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Category: physics – Page 206

Astronomers spot signs of planets forming around dying stars

Aging binary systems could be giving birth to second-generation planets.

When a Sun-like star exhausts the helium fuel in its core, it enters its death throes. Starved for fuel, it swells to a red giant, likely swallowing its innermost planets, and begins burning scraps of leftover hydrogen to helium. Periodically, these helium ashes reignite, causing the star to once again burn brightly and throw off its outer layers into space.

This volatile phase of stellar life is called the asymptotic giant branch (AGB). With so much happening, it would seem like a terrible environment for the delicate process of forming planets. But over the past couple decades, astronomers have begun to suspect that under some circumstances, this stage could result in a new disk of material surrounding the star, giving rise to a second generation of planets.

Now, an analysis published Feb. 1 in Astronomy and Astrophysics gives some of the first observational hints that dying stars in binary systems could be giving birth to new planets. Roughly 10 percent of the post-AGB stars they studied are surrounded by disks of gas and dust that have gaps and cavities in them, a telltale sign that planets are possibly present — or forming — in them.

Google Engineer Says Lawyer Hired

Suspended Google engineer Blake Lemoine made some serious headlines earlier this month when he claimed that one of the company’s experimental AIs called LaMDA had achieved sentience — prompting the software giant to place him on administrative leave.

“If I didn’t know exactly what it was, which is this computer program we built recently, I’d think it was a seven-year-old, eight-year-old kid that happens to know physics,” he told the Washington Post at the time.

The subsequent news cycle swept up AI experts, philosophers, and Google itself into a fierce debate about the current and possible future capabilities of machine learning, other ethical concerns around the tech, and even the nature of consciousness and sentience. The general consensus, it’s worth noting, was that the AI is almost certainly not sentient.

Combat robotics

TV robot fights are not just entertainment – they can also help turn students on to physics and engineering, as Robert P Crease finds out.

The two 110 kg combat robots squared off. One, known as Poison Arrow, was armed with a toothed spinning drum. Its adversary, Son of Wyachi (SOW), had whirling hammers. Poison Arrow smashed into SOW, sending it flying across the arena. SOW broke its radio receiver as it crash-landed, lying motionless as the referee declared a knockout.

The action took place in 2016 in BattleBots – a US “robot-combat” TV series aired by ABC in 2015–2016, and then by the Discovery Channel since 2018. BattleBots is inspired by the original Robot Wars events held in the US in the 1990s; these events also inspired the famed British TV series Robot Wars. Dubbed “the ultimate robot-fighting competition”, BattleBots features fights to the finish between remote-controlled “bots” that employ an array of destructive weapons.

High-power lasers promise new defence strategy

Physicists at QinetiQ are developing systems that combine and control high-energy laser beams to provide a powerful and cost-effective countermeasure against drones and other uncrewed objects.

Around the world interest is growing in using high-power laser beams to disable airborne invaders such as drones and other uncrewed objects. These so-called directed-energy systems have the potential to damage or destroy small aerial devices at a fraction of the cost of launching conventional defence missiles or munitions. They have the added advantage that they can be reused many times to counter multiple attacks as well as the growing threat of drone swarms.

At QinetiQ, a UK-based technology company specializing in defence and security solutions, around 10 years of research effort into the physics underpinning these directed-energy systems has demonstrated enough potential to start building and testing practical prototypes. “We have taken a high-risk, high-reward approach to developing these systems,” says Richard Hoad, capability area lead for novel effectors and resilience at QinetiQ. “Our company and our customers in the defence sector have just significantly increased their investment to enable us to prove that our solution is as effective in a wide range of real environments as it is in testing.”

Tetraneutron — An Exotic State of Matter discovered

A long-standing question in nuclear physics is whether chargeless nuclear systems can exist. Only neutron stars represent near-pure neutron systems, where neutrons are squeezed together by the gravitational force to very high densities. The experimental search for isolated multi-neutron systems has been an ongoing quest for several decades, with a particular focus on the four-neutron system called the tetraneutron, resulting in only a few indications of its existence so far, leaving the tetraneutron an elusive nuclear system for six decades.

A recently announced experimental discovery of a tetraneutron by an international group led by scientists from Germany’s Technical University of Darmstadt opens doors for new research and could lead to a better understanding of how the universe is put together. This new and exotic state of matter could also have properties that are useful in existing or emerging technologies.

The first announcement of tetraneutron was done by theoretical physicist James Vary during a presentation in the summer of 2014, followed by a research paper in the fall of 2016. He has been waiting to confirm reality through nuclear physics experiments.

Physicists develop printable organic transistors

Scientists at the Institute of Applied Physics at TU Dresden have come a step closer to the vision of a broad application of flexible, printable electronics. The team around Dr. Hans Kleemann has succeeded for the first time in developing powerful vertical organic transistors with two independent control electrodes. The results have recently been published in the renowned online journal Nature Communications.

High-definition roll-up televisions or foldable smartphones may soon no longer be unaffordable luxury goods that can be admired at international electronics trade fairs. High-performance organic transistors are a key necessity for the mechanically flexible electronic circuits required for these applications. However, conventional horizontal organic thin-film transistors are very slow due to the hopping-transport in organic semiconductors, so they cannot be used for applications requiring high frequencies. Especially for logic circuits with low power consumption, such as those used for Radio Frequency Identification (RFID), it is mandatory to develop transistors enabling high operation frequency as well as adjustable device characteristics (i.e., threshold-voltage). The research group Organic Devices and Systems (ODS) at the Dresden Integrated Center for Applied Photophysics (IAPP) of the Institute of Applied Physics headed by Dr.

Gravitational Wave Events With Split Personalities

Deep Follow-up of GW151226 — an ordinary binary or a low-mass ratio merger?

Now that we’ve been detecting gravitational waves.

Gravitational waves are distortions or ripples in the fabric of space and time. They were first detected in 2015 by the Advanced LIGO detectors and are produced by catastrophic events such as colliding black holes, supernovae, or merging neutron stars.

Dead star’s cannibalism of its planetary system is most far-reaching ever witnessed

The violent death throes of a nearby star so thoroughly disrupted its planetary system that the dead star left behind—known as a white dwarf—is sucking in debris from both the system’s inner and outer reaches, UCLA astronomers and colleagues report today.

This is the first case of cosmic cannibalism in which astronomers have observed a white dwarf consuming both rocky-metallic material, likely from a nearby asteroid, and icy material, presumed to be from a body similar to those found in the Kuiper belt at the fringe of our own solar system.

“We have never seen both of these kinds of objects accreting onto a white dwarf at the same time,” said lead researcher Ted Johnson, a physics and astronomy major at UCLA who graduated last week. “By studying these white dwarfs, we hope to gain a better understanding of planetary systems that are still intact.”

Researcher uses math to investigate possibility of time travel

After some serious number crunching, a UBC researcher has come up with a mathematical model for a viable time machine.

Ben Tippett, a mathematics and physics instructor at UBC’s Okanagan campus, recently published a study about the feasibility of . Tippett, whose field of expertise is Einstein’s theory of general relativity, studies black holes and science fiction when he’s not teaching. Using math and physics, he has created a formula that describes a method for time travel.

“People think of time travel as something as fiction,” says Tippett. “And we tend to think it’s not possible because we don’t actually do it. But, mathematically, it is possible.”

Can wormholes act like time machines?

Time travel into the past is a tricky thing. We know of no single law of physics that absolutely forbids it, and yet we can’t find a way to do it, and if we could do it, the possibility opens up all sorts of uncomfortable paradoxes (like what would happen if you killed your own grandfather).

But there could be a way to do it. We just need to find a wormhole first.

Wormholes are shortcuts through space, a tunnel that connects two distant parts of the universe through a very short path. If you could somehow construct a wormhole, you can casually walk down through the tunnel and end up thousands of light years away without even breaking a sweat.

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