The cards keep on stacking up in favor of Albert Einstein being right about the speed of light: It's looking like its limit is approximately 300,000 kilometers per second, or the "c" in the famous equation E=mc2.
The ICARUS experiment at the Gran Sasso laboratory in Italy reported Friday that tiny particles called neutrinos did not surpass this commonly recognized speed of light as they traveled from the European Organization for Nuclear Research (CERN) in Switzerland to the Italian underground laboratory.
That's what the established laws of physics would predict. The result wouldn't be special, except that it flies in the face of a measurement from 2011 that challenged the foundations that Einstein had laid out.
Last September, scientists at OPERA - which stands for Oscillation Project with Emulsion-tRacking Apparatus - had found that neutrinos from CERN were arriving at Gran Sasso faster than the speed of light. If the particles really did exceed the established speed of light, scientists would have to completely rethink their understanding of how the universe works.
Since then, however, additional details have emerged to call this finding into question. In February, CERN acknowledged that faulty wiring may have produced the faster-than-light measurements.
Today's news isn't the end of the story, however. Four Gran Sasso particle detector experiments - BOREXINO, ICARUS, LVD and OPERA - will all be making new measurements with beams from CERN in May to give the "final verdict," CERN Research Director Sergio Bertolucci said in a statement.
Theoretical physicist Brian Greene, at Columbia University, told CNN in February that the faster-than-light measurements would probably not hold up to scrutiny. There's already a lot of experimental evidence suggesting that no particles can travel beyond that universal speed limit of light speed.
“They need to have completely independent confirmation by a separate experiment, ideally using different experimental methods," Greene said. "And if that were to happen, that would make many of us sit up in our chairs, or maybe even fall off our chairs."