In the 2011 edition of our annual Top 100 Stories of the Year issue, DISCOVER chose the OPERA experiment’s announcement of neutrinos that apparently move faster than light as the #1 story. This raises the question of whether the top spot should go to a “discovery” that many researchers think is wrong.
After much heated debate, we landed on not one but two answers. First, there is the extraordinary nature of the experiment itself. Shooting shadowy neutrinos through 454 miles of rock and then collecting and precisely measuring them at the other end is a historic technical achievement, one that may turn up new physics even if this particular result does not hold up. Second, and more important, there is the inspiring nature of the claim. This is the most credible evidence in years that our basic understanding of space and time needs an overhaul. No physicist believes that relativity has all the answers and that humans now understand everything there is to know about how the universe works. Someday some experiment will lead to insights that eluded even Einstein. If the neutrino experiment does not achieve that, it certainly points the way.
Also see the top 100 lists from previous years:
Worst Oil Spill of All-Time, and a Future Full of Oil
First Synthetic Organism Created
E.O. Wilson’s Theory of Altruism Shakes Up Understanding of Evolution
Climate Science Wins a Round, But the Campaign Goes Poorly
Family Genomics Links DNA to Disease
The Post-Oil Era Begins
The LHC Begins Its Search for the “God Particle”
The FDA Tackles Tainted Drugs From China
Slime Is Turning the Seas Into Dead Zones
Nations Stake Their Claims to a Melting Arctic
Coal ash: Two years after the coal ash spill in Roane County, Tennessee residents are still grappling with ash dust, housing buyouts, and potentially toxic water. The Tennessee Valley Authority, a government-owned corporation who runs the plant, claims the ash is non-toxic, while the EPA takes it’s time deciding if it should be classified as hazardous waste.
Wolves: Activist group Center For Biological Diversity is planning to sue the Department of the Interior if they don’t expand wolf ranges in the lower 48. Some states in the Northern Rocky Mountains, where the population has made a comeback, have legalized hunting to protect their herds.
Elephant genomes: New genetics data is showing that the African elephant is actually two species: the forest elephant is smaller than the savanna elephant and has a much smaller population. Dividing the “African elephant” into two species is going to be important to conservation of the forest elephant’s habitat and save them from poachers.
New sea creatures, humongous stars, and cockroach antibiotics: Those are just a few reader favorites from this year in science. As 2010 comes to a close, we bring you a dozen of the most popular 80beats posts of the year.
For more great stories from the year in science, check out DISCOVER’s Top 100 Stories of the Year.
When neutrinos change from one phase to another, they tell us something about their mysterious nature. These ghostly subatomic particles come in three flavors, physicists say: muon, tau, and electron. Just this summer, a team caught a neutrino in the act of changing from muon to tau, a finding that backed up the argument that these particles do, in fact, have mass. This week, a new study of neutrino oscillation—the changing of flavors—suggests an deeper mystery, and implies that these three flavors of neutrino may not be enough to account for these particles’ behavior.
In Physical Review Letters, a large group of physicists published their study from the MiniBooNE experiment at Fermilab in Illinois. When the physicists looked at oscillations of muon antineutrinos into electron antineutrinos, they found the process happening faster than known physics predicts. Neutrinos followed the rules, but antineutrinos didn’t behave the same way did.
So what does it mean? We asked physicist Silvia Pascoli at the U.K.’s Durham University to explain:
The sun is breaking the known rules of physics—so said headlines that made the rounds of the Web this week.
That claim from a release out about a new study by researchers Jere Jenkins and Ephraim Fischbach of Purdue, and Peter Sturrock of Stanford. The work suggests that the rates of radioactive decay in isotopes—thought to be a constant, and used to date archaeological objects—could vary oh-so-slightly, and interaction with neutrinos from the sun could be the cause. Neutrinos are those neutral particles that pass through matter and rarely interact with it; trillions of neutrinos are thought to pass through your body every second.
In the release itself, the researchers say that it’s a wild idea: “‘It doesn’t make sense according to conventional ideas,’ Fischbach said. Jenkins whimsically added, ‘What we’re suggesting is that something that doesn’t really interact with anything is changing something that can’t be changed.’”
Could it possibly be true? I consulted with Gregory Sullivan, professor and associate chair of physics at the University of Maryland who formerly did some of his neutrino research at the Super-Kamiokande detector in Japan, and with physicist Eric Adelberger of the University of Washington.
Detectors buried thousands of feet under the Antarctic ice recently confirmed a mysterious cosmic lopsidedness. Though it might seem reasonable for our planet to receive energetic particles, called cosmic rays, on average from all directions equally, more cosmic rays’ seem to approach Earth from certain preferred directions.
The IceCube Neutrino Observatory, which is still under construction, confirmed these odd cosmic ray preferences, previously detected in the northern hemisphere.
Cosmic rays–energetic particles flung from as nearby as the sun and light years away–are the extra “noise” in the observatory’s experiments; to filter out this noise, researchers needed to map where the cosmic rays are coming from. In a paper published earlier this month in The Astrophysical Journal they confirmed that more cosmic rays seem to come from certain directions–an observation known as anisotropy–in the Earth’s southern hemisphere too.
[T]hey used IceCube to study a longstanding puzzle: whether the distribution of cosmic ray arrivals is uneven across the southern sky, as scientists have previously observed in the northern hemisphere. Indeed, the team found, IceCube detected a disproportionate number of cosmic rays arriving from some parts of the sky. But the reason for this uneven distribution remains unclear. [ScienceNOW]
For the first time, physicists say they have witnessed a subatomic particle change its “flavor.” Physicists at OPERA, run by Italy’s national nuclear physics institute, announced yesterday that they have observed one neutrino change its type, or flavor, spontaneously. The experiment solves a 50-year-old physics mystery, and may uncover some of the universe’s hidden mass.
Neutrinos, which come in three different flavors, can have fairly violent births: they can come into the world via nuclear reactions in the sun, particle decay, or collisions in particle accelerators. But, once formed, they seem to ignore almost everything around them, including magnetic fields, electric fields, and matter. In fact, there are trillions of them zipping through each of us every second; they go right through our bodies and keep on moving through the planet itself.
The mystery of “neutrino oscillations” began with the number of neutrinos that should be coming from the sun. Theory predicted a certain number of various flavors to arrive, but observation showed much less:
The neutrino puzzle began with a pioneering and ultimately Nobel Prize winning experiment conducted by US scientist Ray Davis beginning in the 1960s. He observed far fewer neutrinos arriving at the Earth from the Sun than solar models predicted: either solar models were wrong, or something was happening to the neutrinos on their way. [CERN]
In 1969, Bruno Pontecorvo and Vladimir Gribov theorized that the neutrinos weren’t disappearing, they were changing their flavors mid-journey. Though physicists were looking for one type, they weren’t finding what they ordered.
While the oft-troubled Large Hadron Collider is starting back up today after a weekend glitch, another big physics project is under way halfway around the world. The British and Japanese researchers behind the project called T2K (Tokai-to-Kamioka) announced their first neutrino detection, the initial step in an experiment to understand these mysterious subatomic particles.
Neutrinos are tiny particles that rarely interact with matter, making them incredibly difficult to study. But physicists have done it by looking for the signature left behind when one of the torrent of neutrinos flying through the Earth at any given time happens to crash into the nucleus of an atom within view of a neutrino detector. Japan’s Super Kamiokande is one of the largest neutrino detectors, and now it has a new mission under the T2K project. The goal is to understand a strange kind of subatomic metamorphosis. These particles come in three types or flavours: electron, muon and tau neutrinos. From earlier experiments, physicists know that neutrinos spontaneously change their flavour, oscillating back and forth from one kind to another. But the details are still hazy [New Scientist].