Lifeboat Foundation

(Phys.org)—The fundamental constants of nature—such as the speed of light, Planck’s constant, and Newton’s gravitational constant—are thought to be constant in time, as their name suggests. But scientists have questioned this assumption as far back as 1937, when Paul Dirac hypothesized that Newton’s gravitational constant might decrease over time.

Now in a new paper published in Physical Review Letters, Yevgeny V. Stadnik and Victor V. Flambaum at the University of New South Wales in Sydney, Australia, have theoretically shown that dark matter can cause the fundamental constants of nature to slowly evolve as well as oscillate due to oscillations in the dark matter field. This idea requires that the weakly interacting dark matter particles be able to interact a small amount with standard model particles, which the scientists show is possible.

In their paper, the scientists considered a model in which dark matter is made of weakly interacting, low-mass particles. In the early Universe, according to the model, large numbers of such dark matter particles formed an oscillating field. Because these particles interact so weakly with standard model particles, they could have survived for billions of years and still exist today, forming what we know as dark matter.

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Dark matter is called “dark” for a good reason. Although they outnumber particles of regular matter by more than a factor of 10, particles of dark matter are elusive. Their existence is inferred by their gravitational influence in galaxies, but no one has ever directly observed signals from dark matter. Now, by measuring the mass of a nearby dwarf galaxy called Triangulum II, Assistant Professor of Astronomy Evan Kirby may have found the highest concentration of dark matter in any known galaxy.

Triangulum II is a small, faint galaxy at the edge of the Milky Way, made up of only about 1,000 stars. Kirby measured the mass of Triangulum II by examining the velocity of six stars whipping around the galaxy’s center. “The galaxy is challenging to look at,” he says. “Only six of its stars were luminous enough to see with the Keck telescope.” By measuring these stars’ velocity, Kirby could infer the gravitational force exerted on the stars and thereby determine the mass of the galaxy.

“The total mass I measured was much, much greater than the mass of the total number of stars—implying that there’s a ton of densely packed dark matter contributing to the total mass,” Kirby says. “The ratio of dark matter to luminous matter is the highest of any galaxy we know. After I had made my measurements, I was just thinking—wow.”

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What seemed to be flaws in the structure of a mystery metal may have given physicists a glimpse into as-yet-undiscovered laws of the universe.

The qualities of a high-temperature superconductor — a compound in which electrons obey the spooky laws of quantum physics, and flow in perfect synchrony, without friction — appear linked to the fractal arrangements of seemingly random oxygen atoms.

Those atoms weren’t thought to matter, especially not in relation to the behavior of individual electrons, which exist at a scale thousands of times smaller. The findings, published Aug. 12 in Nature, are a physics equivalent of discovering a link between two utterly separate dimensions.

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It’s made of just 244 atoms.

In the nearly 400 years since the first submarine was invented, these underwater machines have become incredibly sophisticated. They’re armed and they’re really stealthy. We’re even planning on sending subs to oceans on distant moons. Trippy.

But now, a submarine is going where no submarine has gone before. To the molecular level. In a paper published this month in NanoLetters, researchers announced that they’ve invented a submarine so small that it’s made out of a single molecule.

Continue reading “Speedy Submarine Is Made Of A Single Molecule” »

One of the weirdest aspects of quantum mechanics is entanglement, because two entangled particles affecting each other across vast distances seems to violate a fundamental principle of physics called locality: things that happen at a particular point in space can only influence the points closest to it. But what if locality — and space itself — is not so fundamental after all? Author George Musser explores the implications in his new book, Spooky Action At a Distance.

When the philosopher Jenann Ismael was ten years old, her father, an Iraqi-born professor at the University of Calgary, bought a big wooden cabinet at an auction. Rummaging through it, she came across an old kaleidoscope, and she was entranced. For hours she experimented with it and figured out how it worked. “I didn’t tell my sister when I found it, because I was scared she’d want it,” she recalls.

As you peer into a kaleidoscope and turn the tube, multicolored shapes begin to blossom, spin and merge, shifting unpredictably in seeming defiance of rational explanation, almost as if they were exerting spooky action at a distance on one another. But the more you marvel at them, the more regularity you notice in their motion. Shapes on opposite sides of your visual field change in unison, and their symmetry clues you in to what’s really going on: those shapes aren’t physical objects, but images of objects — of shards of glass that are jiggling around inside a mirrored tube.

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Scientists have discovered a way to authenticate or identify any object by generating an unbreakable ID based on atoms.

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SANTA CLARA, California — Robotic spacecraft may ride the solar wind toward interstellar space at unprecedented speeds a decade or so from now.

Researchers are developing an “electric sail” (e-sail) propulsion system that would harness the solar wind, the stream of protons, electrons and other charged particles that flows outward from the sun at more than 1 million mph (1.6 million kilometers per hour).

“It looks really, really promising for ultra-deep-space exploration,” Les Johnson, of NASA’s Marshall Space Flight Center in Huntsville, Alabama, said of the e-sail concept here at the 100-Year Starship Symposium on Oct. 30. [Superfast Spacecraft Propulsion Concepts (Images)].

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If “The Stellarator” sounds like an energy source of comic book legend to you, you’re not that far off. It’s the largest nuclear fusion reactor in the world, and it’s set to turn on later this month.

Housed at the Max Planck Institute in Germany, the Wendelstein 7-X (W7-X) stellarator looks more like a psychotic giant’s art project than the future of energy. Especially when you compare it with the reactor’s symmetrical, donut-shaped cousin, the tokamak. But stellarators and tokamaks work according to similar principles: In both cases, coiled superconductors are used to create a powerful magnetic cage, which serves to contain a gas as it’s heated to the ungodly temperatures needed for hydrogen atoms to fuse.

Continue reading “World’s Largest Fusion Reactor is About to Switch On” »

For the first time, physicists in the US have managed to measure the force that attracts antimatter particles to each other. And, surprisingly, it’s not that different to the attractive force that holds regular matter together.

The results take us one step closer to understanding one of the biggest mysteries of our Universe: why there’s so much more matter than antimatter, and suggest that the imbalance isn’t a result of antiparticles not being able to ‘stick’ together.

For every particle that exists – electrons, protons, quarks – there’s an equal and opposite antiparticle, which has the opposite electrical charge and spin, and these antiparticles make up what’s known as antimatter. When the Universe was formed, physicists believe that equal amounts of antimatter and matter were produced, but today it’s very hard to find any naturally occurring antimatter left.

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