Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: quantum physics – Page 739

In quantum physics, particles can ’tunnel’ through seemingly impenetrable barriers, even when they apparently don’t have the energy to do so. Now, researchers have gleaned behind the curtain to better understand how this trick is done.

This problem has puzzled scientists for decades – in particular, the time it takes for particles to do their quantum tunnelling, and get from one side of a barrier to another.

In the case of the atomic hydrogen particles used in these experiments, the researchers found that it happens instantaneously.

Read more

For the first time, one of the top prizes in mathematics has been given to a woman.

On Tuesday, the Norwegian Academy of Science and Letters announced it has awarded this year’s Abel Prize — an award modeled on the Nobel Prizes — to Karen Uhlenbeck, an emeritus professor at the University of Texas at Austin. The award cites “the fundamental impact of her work on analysis, geometry and mathematical physics.”

One of Dr. Uhlenbeck’s advances in essence described the complex shapes of soap films not in a bubble bath but in abstract, high-dimensional curved spaces. In later work, she helped put a rigorous mathematical underpinning to techniques widely used by physicists in quantum field theory to describe fundamental interactions between particles and forces.

Read more

Researchers from the Moscow Institute of Physics and Technology teamed up with colleagues from the U.S. and Switzerland and returned the state of a quantum computer a fraction of a second into the past. They also calculated the probability that an electron in empty interstellar space will spontaneously travel back into its recent past. The study is published in Scientific Reports.

“This is one in a series of papers on the possibility of violating the . That law is closely related to the notion of the arrow of time that posits the one-way direction of time from the past to the future,” said the study’s lead author Gordey Lesovik, who heads the Laboratory of the Physics of Quantum Information Technology at MIPT.

“We began by describing a so-called local perpetual motion machine of the second kind. Then, in December, we published a paper that discusses the violation of the second law via a device called a Maxwell’s demon,” Lesovik said. “The most recent paper approaches the same problem from a third angle: We have artificially created a state that evolves in a direction opposite to that of the thermodynamic arrow of time.”

Read more

Time: it’s constantly running out and we never have enough of it. Some say it’s an illusion, some say it flies like an arrow. Well, this arrow of time is a big headache in physics. Why does time have a particular direction? And can such a direction be reversed?

A new study, published in Scientific Reports, is providing an important point of discussion on the subject. An international team of researchers has constructed a time-reversal program on a quantum computer, in an experiment that has huge implications for our understanding of quantum computing. Their approach also revealed something rather important: the time-reversal operation is so complex that it is extremely improbable, maybe impossible, for it to happen spontaneously in nature.

As far as laws of physics go, in many cases, there’s nothing to stop us going forward and backward in time. In certain quantum systems it is possible to create a time-reversal operation. Here, the team crafted a thought experiment based on a realistic scenario.

Read more

A team of researchers from the University of St Andrews (St Andrews, Scotland) has achieved a breakthrough in the measurement of lasers that they say could revolutionize the future of fiber-optic communications. They also say the wavelength meter (or wavemeter) will boost optical and quantum sensing technology, enhance the performance of next-generation sensors, and expand the information-carrying capacity of fiber-optic networks.

A team of researchers from the University of St Andrews has achieved a breakthrough in the measurement of lasers which could revolutionise the future of fiber-optic communications.

The new research, published in Optics Letters (Wednesday 6 March), reveals the team of scientists has developed a low-cost and highly-sensitive device capable of measuring the wavelength of light with unprecedented accuracy.

The wavemeter development will boost optical and quantum sensing technology, enhancing the performance of next generation sensors and the information-carrying capacity of fiber-optic communications networks.

Read more

A new quantum physics experiment just lent evidence to a mind-boggling idea that was previously limited to the realm of theory, according to the MIT Technology Review — that under the right conditions, two people can observe the same event, see two different things happen, and both be correct.

According to research shared to the preprint server arXiv on Tuesday, physicists from Heriot-Watt University demonstrated for the first time how two people can experience different realities by recreating a classic quantum physics thought experiment.

The experiment involves two people observing a single photon, the smallest quantifiable unit of light that can act as either a particle or a wave under different conditions.

Read more

But no other new particles have materialized at the LHC, leaving open many mysteries about the universe that the Standard Model doesn’t address. A debate has ensued over whether to build an even more enormous successor to the LHC — a proposed machine 100 kilometers in circumference, possibly in Switzerland or China — to continue the search for new physics.

Physicists say there’s much we can still learn from the Higgs boson itself. What’s known is that the particle’s existence confirms a 55-year-old theory about the origin of mass in the universe. Its discovery won the 2013 Nobel Prize for Peter Higgs and François Englert, two of six theorists who proposed this mass-generating mechanism in the 1960s. The mechanism involves a field permeating all of space. The Higgs particle is a ripple, or quantum fluctuation, in this Higgs field. Because quantum mechanics tangles up the particles and fields of nature, the presence of the Higgs field spills over into other quantum fields; it’s this coupling that gives their associated particles mass.

But physicists understand little about the omnipresent Higgs field, or the fateful moment in the early universe when it suddenly shifted from having zero value everywhere (or in other words, not existing) into its current, uniformly valued state. That shift, or “symmetry-breaking” event, instantly rendered quarks, electrons and many other fundamental particles massive, which led them to form atoms and all the other structures seen in the cosmos.

Read more