Daily Archives: June 14, 2022

The Earth moves far under our feet: A new study shows that the inner core oscillates

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USC scientists have found evidence that the Earth’s inner core oscillates, contradicting previously accepted models that suggested it consistently rotates at a faster rate than the planet’s surface.

Their study, published today in Science Advances, shows that the inner core changed direction in the six-year period from 1969–74, according to the analysis of seismic data. The scientists say their model of inner core movement also explains the variation in the length of day, which has been shown to oscillate persistently for the past several decades.

“From our findings, we can see the Earth’s surface shifts compared to its inner core, as people have asserted for 20 years,” said John E. Vidale, co-author of the study and Dean’s Professor of Earth Sciences at USC Dornsife College of Letters, Arts and Sciences. “However, our latest observations show that the inner core spun slightly slower from 1969–71 and then moved the other direction from 1971–74. We also note that the length of day grew and shrank as would be predicted.

“The coincidence of those two observations makes oscillation the likely interpretation.”

[…]

Utilizing data from the Large Aperture Seismic Array (LASA), a U.S. Air Force facility in Montana, researcher Wei Wang and Vidale found the inner core rotated slower than previously predicted, approximately 0.1 degrees per year. The study analyzed waves generated from Soviet underground nuclear bomb tests from 1971–74 in the Arctic archipelago Novaya Zemlya using a novel beamforming technique developed by Vidale.

The new findings emerged when Wang and Vidale applied the same methodology to a pair of earlier atomic tests beneath Amchitka Island at the tip of the Alaskan archipelago—Milrow in 1969 and Cannikin in 1971. Measuring the compressional waves resulting from the , they discovered the inner core had reversed direction, sub-rotating at least a tenth of a degree per year.

[…]

The study does support the speculation that the inner core oscillates based on variations in the length of day—plus or minus 0.2 seconds over six years—and geomagnetic fields, both of which match the theory in both amplitude and phase. Vidale says the findings provide a compelling theory for many questions posed by the research community.

“The inner core is not fixed—it’s moving under our feet, and it seems to going back and forth a couple of kilometers every six years,” Vidale said. “One of the questions we tried to answer is, does the inner core progressively move or is it mostly locked compared to everything else in the long term? We’re trying to understand how the formed and how it moves over time—this is an important step in better understanding this process.”

Source: The Earth moves far under our feet: A new study shows that the inner core oscillates

US Copyright Office sued for denying AI model authorship

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The US Copyright Office and its director Shira Perlmutter have been sued for rejecting one man’s request to register an AI model as the author of an image generated by the software.

You guessed correct: Stephen Thaler is back. He said the digital artwork, depicting railway tracks and a tunnel in a wall surrounded by multi-colored, pixelated foliage, was produced by machine-learning software he developed. The author of the image, titled A Recent Entrance to Paradise, should be registered to his system, Creativity Machine, and he should be recognized as the owner of the copyrighted work, he argued.

(Owner and author are two separate things, at least in US law: someone who creates material is the author, and they can let someone else own it.)

Thaler’s applications to register and copyright the image behalf of Creativity Machine, however, have been turned down by the Copyright Office twice. Now, he has sued the government agency and Perlmutter. “Defendants’ refusal to register the copyright claim in the work is contrary to law,” Thaler claimed in court documents [PDF] filed this month in a federal district court in Washington DC.

“The agency actions here were arbitrary, capricious, an abuse of discretion and not in accordance with the law, unsupported by substantial evidence, and in excess of Defendants’ statutory authority,” the lawsuit claimed.

Thaler’s lawyer, Ryan Abbott, believes the Copyright Office should overturn its previous decision and process Thaler’s original application. “The refusal to register the copyright claim in the work should be set aside and the application reinstated,” he argued.

[…]

Source: US Copyright Office sued for denying AI model authorship • The Register

Scientists covered a robot finger in living human skin

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[…] At the moment, robots are sometimes coated in silicone rubber to give them a fleshy appearance, but the rubber lacks the texture of human skin, he says.

To make more realistic-looking skin, Takeuchi and his colleagues bathed a plastic robot finger in a soup of collagen and human skin cells called fibroblasts for three days. The collagen and fibroblasts adhered to the finger and formed a layer similar to the dermis, which is the second-from-top layer of human skin.

Next, they gently poured other human skin cells called keratinocytes onto the finger to recreate the upper layer of human skin, called the epidermis.

The resulting 1.5-millimetre-thick skin was able to stretch and contract as the finger bent backwards and forwards. As it did this, it wrinkled like normal skin, says Takeuchi. “It is much more realistic than silicone.”

The robot skin could also be healed when it was cut by grafting a collagen sheet onto the wound.

However, the skin began to dry out after a while since it didn’t have blood vessels to replenish it with moisture.

In the future, it may be possible to incorporate artificial blood vessels into the skin to keep it hydrated, as well as sweat glands and hair follicles to make it more realistic, says Takeuchi.

It should also be possible to make different skin colours by adding melanocytes, he says.

The researchers now plan to try coating a whole robot in the living skin. “But since this research field has the potential to build a new relationship between humans and robots, we need to carefully consider the risks and benefits of making it too realistic,” says Takeuchi.

Source: Scientists covered a robot finger in living human skin | New Scientist