Impossible cosmic rays are shooting out of Antartica
No particle we know of can explain what's going on.
- Cosmic rays have been discovered coming out of Antarctica.
- No high-speed particle we know of could possibly go in one side of the earth and come out the other.
- All of the proposed explanations are exciting, especially the most likely one.
Meet ANITA. ANITA stands for "Antarctic Impulsive Transient Antenna." It seeks out cosmic rays from space as while hanging from a balloon suspended over Antarctica. In the last two years, though, it has twice detected cosmic rays coming from a direction no one expected: inside the earth. According to the Standard Model (SM) of physics, this shouldn't be possible.
ANITA, foreground, and its balloon, background(NASA)
And guess what? ANITA’s not alone
In September, a paper was submitted for peer review by astrophysicists at Penn State led by Derek Fox. "I was like, 'Well this model doesn't make much sense,'" Fox tells Live Science, "but the [ANITA] result is very intriguing, so I started checking up on it. I started talking to my office neighbor [and paper co-author] Steinn Sigurdsson about whether maybe we could gin up some more plausible explanations than the papers that have been published to date." Lacking any, they looked for other similar events and found three. They'd been detected by a surface-based Antarctic neutrino detector called, sensibly enough, IceCube. And when the data from ANITA and IceCube when combined, the Penn State scientists started getting excited. They calculate that whatever kind of particle is flying up and away from Earth has a less than 1-in-3.5 million chance of being any of the particles predicted by the Standard Model. Obviously, this has physicists scratching their heads trying to figure out what on earth is going on.
How cosmic rays are supposed to behave
First of all, of course, cosmic rays are supposed to come from out there somewhere, not here. The earth is bombarded with them all the time. The suspicion is that the newly detected particles are cosmic rays slamming into the earth on one side and somehow making it out the other.
Cosmic rays, though, are high-energy particles with relatively wide cross-sections that lead to their demise by causing them to crash into matter inside the Earth. They're "mainly (89%) protons — nuclei of hydrogen, the lightest and most common element in the universe — but they also include nuclei of helium (10%) and heavier nuclei (1%), all the way up to uranium particles," according to CERN. Low-energy neutrinos, on the other hand, can pass through the earth's rocky mass, but they're not involved with cosmic rays.
Both ANITA and IceCube track neutrinos indirectly by detecting their remains, if you will. They detect the particles neutrinos produce when they decay post-collision. Since neutrinos can't get through the earth, though, something else is producing these particles. But what?
Artist rendition of cosmic rays
They could be a new kind of particle…
One candidate put forward as responsible for the event is the elusive "sterile neutrino," first hinted at by evidence captured in the mid 1990s at the Liquid Scintillator Neutrino Detector (LSND) at Los Alamos. The data was interpreted as suggesting a weird kind of high-speed neutrino that simply passes through matter without any interaction. No one else was able to reproduce the result, and the idea fell out of favor. Until this last spring, that is, when MiniBooNE at Chicago's FermiLab captured new signs that it might exist. The sterile neutrino would break the Standard Model if confirmed, which is one of the things that make MiniBoonE's data exciting. "That would be huge," says Duke physicist Kate Scholberg, who wasn't involved with the research, "…that would require new particles ... and an all-new analytical framework."
Others have suggested that it could be a product of dark matter. Cool as either of these ideas would be, perhaps the strongest reason for the detected upward cosmic rays is even more thrilling.
…or they could be long-sought supersymetrical particles
According to the Standard Model, every particle has a symmetrical partner, but the particles we know about don't match up. To resolve this apparent imbalance, a class of thus-far-hidden "supersymmetrical" particles has been proposed. It was hoped that the Large Hadron Collider could detect these mysterious — and so far just theoretical — particles, but no. Since 2012, when the last known particle predicted the Standard Model, the Higgs-Boson, was detected, nothing new's been found.
Until, maybe, now.
What the Penn paper proposes
The Penn State paper suggests these South Pole upward cosmic rays could be our first sign of supersymmetricals, specifically the partner of the Standard Model's tau leptons. With a a couple of "S"es added to signify supersymmetry, they'd be stau sleptons.
Others agree that they could be the first actual evidence of supersymmetry. Los Alamos physicist Bill Louis tells LiveScience, "I think it's very compelling," though he adds that the pinpointing of a stau slepton is "a bit of a stretch."
Fox admits he certainly can't be sure, but that, "From my perspective, I go trawling around trying to discover new things about the universe, I come upon some really bizarre phenomenon, and then with my colleagues, we do a little literature search to see if anybody has ever thought that this might happen. And then if we find papers in the literature, including one from 14 years ago that predict something just like this phenomenon, then that gets really high weight from me." And, guess what, he did find a prediction from 2003 of stau sleptons showing up just like this.
- Neutrino observation points to one source of high-energy cosmic rays ›
- Searching for Tiny Neutrinos in the South Pole | Inverse ›
- IceCube Observatory Finds Source of Mysterious High-Energy ... ›
What can 3D printing do for medicine? The "sky is the limit," says Northwell Health researcher Dr. Todd Goldstein.
- Medical professionals are currently using 3D printers to create prosthetics and patient-specific organ models that doctors can use to prepare for surgery.
- Eventually, scientists hope to print patient-specific organs that can be transplanted safely into the human body.
- Northwell Health, New York State's largest health care provider, is pioneering 3D printing in medicine in three key ways.
Great ideas in philosophy often come in dense packages. Then there is where the work of Marcus Aurelius.
- Meditations is a collection of the philosophical ideas of the Roman Emperor Marcus Aurelius.
- Written as a series of notes to himself, the book is much more readable than the dry philosophy most people are used to.
- The advice he gave to himself 2,000 years ago is increasingly applicable in our hectic, stressed-out lives.
Can dirt help us fight off stress? Groundbreaking new research shows how.
- New research identifies a bacterium that helps block anxiety.
- Scientists say this can lead to drugs for first responders and soldiers, preventing PTSD and other mental issues.
- The finding builds on the hygiene hypothesis, first proposed in 1989.
Are modern societies trying too hard to be clean, at the detriment to public health? Scientists discovered that a microorganism living in dirt can actually be good for us, potentially helping the body to fight off stress. Harnessing its powers can lead to a "stress vaccine".
Researchers at the University of Colorado Boulder found that the fatty 10(Z)-hexadecenoic acid from the soil-residing bacterium Mycobacterium vaccae aids immune cells in blocking pathways that increase inflammation and the ability to combat stress.
The study's senior author and Integrative Physiology Professor Christopher Lowry described this fat as "one of the main ingredients" in the "special sauce" that causes the beneficial effects of the bacterium.
The finding goes hand in hand with the "hygiene hypothesis," initially proposed in 1989 by the British scientist David Strachan. He maintained that our generally sterile modern world prevents children from being exposed to certain microorganisms, resulting in compromised immune systems and greater incidences of asthma and allergies.
Contemporary research fine-tuned the hypothesis, finding that not interacting with so-called "old friends" or helpful microbes in the soil and the environment, rather than the ones that cause illnesses, is what's detrimental. In particular, our mental health could be at stake.
"The idea is that as humans have moved away from farms and an agricultural or hunter-gatherer existence into cities, we have lost contact with organisms that served to regulate our immune system and suppress inappropriate inflammation," explained Lowry. "That has put us at higher risk for inflammatory disease and stress-related psychiatric disorders."
University of Colorado Boulder
This is not the first study on the subject from Lowry, who published previous work showing the connection between being exposed to healthy bacteria and mental health. He found that being raised with animals and dust in a rural environment helps children develop more stress-proof immune systems. Such kids were also likely to be less at risk for mental illnesses than people living in the city without pets.
Lowry's other work also pointed out that the soil-based bacterium Mycobacterium vaccae acts like an antidepressant when injected into rodents. It alters their behavior and has lasting anti-inflammatory effects on the brain, according to the press release from the University of Colorado Boulder. Prolonged inflammation can lead to such stress-related disorders as PTSD.
The new study from Lowry and his team identified why that worked by pinpointing the specific fatty acid responsible. They showed that when the 10(Z)-hexadecenoic acid gets into cells, it works like a lock, attaching itself to the peroxisome proliferator-activated receptor (PPAR). This allows it to block a number of key pathways responsible for inflammation. Pre-treating the cells with the acid (or lipid) made them withstand inflammation better.
Lowry thinks this understanding can lead to creating a "stress vaccine" that can be given to people in high-stress jobs, like first responders or soldiers. The vaccine can prevent the psychological effects of stress.
What's more, this friendly bacterium is not the only potentially helpful organism we can find in soil.
"This is just one strain of one species of one type of bacterium that is found in the soil but there are millions of other strains in soils," said Lowry. "We are just beginning to see the tip of the iceberg in terms of identifying the mechanisms through which they have evolved to keep us healthy. It should inspire awe in all of us."
Check out the study published in the journal Psychopharmacology.
SMARTER FASTER trademarks owned by The Big Think, Inc. All rights reserved.