Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: physics – Page 91

Dark Matter Solves Longstanding Black Hole Problem, Astrophysicists Say

🌏 Get NordVPN 2Y plan + 4 months extra here plus up to 20 GB Saily data voucher ➌ https://NordVPN.com/sabine It’s risk-free with Nord’s 30-day money-back guarantee! ✌

Physicists say that they might have solved a long standing problem: How do supermassive black holes manage to merge to larger ones. Their idea: dark matter gets the job done. Or does it? I’ve had a look.

Paper: https://journals.aps.org/prl/abstract


đŸ€“ Check out my new quiz app ➜ http://quizwithit.com/
💌 Support me on Donorbox ➜ https://donorbox.org/swtg.
📝 Transcripts and written news on Substack ➜ https://sciencewtg.substack.com/
👉 Transcript with links to references on Patreon ➜ / sabine.
đŸ“© Free weekly science newsletter ➜ https://sabinehossenfelder.com/newsle

👂 Audio only podcast ➜ https://open.spotify.com/show/0MkNfXl

🔗 Join this channel to get access to perks ➜
/ @sabinehossenfelder.
đŸ–Œïž On instagram ➜ / sciencewtg.

#science #sciencenews #physics

Five new ways to catch gravitational waves — and the secrets they’ll reveal

Innovative techniques being developed to detect gravitational waves beyond the current capabilities of laser interferometers like LIGO and Virgo.

That rare bright spot looks set to become brighter.

All of the more than 100 gravitational-wave events spotted so far have been just a tiny sample of what physicists think is out there. The window opened by LIGO and Virgo was rather narrow, limited mostly to frequencies in the range 100–1,000 hertz. As pairs of heavy stars or black holes slowly spiral towards each other, over millions of years, they produce gravitational waves of slowly increasing frequency, until, in the final moments before the objects collide, the waves ripple into this detectable range. But this is only one of many kinds of phenomenon that are expected to produce gravitational waves.

LIGO and Virgo are laser interferometers: they work by detecting small differences in travel time for lasers fired along perpendicular arms, each a few kilometres long. The arms expand and contract by minuscule amounts as gravitational waves wash over them. Researchers are now working on several next-generation LIGO-type observatories, both on Earth and, in space, the Laser Interferometer Space Antenna; some have even proposed building one on the Moon1. Some of these could be sensitive to gravitational waves at frequencies as low as 1 Hz.

Nonreciprocal Interactions Go Nonlinear: How Nanoparticles Are Changing the Rules of Physics

Using two optically trapped glass nanoparticles, researchers observed a novel collective Non-Hermitian and nonlinear dynamic driven by nonreciprocal interactions. This contribution expands traditional optical levitation with tweezer arrays by incorporating the so-called non-conservative interactions. Their findings, supported by an analytical model developed by collaborators from Ulm University and the University of Duisburg-Essen, were recently published in Nature Physics.

Understanding Nonreciprocal Interactions

Fundamental forces like gravity and electromagnetism are reciprocal, meaning two objects either attract or repel each other. However, for some more complex interactions arising in nature, this symmetry is broken and some form of nonreciprocity exists. For example, the interaction between a predator and a prey is inherently nonreciprocal as the predator wants to catch (is attracted to) the prey and the latter wants to escape (is repelled).

Self-powered electrostatic tweezer for adaptive object manipulation and microfluidics

In a study published in Device (“Self-powered electrostatic tweezer for adaptive object manipulation”), a research team led by Dr. DU Xuemin from the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences has reported a new self-powered electrostatic tweezer that offers superior accumulation and tunability of triboelectric charges, enabling unprecedented flexibility and adaptability for manipulating objects in various working scenarios.

The ability to manipulate objects using physical tweezers is essential in fields such as physics, chemistry, and biology. However, conventional tweezers often require complex electrode arrays and external power sources, have limited charge-generation capabilities, or produce undesirable temperature rises.

The newly proposed self-powered electrostatic tweezer (SET) features a polyvinylidene fluoride trifluoroethylene (P(VDF-TrFE))-based self-powered electrode (SE) that generates large and tunable surface charge density through the triboelectric effect, along with a dielectric substrate that functions as both a tribo-counter material and a supportive platform, and a slippery surface to reduce resistance and biofouling during object manipulation.

17th Century Sunspot Drawings Could Help Solve 400-Year-Old Solar Cycle Mystery

“Kepler contributed many historical benchmarks in astronomy and physics in the 17th century, leaving his legacy even in the space age,” said Hisashi Hayakawa.

How can 400-year-old sunspot drawings help modern-day scientists with solar cycles? This is what a recent study published in The Astrophysical Journal Letters hopes to address as an international team of researchers used 400-year-old drawings of sunspots to better understand solar cycles and how we can study them in the future. This study holds the potential to help researchers use non-electronic scientific tools to gain greater insight into scientific discoveries around the world.

For the study, the researchers examined drawings of sunspots made by Johannes Kepler in 1,607 along with past notes to ascertain which solar cycle these sunspots belonged to, which could help astronomers piece together solar cycles during that time and predict them, as well.

Cosmic Simulation Reveals How Black Holes Grow and Evolve

A team of astrophysicists led by Caltech has managed for the first time to simulate the journey of primordial gas dating from the early universe to the stage at which it becomes swept up in a disk of material fueling a single supermassive black hole. The new computer simulation upends ideas about such disks that astronomers have held since the 1970s and paves the way for new discoveries about how black holes and galaxies grow and evolve.

“Our new simulation marks the culmination of several years of work from two large collaborations started here at Caltech,” says Phil Hopkins, the Ira S. Bowen Professor of Theoretical Astrophysics.

The first collaboration, nicknamed has focused on the larger scales in the universe, studying questions such as how galaxies form and what happens when galaxies collide. The other, dubbed STARFORGE, was designed to examine much smaller scales, including how stars form in individual clouds of gas.

Escaping kinetic traps: How molecular interactions make it possible to overcome the energy barrier

In a paper in Physical Review Letters scientists from the department Living Matter Physics at the Max Planck Institute for Dynamics and Self-Organization (MPI-DS) propose a mechanism on how energy barriers in complex systems can be overcome. These findings can help to engineer molecular machines and to understand the self-organization of active matter.

/* */