Science & TechnologyS


HAL9000

The world's first human brain-scale supercomputer will go live next year

deep south
Our brains are remarkably energy efficient.

Using just 20 watts of power, the human brain is capable of processing the equivalent of an exaflop — or a billion-billion mathematical operations per second.

Now, researchers in Australia are building what will be the world's first supercomputer that can simulate networks at this scale.

The supercomputer, known as DeepSouth, is being developed by Western Sydney University.

When it goes online next year, it will be capable of 228 trillion synaptic operations per second, which rivals the estimated rate of operations in the human brain.

The hope is to better understand how brains can use such little power to process huge amounts of information.


Airplane Paper

Physicist discovers 'paradox-free' time travel is theoretically possible

hole
© andrey_I/ShutterstockTime Travel Web
No one has yet managed to travel through time - at least to our knowledge - but the question of whether or not such a feat would be theoretically possible continues to fascinate scientists.

As movies such as The Terminator, Donnie Darko, Back to the Future and many others show, moving around in time creates a lot of problems for the fundamental rules of the Universe: if you go back in time and stop your parents from meeting, for instance, how can you possibly exist in order to go back in time in the first place?

It's a monumental head-scratcher known as the 'grandfather paradox', but a few years ago physics student Germain Tobar, from the University of Queensland in Australia, worked out how to "square the numbers" to make time travel viable without the paradoxes.

Tobar explained back in 2020:
"Classical dynamics says if you know the state of a system at a particular time, this can tell us the entire history of the system. However, Einstein's theory of general relativity predicts the existence of time loops or time travel - where an event can be both in the past and future of itself - theoretically turning the study of dynamics on its head."
What the calculations show is that space-time can potentially adapt itself to avoid paradoxes.

Magnify

Reindeer's blue eyes act as night vision goggles to help them find food in winter

reindeer eye color change
© Alexandre BuisseReindeer eyes change color with the seasons
Animals' eyes change colour as colder months approach to enhance UV sight, helping them spot lichen vital for their survival

Rudolph does not need to use his famous red nose to guide his fellow reindeer as the animals have a special form of night vision that they use to forage for food, scientists have concluded.

Researchers looked into why the species are the only mammals whose eyes change colour depending on the season, from golden-orange in summer to a blue hue in the winter months.

The study found that while the colour shift may help them see better in the peak of winter when snowfall is heavy, it also allows their eyes to transmit ultraviolet light.

Telescope

JWST spots new rings, moons around Uranus

uranus rings moons
© JWST/NASARings and moons of Uranus captured by the James Web Space Telescope
NASA's James Webb Space Telescope recently trained its sights on unusual and enigmatic Uranus, an ice giant that spins on its side. Webb captured this dynamic world with rings, moons, storms, and other atmospheric features - including a seasonal polar cap. The image expands upon a two-color version released earlier this year, adding additional wavelength coverage for a more detailed look.

With its exquisite sensitivity, Webb captured Uranus' dim inner and outer rings, including the elusive Zeta ring - the extremely faint and diffuse ring closest to the planet. It also imaged many of the planet's 27 known moons, even seeing some small moons within the rings.

In visible wavelengths as seen by Voyager 2 in the 1980s, Uranus appeared as a placid, solid blue ball. In infrared wavelengths, Webb is revealing a strange and dynamic ice world filled with exciting atmospheric features.

One of the most striking of these is the planet's seasonal north polar cloud cap. Compared to the Webb image from earlier this year, some details of the cap are easier to see in these newer images. These include the bright, white, inner cap and the dark lane in the bottom of the polar cap, toward the lower latitudes.

Galaxy

Astronomers detect almost 100 new extremely metal-poor galaxies

galaxies
© unknownTwo most metal-poor galaxies identified in this work. The left, middle and right.
By analyzing the early data from the Dark Energy Spectroscopic Instrument (DESI), an international team of astronomers has identified 95 new extremely metal-poor galaxies at a low redshift. The finding is detailed in a paper published December 1 on the pre-print server arXiv.

Extremely metal-poor galaxies (XMPGs) are the ones with metallicity below 0.1 of the solar metallicity. Given that these galaxies are chemically unevolved, they can serve as excellent laboratories for investigating the chemical evolution theories of galaxies and studying the physical processes in the early stages of their evolution.

Although XMPGs are assumed to be quite common at high redshift, they are difficult to observe due to their low masses. Therefore, astronomers are interested in the observations of local XMPGs at low redshift, as they are perceived as possible analogs of primeval high-redshift young galaxies of this type in terms of mass and metallicity.

Now, a group of astronomers led by Hu Zou of the University of Chinese Academy of Sciences in Beijing, China, has obtained a large sample of XMPGs based on the early data from DESI.

Info

The 8.5-year rhythm of Earth's inner core

tilted inner core wobble
© Dr. Ding/Nature Communications. 10.1038/s41467-023-43894-9.A schematic depiction of the tilted inner core wobble.
Researchers from China have confirmed the existence of an approximately 8.5-year Inner Core Wobble (ICW) in both polar motion and length-of-day variations, revealing a static tilt of about 0.17 degrees between the Earth's inner core and mantle, challenging traditional assumptions and providing insights into the Earth's internal dynamics and density distribution.

The findings of the study are published in Nature Communications.

The Earth's inner core is a solid, dense sphere composed primarily of iron and nickel. Located beneath the liquid outer core, it spans a radius of about 1,200 kilometers (746 miles). This region plays a crucial role in Earth's geophysical processes, influencing the planet's magnetic field and contributing to the overall dynamics of the Earth's interior.

Understanding the properties and behavior of the inner core is essential for unraveling mysteries related to Earth's structure, seismic activity, and magnetic field.

The ICW refers to the wobbling motion of the Earth's inner core around its rotation axis. This phenomenon is characterized by a periodic oscillation of the inner core's figure axis.

A new study has confirmed that the ICW of Earth has a periodic motion with a cycle lasting approximately 8.5 years. This wobbling motion has been observed in measurements of polar motion, the Earth's rotational axis' periodic movement and length-of-day variations (ΔLOD), and the changes in Earth's rotational speed.

Professor Hao Ding, co-author of this research and Dean of the Geophysics Department at Wuhan University, was inspired by the unconventional density structures revealed in Earth's free oscillation.

He told Phys.org, "My then Ph.D. student, Dr. Yachong An, and I discovered an 8.5-year signal in PM and ΔLOD, prompting us to conduct the present study."

Galaxy

Astronomers discover 25 'stripped stars' that may be a missing link in supernova science

The Large Magellanic Cloud
© NASA/Swift/ Immler (Goddard)/ Siegel (Penn StateThe Large Magellanic Cloud. a satellite galaxy of the Milky Way where these stripped stars were found.
Astronomers have discovered 25 stars in two satellite galaxies of the Milky Way that have had their hydrogen-rich outer layers stripped away by a binary companion, leaving them as exposed helium stars. The hydrogen-stripped stars represent the progenitors of a special type of supernova — an explosion that occurs when massive stars die and birth black holes or neutron stars — and fill in a glaring hole in our understanding of some of the universe's most powerful events.

When massive stars die in bright supernova explosions, they often outshine the combined light of every star in the galaxy around them. Some of these events lack evidence of hydrogen, so it follows that they must begin with stars that also lack hydrogen in their outer layers. Until now, evidence of these hydrogen-stripped stars has largely eluded scientists.

This is the first time a population of these hydrogen-stripped stars has ever been discovered.

Telescope

Has dark matter's identity been revealed? Scientists searching for mysterious hypothetical particle may soon have an answer

pulsar
© UnknownPulsar
Scientists may be closing in on solving the mystery of dark matter, a hypothetical, nonluminous material that is believed to comprise a large majority of the mass in our universe, in new research that may link it to the existence of a hypothetical subatomic particle.

Among the primary questions scientists have about dark matter is what it could be made of. However, new research by an international team of astrophysicists proposes a possible candidate, meaning that this elusive cosmic material might be detectable in the form of a glow emanating from certain kinds of stars.

The research, conducted by astrophysicists at the universities of Amsterdam and Princeton, suggests that dark matter, which presently is believed to constitute around 85% of the matter in the universe, could be composed of hypothetical particles known as axions.

First proposed in the 1970s to resolve an unrelated problem involving neutrons, axions are of interest to dark matter researchers because if they possess a low mass within a certain range, they could be good candidates in the search for dark matter. Not only that, but they might help to potentially explain how and why dark matter has remained so elusive.

Satellite

Voyager 1 is returning garbled mess of 1s and 0s from space. NASA is baffled

Raumsonde Voyager 1
© dpaNASA illustration of the American space probe "Voyager 1". The probe has been flying through space since its launch on September 5, 1977.
Voyager 1, the most distant human-made object from Earth, is sending back a repetitive jumble of 1s and 0s that don't make any sense.

Scientists at NASA are desperately trying to fix the glitch from 24 billion kilometers (15 billion miles) away .

The probe can still receive commands from Earth but messages to interstellar space require approximately 22.5 hours of travel. That means it will take days before experts know if their attempts to restore the probe's nearly 50-year-old computers have worked or not.

This isn't the first time that Voyager 1 has sent back random readouts. In 2022, the probe started returning some of its data through a broken computer onboard, corrupting the outgoing messages.

Engineers at NASA managed to figure the problem out and fix it. But it took several months.

Saturn

Signs of life shooting from Saturn's moon could be collected with spacecraft, scientists say

ice plumes enceladus
© NASAThis artistic rendering shows ice plumes being ejected from Enceladus at major speeds.
When NASA's Cassini spacecraft turned its instruments to Saturn's moon Enceladus, it observed plumes of ice shooting up from the moon's surface at speeds of about 900 miles per hour (1,448 kilometers per hour). These geysers seemed to be the tendrils of a vast subsurface ocean — and made scientists curious if their fluid might carry life signs, organic molecules.

But if scientists want to study those organic molecules, they'll need to find a careful way of collecting them without destroying them. There is now good news on that front: If one lab experiment is correct, then any possible amino acids in those geysers' fluid are expected to easily survive contact with a spacecraft.

Researchers learned this in the lab by working with a physical apparatus designed to examine collisions. The researchers created ice particles by pushing water through a high-voltage needle; the charge fragmented the water into tiny droplets, each of which crystallized into an ice grain as it entered a vacuum. Then, the researchers shot the hardened grains through a spectrometer and imaged each grain as well as recorded impact times.

Comment: See also: Scientists discovered a crucial element for life gushing out of Saturn's icy ocean moon