backtop


Print 102 comment(s) - last by UraPhake.. on Oct 14 at 1:22 PM


Albert Einstein's Theory of Relativity states that no object in the universe can travel faster than the speed of light in the vacuum.  (Source: AP)

CERN's headquarters in Geneva, Switzerland gleams in the night.  (Source: AP/Anja Niedringhaus)

The OPERA experiment shoots a neutrino beam from Switzerland to Italy. As neutrinos only interact with matter via the weak force and gravitational attractions, they can pass right through the ground.  (Source: OPERA/CERN)

The final destination of the beam is the OPERA detector in Italy.  (Source: OPERA/CERN)
Neutrinos are first ever observed example of faster-than-light travel in a non-medium, defy laws of physics

Einstein's Theory of Relativity was unequivocal -- the fastest objects in the universe could move was the speed of light in a vacuum, which works out to around 299,792,458 meters per second (approximately 7e8 miles an hour).  To travel faster than the speed of light would allow fast travel to other worlds and even the possibility of travelling back in time.  But Einstein's 1905 theory was firm -- objects cannot travel faster than the speed of light.

I. The Erosion of Relativity?

Over the last several decades, exceptions to the Theory of Relativity have cropped up in experiments.  For example physicists have discovered that photons can pass through certain mediums at a faster than light pace 
via quantum tunneling, and another study revealed pulses of sound can also outpace photons in a medium.

Now, for the first time, subatomic particles have been witnessed as travelling faster than the speed of light.  
CERN, the European physics organization known for maintaining the Large Hadron Collider, has been playing with neutrinos in its OPERA experiment.  As they don't interact with normal particles it's been sending them through the Earth, hurtling from CERN in Geneva, Switzerland to INFN Gran Sasso Laboratory in Italy.  The journey is 454-miles (730-kilometers) long.

But the CERN researchers noticed something intriguing.  The neutrino traversed the distance 60±10 nanoseconds faster than light would have according to advanced analysis using GPS systems and atomic clocks to measure the time it took the roughly 15,000 neutrinos produced to complete their journey.  Those results indicate that the neutrinos were travelling two-parts-per-million faster than the speed of light.

CERN has published 
the results [press release] and presented a live webcast late last week on the discovery.

Robert Plunkett of the 
Fermilab laboratory in Batavia, Ill. in an interview with LiveScience states, "The consequences [of faster than light travel] would be absolutely revolutionary and very profound. That's why such a claim should be treated very carefully and validated as many ways as you can."

"According to relativity, it takes an infinite amount of energy to make anything go faster than light. If these things are going faster than light, then these rules would have to be rewritten."

Michael Peskin, a theoretical physicist at SLAC National Accelerator Laboratory in Menlo Park, Calif., concurs, adding, "It's really thought to be an absolute speed limit. Quantum field theory, the mathematical theory on which basically all results in particle physics are based, has the property that signals cannot travel faster than the speed of light through a vacuum. It’s really an absolute prohibition."

II. Physics Gets More Complicated

Absolute prohibition?  Maybe not.  The rules of physics seem on the verge of getting a bit weirder.  After all, to the best knowledge of most physics professionals, the CERN results look accurate.  But they seem in direct contradiction to the Japanese Kamiokande II experiment, which measured neutrinos emitted from a Large Magellanic Cloud supernova SN1987A, which sits 168,000 light years from Earth.  Measurements from that exploded star indicate that neutrinos travel within 1 part per 100,000,000 of the speed of light.

That's drastically different than the new results -- 2,000 times different, to be precise.  But both results could prove correct.  
Derek Fox of Pennsylvania State University suggests that a quirk of string theory or other advanced physics theory could reconcile the measurements.

CERN isn't shying away from criticism.  It is publishing all its data in hopes that other theoretical physicists will help to verify it -- or disprove the stunning conclusion.

One indication the results may be correct, though, comes from Fermilab, a physics lab located just outside Batavia, Illinois.  In its 
MINOS experiment, Femilab researchers have been sending neutrinos in a similar experiment to a detector at the bottom of the Soudan mine in Minnesota.

In 2007 they also seemed to observe faster-than-light travel of neutrinos, but unfortunately their lesser experimental equipment made it impossible to determine whether the measurement was legitimate or merely an artifact of the high level of statistical deviation in the measurements.

Professor Plunkett, who also serves as co-spokesperson for the MINOS experiment, is excited to find out if the results were authentic.  He states, "There was something that could have been a fluctuation in the direction of things arriving early, but it didn't have enough significance for us to make such a claim. Obviously, the hunt is on and we'll be upgrading that previous measurement and also implementing something we already had in the works, which is a plan to make improvements so we can reduce our errors. One of our next objectives is going to be trying to verify or disprove this result as hard as we can."

III. Just How Weird is Physics?

One thing that's important to bear in mind is that while this appears to be macroscopic and substantial violation of the Theory of Relativity, it only applies in a special scenario.  By and large most objects in the universe still appear to be behaving as expected.

In other words, basic physics education is unlikely to change much or get much harder based on all these radical discoveries.  However, for graduate researchers in the field of physics, they better prepare themselves to deal with a lot more weird.

The possibility of harnessing faster than light travel would seemingly be wealth worth the headache, though.  Many researchers are 
already dreaming up faster than light spaceship engines.  With such engines the vast time it would take to travel to the stars could be drastically reduced.

Some quick background for the physics layperson, a neutrino is somewhat akin to an uncharged electron, though it can come in several flavors -- electron neutrinos, muon neutrinos and tau neutrinos.  Neutrinos are typically produced in nuclear reactions (including those inside stars) and when high-energy cosmic rays collide with matter.

Neutrinos are hardly rare -- 6.5e10 (65 billion) pass through every square centimeter perpendicular to the direction of the Sun in the region of the Earth each second, 
courtesy of solar generation.  For that reason, researchers typically emit their neutrinos in a direction roughly perpendicular to the solar neutrons, so they can be easily distinguished and rely on careful calibration to filter out remaining inaccuracies in the detector.

Like other particles, as per the Symmetry Theory, neutrinos have an antiparticle, known as antineutrinos.  However, some believe that antineutrinos and neutrinos are actually the same particle type (it's hard to determine as they lack distinguishing charge).  If this is true, it would make neutrinos/antineutrinos the only known (fermion) example of a "Majorna" particle -- a particle that is it's own antiparticle.

If neutrinos and antineutrinos are not identical, it should be interesting going ahead to see if antineutrinos -- produced from nuclear decay and fission, among other things -- can also travel faster than light.  One might expect this to be the case, given that they only interact with matter gravitationally and through the weak force, as with neutrinos.



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

RE: how about...
By MarkHark on 10/2/2011 7:27:31 AM , Rating: 2
Even in the case you propose, for the secondary neutrinos to be created closer to the target than the primary ones, a signal would have to travel at faster-than-light speeds from
the primary neutrinos to wherever the secondary ones should appear.


RE: how about...
By Nelson Lam on 10/10/2011 11:35:15 AM , Rating: 2
So, it could be some kind of signal that travelled faster than the speed of light and not the particle itself. It could be something without a mass and beyond what we think we understand.


"We can't expect users to use common sense. That would eliminate the need for all sorts of legislation, committees, oversight and lawyers." -- Christopher Jennings














botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki