This week on Talk nerdy to me, we cover interesting technologies in deep-sea exploration, supersonic flight, archeology, and environmentalism.
Simulating ancient “superhighways”
When humans first arrived in ancient Australia more than 65,000 years ago, they had no idea what lay before them. The landscape was unfamiliar and uncharted, and they would have had no idea whether its topology, weather, resources, and fauna were hostile to human life.
Researchers have long believed these ancient immigrants stayed near water sources, avoiding deserts as they made their first forays into the continent. Despite this, their exact paths have never been clear.
Recently, however, researchers have used supercomputer simulations to identify 125 billion possible routes they could have taken, as well as the most likely among them.
Upon comparison, many of these supercomputer-generated “superhighways” align with oral histories, ancient trade routes, and archeological sites dating back 35,000 years.
Others sit on little-explored and long-submerged coastal regions, and their identification provides guidance for future marine archeology. Perhaps most intriguing are the paths, like Queensland highway, that cut through arid regions of central and northeastern Australia. This contrasts the view that early people avoided deserts and provides ground for future surveys.
The future of hypersonic flight
Frugal travelers and businesspeople alike are experienced in the discomforting eight-hour red-eye flight from Los Angeles to New York. But with future hypersonic technologies, this trip could take less than 30 minutes.
International competition to create hypersonic propulsion systems has intensified in the last few years. By 2019, a handful of firms like Boom, Aerion, and Engine Reactions expressed goals of reaching speeds between Mach 1 to Mach 5 (or one to five times the speed of sound) as early as the mid-2020s.
At these speeds of thousands of miles per hour, existing jet engines would melt. Recently, however, researchers have found a way to stabilize oblique detonations, which could be used to propel jets to even greater speeds of Mach 6 to 17.
Detonation propulsion has been studied for half a century, but with no success as the detonations themselves last only milliseconds, making them impractical for study and use.
Their new technology uniquely harnesses the power of detonations by extending their duration for three seconds in a specially designed reaction chamber. The researchers liken it to freezing an intense explosion in physical space.
Oblique detonation requires further investigation through fluid-dynamics simulations, but the technique could be brought to fruition in flight in the next couple of decades.
Surveying deep sea sponges
Unlike the whimsical, intrepid sponge in pop culture’s SpongeBob SquarePants, deep sea sponges don’t move. Or that was the consensus until a recent expedition to the Artic brought back new evidence, dredged from the depths of an underwater mountain ridge near the North Pole.
The icebreaking vessel behind the discovery, Polerstern, is an icon of German polar research and logs about 50,000 nautical miles a year — the equivalent of two trips around the equator. The ship’s nine laboratories are stripped and reequipped between expeditions, depending on the research objectives of the roughly 55 scientists on each given expedition.
During its 2016 cruise, scientists aboard surveyed the sea hundreds of feet below the reach of sunlight using a boat-towed camera and remote aquatic vehicle.
Recently, from the underwater footage, they identified small fragments of sponge remnants trailing along the ridge, showing the meandering paths of over 10,000 sponges.
The researchers ruled out the possibility that gravity pulled the sponges along because many of the sponges were located uphill of their trails. The area also lacks disruptive currents which might otherwise explain their movement.
While sponges have occasionally slowly crawled in laboratory experiments, researchers had not seen them do so in the wild nor had they expected it. It’s now thought that thousands of sponges could be moving around the world without us noticing, and future research will investigate how and why they move.
Printing recyclable electronics
Discarded electronics are the fastest-growing source of global waste. And of America’s share, about 10 to 40 percent is exported to countries like China, Taiwan, and Mexico, where it can be dismantled cheaply in poorly regulated facilities, in often dangerous conditions.
Part of the problem is that e-waste is difficult to recycle. Silicon computer chips cannot be recycled at all. Yet they are essential to modern smartphones, laptops, game consoles, cars, and other appliances.
Now, however, researchers have demonstrated a fully functional transistor — a complex computer bit that, en masse, makes up computer chips — that is also fully recyclable. Their transistor is made of three carbon-based inks, which can be 3-D printed onto environmentally friendly surfaces.
Two of the inks are not new to printed electronics, but the third, nanocellulose, has never been used as a printable ink before. The researchers developed a method for harvesting it by extracting nanocellulose crystals from wood fibers and then sprinkling them with salt.
In terms of complexity, transistors fall somewhere between capacitors and processors. The development of a somewhat complex electronics part is considered a first step toward fully recyclable, simple devices.