This piece appeared in The Ph-Word when it was a newsletter; the actual issue can still be read here. Two years have almost passed but it still rings true.
During a recent chat I realized that there’s one topic suffering a huge gap in popularized physics. This is experimental discoveries which became very widely known, but which nobody told the public later that they were actually found to be wrong! Let’s talk about the top two of the last years. I’ll keep it really brief otherwise I could get switched on for hours.
Was it found that neutrinos can travel faster than light? Answer: No.
The OPERA experiment in Gran Sasso, Italy, works with neutrinos sent out from CERN and traversing 750km of solid rock; neutrinos don’t interact much with anything so they can indeed be sent through ground without needing a tunnel or anything of the kind. Anyway — in 2011 OPERA announced that some of the little foxy ones had arrival times which implied a speed faster than even light’s.
I bet that not a single physicist anywhere was impressed, since the “speed limit” of light is the number one pillar of modern physics and it’d take a lot more to bring it down (even some of OPERA’s members didn’t put their names on the relevant publication). And they were right. A few months later the culprit was found to be the connection of an optical fiber which resulted in wrong measurements…
Did the BICEP experiment find strong proof for the theory of cosmological inflation? Answer: No.
This is a little more technical, but folks who follow the news in cosmology were bombarded with enthusiastic reports in 2014. BICEP, a telescope in Antarctica, had announced the detection of “B-modes polarization” in the cosmic microwave background.
The cosmic microwave background is the ancient light that bathes the sky, and whose mapping has revolutionized cosmology with its wealth of info about the structure and history of the universe. And cosmological inflation is a philosophically rather daring theory about what might have happened before the big bang (spoiler: the universe might have grown far too quickly, resulting in countless isolated areas; everything we see might be inside just one of them). Although promising, extreme theories need extreme proofs, and the predicted special pattern of polarization of the cosmic light would be one of them.
Eventually though, the polarized signal turned out to come from grains of dust scattered throughout the Milky Way. And the only overinflated thing in the story was the amount of positive publicity people at BICEP received.
For the sake of completeness, we can pass briefly from experimental to theoretical physics: Though stories are told, actually there haven’t been any verifications so far for string theory, supersymmetry or the multiverse. Thought you might like to know.