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Archive for the ‘physics’ category: Page 120

Jun 25, 2021

The first observation of the superscattering effect of metamaterials

Posted by in categories: materials, physics

Entering an invisible doorway to catch a train at King’s Cross station in London is a renowned fictional scene from the Harry Potter series. In recent decades, physicists have been trying to produce a similar effect by focusing their research efforts on illusion devices.

Illusion devices are devices that can change the optical properties of objects to match those of other virtual objects or make them apparently invisible, producing an . Two common types of illusion devices are super-scatterers and invisible gateways. The first are designed to scatter light and the second to bounce back light rays through a physical gateway.

From a theoretical standpoint, super-scatterers and invisible gateways have so far been primarily studied in the context of transformation optics and folded geometry transformations (i.e., the visual, illusory transformation of objects into other objects). Experimentally realizing these devices, however, requires the use of metamaterials with specific properties (e.g., a negative permittivity and permeability) that can be difficult to employ in fabrication processes.

Jun 24, 2021

The World Just Moved Even Closer to a Real, Working Warp Drive

Posted by in categories: physics, space travel

Scientists have given the all-clear.


Warp drive is having a moment. Just last week, scientists dropped a bombshell when they unveiled the first physical model for a warp drive, the holy grail of space travel that would allow us to bend the fabric of space and time to their will and overcome the vast distances separating humans from the stars. Now, another astrophysicist has delivered an equally exciting warp drive breakthrough.

Up until this point, scientists have slowly chipped away at the fantasy of faster-than-light (FTL) travel by relying on theories of bizarre physics and exotic matter. But in a new paper, Göttingen University’s Erik Lentz has created a theoretical design of a warp drive that’s actually grounded in conventional physics. Lentz’s theory overcomes the need for a source of exotic matter in previous designs by reimagining the shape of warped space.

Continue reading “The World Just Moved Even Closer to a Real, Working Warp Drive” »

Jun 24, 2021

Highly Chirped Laser Pulses Defy “Conventional Wisdom”

Posted by in category: physics

University of Rochester researchers describe first highly chirped pulses created by a using a spectral filter in a Kerr resonator.

The 2018 Nobel Prize in Physics was shared by researchers who pioneered a technique to create ultrashort, yet extremely high-energy laser pulses at the University of Rochester.

Now researchers at the University’s Institute of Optics have produced those same high-powered pulses—known as chirped pulses—in a way that works even with relatively low-quality, inexpensive equipment. The new work could pave the way for:

Jun 22, 2021

Astronomers saw the Same Supernova Three Times Thanks to Gravitational Lensing. And in Twenty Years They Think They’ll see it one More Time

Posted by in categories: cosmology, physics

It is hard for humans to wrap their heads around the fact that there are galaxies so far away that the light coming from them can be warped in a way that they actually experience a type of time delay. But that is exactly what is happening with extreme forms of gravitational lensing, such as those that give us the beautiful images of Einstein rings. In fact, the time dilation around some of these galaxies can be so extreme that the light from a single event, such as a supernova, can actually show up on Earth at dramatically different times. That is exactly what a team led by Dr. Steven Rodney at the University of South Carolina and Dr. Gabriel Brammer of the University of Copenhagen has found. Except three copies of this supernova have already appeared – and the team thinks it will show up again one more time, 20 years from now.

Finding such a supernova is important not just for its mind bending qualities – it also helps to settle an important debate in the cosmological community. The rate of expansion of the universe has outpaced the rate expected when calculated from the cosmic microwave background radiation. Most commonly, this cosmological conundrum is solved by invoking “dark energy” – a shadowy force that is supposedly responsible for increasing the acceleration rate. But scientists don’t actually know what dark energy is, and to figure it out they need a better model of the physics of the early universe.

One way to get that better model is to find an event that is actively being distorted through a gravitational lens. Importantly – the same event must show up at two separate, distinct times in order to provide input to a calculation about the ratio of the distance between the galaxy doing the lensing and the background galaxy that was the source of the event.

Jun 22, 2021

Helion Energy Achieves 100 Million Degrees Celsius Fusion Fuel Temperature and Confirms 16-Month Continuous Operation of Its Fusion Generator Prototype

Posted by in categories: business, climatology, engineering, physics

REDMOND, Wash.—()—Helion Energy (Helion), a clean electricity company committed to creating a new era of clean energy through fusion, today became the first private company to announce exceeding 100 million degrees Celsius in their 6th fusion generator prototype, Trenta. Reaching this temperature is a critical engineering milestone as it is considered the ideal fuel temperature at which a commercial power plant would need to operate. Helion will be presenting these operational results at the 63rd Annual Meeting of the APS Division of Plasma Physics. See abstract below.

“These achievements represent breakthroughs with major implications for how the world meets its expanding future electricity needs while dramatically reducing climate impact on a relevant timescale” Tweet this

Helion also announced their Trenta prototype recently completed a 16-month testing campaign, which pushed fusion fuel performance to unprecedented levels and performed lifetime and reliability testing on key components of the fusion system. Helion will be presenting these results at the 2021 IEEE Pulsed Power Conference & Symposium on Fusion Engineering. See abstract below.

Jun 22, 2021

An ally for alloys: AI helps design high-performance steels

Posted by in categories: economics, health, physics, robotics/AI

Machine learning techniques have contributed to progress in science and technology fields ranging from health care to high-energy physics. Now, machine learning is poised to help accelerate the development of stronger alloys, particularly stainless steels, for America’s thermal power generation fleet. Stronger materials are key to producing energy efficiently, resulting in economic and decarbonization benefits.

“The use of ultra-high-strength steels in power plants dates back to the 1950s and has benefited from gradual improvements in the materials over time,” says Osman Mamun, a postdoctoral research associate at Pacific Northwest National Laboratory (PNNL). “If we can find ways to speed up improvements or create new materials, we could see enhanced efficiency in plants that also reduces the amount of carbon emitted into the atmosphere.”

Mamun is the lead author on two recent, related journal articles that reveal new strategies for machine learning’s application in the design of advanced alloys. The articles chronicle the research outcomes of a joint effort between PNNL and the National Energy Technology Laboratory (NETL). In addition to Mamun, the research team included PNNL’s Arun Sathanur and Ram Devanathan and NETL’s Madison Wenzlick and Jeff Hawk.

Jun 22, 2021

New drone can pollinate flowers, just like honeybees

Posted by in categories: drones, physics

#Drone #Technology #Innovation #Research #Honeybees #Pollination #Physics

Jun 21, 2021

Investigating the lives of double neutron stars

Posted by in categories: physics, space

Using observations from radio astronomy and gravitational waves we can get a better picture of the population of double neutron stars. PhD student Shanika Galaudage discusses her latest research on how to combine these observations — with the key in understanding how these systems evolve.

Jun 21, 2021

Indiana Jones in space: Inside the fascinating world of galactic archaeology

Posted by in categories: physics, space

Astrophysicists now have the data and models to uncover subtle imprints from our galaxy’s past.

Jun 17, 2021

Reaping the Benefits of Noise: Scientists Show 10x Efficiency Increase in Harvesting Energy From Noise

Posted by in categories: energy, media & arts, physics

Signals can be amplified by an optimum amount of noise, but this so-called stochastic resonance is a rather fragile phenomenon. Researchers at AMOLF were the first to investigate the role of memory for this phenomenon in an oil-filled optical microcavity. The effects of slow non-linearity (i.e. memory) on stochastic resonance were never considered before, but these experiments suggest that stochastic resonance becomes robust to variations in the signal frequency when systems have memory. This has implications in many fields of physics and energy technology. In particular, the scientists numerically show that introducing slow non-linearity in a mechanical oscillator harvesting energy from noise can increase its efficiency by tenfold. They published their findings in Physical Review Letters on May 27th.

It is not easy to concentrate on a difficult task when two people are having a loud discussion right next to you. However, complete silence is often not the best alternative. Whether it is some soft music, remote traffic noise or the hum of people chatting in the distance, for many people, an optimum amount of noise enables them to concentrate better. “This is the human equivalent of stochastic resonance,” says AMOLF group leader Said Rodriguez. “In our scientific labs stochastic resonance happens in non-linear systems that are bistable. This means that, for a given input, the output can switch between two possible values. When the input is a periodic signal, the response of a non-linear system can be amplified by an optimum amount of noise using the stochastic resonance condition.”