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If travel to distant stars within an individual’s lifetime is going to be possible, a means of faster-than-light propulsion will have to be found. To date, even recent research about superluminal (faster-than-light) transport based on Einstein’s theory of general relativity would require vast amounts of hypothetical particles and states of matter that have “exotic” physical properties such as negative energy density. This type of matter either cannot currently be found or cannot be manufactured in viable quantities. In contrast, new research carried out at the University of Göttingen gets around this problem by constructing a new class of hyper-fast ‘solitons’ using sources with only positive energies that can enable travel at any speed. This reignites debate about the possibility of faster-than-light travel based on conventional physics. The research is published in the journal Classical and Quantum Gravity.

The author of the paper, Dr Erik Lentz, analysed existing research and discovered gaps in previous ‘warp drive’ studies. Lentz noticed that there existed yet-to-be explored configurations of space-time curvature organized into ‘solitons’ that have the potential to solve the puzzle while being physically viable. A soliton — in this context also informally referred to as a ‘warp bubble’ — is a compact wave that maintains its shape and moves at constant velocity. Lentz derived the Einstein equations for unexplored soliton configurations (where the space-time metric’s shift vector components obey a hyperbolic relation), finding that the altered space-time geometries could be formed in a way that worked even with conventional energy sources. In essence, the new method uses the very structure of space and time arranged in a soliton to provide a solution to faster-than-light travel, which — unlike other research — would only need sources with positive energy densities.

Researchers have developed a new method that can automatically produce clear images through murky water. The new technology could be useful for searching for drowning victims, documenting submerged archaeological artifacts and monitoring underwater farms.

Imaging clearly underwater is extremely challenging because the and the particles in it tend to scatter light. But, because scattered light is partially polarized, imaging using a camera that is sensitive to polarization can be used to suppress scattered light in underwater .

“Our new method overcomes the limitations of traditional polarimetric underwater imaging, laying the groundwork for taking this method out of the lab and into the field,” said research team leader Haofeng Hu from Tianjin University in China. “Unlike previous methods, there’s no requirement for the image to include a background area to estimate the backscattered light.”

Circa 2017

Livescience.com | By LIVESCIENCE


Sound has negative mass, and all around you it’s drifting up, up and away — albeit very slowly.

That’s the conclusion of a paper submitted on July 23 to the preprint journal arXiv, and it shatters the conventional understanding that researchers have long had of sound waves: as massless ripples that zip through matter, giving molecules a shove but ultimately balancing any forward or upward motion with an equal and opposite downward motion. That’s a straightforward model that will explain the behavior of sound in most circumstances, but it’s not quite true, the new paper argues. [The Mysterious Physics of 7 Everyday Things]

No Man’s Sky

Researchers have created what they say is the largest computer simulation of the universe, and have made the data available for anyone to download for free.

An international team associated with the Center for Computational Astrophysics created the virtual universe using ATERUI II, the world’s most powerful astronomical supercomputer, according to a press release by the organization. Dubbed Uchuu (the Japanese word for “outer space”), the simulation contains a staggering 2.1 trillion particles spanning 9.6 billion virtual light-years. That’s big. Real big.

Using a groundbreaking new technique at the National Institute of Standards and Technology (NIST), an international collaboration led by NIST researchers has revealed previously unrecognized properties of technologically crucial silicon crystals and uncovered new information about an important subatomic particle and a long-theorized fifth force of nature.

By aiming subatomic particles known as neutrons at silicon crystals and monitoring the outcome with exquisite sensitivity, the NIST scientists were able to obtain three extraordinary results: the first measurement of a key neutron property in 20 years using a unique method; the highest-precision measurements of the effects of heat-related vibrations in a silicon crystal; and limits on the strength of a possible “fifth force” beyond standard physics theories.

The researchers report their findings in the journal Science.

One of the many areas graphene promises to have transformative effects is in fortifying construction materials like concrete and asphalt. A first-of-a-kind trial now underway seeks to apply the wonder material’s impressive attributes to one of the UK’s major thoroughfares, by deploying it in a road resurfacing project along a stretch of the A1 motorway.

Made up of a single sheet of carbon atoms arranged in a honeycomb pattern, graphene offers incredible strength and flexibility, and by incorporating it into materials like asphalt scientists hope to develop road surfaces that last far longer, and therefore cost less to maintain.

Back in 2017 we looked at an interesting take on this from a pair of Italian companies that developed an asphalt material doped with a graphene additive to make it less likely to soften in the heat and crack in the cold under high loads. This product, known as Gipave, also incorporates plastic pellets and was recently rolled out along stretches of UK roads as part of trials to see how it can extend the lifespan of the surface.

Forget about online games that promise you a “whole world” to explore. An international team of researchers has generated an entire virtual universe, and made it freely available on the cloud to everyone.

Uchuu (meaning “outer space” in Japanese) is the largest and most realistic simulation of the to date. The Uchuu simulation consists of 2.1 trillion particles in a computational cube an unprecedented 9.63 billion light-years to a side. For comparison, that’s about three-quarters the distance between Earth and the most distant observed . Uchuu reveals the evolution of the universe on a level of both size and detail inconceivable until now.

Uchuu focuses on the large-scale structure of the universe: mysterious halos of dark matter that control not only the formation of galaxies, but also the fate of the entire universe itself. The scale of these structures ranges from the largest galaxy clusters down to the smallest galaxies. Individual stars and planets aren’t resolved, so don’t expect to find any alien civilizations in Uchuu. But one way that Uchuu wins big in comparison to other virtual worlds is the ; Uchuu simulates the evolution of matter over almost the entire 13.8 billion year history of the universe from the Big Bang to the present. That is over 30 times longer than the since animal life first crawled out of the seas on Earth.