Astronomers Suggest More Galaxies Were Formed in the Early Universe Than Previously Thought

By U. OF MISSOURI JANUARY 30, 2023

https://scitechdaily.com/astronomers-suggest-more-galaxies-were-formed-in-the-early-universe-than-previously-thought/

The discovery of such a vast number of galaxies in the early universe suggests a potential revision of prior knowledge on galaxy formation.

Exploring the universe’s earliest galaxies with NASA’s new space telescope.

A team of astronomers, headed by Haojing Yan at the University of Missouri, have used NASA’s James Webb Space Telescope (JWST) Early Release Observations and discovered 87 galaxies that could be the earliest known galaxies in the universe.

The discovery brings the astronomers closer to determining the appearance of galaxies in the universe, estimated to be 200-400 million years after the Big Bang, according to Yan, lead author and associate professor of physics and astronomy at MU.

“Finding such a large number of galaxies in the early parts of the universe suggests that we might need to revise our previous understanding of galaxy formation,” Yan said. “Our finding gives us the first indication that a lot of galaxies could have been formed in the universe much earlier than previously thought.”

A pair of color composite images from the galaxy cluster SMACS 0723-27 and its surrounding area taken by NASA’s James Webb Space Telescope through its Early Release Observations (ERO). A team of astronomers led by Haojing Yan at the University of Missouri used the data from these images to identify the objects of interest for their study. These include galaxies that could be the earliest known galaxies in the universe — about 200-400 million years after the Big Bang. The location of each object of interest is indicated by one of three different colored circles — blue, green, or red — on the color images. These colors correspond with the range of redshifts where they were found — high (blue), very high (green), or extremely high (red). Graphic by Haojing Yan and Bangzheng Sun. 

Credit: NASA, European Space Agency, Canadian Space Agency, and the Space Telescope Science Institute.

In the study, the astronomers searched for potential galaxies at “very high redshifts.” Yan said the concept of redshifts in astronomy allows astronomers to measure how far away distant objects are in the universe — like galaxies — by looking at how the colors change in the waves of light that they emit.

Haojing Yan. Credit: University of Missouri

“If a light-emitting source is moving toward us, the light is being ‘squeezed,’ and that shorter wavelength is represented by blue light, or blueshift,” Yan said. “But if that source [of light] is moving away from us, the light it produces is being ‘stretched,’ and changes to a longer wavelength that is represented by red light, or redshift.”

Yan said Edwin Hubble’s discovery in the late 1920s that our universe is ever-expanding is key to understanding how redshifts are used in astronomy.

“Hubble confirmed that galaxies external to our Milky Way galaxy are moving away from us, and the more distant they are, the faster they are moving away,” Yan said. “This relates to redshifts through the notion of distances — the higher the redshift an object is at, such as a galaxy, the further away it is from us.”

Therefore, Yan said the search for galaxies at very high redshifts gives astronomers a way to construct the early history of the universe.

“The speed of light is finite, so it takes time for light to travel over a distance to reach us,” Yan said. “For example, when we look at the sun, we aren’t looking at it as what it looks like in the present, but rather what it looked like some eight minutes ago. That’s because that’s how long it takes for the sun’s radiation to reach us. So, when we are looking at galaxies which are very far away, we are looking at their images from a long time ago.”

Using this concept, Yan’s team analyzed the infrared light captured by the JWST to identify the galaxies.

“The higher the redshift a galaxy is at, the longer it takes for the light to reach us, so a higher redshift corresponds to an earlier view of the universe,” Yan said. “Therefore, by looking at galaxies at higher redshifts, we are getting earlier snapshots of what the universe looked like a long time ago.”

The JWST was critical to this discovery because objects in space like galaxies that are located at high redshifts — 11 and above — can only be detected by infrared light, according to Yan. This is beyond what NASA’s Hubble Space Telescope can detect because the Hubble telescope only sees from ultraviolet to near-infrared light.

“JWST, the most powerful infrared telescope, has the sensitivity and resolution for the job,” Yan said. “Up until these first JWST data sets were released [in mid-July 2022], most astronomers believed that the universe should have very few galaxies beyond redshift 11. At the very least, our results challenge this view. I believe this discovery is just the tip of the iceberg because the data we used only focused on a very small area of the universe. After this, I anticipate that other teams of astronomers will find similar results elsewhere in the vast reaches of space as JWST continues to provide us with a new view of the deepest parts of our universe.”

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NASA, Pentagon developing nuclear-powered rocket for Mars voyage

JANUARY 24, 2023

https://phys.org/news/2023-01-nasa-pentagon-nuclear-powered-rocket-mars.html

NASA Administrator Bill Nelson.

NASA is partnering with a Pentagon research agency to develop a nuclear-powered rocket engine in preparation for sending astronauts to Mars.

NASA Administrator Bill Nelson said Tuesday that the US space agency will team up with the Defense Advanced Research Projects Agency (DARPA) to "develop and demonstrate advanced nuclear thermal propulsion technology as soon as 2027."

"With the help of this new technology, astronauts could journey to and from deep space faster than ever –- a major capability to prepare for crewed missions to Mars," Nelson said in a statement.

DARPA is the Pentagon's research and development arm and has played a role in many of the notable innovations of the 20th century including the internet.

NASA said nuclear thermal rockets can be three or more times more efficient than conventional chemical propulsion and would reduce transit time, essential for an eventual mission to Mars.

In a nuclear thermal engine, a fission reactor is used to generate extremely high temperatures.

Heat from the reactor is transferred to liquid propellant which is then converted into gas, which expands through a nozzle and provides thrust.

"DARPA and NASA have a long history of fruitful collaboration," DARPA director Stefanie Tompkins said, citing the Saturn V rocket that took the first astronauts to the Moon.

"The nuclear thermal rocket program will be essential for more efficiently and quickly transporting material to the Moon and, eventually, people to Mars," Tompkins said.

NASA conducted its last nuclear thermal rocket engine tests more than 50 years ago but the program was abandoned due to budget cuts and Cold War tensions.

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Defense News: Elbit Systems presents the Crossbow – its new 120mm turreted mortar

 

Elbit Systems presents the Crossbow – its new 120mm turreted mortar

The new mortar is scheduled to enter service in 2024 with the Israel Defense Forces (IDF), which financed its development.

By Eyal Boguslavsky, Defense News, 01/29/23

https://www.israeldefense.co.il/en/node/57044

Photo: Elbit Systems

Israel’sElbit Systems presented the Crossbow 120mm turreted mortar at Defence iQ's International Armoured Vehicles (IAV) 2023 conference, held in London this week.

According to Elbit, the weapon can be installed in a mission module with minimal protrusion, can be easily operated by a single crew member, and is fused for fully automatic operation

Elbit officials told Janes that the mortar can fire the company's range of mortar rounds, including those with an extended range and precision guidance. It has a range of 10 km and a rate of fire exceeding 12 rds/min, achieving 16 rounds for the first minute. Crossbow is designed to be fired on the move and to shoot and scoot with a multiple round simultaneous impact (MRSI) capability.

They also said that it was developed over the last three years based on Elbit's experience in ammunition, fuzes, fire control, and command, control, communications, computers, and intelligence (C4I) integration. It is scheduled to enter service in 2024 with the Israel Defense Forces (IDF), which financed its development. 

The Janes report notes that the IDF will receive dozens of Crossbows installed in Oshkosh Defense's Family of Medium Tactical Vehicles (FMTV). At IAV 2023, Elbit showed an artist's impression of Crossbow mounted on a Boxer armoured vehicle.

Elbit is marketing the Crossbow to NATO countries and partners, including for Czech CV90 tracked armoured vehicles, Austrian Pandurs, and US Stryker wheeled armoured vehicles.

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Space News: Long-distance call: Scientists find 8.8 billion-year-old galaxy signal - study

 

Long-distance call: Scientists find 8.8 billion-year-old galaxy signal - study

The signal was detected by the Giant Metrewave Radio Telescope in India and may indicate that humanity is ready to study galaxies in the farther reaches of space.

By JERUSALEM POST STAFF, JANUARY 22, 2023

https://www.jpost.com/science/article-729285

 Webb’s First Deep Field. Thousands of galaxies flood this near-infrared, high-resolution image of galaxy cluster SMACS 0723. (photo credit: NASA, ESA, CSA, STScI)

Scientists have managed to detect the earliest and farthest known radio signal from a galaxy ever discovered, with the signal having originated some 8.8 billion years ago.

The findings of this study were published in the peer-reviewed academic journal the Monthly Notices of the Royal Astronomical Society.

The signal was detected by the Giant Metrewave Radio Telescope in India and may indicate that humanity is ready to study galaxies in the farther reaches of space to get a better look at the universe's earlier years.

Talk about long-distance: Getting radio signals from different galaxies

One of the reasons scientists spend so much effort in trying to study distant galaxies is because of how time works with distance.

Basically, it takes a long time for signals sent from a galaxy to reach Earth. This means that by the time it gets to us, a considerable amount of time has passed.

 The Andromeda Galaxy is the nearest large spiral galaxy from the Earth, and contains within itself over a trillion stars. (credit: Wikimedia Commons)

Likewise, the farther away something is in space, the longer it will take.

What this all means is that the farthest galaxies will likely have the oldest messages. This is important as it acts as our best means of understanding how stars in different galaxies form.

However, the problem is that signals get weaker over time, meaning that most radio telescopes on Earth may be too weak to pick up some of them.

This latest signal was found at a very specific wavelength, known as the 21-centimeter line.

Also as the hydrogen line, this is an electromagnetic radiation spectral line created when neutral hydrogen atoms change their energy state. This is an extremely specific and precise frequency of 1420.405751768(2) MHz. 

This galaxy in question is the faraway galaxy known as SDSSJ0826+5630, and the signal itself was thought to be 8.8 billion years old, back when the universe itself was just 4.9 billion years old (it is now widely estimated to be 13.8 billion years old).

How did we pick up this galaxy's signal?

This visibility was made possible thanks to a technique called gravitational lensing. This essentially magnifies the signal and lets us look closer when the signal gets bent. This happens when there is another massive object between the signal's source and us. In this case, that other massive object was another galaxy. 

Because of this, the radio signal is essentially magnified – and in this case, it was magnified by around a factor of 30.

Now, gravitational lensing isn't anything new, and is even part of Albert Einstein's General Theory of Relativity. Scientists have used it before to conduct other studies, such as taking a look at faraway galaxies to scan for dark matter. However, this latest study shows that this technique can also help radio telescopes study galaxies farther away from Earth.

This is because, as the study notes, they expect to find more faraway and old galaxies this way thanks to gravitational lens-boosted signals just like this one. 

And like that, our understanding of the puzzle of the cosmos gets just a little bit more complete.

Radio signal from 8 billion light-years away could reveal the secrets of the universe's 'dark age'

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Saab Receives Order for AT4 Anti-Armour Weapon from France

26.01.2023

https://www.canadiandefencereview.com/news/saab-receives-order-for-at4-anti-armour-weapon-from-france

Saab received an order for the anti-armour weapon AT4 from the French Armament General Directorate (DGA). The order value is approximately EUR 24 million and deliveries will take place in 2023. The order was booked in Q4 2022.

The AT4 family is a range of lightweight, man-portable, disposable weapons characterised by ease of use. AT4 can be used against tanks and heavy combat vehicles as well as threats in buildings and fortifications and to protect fixed installations, supply points and other vital assets.

“We are proud to yet again be chosen to deliver our world class single-shot AT4 system to France. Our future ready AT4 will ensure the French armed forces have the necessary firepower to give them the advantage on the battlefield,” says Görgen Johansson, head of Saab´s business area Dynamics.

France has previously ordered Saab’s AT4CS ER (Extended Range), the AT4CS HE (High Explosive) and the AT4CS AST (Anti-Structure). The AT4 family is known as the Roquette NG (Nouvelle Génération) in France.

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Plasma thrusters used on satellites could be much more powerful than previously believed

JANUARY 24, 2023, by Kate McAlpine, U. of Michigan

https://phys.org/news/2023-01-plasma-thrusters-satellites-powerful-previously.html

The glow of the plasma from the H9 MUSCLE Hall thruster during a test with krypton propellant. 

Credit: Plasmadynamic and Electric Propulsion Laboratory

It has been believed that Hall thrusters, an efficient kind of electric propulsion widely used in orbit, must be large to produce a lot of thrust. Now, a new study from the University of Michigan suggests that smaller Hall thrusters can generate much more thrust—potentially making them candidates for interplanetary missions.

"People had previously thought that you could only push a certain amount of current through a thruster area, which in turn translates directly into how much force or thrust you can generate per unit area," said Benjamin Jorns, U-M associate professor of aerospace engineering who led the new Hall thruster study to be presented at the AIAA SciTech Forum in National Harbor, Maryland, today.

His team challenged this limit by running a 9 kilowatt Hall thruster up to 45 kilowatts, maintaining roughly 80% of its nominal efficiency. This increased the amount of force generated per unit area by almost a factor of 10.

Whether we call it a plasma thruster or an ion drive, electric propulsion is our best bet for interplanetary travel—but science is at a crossroads. While Hall thrusters are a well-proven technology, an alternative concept, known as a magnetoplasmadynamic thruster, promises to pack much more power into smaller engines. However, they are yet unproven in many ways, including lifetime.

Hall thrusters were believed to be unable to compete because of the way they operate. The propellant, typically a noble gas like xenon, moves through a cylindrical channel where it is accelerated by a powerful electric field. It generates thrust in the forward direction as it departs out the back. But before the propellant can be accelerated, it needs to lose some electrons to give it a positive charge.

https://youtu.be/jM_wcsTQxek

Electrons accelerated by a magnetic field to run in a ring around that channel—described as a "buzz saw" by Jorns—knock electrons off the propellant atoms and turn them into positively charged ions. However, calculations suggested that if a Hall thruster tried to drive more propellant through the engine, the electrons whizzing in a ring would get knocked out of the formation, breaking down that "buzz saw" function.

"It's like trying to bite off more than you can chew," Jorns said. "The buzz saw can't work its way through that much material."

In addition, the engine would become extremely hot. Jorns' team put these beliefs to the test.

"We named our thruster the H9 MUSCLE because essentially, we took the H9 thruster and made a muscle car out of it by turning it up to '11'—really up to a hundred, if we're going by accurate scaling," said Leanne Su, a doctoral student in aerospace engineering who will present the study.

They tackled the heat problem by cooling it with water, which let them see how big a problem the buzz saw breakdown was going to be. Turns out, it wasn't much trouble. Running with xenon, the conventional propellant, the H9 MUSCLE ran up to 37.5 kilowatts, with an overall efficiency of about 49%, not far off the 62% efficiency at its design power of 9 kilowatts.

Running with krypton, a lighter gas, they maxed out their power supply at 45 kilowatts. At an overall efficiency of 51%, they achieved their maximum thrust of about 1.8 Newtons, on par with the much larger 100-kilowatt-class X3 Hall thruster.

Ph.D student Will Hurley leaves the chamber where the new Hall plasma thruster is tested at the PEPL lab.

 Credit: Marcin Szczepanski/Michigan Engineering

"This is kind of a crazy result because typically, krypton performs a lot worse than xenon on Hall thrusters. So it's very cool and an interesting path forward to see that we can actually improve krypton's performance relative to xenon by increasing the thruster current density," Su said.

Nested Hall thrusters like the X3—also developed in part by U-M—have been explored for interplanetary cargo transport, but they are much larger and heavier, making it difficult for them to transport humans. Now, ordinary Hall thrusters are back on the table for crewed journeys.

Jorns says that the cooling problem would need a space-worthy solution if Hall thrusters are to run at these high powers. Still, he is optimistic that individual thrusters could run at 100 to 200 kilowatts, arranged into arrays that provide a megawatt's worth of thrust. This could enable crewed missions to reach Mars even on the far side of the sun, traveling a distance of 250 million miles.

The team hopes to pursue the cooling problem as well as challenges in developing both Hall thrusters and magnetoplasmadynamic thrusters on Earth, where few facilities can test Mars-mission-level thrusters. The amount of propellant exhausting from the thruster comes too fast for the vacuum pumps to keep the conditions inside the testing chamber space-like.

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Copper transformed way the world works before, and it's about to do so again

JANUARY 23, 2023, by D. Money and R Declercq, The Conversation

https://phys.org/news/2023-01-copper-world.html

Credit: Shutterstock

Copper is all around us. The metal is both ever-present and invisible in our world. Copper makes reading the words on this screen possible. And the global spread of artificial light, electric power and telecommunications all required ever-increasing quantities of copper.

Where does all of this copper come from? How was it produced, distributed, controlled, and sold on an ever-increasing scale? These are some of the questions addressed in a recenty published book, Born with a Copper Spoon: A Global History of Copper.

The book is a global study of a metal that has transformed the globe. Contributors to the book cover North America, Latin America, Europe, Central Africa, the Middle East, East Asia and Oceania and stretch from the early nineteenth to the early twenty-first centuries.

Why are these important questions? Because of the ubiquity of copper and the fact that the world's collective rehab from fossil fuels may cause a renewed addiction to a new mineral-based economy. Electrification, the pillar of the green transition, requires huge amounts of copper. Projections expect a doubling of copper consumption by 2035 in order to reach zero-emission energy goals. Faced with the enormous task of electrification, the share of the global energy sector will increase to 40 % of total copper consumption in the next two decades

They are also important questions because countries that have an abundance of copper have failed to benefit from it. Zambia is a case in point. It produces 6% of the world's copper but is still one of the poorest countries in the world.

Born with a Copper Spoon requires us to think differently about our material lives and energies we use, by looking at the places where our minerals are actually produced and the way in which the production and distribution of these minerals are organized.

Will the next world of copper finally evolve as the long-anticipated resource blessing, or is a new global scramble, in which states and companies seek to secure access to the precious metal, going to determine otherwise? Copper became associated with the idea of a resource curse for many people. Zambia's first President Kenneth Kaunda once remarked that his country is "paying the price for having been born with a copper spoon in our mouths."

He knew too well that the abundance of copper had caused Zambia a host of problems.

Worlds of copper

Our book looks at different 'worlds of copper' that have arisen over the last century and a half. The term 'world of copper' was first coined by British historians Chris Evans and Olivia Saunders to describe a globally integrated production system that connected the smelters of South Wales to copper mines across the globe between 1830 and 1870.

We see this as the first world of copper. This world was then supplanted by a second world of copper centered on the US. This involved the rise and dominance of American mining companies as huge integrated enterprises controlling the production, processing and distribution of the commodity. "From mine to consumer" was the slogan of the notorious American copper mining company Anaconda, active in Montana and Chile. Underpinning the American world of copper was control over the production chain through the use of new business organizations and technologies.

Technological changes in mining and processing that were quite literally ground-breaking allowed for ever-greater quantities of copper to be mined and processed. Open pit extraction was first developed in North America and soon spread to Latin America and Central Africa, with often comprehensively destructive environmental consequences. Many of these pits are still being mined today.

The American world of copper denotes both the power of American companies, as well as the model of controlling copper chains that is eagerly copied by non-American copper companies. This patterns becomes global: it is applied in Japan, the European empires that control the Copperbelt as well as in Latin America.

In the mid-twentieth century, the American world of copper disintegrated during decolonisation in the face of resource nationalism and a shifting geography of production. A wave of nationalizations by new states brought about a postcolonial world of copper, built around state power, economic sovereignty and state-level international co-operation. Developing states saw copper as their ticket to economic development and modernity. The dream of the red metal was however short-lived.

This postcolonial world of copper collapsed in the 1990s after a long slump in the industry. Multinational private companies reasserted themselves over the industry, but the US and European companies never regained their once dominant position.

Each copper world was marked by several defining features: underlying institutions, organizations, labor practices and produced by global connections and interactions. Identifying and understanding consecutive worlds of copper is crucial to how we understand the development of the global copper industry.

Our current energy transition could herald a new copper world. Renewed demand for copper will likely intensify mining activity in DR Congo, Zambia and other parts of the African continent and could place states in a stronger bargaining position.

The need to think differently

Copper's status as a global industry has waxed and waned. The history of the metal is not a story of steadily increasing and depending global connections as we move towards the present. It is also a history of disconnections and efforts to de-couple regions from the global economy.

Our book is a contribution to global history and the story of copper is necessarily a global one as extracting, refining, buying, shipping and consuming the metal takes place around the world. Global history is about more than connections, however.

Our book is also about periods of deglobalisation and attempts to sever connections, especially in the mid-twentieth century when a bitter contest over ownership of mineral resources briefly threatened a major realignment of the world economy. In 1967, several of the world's largest copper producers (Congo, Chile, Peru and Zambia) met in Lusaka to establish a copper cartel that would control the industry and turn an abundance of natural resources into national economic growth.

That's an ambition that still needs to be fulfilled.

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Earth's inner core may have started spinning other way: Study

JANUARY 24, 2023, by Daniel Lawler

https://phys.org/news/2023-01-earth-core.html

Deep below the surface, the Earth's inner core may have changed direction, new research suggests.

Far below our feet, a giant may have started moving against us.

Earth's inner core, a hot iron ball the size of Pluto, has stopped spinning in the same direction as the rest of the planet and might even be rotating the other way, research suggested on Monday.

Roughly 5,000 kilometers (3,100 miles) below the surface we live on, this "planet within the planet" can spin independently because it floats in the liquid metal outer core.

Exactly how the inner core rotates has been a matter of debate between scientists—and the latest research is expected to prove controversial.

What little is known about the inner core comes from measuring the tiny differences in seismic waves—created by earthquakes or sometimes nuclear explosions—as they pass through the middle of the Earth.

Seeking to track the inner core's movements, new research published in the journal Nature Geoscience analyzed seismic waves from repeating earthquakes over the last six decades.

The study's authors, Xiaodong Song and Yi Yang of China's Peking University, said they found that the inner core's rotation "came to near halt around 2009 and then turned in an opposite direction".

"We believe the inner core rotates, relative to the Earth's surface, back and forth, like a swing," they told AFP.

"One cycle of the swing is about seven decades", meaning it changes direction roughly every 35 years, they added.

They said it previously changed direction in the early 1970s, and predicted the next about-face would be in the mid-2040s.

The researchers said this rotation roughly lines up with changes in what is called the "length of day"—small variations in the exact time it takes Earth to rotate on its axis.

Stuck in the middle

So far there is little to indicate that what the inner core does has much effect on surface dwellers.

But the researchers said they believed there were physical links between all Earth's layers, from the inner core to the surface.

"We hope our study can motivate some researchers to build and test models which treat the whole Earth as an integrated dynamic system," they said.

Experts not involved in the study expressed caution about its findings, pointing to several other theories and warning that many mysteries remain about the center of the Earth.

"This is a very careful study by excellent scientists putting in a lot of data," said John Vidale, a seismologist at the University of Southern California.

"(But) none of the models explain all the data very well in my opinion," he added.

Vidale published research last year suggesting that the inner core oscillates far more quickly, changing direction every six years or so. His work was based on seismic waves from two nuclear explosions in the late 1960s and early 1970s.

That timeframe is around the point when Monday's research says the inner core last changed direction—which Vidale called "kind of a coincidence".

Geophysicists 'divided'

Another theory—which Vidale said has some good evidence supporting it—is that the inner core only moved significantly between 2001 to 2013 and has stayed put since.

Hrvoje Tkalcic, a geophysicist at the Australian National University, has published research suggesting that the inner core's cycle is every 20 to 30 years, rather than the 70 proposed in the latest study.

"These mathematical models are most likely all incorrect because they explain the observed data but are not required by the data," Tkalcic said.

"Therefore, the geophysical community will be divided about this finding and the topic will remain controversial."

He compared seismologists to doctors "who study the internal organs of patients' bodies using imperfect or limited equipment".

Lacking something like a CT scan, "our image of the inner Earth is still blurry", he said, predicting more surprises ahead.

That could include more about a theory that the inner core might have yet another iron ball inside it—like a Russian doll.

"Something's happening and I think we're gonna figure it out," Vidale said.

"But it may take a decade."

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Space News: NASA telescope catches black hole twisting captured star into donut shape

 

NASA telescope catches black hole twisting captured star into donut shape

The telescope was not able to capture the whole process up close because the star that was swallowed was 300 million light years away.

By JERUSALEM POST STAFF, JANUARY 22, 2023

https://www.jpost.com/science/article-729209

 

     A supermassive black hole is seen in the center of a galaxy (illustrative).(photo credit: PIXABAY)

NASA's Hubble Space Telescope recorded a black hole enveloping a star in its final moments in a donut shape, the US space agency reported earlier this month.

The incident took place in March of last year but was only reported by NASA this month.

In the report, NASA also describes the process of a star being swallowed by a black hole.

1. First, a star passes by a black hole
2. If it's close enough, the black hole pulls the star into its gravitational field
3. The star is shredded as the black hole then tears it apart
4. The remnants are then put into a ring around the black hole in the shape of a donut, and then eventually fall into the hole

Black holes also do not naturally seek out starts, the report says, but rather remain in one place until a star passes by.

Hubble Finds Hungry Black Hole Twisting Captured Star Into Donut Shape

Hubble Space Telescope unable to capture the incident up close

The telescope was unable to capture the whole process up close because the star that was swallowed was 300 million light years away, NASA said, but astronomers at the space agency still took the opportunity to study the light from the shredded star.

About 100 black hole incidents were detected by astronomers and their various telescopes. 

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Ripples in fabric of universe may reveal start of time

JAN. 20, 2023, by Raphael Rosen, Princeton Plasma Physics Laboratory

https://phys.org/news/2023-01-ripples-fabric-universe-reveal.html

Numerical simulation of the neutron stars merging to form a black hole, with their accretion disks interacting to produce electromagnetic waves. 

Credit: L. Rezolla (AEI) & M. Koppitz (AEI & Zuse-Institut Berlin)

Scientists have advanced in discovering how to use ripples in space-time known as gravitational waves to peer back to the beginning of everything we know. The researchers say they can better understand the state of the cosmos shortly after the Big Bang by learning how these ripples in the fabric of the universe flow through planets and the gas between the galaxies.

"We can't see the early universe directly, but maybe we can see it indirectly if we look at how gravitational waves from that time have affected matter and radiation that we can observe today," said Deepen Garg, lead author of a paper reporting the results in the Journal of Cosmology and Astroparticle Physics. Garg is a graduate student in the Princeton Program in Plasma Physics, which is based at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL).

Garg and his advisor Ilya Dodin, who is affiliated with both Princeton University and PPPL, adapted this technique from their research into fusion energy, the process powering the sun and stars that scientists are developing to create electricity on Earth without emitting greenhouse gases or producing long-lived radioactive waste. Fusion scientists calculate how electromagnetic waves move through plasma, the soup of electrons and atomic nuclei that fuels fusion facilities known as tokamaks and stellarators.

It turns out that this process resembles the movement of gravitational waves through matter. "We basically put plasma wave machinery to work on a gravitational wave problem," Garg said.

Gravitational waves, first predicted by Albert Einstein in 1916 as a consequence of his theory of relativity, are disturbances in space-time caused by the movement of very dense objects. They travel at the speed of light and were first detected in 2015 by the Laser Interferometer Gravitational Wave Observatory (LIGO) through detectors in Washington State and Louisiana.

Garg and Dodin created formulas that could theoretically lead gravitational waves to reveal hidden properties about celestial bodies, like stars that are many light years away. As the waves flow through matter, they create light whose characteristics depend on the matter's density.

A physicist could analyze that light and discover properties about a star millions of light years away. This technique could also lead to discoveries about the smashing together of neutron stars and black holes, ultra-dense remnants of star deaths. They could even potentially reveal information about what was happening during the Big Bang and the early moments of our universe.

The research began without any sense of how important it might become. "I thought this would be a small, six-month project for a graduate student that would involve solving something simple," Dodin said. "But once we started digging deeper into the topic, we realized that very little was understood about the problem and we could do some very basic theory work here."

The scientists now plan to use the technique to analyze data in the near future. "We have some formulas now, but getting meaningful results will take more work," Garg said.

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Technology News: TAU robot able to ‘smell’ odors like a dog using a biological sensor

TAU (Tel Aviv University) robot able to ‘smell’ Odors like a dog using a biological sensor.

Researchers have developed a biological sensor whose sensitivity rivals that of dogs – 10,000 times higher than that of existing electronic devices.

By JUDY SIEGEL-ITZKOVICH, Jerusalem Post, JANUARY 17, 2023

https://www.jpost.com/science/article-728797

          

               The robot with the biological sensor. (photo credit: Courtesy of Tel Aviv University)

Scientists believe that a dog’s sense of smell is somewhere between 10,000 to 100,000 times more acute than that of humans because for every scent receptor a human has, a dog has about 50.

Now, researchers at Tel Aviv University (TAU) have developed a biological sensor whose sensitivity rivals that of dogs. The sensor sends electrical signals as a response to the presence of a nearby odor that the robot can detect and interpret.

In this new study, the researchers successfully connected the biological sensor to an electronic system and using a machine-learning algorithm were able to identify odors with a level of sensitivity 10,000 times higher than that of a commonly used electronic device. The researchers believe that thanks to the success of their research, this technology may also be used in the future to identify explosives, drugs, diseases and more.

The biological and technological breakthrough was led by doctoral student Neta Shvil of TAU’s Sagol School of Neuroscience; Dr. Ben Maoz of Sagol and the Fleischman Faculty of Engineering; and professors Yossi Yovel and Amir Ayali of Sagol and the School of Zoology. The results of the study were published in the prestigious journal Biosensor and Bioelectronics under the title “The Locust Antenna as an odor discriminator.”

Competing with evolution

 

                      Dr. Ben Maoz and Neta Shvil. (credit: Courtesy of Tel Aviv University)

“Man-made technologies still can’t compete with millions of years of evolution,” Maoz and Ayali explained. One area in which we particularly lag behind the animal world is that of smell perception.

"An example of this can be found at the airport where we go through a magnetometer that costs millions of dollars and can detect whether we are carrying any metal devices – but when they want to check if a passenger is smuggling drugs, they bring in a dog to sniff him,” they said. In the animal world, insects excel at receiving and processing sensory signals. A mosquito, for example, can detect a 0.01 percent difference in the level of carbon dioxide in the air. Today, we are far from producing sensors whose capabilities come close to those of insects.”

The researchers noted that, in general, our sensory organs such as the eye, ear and nose – as well as those of all other animals – use receptors that identify and distinguish between different signals. Then, the sensory organ translates these findings into electrical signals, which the brain decodes as information. The challenge of biosensors is in the connection of a sensory organ, like the nose, to an electronic system that knows how to decode the electrical signals received from the receptors.

“We connected the biological sensor and let it smell different odors while we measured the electrical activity that each odor induced. The system allowed us to detect each odor at the level of the insect’s primary sensory organ,” said Yovel. “Then, in the second step, we used machine learning to create a ‘library’ of smells. In the study, we were able to characterize eight odors, such as geranium, lemon and marzipan, in a way that allowed us to know when the smell of lemon or marzipan was presented.”

After the experiment was over, they continued to identify additional different and unusual smells, such as various types of Scotch whiskey. A comparison with standard measuring devices showed that the sensitivity of the insect’s nose in our system is about 10,000 times higher than the devices that are in use today.”

“Nature is much more advanced than we are, so we should use it,” Maoz concluded. “The principle we have demonstrated can be used and applied to other senses such as sight and touch. For example, some animals have amazing abilities to detect explosives or drugs; the creation of a robot with a biological nose could help us preserve human life and identify criminals in a way that is not possible today. Some animals know how to detect diseases; others can sense earthquakes. The sky is the limit.” In future work, the researchers plan to give the robot a navigation ability to allow it to localize the odor source and later, its identity.

A scientific first: A robot able to “smell” using a biological sensor

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Visibility of stars in the night sky declines faster than previously thought

JANUARY 19, 2023, by Helmholtz Association of German Research Centres

https://phys.org/news/2023-01-visibility-stars-night-sky-declines.html

Light Pollution Impact 1—From excellent dark sky (left) to inner city sky (right). 

Credit: NOIRLab/NSF/AURA, P. Marenfeld

People around the world are seeing fewer and fewer stars in the night sky. The change in star visibility can be explained by an increase in the sky brightness of 7–10% per year. The rate of change is faster than satellite measurements of artificial light emissions on Earth would at first suggest.

This is the finding of a study published in the journal Science, conducted by a research group led by Christopher Kyba of the GFZ German Research Center for Geosciences and the Ruhr-Universität Bochum with colleagues from the GFZ and the U.S. National Science Foundation's NOIRLab.

They analyzed more than 50,000 naked-eye observations by citizen scientists around the world from 2011 to 2022 as part of the "Globe at Night" Citizen Science Project. The results show that citizen science data are an important supplement to previous measurement methods.
Light pollution background

Over a large part of the Earth's land surface, the sky continues to glow with an artificial twilight long after sunset. This "skyglow" is a form of light pollution that has serious effects on the environment and should therefore be the focus of research, as Constance Walker, co-author of the study and head of the Globe at Night project of NSF's NOIRLab since its inception, emphasizes.

After all, many behaviors and physiological processes of living creatures are determined by daily and seasonal cycles—and thus influenced by light. "Skyglow affects both diurnal and nocturnal animals and also destroys an important part of our cultural heritage," says Walker. The appearance of the night sky is changing, with negative effects on stargazing and astronomy.

https://youtu.be/boc2OoqC3rU

Credit: NOIR Lab

Need for suitable measurement methods

The change in skyglow over time has not previously been measured globally. While it could in principle be measured by satellites, the only current sensors that monitor the entire Earth do not have sufficient accuracy or sensitivity.

A promising approach is therefore to use the observational power of people using the human eye as a sensor, and in doing so—within the framework of Citizen Science experiments—to rely on the power of the crowd. The "Globe at Night" project, initiated by the U.S. National Science Foundation's NOIRLab, has been running since 2006. People all over the world can participate in this project.
Citizen Science

Participants look at their night sky, and then report which of a set of eight star charts best matches what they see using an online form. Each chart shows the sky under different levels of light pollution.

Light Pollution Impact 2—From excellent dark sky (left) to inner city sky (right). 

Credit: NOIRLab/NSF/AURA, P. Marenfeld

"The contributions of individual people work together as if they were a global sensor network, making new science possible," says Christopher Kyba from the GFZ German Research Center for Geosciences in Potsdam and the Ruhr University Bochum. Together with his GFZ colleague Yigit Öner Altıntas and Constance E. Walker and Mark Newhouse from NOIRLab, he has analyzed data from 51,351 participants around the world taken on cloud- and moon-free nights between 2011 and 2022. They were obtained from 19,262 locations worldwide, including 3,699 locations in Europe and 9,488 locations in North America.

In order to calculate a rate of change in sky brightness from this data and to take into account that the observers were also at different locations over the years, they made use of a global model for sky brightness based on satellite data from 2014.
Surprising findings

"The rate at which stars are becoming invisible to people in urban environments is dramatic," sums up Christopher Kyba, lead author of the study. The researchers found that the change in the number of visible stars can be explained by increases in night sky brightness. In Europe, they found a 6.5% increase in brightness per year matched the data; in North America, it's 10.4%.

To put these numbers into a more understandable context, Kyba explains the consequences for seeing stars in a place with a 9.6% per year increase, which was the average over all locations worldwide. "If the development were to continue at that rate, a child born in a place where 250 stars are visible will only be able to see 100 stars there on his 18th birthday."

Based on the slower growth in upward emissions seen in satellite data, the researchers were surprised by the speed of this development in skyglow. In fact, for the locations of the observers, the artificial brightness measured by satellite had slightly decreased (by 0.3% per year in Europe, by 0.8% in North America).
Causes for the difference between measurements from Earth and from space

Christopher Kyba believes that the difference between human observation and satellite measurements is probably due to changes in lighting practices. "Satellites are most sensitive to light that is directed upwards towards the sky. But it is horizontally emitted light that accounts for most of the skyglow," Kyba explains. "So, if advertisements and facade lighting become more frequent, bigger or brighter, they could have a big impact on skyglow without making much of a difference on satellite imagery."

Another factor the authors cite is the widespread switch from orange sodium vapor lamps to white LEDs, which emit much more blue light. "Our eyes are more sensitive to blue light at night, and blue light is more likely to be scattered in the atmosphere, so contributes more to skyglow," Kyba says. "But the only satellites that can image the whole Earth at night are not sensitive in the wavelength range of blue light."

Astronaut photographs of parts of Calgary (Canada) show examples of how lighting changed from 2010–2021: New lighting has been installed and many streetlights have been converted from orange high pressure sodium to white LED. (Note: The photos are not taken with the same settings, and have different spatial resolution. Thus, the 2010 photo appears somewhat brighter. 

Credit: Images courtesy of the Earth Science and Remote Sensing Unit, NASA Johnson Space Center, georeferencing by GFZ Potsdam

Limits of the study and further potential

However, the Citizen Science approach also has its limitations. For example, the number of participants from different regions of the world determines the significance of spatial and temporal trends. So far people from North America and Europe have had the largest participation in the experiment, and half of the Asian contributions come from a single country: Japan.

"The most data comes from the regions of Earth where skyglow is currently most prevalent. That's useful, but it means that we can't say much about skyglow change in regions with few observations," Kyba emphasizes. Especially in developing countries, rapid changes in artificial skyglow are suspected, but there have been few observations so far.

Two conclusions: Lighting policy and Citizen Science

The researchers draw two main conclusions from their findings: On the one hand, they show that current lighting policies, such as the use of LEDs, have not yet brought about any improvement, at least on a continental level, despite growing awareness of light pollution.

"And on the other hand, we were able to demonstrate that the Citizen Science data represent an important supplement to the previous measurement methods," Kyba says.

Constance Walker adds, "If we had broader participation, we could identify trends for other continents, and possibly even for individual states and cities. The project is ongoing, so feel free to take a look tonight and let us know what you see."

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