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Dec 20, 2021
Why Is December 21 The Shortest Day Of The Year?
Posted by Gemechu Taye in categories: education, physics, space
The empirical fact of short winter days and long winter nights has been known essentially forever, and has driven enormous amounts of human activity including the construction of monuments like the passage tomb at Newgrange that I keep banging on about in previous posts about timekeeping. The correct explanation of the phenomenon has only been understood for around 400 years, dating back to Johannes Kepler’s description of the orbits of the planets.
The change in the relative length of days and nights is due to a combination of the motion of the Earth about the Sun, and the rotation of the Earth on its axis. Specifically, it happens because the Earth’s axis is tilted by about 23 degrees relative to the axis of its orbit. And because angular momentum is conserved, that axis stays pointing in the same direction through the whole orbit, in the same way that a gyroscope on a gimbal mount will remain pointed in the same direction in space as it’s moved around.
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Dec 20, 2021
Scientists Taught Human Brain Cells In a Dish How to Play ‘Pong’
Posted by Gemechu Taye in categories: biotech/medical, robotics/AI
And they’re faster than AI.
Researchers at Cortical Labs, a biotechnology startup, have successfully taught human brain cells in a petri dish how to play the 2D table tennis simulation video game “Pong”.
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Dec 20, 2021
France Built the World’s First Carbon-Negative Public Building. And It’s Made of Hemp?
Posted by Gemechu Taye in categories: health, materials
It’s a sports hall.
A French architecture and landscaping company from the town of Croissy-Beaubourg has completed the country’s first hempcrete public building: Pierre Chevet sports hall.
The 4,000-square foot (380 square meters) building includes an exercise hall and changing rooms. What is Hempcrete? A mixture of hemp with lime and water, the sports hall that’s made of Hempcrete is a carbon-negative building.
Dec 20, 2021
A New Hypersonic Wind Tunnel Will Put China ‘20 to 30 Years Ahead’ of the West
Posted by Gemechu Taye in category: military
JF-22 will reach speeds of up to Mach 30.
A Chinese physicist revealed that a new wind tunnel in Beijing will “soon” be unveiled that will put China decades ahead of the rest of the world when it comes to testing hypersonic weapons technology, a South China Morning Post article reveals.
In an online lecture last week, Han Guilai, of the Chinese Academy of Sciences, revealed new information about the JF-22 wind tunnel in Beijing, which will be capable of simulating flights at Mach 30 — 30 times the speed of sound and approximately 6.2 miles (10 km) per second. The launch date for the JF-22 wind tunnel is currently classified.
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Dec 20, 2021
Cuttlefish-Like Robots Are Far More Efficient Than Propeller-Powered Machines
Posted by Gemechu Taye in category: robotics/AI
And they could soon help explore the deep sea.
New York-based firm Pliant Energy Systems is building a marine system reminiscent of the cuttlefish with its rippling underwater motion, a report from The Economist reveals.
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Dec 20, 2021
Science fiction revisited: Ramjet propulsion
Posted by Quinn Sena in categories: nuclear energy, space travel
In science fiction stories about contact with extraterrestrial civilisations, there is a problem: What kind of propulsion system could make it possible to bridge the enormous distances between the stars? It cannot be done with ordinary rockets like those used to travel to the moon or Mars. Many more or less speculative ideas about this have been put forward—one of them is the “Bussard collector” or “Ramjet propulsion”. It involves capturing protons in interstellar space and then using them for a nuclear fusion reactor.
Peter Schattschneider, physicist and science fiction author, has now analyzed this concept in more detail together with his colleague Albert Jackson from the USA. The result is unfortunately disappointing for fans of interstellar travel: it cannot work the way Robert Bussard, the inventor of this propulsion system, thought it up in 1960. The analysis has now been published in the scientific journal Acta Astronautica.
Dec 20, 2021
Hacking Fingerprints Is Actually Pretty Easy—and Cheap
Posted by Omuterema Akhahenda in categories: cybercrime/malcode, mobile phones, privacy
People in movies are often quick to resort to sawing off someone’s hand to get past a fingerprint scanner. A report from the Kraken Security Labs Team shows that it would be much easier—and less gruesome—to recreate someone’s fingerprint using a little bit of off-the-shelf wood glue.
Kraken notes that biometric security has become increasingly common as smartphone, tablet, and laptop manufacturers have incorporated fingerprint scanners into their products. These scanners offer a convenient way to access those devices without entering a password.
The report says a fingerprint scanner can be “hacked” by using a picture of the target’s fingerprint, creating a negative in Photoshop, printing the resulting image, and then putting some wood glue on top of the imitated fingerprint so it can be used to trick many commercial scanners.
Dec 20, 2021
Iowa State University gets $1.4 million to buy 3D concrete printer for low-cost homebuilding
Posted by Shubham Ghosh Roy in categories: 3D printing, economics, habitats
Iowa’s first 3D-printed home could be ready for its new owners by this time next year.
The Iowa Economic Development Authority on Friday approved $1.4 million for the Iowa State University College of Design to purchase a 3D printer capable of producing concrete houses. Its goal is to build a neighborhood of up to 34 3D-printed homes in Hamburg, a southwest Iowa town recovering from a massive flood two years ago.
The agency’s director, Debi Durham, said the college also will develop a curriculum for training contractors on 3D printing and new state building codes in order to allow wide use of the technique in Iowa.
Dec 20, 2021
Tesla releases new Full Self-Driving Beta update (10.7) with improved phantom braking and efficiency
Posted by Kelvin Dafiaghor in categories: robotics/AI, transportation
Tesla has started to release a new Full Self-Driving Beta software update (10.7) that improves the situation with “phantom braking” and even helps the FSD beta be more energy efficient.
For more than a year now, Tesla has been slowly rolling out what it is calling “Full Self-Driving Beta” (FSD Beta), which is an early version of its self-driving software that is currently being tested by a fleet of Tesla owners selected by the company and through its “safety test score.”
The software enables the vehicle to drive autonomously to a destination entered in the car’s navigation system, but the driver needs to remain vigilant and ready to take control at all times.