Mysterious holes found on ocean floor have scientists ‘stumped’

These linear, peculiar-looking openings in the sand could be human made. But a more plausible explanation might be that they’re tracks left behind by an undiscovered species lurking in the deep sea. The depths of the Earth's oceans contain many secrets that often take researchers years of investigation to solve. A new mystery in the Atlantic Ocean is almost literally taking them down the rabbit hole. On July 23, along the seafloor off the coast of Portugal beneath the island chain of the Azores, scientists working with the National Oceanic and Atmospheric Administration (NOAA) found a dozen sets of small holes in the sand at a depth of nearly 2 miles, with no clues of how they got there. Two weeks later and 300 miles away, they found even more mysterious holes, exactly the same as the first.

A close look at the sets of holes along the floors of the Atlantic Ocean. The origins of the holes are unclear. (NOAA Ocean Exploration) From May to September 2022, NOAA is carrying out an expedition called Voyage to the Ridge 2022 in this relatively unexplored region of the Atlantic. NOAA scientists set off from Newport, Rhode Island, to Newfoundland, Canada, on the first leg of the trip and then left Norfolk, Virginia, for the Azores. They will finish up by traversing the Atlantic in the other direction, to Puerto Rico and the Caribbean. Their research vessel, called the Okeanos Explorer, is investigating the coral and sponge colonies on volcanic ridges. Finding the holes was more of a happy accident. This isn't the first time scientists encountered these strange-looking patterns. NOAA spokesperson Emily Crum told The New York Times that in 2004, right in the vicinity of this initial discovery, researchers recorded the first sighting of the holes. “The origin of the holes has scientists stumped,” NOAA's Ocean Exploration project tweeted. “The holes look human made, but the little piles of sediment around them suggest they were excavated by … something.” “There is something important going on there and we don’t know what it is,” NOAA deep-sea biologist Michael Vecchione told the Times. “This highlights the fact that there are still mysteries out there.” Hypotheses regarding the origins of the holes range from human-made causes to the tracks of an undiscovered species of animal or a gas vent blowing bubbles up through the sand. Vecchione co-authored a paper in 2022 discussing the gaps in current knowledge of the holes and what could be causing them. According to the paper, the holes appear to have been either excavated from the top or pierced up from underneath, meaning whatever created them could have been digging the holes or burrowed under the sediment and potentially used the holes as a breathing apparatus -- like a snorkel. There's no definitive evidence to say for sure, though, and it will take more time and investigations to find the truth.

NOAA scientists use this underwater drone, called Deep Discoverer, to examine features of the seafloor up to 19,000 feet below the ocean's surface. (NOAA Ocean Exploration) Vecchione, who was present for this latest run-in with the mysterious holes, said he was happy to see them again after nearly two decades but also expressed disappointment that there are still no answers. The Okeanos Explorer is currently docked in the Azores until Aug. 6, when the vessel will set out for its third Voyage to the Ridge expedition.

Low-energy solar particles from beyond Earth found near the Sun

Sun (stock image; elements furnished by NASA).

Using data from NASA's Parker Solar Probe (PSP), a team led by Southwest Research Institute identified low-energy particles lurking near the Sun that likely originated from solar wind interactions well beyond Earth orbit. PSP is venturing closer to the Sun than any previous probe, carrying hardware SwRI helped develop. Scientists are probing the enigmatic features of the Sun to answer many questions, including how to protect space travelers and technology from the radiation associated with solar events.

"Our main goal is to determine the acceleration mechanisms that create and transport dangerous high-energy particles from the solar atmosphere into the solar system, including the near-Earth environment," said Dr. Mihir Desai, a mission co-investigator on the Integrated Science Investigation of the Sun (IS?IS) instrument suite, a multi-institutional project led by Principal Investigator Prof. Dave McComas of Princeton University.. IS?IS consists of two instruments, Energetic Particle Instrument-High (EPI-Hi) and Energetic Particle Instrument-Low (EPI-Lo). "With EPI-Lo, we were able to measure extremely low-energy particles unexpectedly close to the solar environment. We considered many explanations for their presence, but ultimately determined they are the smoking gun pointing to interactions between slow- and fast-moving regions of the solar wind that accelerate high-energy particles from beyond the orbit of Earth. Some of those travel back toward the Sun, slowing against the tide of the outpouring solar wind but still retaining surprisingly high energies."

PSP, which will travel within 4 million miles of the Sun's surface, is collecting new solar data to help scientists understand how solar events, such as coronal mass ejections, impact life on Earth. During the rising portion of the Sun's activity cycle, our star releases huge quantities of energized matter, magnetic fields and electromagnetic radiation in the form of coronal mass ejections (CMEs). This material is integrated into the solar wind, the steady stream of charged particles released from the Sun's upper atmosphere. The high-energy solar energetic particles (SEPs) present a serious radiation threat to human explorers living and working outside low-Earth orbit and to technological assets such as communications and scientific satellites in space. The mission is making the first-ever direct measurements of both the low-energy source populations as well as the more hazardous, higher-energy particles in the near-Sun environment, where the acceleration takes place.

When the Sun's activity reaches a lull, roughly about every 11 years, solar equatorial regions emit slower solar wind streams, traveling around 1 million miles per hour, while the poles spew faster streams, traveling twice as fast at 2 million miles per hour. Stream Interaction Regions (SIRs) are created by interactions at boundaries between the fast and slow solar wind. Fast-moving streams tend to overtake slower streams that originate westward of them on the Sun, forming turbulent corotating interaction regions (CIRs) that produce shock waves and accelerated particles, not unlike those produced by CMEs.

"For the first time, we observed low-energy particles from these CIRs near the orbit of Mercury," Desai said. "We also compared the PSP data with data from STEREO, another solar energy probe. By measuring the full range of energetic populations and correlating the data with other measurements, we hope to get a clear picture of the origin and the processes that accelerate these particles. Our next step is to integrate the data into models to better understand the origin of SEPs and other materials. Parker Solar Probe will solve many puzzling scientific questions -- and is guaranteed to generate new ones as well."

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Billions of quantum entangled electrons found in 'strange metal'

Partial view of periodic table of the elements (stock image).

In a new study, U.S. and Austrian physicists have observed quantum entanglement among "billions of billions" of flowing electrons in a quantum critical material.

The research, which appears this week in Science, examined the electronic and magnetic behavior of a "strange metal" compound of ytterbium, rhodium and silicon as it both neared and passed through a critical transition at the boundary between two well-studied quantum phases.

The study at Rice University and Vienna University of Technology (TU Wien) provides the strongest direct evidence to date of entanglement's role in bringing about quantum criticality, said study co-author Qimiao Si of Rice.

"When we think about quantum entanglement, we think about small things," Si said. "We don't associate it with macroscopic objects. But at a quantum critical point, things are so collective that we have this chance to see the effects of entanglement, even in a metallic film that contains billions of billions of quantum mechanical objects."

Si, a theoretical physicist and director of the Rice Center for Quantum Materials (RCQM), has spent more than two decades studying what happens when materials like strange metals and high-temperature superconductors change quantum phases. Better understanding such materials could open the door to new technologies in computing, communications and more.

The international team overcame several challenges to get the result. TU Wien researchers developed a highly complex materials synthesis technique to produce ultrapure films containing one part ytterbium for every two parts rhodium and silicon (YbRh2Si2). At absolute zero temperature, the material undergoes a transition from one quantum phase that forms a magnetic order to another that does not.

At Rice, study co-lead author Xinwei Li, then a graduate student in the lab of co-author and RCQM member Junichiro Kono, performed terahertz spectroscopy experiments on the films at temperatures as low as 1.4 Kelvin. The terahertz measurements revealed the optical conductivity of the YbRh2Si2 films as they were cooled to a quantum critical point that marked the transition from one quantum phase to another.

"With strange metals, there is an unusual connection between electrical resistance and temperature," said corresponding author Silke Bühler-Paschen of TU Wien's Institute for Solid State Physics. "In contrast to simple metals such as copper or gold, this does not seem to be due to the thermal movement of the atoms, but to quantum fluctuations at the absolute zero temperature."

To measure optical conductivity, Li shined coherent electromagnetic radiation in the terahertz frequency range on top of the films and analyzed the amount of terahertz rays that passed through as a function of frequency and temperature. The experiments revealed "frequency over temperature scaling," a telltale sign of quantum criticality, the authors said.

Kono, an engineer and physicist in Rice's Brown School of Engineering, said the measurements were painstaking for Li, who's now a postdoctoral researcher at the California Institute of Technology. For example, only a fraction of the terahertz radiation shined onto the sample passed through to the detector, and the important measurement was how much that fraction rose or fell at different temperatures.

"Less than 0.1% of the total terahertz radiation was transmitted, and the signal, which was the variation of conductivity as a function of frequency, was a further few percent of that," Kono said. "It took many hours to take reliable data at each temperature to average over many, many measurements, and it was necessary to take data at many, many temperatures to prove the existence of scaling.

"Xinwei was very, very patient and persistent," Kono said. "In addition, he carefully processed the huge amounts of data he collected to unfold the scaling law, which was really fascinating to me."

Making the films was even more challenging. To grow them thin enough to pass terahertz rays, the TU Wien team developed a unique molecular beam epitaxy system and an elaborate growth procedure. Ytterbium, rhodium and silicon were simultaneously evaporated from separate sources in the exact 1-2-2 ratio. Because of the high energy needed to evaporate rhodium and silicon, the system required a custom-made ultrahigh vacuum chamber with two electron-beam evaporators.

"Our wild card was finding the perfect substrate: germanium," said TU Wien graduate student Lukas Prochaska, a study co-lead author. The germanium was transparent to terahertz, and had "certain atomic distances (that were) practically identical to those between the ytterbium atoms in YbRh2Si2, which explains the excellent quality of the films," he said.

Si recalled discussing the experiment with Bühler-Paschen more than 15 years ago when they were exploring the means to test a new class of quantum critical point. The hallmark of the quantum critical point that they were advancing with co-workers is that the quantum entanglement between spins and charges is critical.

"At a magnetic quantum critical point, conventional wisdom dictates that only the spin sector will be critical," he said. "But if the charge and spin sectors are quantum-entangled, the charge sector will end up being critical as well."

At the time, the technology was not available to test the hypothesis, but by 2016, the situation had changed. TU Wien could grow the films, Rice had recently installed a powerful microscope that could scan them for defects, and Kono had the terahertz spectrometer to measure optical conductivity. During Bühler-Paschen's sabbatical visit to Rice that year, she, Si, Kono and Rice microscopy expert Emilie Ringe received support to pursue the project via an Interdisciplinary Excellence Award from Rice's newly established Creative Ventures program.

"Conceptually, it was really a dream experiment," Si said. "Probe the charge sector at the magnetic quantum critical point to see whether it's critical, whether it has dynamical scaling. If you don't see anything that's collective, that's scaling, the critical point has to belong to some textbook type of description. But, if you see something singular, which in fact we did, then it is very direct and new evidence for the quantum entanglement nature of quantum criticality."

Si said all the efforts that went into the study were well worth it, because the findings have far-reaching implications.

"Quantum entanglement is the basis for storage and processing of quantum information," Si said. "At the same time, quantum criticality is believed to drive high-temperature superconductivity. So our findings suggest that the same underlying physics -- quantum criticality -- can lead to a platform for both quantum information and high-temperature superconductivity. When one contemplates that possibility, one cannot help but marvel at the wonder of nature."

Si is the Harry C. and Olga K. Wiess Professor in Rice's Department of Physics and Astronomy. Kono is a professor in Rice's departments of Electrical and Computer Engineering, Physics and Astronomy, and Materials Science and NanoEngineering and the director of Rice's Applied Physics Graduate Program. Ringe is now at the University of Cambridge.

Additional co-authors include Maxwell Andrews, Maximilian Bonta, Werner Schrenk, Andreas Limbeck and Gottfried Strasser, all of the TU Wien; Hermann Detz, formerly of TU Wien and currently at Brno University; Elisabeth Bianco, formerly of Rice and currently at Cornell University; Sadegh Yazdi, formerly of Rice and currently at the University of Colorado Boulder; and co-lead author Donald MacFarland, formerly of TU Wien and currently at the University at Buffalo.

The research was supported by the European Research Council (ERC-227378), the Army Research Office (W911NF-14-1-0496, W911NF-17-1-0259, W911NF-14-1-0525), the Austrian Science Fund (FWF-W1243, P29279-N27, P29296-N27), the European Union's Horizon 2020 program (824109-EMP), the National Science Foundation (DMR-1720595, DMR-1920740, PHY-1607611), the Robert A. Welch Foundation (C-1411), Los Alamos National Laboratory and Rice University.

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Materials provided by Rice University. Original written by Jade Boyd. Note: Content may be edited for style and length.

First evidence of feathered polar dinosaurs found in Australia

First evidence of feathered polar dinosaurs found in Australia

A cache of 118 million-year-old fossilized dinosaur and bird feathers has been recovered from an ancient lake deposit that once lay beyond the southern polar circle.

Feathered dinosaur fossils are famous, but known from a handful of localities worldwide. Examples from the Southern Hemisphere are especially rare, and mainly include only isolated feathers.

An international team of scientists has analyzed a collection of 10 such fossil feathers found in Australia, which reveal an unexpected diversity of tufted hair-like 'proto-feathers' from meat-eating dinosaurs, together with downy body feathers, and wing feathers from primitive birds that would have been used for flight.

Uniquely, the fossil feathers from Australia were all entombed in fine muddy sediments that accumulated at the bottom of a shallow lake close to the South Pole during the Age of Dinosaurs.

"Dinosaur skeletons and even the fragile bones of early birds have been found at ancient high-latitudes before. Yet, to date, no directly attributable integumentary remains have been discovered to show that dinosaurs used feathers to survive in extreme polar habitats," said Dr Benjamin Kear from Uppsala University in Sweden, a leading author on the study.

"These Australian fossil feathers are therefore highly significant because they came from dinosaurs and small birds that were living in a seasonally very cold environment with months of polar darkness every year."

The fossil feathers were discovered in the Koonwarra Fish Beds Geological Reserve, which is a heritage listed site 145 km southeast of Melbourne in Victoria, Australia.

"Fossil feathers have been known from Koonwarra since the early 1960s, and were recognized as evidence of ancient birds, but have otherwise received very little scientific attention. Our study is thus the first to comprehensively document these remains, which include new specimens that were examined using cutting-edge technologies," said Dr Thomas Rich of the Melbourne Museum in Australia, who has led numerous expeditions to the Koonwarra locality.

A suite of advanced microscopic and spectroscopic techniques was employed to determine the anatomy and preservation of the Koonwarra fossil dinosaur and bird feathers.

"The Koonwarra feathers are preserved in incredible detail," said fossil bird expert Professor Patricia Vickers-Rich of Monash University and the Swinburne University of Technology in Melbourne.

"There are even tiny filament-like structures that would have 'zipped' the feather vanes together, just as in the flight feathers of modern birds."

However, unlike the structurally complex feathers of birds today, which are characterized by interlocking branches called barbs and barbules, different kinds of small dinosaurs had coverings that comprised much more simpler hair-like 'proto-feathers'.

"Dinosaur 'proto-feathers' would have been used for insulation," said Dr Martin Kundrát, of Pavol Jozef Safarik University in Slovakia, a leading author on the study.

"The discovery of 'proto-feathers' at Koonwarra therefore suggests that fluffy feather coats might have helped small dinosaurs keep warm in ancient polar habitats."

Microscopic remains of possible melanosomes ? cellular structures that contain colour pigments ? were also detected on several of the fossil feathers found at Koonwarra.

These traces occurred across the uniformly dark feather surfaces, as well as in distinct bands that might represent original patterning from the polar dinosaurs and birds.

Melanic residues have been reported on fossil feathers from elsewhere around the world, and are widely acknowledged as indicators of dinosaur colouration.

The densely packed fossil melanosomes occurring on the Koonwarra feathers could suggest dark colours that perhaps assisted in camouflage, visual communication, and/or heat absorbance in cold polar climates.

Possible preservation of biomolecules was also assessed, but proved to be too degraded, and were apparently lost during weathering of the rock.

The Koonwarra fossil feathers provide the first record of dinosaur integument from the ancient polar regions, and hint what was once a global distribution of feathered dinosaurs and early birds.

Some of the fossil feathers found at Koonwarra are on display in the '600 Million Years' exhibition at the Melbourne Museum in Australia.

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