Lifeboat Foundation

Surrogate models supported by neural networks can perform as well, and in some ways better, than computationally expensive simulators and could lead to new insights in complicated physics problems such as inertial confinement fusion (ICF), Lawrence Livermore National Laboratory (LLNL) scientists reported.

In a paper published by the Proceedings of the National Academy of Sciences (PNAS), LLNL researchers describe the development of a deep learning-driven Manifold & Cyclically Consistent (MaCC) surrogate model incorporating a multi-modal neural network capable of quickly and accurately emulating complex scientific processes, including the high-energy density physics involved in ICF.

The research team applied the model to ICF implosions performed at the National Ignition Facility (NIF), in which a computationally expensive numerical simulator is used to predict the energy yield of a target imploded by shock waves produced by the facility’s high-energy laser. Comparing the results of the neural network-backed surrogate to the existing simulator, the researchers found the surrogate could adequately replicate the simulator, and significantly outperformed the current state-of-the-art in surrogate models across a wide range of metrics.

Last year, the Advanced LIGO-VIRGO gravitational-wave detector network recorded data from 35 merging black holes and neutron stars. A great result—but what did they miss? According to Dr. Rory Smith from the ARC Centre of Excellence in Gravitational Wave Discovery at Monash University in Australia—it’s likely there are another 2 million gravitational wave events from merging black holes, “a pair of merging black holes every 200 seconds and a pair of merging neutron stars every 15 seconds” that scientists are not picking up.

Dr. Smith and his colleagues, also at Monash University, have developed a method to detect the presence of these weak or “background” events that to date have gone unnoticed, without having to detect each one individually. The method—which is currently being test driven by the LIGO community—” means that we may be able to look more than 8 billion light years further than we are currently observing,” Dr. Smith said.

“This will give us a snapshot of what the early universe looked like while providing insights into the evolution of the universe.”

Results from the XENON experiment in Italy hint at the possible discovery of long-sought axions.

This mouth-full of a boat uses simple physics to create a cushion of air that allows it to effortlessly fly along the tops of ocean waves with near inexhaustible solar energy. The researchers say that this sleek, solar vessel could act as a mobile charging station for drones in the deep ocean or could conduct oceanic search and rescue missions.

Researchers in Russia have designed a solar-powered, and AI piloted, boat that can walk on water and serve as a mid-ocean fuel-up station for drones.

An element that could hold the key to the long-standing mystery around why there is much more matter than antimatter in our Universe has been discovered by a University of the West of Scotland (UWS)-led team of physicists.

The UWS and University of Strathclyde academics have discovered, in research published in the journal Nature Physics, that one of the isotopes of the element thorium possesses the most pear-shaped nucleus yet to be discovered. Nuclei similar to thorium-228 may now be able to be used to perform new tests to try find the answer to the mystery surrounding matter and antimatter.

UWS’s Dr. David O’Donnell, who led the project, said: “Our research shows that, with good ideas, world-leading nuclear physics experiments can be performed in university laboratories.”

It’s no surprise that Tesla’s next-gen Roadster is going to be lightning-quick, with a claimed 0–60 mph time of 1.9 seconds for the base model. However, the addition of SpaceX cold-gas thrusters that will be hidden behind the car’s license plate could drop Roadster’s 0–60 mph time to a dizzying 1.1 seconds.

YouTube channel Engineering Explained used some of Isaac Newton’s basic physics principles to determine that the Roadster could become one of the quickest cars in the world. By plugging in existing information that CEO Elon Musk has revealed about Tesla’s next-gen Roadster, host Jason Fenske determined that the vehicle will weigh roughly 2000 kg (4,400 lbs), which backs into acceleration g-forces of approximately 1.44 G’s.

An international collaboration of scientists has recorded the most accurate confirmation to date for one of the cornerstones of Einstein’s theory of general relativity, ‘the universality of free fall.’

The new research shows that the theory holds for strongly self-gravitating objects such as neutron stars. Using a radio telescope, scientists can very accurately observe the signal produced by pulsars, a type of neutron star and test the validity of Einstein’s theory of gravity for these extreme objects. In particular, the team analyzed the signals from a pulsar named ‘PSR J0337+1715’ recorded by the large radio telescope of Nançay, located in the heart of Sologne (France).

The universality of free fall principle states that two bodies dropped in a gravitational field undergo the very same acceleration independently of their composition. This was first demonstrated by Galileo who famously would have dropped objects of different masses from the top of Pisa’s tower to verify that they both reach the ground simultaneously.

A team of scientists, including Chief Investigator Ilya Mandel from the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) at Monash University, recently studied what happens to rotating massive stars when they reach the end of their lives.

Stars produce energy by fusing lighter elements into heavier ones in their core: hydrogen into helium, then helium into carbon, oxygen, and so on, up to iron. The energy produced by this nuclear fusion also provides pressure support inside the star, which balances the force of gravity and allows the star to remain in equilibrium.

This process stops at iron. Beyond iron, energy is required to sustain fusion rather than being released by fusion. A heavy iron star core contracts under gravity, creating a neutron star, or if it is heavy enough, a black hole. Meanwhile, the outer layers of the star explode in a brilliant flash, observable as a supernova. However, some massive stars seem to completely disappear without any explosion. Theories suggest that these massive stars completely collapse into black holes, but is that possible?

Black holes are the dark remnants of collapsed stars, regions of space cut off from the rest of the universe. If something falls into a black hole, it can never come back out. Not even light can escape, meaning black holes are invisible even with powerful telescopes. Yet physicists know black holes exist because they’re consistent with time-tested theories, and because astronomers have observed how matter behaves just outside a black hole.

Naturally, science fiction loves such an enigmatic entity. Black holes have played starring roles in popular books, movies and television shows, from “Star Trek” and “Doctor Who” to the 2014 blockbuster “Interstellar.”

But black holes aren’t quite as menacing as they are commonly portrayed. “They definitely do not suck,” says Daryl Haggard, an astrophysicist at McGill University in Montreal. “A black hole just sits there, passively. Things can fall onto it, just as meteors can fall to Earth, but it doesn’t pull stuff in.”