Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: particle physics – Page 533

You probably scratched your head last year if you read about time crystals, likely 2017’s most esoteric, widely covered popular science story. Even if you understood how they worked, you might not have known what use they could have. Time crystals, systems of atoms that maintain a periodic ticking behavior in the presence of an added electromagnetic pulse, have now piqued the interest of one well-funded government agency: the Department of Defense.

The DoD’s Defense Advanced Research Projects Agency, or DARPA, announced a new program to fund research on these systems. More generally, the new DRINQS program will study exactly what its acronym stands for: “Driven and Nonequilibrium Quantum Systems.” But why?

“The applications could be for atomic clocks, where you have an ensemble of atoms you’re vibrating to extract time information,” Ale Lukaszew, program manager in DARPA’s defense sciences offices, told Gizmodo. “There might be applications related to measuring things with exquisite sensitivity in time and magnetic field domains. Not a lot of these applications are open for discussion.” In other words, time crystal-based military technology is classified.

Read more

The European Space Agency created the world’s first thruster which allows satellites to remain in orbit for years longer than they currently do. The secret? The thruster runs on particles of air in the atmosphere.

Others have tried to improve the staying power of satellites before, but most are still limited by the amount of fuel they can carry. The new ion thruster “breathes” the rare air particles in the top of the atmosphere, allowing the satellites to remain without immediate need for refueling.

The thruster was developed by an ESA team and built by SITAEL, a private company in Italy. The air particles bounce away from satellites normally, but the thruster collects them and gives them an electric charge, after which they are ejected to provide thrust that counteracts atmospheric drag.

Read more

In 1935, when both quantum mechanics and Albert Einstein’s general theory of relativity were young, a little-known Soviet physicist named Matvei Bronstein, just 28 himself, made the first detailed study of the problem of reconciling the two in a quantum theory of gravity. This “possible theory of the world as a whole,” as Bronstein called it, would supplant Einstein’s classical description of gravity, which casts it as curves in the space-time continuum, and rewrite it in the same quantum language as the rest of physics.

Bronstein figured out how to describe gravity in terms of quantized particles, now called gravitons, but only when the force of gravity is weak — that is (in general relativity), when the space-time fabric is so weakly curved that it can be approximated as flat. When gravity is strong, “the situation is quite different,” he wrote. “Without a deep revision of classical notions, it seems hardly possible to extend the quantum theory of gravity also to this domain.”

His words were prophetic. Eighty-three years later, physicists are still trying to understand how space-time curvature emerges on macroscopic scales from a more fundamental, presumably quantum picture of gravity; it’s arguably the deepest question in physics. Perhaps, given the chance, the whip-smart Bronstein might have helped to speed things along. Aside from quantum gravity, he contributed to astrophysics and cosmology, semiconductor theory, and quantum electrodynamics, and he also wrote several science books for children, before being caught up in Stalin’s Great Purge and executed in 1938, at the age of 31.

Read more

March 2 (UPI) — Forty years after scientists first theoretically predicted the existence of a three-dimensional skyrmion, scientists have observed the particle in the lab.

The particle, observed cold quantum gas, isn’t a normal particle composed of electrons, protons and electrons. It is a quantum particle, the energy signature created by the interactions between a particle and the surrounding system.

In this instance, the quantum particle is a tangled knot of magnetic moments in the quantum gas.

Read more

Scientists at Amherst College and Aalto University have created, for the first time a three-dimensional skyrmion in a quantum gas. The skyrmion was predicted theoretically over 40 years ago, but only now has it been observed experimentally.

In an extremely sparse and cold , the physicists have created knots made of the magnetic moments, or spins, of the constituent atoms. The knots exhibit many of the characteristics of , which some scientists believe to consist of tangled streams of . The persistence of such knots could be the reason why ball lightning, a ball of plasma, lives for a surprisingly long time in comparison to a lightning strike. The new results could inspire new ways of keeping plasma intact in a stable ball in fusion reactors.

‘It is remarkable that we could create the synthetic electromagnetic knot, that is, quantum ball lightning, essentially with just two counter-circulating electric currents. Thus, it may be possible that a natural ball lighting could arise in a normal ,’ says Dr Mikko Möttönen, leader of the theoretical effort at Aalto University.

Read more

Scientists create ‘quantum ball lightning’ in the lab in breakthrough that could pave the way for stable fusion reactors…

In the new research, led by scientists at Amherst College and Aalto University, the team created a three-dimensional skyrmion in an extremely cold quantum gas.

The three-dimensional particle consists of knots made from the spin fields of a Bose-Einstein condensate – or, atoms cooled to a point just above absolute zero.

Continue reading “Scientists create ‘quantum ball lightning’ for the first time” | >

A team of astronomers led by Prof. Judd Bowman of Arizona State University unexpectedly stumbled upon “dark matter,” the most mysterious building block of outer space, while attempting to detect the earliest stars in the universe through radio wave signals, according to a study published this week in Nature.

The idea that these signals implicate dark matter is based on a second Nature paper published this week, by Prof. Rennan Barkana of Tel Aviv University, which suggests that the signal is proof of interactions between normal matter and dark matter in the early universe. According to Prof. Barkana, the discovery offers the first direct proof that dark matter exists and that it is composed of low-mass particles.

Read more

What is inside an atom between the nucleus and the electron? Usually there is nothing, but why could there not be other particles too? If the electron orbits the nucleus at a great distance, there is plenty of space in between for other atoms. A “giant atom” could be created, filled with ordinary atoms. All these atoms form a weak bond, creating a new, exotic state of matter at cold temperatures, referred to as Rydberg polarons.

A team of researchers has now presented this state of matter in the journal Physical Review Letters. The theoretical work was done at TU Wien (Vienna) and Harvard University, the experiment was performed at Rice University in Houston (Texas).

Two special fields of atomic physics, which can only be studied in extreme conditions, have been combined in this research project: Bose-Einstein condensates and Rydberg atoms. A Bose-Einstein condensate is a state of matter created by atoms at ultracold temperatures, close to absolute zero. Rydberg atoms are those in which one single electron is lifted into a highly excited state and orbits the nucleus at a very large distance.

Read more

Black holes don’t just sit there munching away constantly on the space around them. Eventually they run out of nearby matter and go quiet, lying in wait until a stray bit of gas passes by.

Then a black hole devours again, belching out a giant jet of particles. And now scientists have captured one doing so not once, but twice — the first time this has been observed.

The two burps, occurring within the span of 100,000 years, confirm that supermassive black holes go through cycles of hibernation and activity.

Read more