A composite showing a high-altitude balloon and Antarctic observing equipment. It does not depict a parallel universe. Source.
While working on an experiment in Antarctica, a NASA-supported collaboration recorded unusual radio events; it did not discover evidence establishing a parallel universe with reversed physics.
Ideas about multiple worlds, including the many-worlds interpretation of quantum mechanics, are distinct theoretical proposals; the ANITA measurements did not establish them. Now, the ANITA experiment recorded radio signals associated with high-energy particle research, prompting questions about their origin rather than confirming another universe. [source] The scientists employed the Antarctic Impulsive Transient Antenna (ANITA), a giant balloon that goes high above Antarctica, where the dryness in the air provides an ideal environment free of radio noise that can affect the Antenna's findings.
Earth constantly receives a 'wind' of high energy particles arriving from outer space. At the same time, neutrinos can pass through matter, with their interaction probability depending on energy. At very high energies, neutrino passage through Earth becomes less likely, making apparently upward-directed events difficult to explain. However, ANITA detected radio events interpreted as resembling upward-going particle showers; a tau-neutrino origin was one hypothesis, not a direct detection of a heavier species. The events did not demonstrate particles traveling backward in time or establish an alternative reality.
ANITA's principal investigator, experimental particle physicist Peter Gorham from the University of Hawaii, discussed possible particle-physics interpretations; no single explanation involving another universe was established. Gorham, whose team’s paper was posted on arXiv, notes that he and his colleagues had observed numerous of these "impossible events", a phenomenon so odd that leaves many skeptical.
He tells New Scientist that, "Not everyone is comfortable with the hypothesis".
Some media accounts connected the events to speculative ideas involving two universes and reversed time. The University of Hawaiʻi explicitly corrected that connection in May 2020: this was not the ANITA team’s discovery or an established explanation. Descriptions of what inhabitants of such a universe might perceive are speculation, not a measurement made by ANITA.
Ibrahim Safa, another member of the team working on the experiment said, “We’re left with the most exciting or most boring possibilities”.
Analyses investigated possible explanations and constraints; the unusual observations did not establish that existing physics had failed. [source]
What was ANITA listening for?
ANITA carried radio antennas high above Antarctica on a balloon. Its observations were designed to investigate extremely energetic particles through the radio signals produced by particle interactions and showers.
In the University of Hawaiʻi’s account of the research, unusual events appeared to resemble cosmic-ray showers coming upward from the ice. Their signal characteristics challenged a straightforward explanation as ordinary downward-going showers reflected from the surface.
That is an interesting physics problem. Direction, reflection and the properties of the signal all matter when researchers try to infer what caused a brief detection.
Where the headline went wrong
In May 2020, the university published a correction to media coverage linking the work to a parallel-universe theory. The ANITA team had not demonstrated such a universe, and the sensational claim did not accurately describe its findings.
There are several steps between seeing a puzzling signal and establishing a new account of reality. Researchers must check the instrument, compare possible sources, examine conventional explanations and test whether a proposed theory makes predictions supported by further evidence.
An unusual result may motivate imaginative ideas. It does not make every imaginative idea an equally supported explanation.
Three useful questions for a surprising science story
- What was directly measured? Here, the starting point was a radio signal recorded by an instrument.
- What did the researchers infer? They used the signal’s characteristics to investigate possible particle events and directions.
- What additional claim appeared in the headline? A universe with reversed time goes far beyond simply reporting an unexplained event.
Keeping these layers separate makes the story easier to follow. It also leaves room for uncertainty without making the research sound like a failure.
The real discovery process is still exciting
Think of an unfamiliar sound in a recording. You can establish that it is present, investigate which microphone captured it and compare it with known sources. Naming the source requires additional evidence. A radio experiment is vastly more technical, but the distinction between a signal and its explanation remains useful.
A related example is the Milky Way radio burst traced to a magnetar. There, observations from different instruments helped connect a fleeting signal with a particular kind of object.
ANITA’s story is a good reason to stay curious and precise at the same time. Antarctica, balloon-borne antennas and particles at extreme energies are already remarkable. They do not need a confirmed parallel universe attached to them to deserve our attention.
Additional source and image references: Large balloon on Antarctic ice beside a scientific payload structure
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