[UPDATE: Nov. 18, 2011; see below] The news from CERN physicists that the speed of light “may have been exceeded” sent a lightning bolt of excitement and disbelief (not quite surpassing the speed of light) throughout the world’s physics community. Fully accepting that their results would be met with great skepticism, the same physicists are inviting other particle physicists and labs to verify — or disprove — their results, which, if validated, will overturn one of the principle tenets of modern physics: that nothing travels faster than the speed of light (notated as ‘c‘ in physical equations).
Based in Switzerland, CERN physicists were experimenting with neutrinos (a mysterious class of virtually massless particles) by shooting them to an underground detector located over 450 miles (730 km) away in Italy*. According to the detector results, the quantum particle reached its destination 60 nanoseconds faster than would a particle of light — that’s 60 billionths of a second — with a margin of error of just 10 nanoseconds. That tiny amount of difference in timing is a huge deal.
According to Einstein’s Special Theory of Relativity (from 1906), the speed at which light travels (whether as a wave form, or as a particle, known as a photon) is constant; no signal or flow of energy can surpass this cosmically limiting speed, which is rounded off to 186, 282 miles per second (decimal places excluded from that figure).
Some theoretical physicists (Feinberg, Sundarshan, etc.) had previously postulated a faster-than-light-speed particle — termed a tachyon — to explain bizarre phenomena such as bosonic ‘string’ theory and quantum entanglement (in which two coupled particles, widely separated, appear to “communicate” instantaneously). But modern quantum theory views such “particles” as representing or indicating an instability in the system (i.e., the tachyon field) and not “real” particles, thus incapable of faster than light transmission.
No, the limiting nature of the speed of light (and its mediating particle) seems necessary for any cosmic, causal sense-making.
For physicist, the finite/constant speed of light (in a vacuum) is necessary to preserve “causality” in the normal sense of the word, wherein a ’cause’ precedes an ‘effect’. But, there is a theoretical paradox in which an effect precedes its cause (see the light cone diagram, left), and in which “faster than light signals” can be sent back into one’s own past, creating a causal paradox (if, and only if, no previous signal was received).
There is also the odd phenomena in which the spot where the beam of a search light hits the bottom of a cloud can move faster than light when the search light is moved quickly (note: this effect/speed is not achieved in a vacuum).**
However, under controlled laboratory conditions, there has been only one serious, experimental challenge to this physical constant: in 2007, physicists working with Fermilab’s Tevatron collider (located in the U.S.), achieved a similar feat with neutrinos, but the margin of error was quite large, and consequently, the results were dismissed by the physics community (too much “noise” in the detectors’ data).
But CERN’s margin of error is much smaller. Currently, physicist the world over are either analyzing the results (for errors), or trying to duplicate the results in other particle accelerators (such as the J-PARC neutrino collider system in Japan, which is conducting its own neutrino and antimatter experiment called T2K).
CERN (the European Organization for Nuclear Research) is located outside Geneva, Switzerland, and is the world’s largest particle physics research laboratory and home to the Large Hadron Collider (LHC), the world’s most powerful particle accelerator (note: the LHC was not used in this experiment).
If verified, these experimental results would be “revolutionary” say some scientists. However, others say maybe not, as the super fast neutrino’s may be drawing energy from a “background field” that only they can interact with, leaving Einstein’s famous constant (for light) mostly intact.
Further, proving the existence of a faster-than-light-speed particle will not change how the Universe works, of course, but it will change our understanding of some of its fundamental features, the most fundamental of which (apart from the three Laws of Thermodynamics) is the speed of light, the square of which was introduced to the world’s consciousness through Einstein’s famous equation E = mc².
For more information and to see a video from CERN, check out the Huff Post article ‘CERN: Light Speed May Have Been Exceeded By Subatomic Particle’
* This neutrino experiment is called OPERA which stands for Oscillation Project with Emulsion-Racking Apparatus (this info was left out of the original post).
** [source]: Salmon, Wesley, Four Decades of Scientific Explanation; referenced on wikipedia.org, ‘speed of light’]
UPDATE: Recent re-examinations of the original neutrino experiment results (taken individually, not averaged together as done previously) seem to confirm that said neutrinos did in fact arrive 60 nanoseconds ahead of (light speed) expectations. Read the Science 2.0 article for more info.
UPDATE FEB. 23, 2012:See my post ‘Einstein May Still Be Right – ‘Faster Than Light Neutrinos’ Now Thought Due to Faulty GPS System’
Top image: (sunlight time to Earth) Brews ohare ; CC – BY – SA 3.0
Bottom diagram: (light cone) r Sakurambo