Lightning strikes can keep electrical substations secure, tiny black holes could power ET’s spaceship, an ultrafast laser can weld metal to glass, and an already incredible material — spider silk — is found to be even more useful. Researchers are harnessing some pretty powerful forces in this week’s coolest scientific discoveries.
What is it? Not only have NASA scientists captured images of the shock waves produced by aircraft in supersonic flight, they’ve also captured images of two GE-powered T-38 jets breaking the sound barrier in formation — from the perspective of a third aircraft flying above the others. It’s the first successful use of this advanced air-to-air photographic technology.
Why does it matter? When a plane flies faster than the speed of sound, it generates shock waves that register on the ground as a sonic boom. That’s probably cool to hear once or twice, but would be fairly annoying if you had to experience it all the time, which is why supersonic flight over land is restricted in the U.S. NASA is developing a quiet supersonic plane in hopes that such restrictions might one day be lifted. (GE Aviation is building the engine for the plane, and also developing the technology to power the next generation of supersonic civilian air travel.) The ability to capture images of the shock waves produced by exceeding the sound barrier will help improve understanding of them.
How does it work? Very … carefully. The agency used something called schlieren photography, which was developed to capture supersonic motion, as well as souped-up cameras that can capture up to 1,400 frames per second. But this was a feat of coordination as much as anything: According to a news release, NASA “flew a B-200, outfitted with an updated imaging system, at around 30,000 feet while the pair of T-38s were required to not only remain in formation, but to fly at supersonic speeds at the precise moment they were directly beneath the B-200. The images were captured as a result of all three aircraft being in the exact right place at the exact right time designated by NASA’s operations team.”
What is it? At Heriot-Watt University in Edinburgh, Scotland, scientists have developed a technique for welding metal and glass using an ultrafast laser.
Why does it matter? “Traditionally it has been very difficult to weld together dissimilar materials like glass and metal due to their different thermal properties — the high temperatures and highly different thermal expansions involved cause the glass to shatter,” said Professor Duncan Hand, who oversaw the research. “Being able to weld glass and metals together will be a huge step forward in manufacturing and design flexibility.” According to the university, such tech could have enormous potential in the healthcare, defense, optical technology and aerospace fields. (And the transportation news site Jalopnik says it could “revolutionize car manufacturing.”)
How does it work? Hand et al used an infrared laser fired at picosecond bursts to fuse the materials together; a picosecond compared to a second, Hand said, “is like a second compared to 30,000 years,” and the technique results in “highly confined melt regions” that successfully join the disparate materials. The laser technique was tested on a variety of materials, including quartz and sapphire, and the welds were tested at temperatures between -50 Celsius and 90 Celsius, to robust results.
What is it? Spider silk, incredibly strong for its weight, is already thought of as a wonder material, but researchers have discovered another important property: supercontraction, meaning the silk shrinks and twists in the presence of moisture.
Why does it matter? The biological reason for this property — that is, why it’s important to spiders — remains unknown, but scientists have some ideas for how it could help humans. In responding to humidity, the spider silk may offer important tips for the development of responsive materials that could be used in artificial muscles or robotic actuators, which move to perform an activity. An expert not involved with the project said: “This is like a rope that twists and untwists itself depending on air humidity. The molecular mechanism leading to this outstanding performance can be harnessed to build humidity-driven soft robots or smart fabrics.” The research team, led by scientists from MIT, described its findings in Science Advances.
How does it work? Dabiao Liu, a professor from China’s Huazhong University of Science and Technology who co-authored the paper, said the initial discovery was accidental: Wanting to study the influence of humidity on spider dragline silk, Liu and colleagues suspended a weight from spider silk, like a pendulum, and enclosed it in a humidity-controlled chamber. “When we increased the humidity, the pendulum started to rotate,” Liu said. “It was out of our expectation. It really shocked me.”
What is it? If aliens exist, it stands to reason that many of their civilizations would be older and more technologically advanced than ours. And if they’re really technologically advanced, they might have figured out a way to harness the radiation emitted by black holes to power their starships. And that, according to a new paper by Kansas State University mathematician Louis Crane, is one way that we might look for them.
Why does it matter? Using a black hole to power a rocket is a pretty wild idea. But a sufficiently advanced civilization wouldn’t have to rely on any old black hole it came across for energy — it could create its own tiny, artificial black hole, which is something that humans themselves might aim for if we want to start colonizing other parts of the solar system. “A black hole can convert matter into energy, so it would be the ultimate power source,” Crane writes in a paper posted to arXiv. That technology remains just a bit out of our grasp, but we might be able to detect from afar if others accomplished it.
How does it work? “If some advanced civilization already had such starships, current [very high energy] gamma ray telescopes could detect it out to 100 to 1,000 light years if we were in its beam,” said Crane, who also proposes that extraterrestrial power could explain some gamma ray sources that astronomers have already detected but “for which no natural explanation has been given.”
What is it? In the future, operators remotely monitoring the security of electrical substations could get an assist from lightning, which can help determine whether the substation is under attack from hackers, according to new research from Georgia Tech. “We should be able to remotely detect any attack that is modifying the magnetic field around substation components,” said engineering professor Raheem Beyah.
Why does it matter? Substations are vulnerable to malicious actors, as demonstrated by a 2015 attack on the power grid in Ukraine. The hackers were also able to get into the monitoring systems of the 30 substations they attacked and hide their work; remote operators thought things were operating normally as 230,000 people lost power. “The electric power grid is difficult to secure because it is so massive,” Beyah said. “It provides an electrical connection from a generating station to the appliances in your home. Because of this electrical connection, there are many places where a hacker could potentially insert an attack. That’s why we need an independent way to know what’s happening on grid systems.”
How does it work? You can’t control lightning, but you can enlist its power — it occurs about 3 million times a day worldwide, with strikes leaving a kind of electrical signature on the ground that can be detected thousands of miles away. Georgia Tech researchers realized that lightning’s electromagnetic signals can be used to independently authenticate the signals emitted by electrical substations, proving if they’re being tampered with or not. They call their technology a radio-frequency-based distributed intrusion detection system, or RFDIDS, and described it last month in San Diego at the 2019 Network and Distributed System Security Symposium.