science

Imagine three people huddled in a circle so when one speaks, only one other hears. Scientists have created a device that works like that, ensuring sound waves ripple in one direction only.

The device, developed by scientists at ETH Zurich and the Swiss Federal Institute of Technology Lausanne, is made up of a disk-shaped cavity with three equally-spaced ports that can each send or receive sound.

In an inactive state, sound transmitted from port 1 is audible to ports 2 and 3 at equal volumes. Sound waves bounce back to port 1 as an echo as well.

When the system is running, however, only port 2 hears port 1's sounds.

The trick is to blow swirling air into the cavity at a specific speed and intensity, which allows the sound waves to synchronize in a repeating pattern. That not only guides the sound waves in a single direction, but gives more energy to those oscillations so they don't dissipate. It's kind of like a roundabout for sound.

The scientists say their technique may inform the design of future communications technologies. New metamaterials could be made to manipulate not just sound waves but potentially electromagnetic waves too.

Please incorporate this technology into TVs so I don't have to hear them through the wall.

Jupiter pics. still don't know why

Laser-induced imaging of radioactive elements was used to work out the age of an ancient cave painting on the Indonesian island of Sulawesi. The results reveal that the narrative scene is 51,200 years old, making it the earliest known example of representational art. This study challenges previous dating methods and suggests a deeper origin for human image-making and storytelling.

TL;DR or if you don't have access to the article: the researchers invented a faster, less-destructive and more-accurate rock art dating method & applied it to humanity's oldest known rock art in Sulawesi, Indonesia. The art is at least 51,200 years old (authors' lower estimate)!

Edit: contrary to what the news title original stated: this is the oldest representational art, not the literal oldest human-created art.

The paper itself (open access): https://doi.org/10.1038/s41586-024-07541-7

Pham Tiep, the Joshua Barlaz Distinguished Professor of Mathematics in the Rutgers School of Arts and Science's Department of Mathematics, has completed a proof of the 1955 Height Zero Conjecture posed by Richard Brauer, a leading German-American mathematician who died in 1977. Proof of the conjecture -- commonly viewed as one of the most outstanding challenges in a field of math known as the representation theory of finite groups -- was published in the September issue of the Annals of Mathematics.

cross-posted from: https://lemmy.ml/post/21130734

NoviOcean’s wave power technology, developed over several years, has been tested in wave pools and a real environment near Stockholm. A small version powers homes on Svanholmen island, proving the concept works at sea.

On one square kilometer, 15 wave power plants can generate 15 MW, compared to offshore wind’s 10 MW. Combined, they can produce 25 MW, sharing the costs of the sea area and transmission cable.

According to the firm, the hybrid approach delivers more consistent energy, as waves generate power for days after the wind subsides. Additionally, wave plants can be placed closer to shore without visually disturbing the coastline.

Despite much anecdotal evidence, few studies show pervasive racial bias in promotion and tenure decisions. By analysing 1,571 real promotion and tenure cases across five US universities, Masters-Waage et al. find double standards negatively applied to scholars of colour, and especially women of colour, even after accounting for scholarly productivity.

Shortcoming of this paper is that it is

• 1500+ individuals from five typical research-intensive US-based institutions, so other countries/types of institutions might see differences. Two HBCUs were also excluded, wouldn't be surprised if they see less racism.
• I believe it was mentioned somewhere that the team only looked at Black and Hispanic faculty members, because other minorities are too few in numbers to look at... If you are wondering, Asians/Asian Americans are not considered minorities in academia.

Original paper, open access & quite easy to read if you are interested

• https://doi.org/10.1038/s41562-024-01977-7

Dataset:

• https://osf.io/9xu65/?view_only=8af03fe8158c43a185ce807a17e43431

The associated Science News articles, both original URL and archive.org ver:

• https://www.science.org/content/article/racial-bias-can-taint-academic-tenure-process-one-particular-point
• https://web.archive.org/web/20241005023358/https://www.science.org/content/article/racial-bias-can-taint-academic-tenure-process-one-particular-point

The Telomere-to-telomere consortium's primate project. We now have complete, diploid genomes of six ape species (chimpanzee, bonobo, gorilla, Bornean orangutan, Sumatran orangutan, and siamang). Maybe this will show up on Nature or somewhere next year :D

Manuscript is literally just out on biorxiv.org past Saturday... So title/details subject to change, and unfortunately there are no fancy news articles making it any easier to read

Links:

• Relevant T2T blog post on UCSC
• The GitHub repo
• Data uploaded to NCBI

Where to look for C/2023 A3 in the night sky

For observers in the Northern Hemisphere, comet C/2023 A3 can be found in the constellation Sextans and will rise one hour before the sun, according to Astronomy.com.

The comet will be best viewed in mid-October, rising up from the western horizon and be visible in the southwestern sky at nightfall, weather permitting. That will likely be its best and brightest appearance until it starts to fade from view by Nov. 7, according to SkyandTelescope.com.