva, Switzerland,
announced that an experiment called OPERA had measured the tiny
subatomic particles apparently breaking what was thought to be the
ultimate cosmic speed limit.
OPERA sends neutrinos 454 miles (730 kilometers) underground to
the INFN Gran Sasso Laboratory in Italy, and measures how fast
they take to make the trip. While researchers expected the
almost-massless particles to travel at near light speed, they
actually appeared to arrive at their destination about 60
billionths of a second sooner than light would have.
If this really occurred, it would contradict Albert Einstein's
special theory of relativity, and throw much of physics into
upheaval. [10
Implications of Faster-Than-Light Neutrinos]
Double check
The discovery was met with shock
and skepticism by most physicists, including the members of
the OPERA team themselves.
Joked Sergio Bertolucci, research director at CERN, the finding
is hard to believe because "nothing in Italy arrives ahead of
time."
The researchers immediately invited other experts to weigh in
and try to reproduce their results to either confirm or disprove
the finding. And that's just what they've been doing.
Several attempts to recreate the OPERA experiment have been
undertaken around the world, including one in Japan called T2K
(Tokai to Kamioka), and another, called MINOS,
at Fermilab.
MINOS sends neutrinos from its location near Chicago to a mine
in northern Minnesota. Last fall, MINOS didn't have the right
equipment to make a measurement sensitive enough to prove or
disprove the OPERA results. Since then, the lab has installed
new hardware and started up the experiment.
"They started two weeks ago collecting data," Roser said. "I
would expect you would hear in May or June what Fermilab's
answer is."
Other sources of error
In addition to looking to outside measurements, the OPERA
researchers have tweaked their experimental setup to address concerns
raised by other scientists about
potential sources of error.
For example, some worried that the use
of GPS satellites to
time the departure of the neutrinos from CERN in the original
experiment was introducing flaws. In response, the OPERA
physicists conducted the experiment again, using only atomic
clocks to measure timing, and still came up with the same
result.
"They’ve changed a number of things, which might have brought
them into some doubt," Bertolucci said. "It is very difficult
and the fact that nobody was able to find an easy solution
immediately means essentially they’ve done their job."
If other experiments like MINOS and T2K also measure neutrinos
traveling faster than light, it doesn't rule out that an
error no one thought of is plaguing all the experiments.
However, it makes the likelihood of an error much more remote,
Roser said.
"I don't know which I'm rooting for," Roser told LiveScence. "If
three or four different experiments around the world see the
same thing it's hard not to be convinced."
For evidence that sometimes shocking results are true,
Bertolucci pointed to the famous 1887 experiment by Albert
Michelson and Edward Morley that disproved the notion, popular
at the time, that the universe was filled with a medium that
carries light called an ether.
"They found a result totally incompatible with the present
theory of the time, but they were right," Bertolucci said. "We
have to just keep an open mind."
You can follow LiveScience senior writer Clara Moskowitz on
Twitter @ClaraMoskowitz. For
more science news, follow LiveScience on twitter @livescience.
Source: LiveScience
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