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Tuesday, March 21, 2023

The early universe was crammed with stars 10,000 times the size of our sun, new study suggests

An illustation showing a twinkling burst of starlight at the center of a turbulent field of crackling orange radiation and glowing black holes. (Image credit: ESA)

The first stars in the cosmos may have topped out at over 10,000 times the mass of the sun, roughly 1,000 times bigger than the biggest stars alive today, a new study has found.

Nowadays, the biggest stars are 100 solar masses. But the early universe was a far more exotic place, filled with mega-giant stars that lived fast and died very, very young, the researchers found.

And once these doomed giants died out, conditions were never right for them to form again.

The cosmic Dark Ages

More than 13 billion years ago, not long after the Big Bang, the universe had no stars. There was nothing more than a warm soup of neutral gas, almost entirely made up of hydrogen and helium. Over hundreds of millions of years, however, that neutral gas began to pile up into increasingly dense balls of matter. This period is known as the cosmic Dark Ages.

In the modern day universe, dense balls of matter quickly collapse to form stars. But that’s because the modern universe has something that the early universe lacked: A lot of elements heavier than hydrogen and helium. These elements are very efficient at radiating energy away. This allows the dense clumps to shrink very rapidly, collapsing to high enough densities to trigger nuclear fusion – the process that powers stars by combining lighter elements into heavier ones.

But the only way to get heavier elements in the first place is through that same nuclear fusion process. Multiple generations of stars forming, fusing, and dying enriched the cosmos to its present state.

Without the ability to rapidly release heat, the first generation of stars had to form under much different, and much more difficult, conditions.

Stars form when clouds of dust and gas collapse, triggering nuclear fusion inside the dense balls of material. (Image credit: NASA/ESA/Hubble Heritage Team (STScI/AURA))

Cold fronts

To understand the puzzle of these first stars, a team of astrophysicists turned to sophisticated computer simulations of the dark ages to understand what was going on back then. They reported their findings in January in a paper published to the preprint database arXiv(opens in new tab) and submitted for peer review to the Monthly Notices of the Royal Astronomical Society.

The new work features all the usual cosmological ingredients: Dark matter to help grow galaxies, the evolution and clumping of neutral gas, and radiation that can cool and sometimes reheat the gas. But their work includes something that others have lacked: Cold fronts – fast-moving streams of chilled matter – that slam into already formed structures.

The researchers found that a complex web of interactions preceded the first star formation. Neutral gas began to collect and clump together. Hydrogen and helium released a little bit of heat, which allowed clumps of the neutral gas to slowly reach higher densities.

But high-density clumps became very warm, producing radiation that broke apart the neutral gas and prevented it from fragmenting into many smaller clumps. That means stars made from these clumps can become incredibly large.

This artist's impression shows the blast from a heatwave detected in a massive, forming star. (Image credit: Katharina Immer/JIVE)

Supermassive stars

These back-and-forth interactions between radiation and neutral gas led to massive pools of neutral gas– the beginnings of the first galaxies. The gas deep within these proto-galaxies formed rapidly spinning accretion disks – fast-flowing rings of matter that form around massive objects, including black holes in the modern universe.

Meanwhile, on the outer edges of the proto-galaxies, cold fronts of gas rained down. The coldest, most massive fronts penetrated the proto-galaxies all the way to the accretion disk.

These cold fronts slammed into the disks, rapidly increasing both their mass and density to a critical threshold, thereby allowing the first stars to appear.

Those first stars weren't just any normal fusion factories. They were gigantic clumps of neutral gas igniting their fusion cores all at once, skipping the stage where they fragment into small pieces. The resulting stellar mass was huge.

— Astronomers catch rare glimpse of oldest known supernova, which dates back to Year 185

— James Webb Space Telescope reveals packed stars in Milky Way's oldest cluster (photos)

Those first stars would have been incredibly bright and would have lived extremely short lives, less than a million years. (Stars in the modern universe can live billions of years). After that, they would have died in furious bursts of supernova explosions.

Those explosions would have carried the products of the internal fusion reactions – elements heavier than hydrogen and helium – that then seeded the next round of star formation. But now contaminated by heavier elements, the process couldn't repeat itself, and those monsters would never again appear on the cosmic scene.

Originally published on LiveScience.com.

New Yorkers friendlier than expected as robots take out the trash

by Peter Grad , Tech Xplore

A quick search of stereotypes of New Yorkers yields one characteristic that turns up most frequently: rudeness.

So it might come as a surprise that a recent study by Cornell University researchers found New Yorkers were, in fact, quite engaging, helpful and kind to two visitors at a busy spot in Greenwich Village last fall.

The visitors were two robotic trash cans.

Researchers Fanjun Bu and Ilan Mandel said they wanted to "study people's interactions with autonomous everyday objects."

"By studying interactions with robots in public spaces," they said, "we can better understand the range of behaviors and norms that robots will need to manage autonomously in longer-term deployments."

The report was presented at the Conference on Human-Robot Interaction in Stockholm last week, and was published as a Companion of the 2023 ACM/IEEE International Conference on Human-Robot Interaction.

Among their findings were that people welcomed the robots and were appreciative of their assistance. Some sought to "help" the robots by offering trash and moving obstacles from their path. Pedestrians even invested the robots with humanlike intentions, assuming, for instance, that wobbling motions were signals of appreciation, when in fact the motions were simply due to uneven pavement.

Notably, the design of the robots was not humanlike. They were constructed simply, with no face-like features, but simply a standard 32-gallon can on a hoverboard base containing a Raspberry Pi 4 mini computer and a 360-degree camera on top. Social interactions were thus based primarily on the robot's functionality, and not on any humanizing appearances.

On-site research assistants controlled the robots' movements.

The robotic trashcans encouraged social interaction, the researchers say.

"Strangers instigated conversations" about the potential roles of robots, they observed. One woman eating lunch at a table turned to another and said, "I guess it knows I've been sitting here long enough, I should give it something."

Bu and Mandel also reported that using more than one robot "change[d] the interaction paradigms at play." Some waved at the cans to come to them so they could dispose of waste.

But the appearance of a second robot led them to a new dynamic. People assumed the robots were aware of each other's existence. They also perceived competition between the cans, as one raced to a human immediately after the other can approached. This was another example of people assigning human characteristics, in this case goal-attainment, to the robots.

Some helped the cans straighten out when they were caught on uneven surfaces.

But, this being New York, not everyone was delighted. Some greeted the mobile garbage bins with, well, trash talk.

"That's creepy. That's just freaking creepy," one woman said, recoiling upon sighting an approaching can. Another chastised a recycling can for accepting non-recyclable trash. "Bad boy," he said.

Another person offered an impolite hand gesture that left no doubt he preferred to be left alone. And one other aggressively kicked the can over.

But humanity won in the end, and with it our hopes that one day humans and environmental endeavors such as mechanized wastebaskets may peacefully coexist as a video accompanying the report showed a little girl walking right up to one of the robots, blowing a kiss and waving goodbye.

More information: Fanjun Bu et al, Trash Barrel Robots in the City, Companion of the 2023 ACM/IEEE International Conference on Human-Robot Interaction (2023). DOI: 10.1145/3568294.3580206

Robots can help improve mental well-being at work—as long as they look right

Fate of 1,000 trafficked lab monkeys at center of US investigation in limbo

Long-tailed macaques at risk of being killed, or laundered or re-trafficked if returned to Cambodia, animal welfare groups say

Claire Colley and Sophie Kevany

Mon 20 Mar 2023

More than a thousand Cambodian monkeys at the center of a US government investigation into wildlife trafficking are at risk of being killed or returned to their country of origin, laundered and re-trafficked, animal welfare groups say.

The monkeys’ plight first came to light last year when the US Fish and Wildlife Service (FWS) asked the animal rights organization Peta about finding a sanctuary for 360 monkeys. Born Free USA, and the US Department of Justice (DoJ) later joined the discussions and the number of monkeys increased to over 1,000 as talks progressed.

Last week, however, discussions stalled when Peta learned on 13 March that the monkeys would instead be flown out of the US.

Under US law the monkeys can only return to their country of origin, Cambodia, said Dr Lisa Jones-Engel of Peta, but neither the DoJ nor the FWS has confirmed this.

The 1,000 or so juvenile long-tailed macaques are understood to be at a primate center in Houston, Texas, owned by Charles River Laboratories, a US company that buys, sells and tests on animals.

Charles River was recently drawn into a US government monkey trafficking investigation that saw several Cambodian officials charged by the DoJ last November for selling wild macaques, falsely labeled as farmed, to US research laboratories. Two unnamed US co-conspirators were also indicted.

Last Wednesday an apparent attempt to transport the 1,000 monkeys out of the US was thwarted by a Peta-organised protest demanding the monkeys be sent to a sanctuary.

Two days later Charles River told the Guardian they would be keeping the monkeys at their center. But, with the company blocked by the US government from selling or carrying testing on the animals until their non-wild status is confirmed, only three options are open to the US government, said Jones-Engel: “Seize and remove to a sanctuary, kill them, or allow re-export.”

During a 22 February conference call about company earnings, James Foster, Charles River CEO, announced the company had been subpoenaed by the DoJ on 17 February as part of its investigations. The company’s share price fell 14% on the day of his announcement.

Foster said Charles River was holding Cambodian monkeys but could not use them until the company proved to the DoJ they were captive bred. According to Peta, the shipment of 1,000 monkeys is worth approximately $30m. Foster also said the Cambodian supplier indicted in November was not one the company works with.

According to the DoJ indictment, at least 2,600 wild macaques are suspected of entering the USA lab system on false permits since 2018. The Guardian recently revealed that primates entering the USA from Cambodia could be carrying highly pathogenic diseases including one deemed a bioterrorism risk.

The US National Association for Biomedical Research recently revealed that the FWS had proposed new DNA testing of all imports to affirm the animals are not wild caught. This has delayed the release of thousands of animals into laboratories.

The US currently imports approximately 30,000 primates a year for research and testing, 60% are usually from Cambodia. The long-tailed macaque was elevated from “vulnerable” to “endangered” in 2022, in part due to exploitation by the research industries.

Any return of the monkey to Cambodia effectively means a return to those suspected of illegally exporting them, said Liz Tyson of Born Free, and involves the risk of a resale, potentially to Charles River or other US labs.

“The monkeys’ future if they are shipped back to Cambodia has no happy ending. Sanctuary in the US is the only way to guarantee their safety,” Tyson told the Guardian. “These young monkeys are scared, stressed, they are suffering right now,” added Tyson.

The US National Association for Biological Research has said that non-human primates remain a critical resource for the United States biomedical research. They warned that halting the import of Cambodian monkeys and additional complications, including worsening China-US relations and animal activist campaigns, mean “the drug development pipeline is grinding to a halt”. Long-tailed macaques are the primate species most often used for toxicology testing in chemical and drug development.

However, some studies show that primates are poor predictors of results in humans and in response, Congress recently passed the FDA Modernization Act which removes the legal requirement to test on animals before human clinical trials.

New, animal free methodologies like cell-based and “organ-on-chip” tests, are increasingly being utilized by scientists.

“The ill-conceived era of relying on stolen, diseased, distressed monkeys to cure human disease has never worked and is coming to an end, hopefully in time for these species to recover in their natural habitats,” said Jones-Engel.

The DoJ declined to comment any ongoing investigation and FWS said: “As a party to the Cites convention, the Service is required to uphold our Cites obligations. This includes not allowing wild caught macaques to be illegally imported into the United States in violation of the Treaty.”

Charles River said in an email it was “steadfastly opposed to the illegal importation of non-human primates that are not purpose-bred into the United States”.

Asked about the investigation, the spokesperson said Charles River has “operated under the belief that all shipments of NHPs [non-human primates] that we received satisfied the material requirements, documentation and related processes and procedures” required by international regulations.

The statement added that the company was cooperating fully with the US government.

In case affecting oil, Norway Supreme Court says EU ships cannot fish Arctic snow crab

Credit: REUTERS/NTB SCANPIX

March 20, 2023 —

Written by Gwladys Fouche for Reuters ->

Ruling has implications for oil, minerals

Non-EU Norway has sovereignty over Svalbard Arctic islands

OSLO, March 20 (Reuters) - Norway's Supreme Court ruled on Monday that EU ships cannot fish for snow crab off the Svalbard archipelago in the Arctic, in a case also deciding who has the right to explore for oil and minerals in the region.

At stake was whether EU vessels had the right to catch snow crab, whose meat is considered a delicacy by gourmets in Japan and South Korea, in the same way as Norwegian vessels did.

But what is valid for the snow crab, a sedentary species living on the seabed, is also valid for oil, minerals and other resources, the Supreme Court ruled in a 2019 case.

A Latvian fisheries company applied to the non-EU country in 2019 for a fishing licence to catch the species, but was turned down on the basis that only Norwegian vessels can.

The Latvian firm argued it had that right under the 1920 Svalbard Treaty, which grants Norway sovereignty over the Arctic islands with the condition that other signatories have access to their territorial waters.

If it had won that right, it would have meant other states than Norway would have had the right of access to the natural resources on the continental shelf around Svalbard.

(Reporting by Gwladys Fouche, editing by Terje Solsvik)

Thailand has found its missing radioactive cylinder. That’s where the good news ends

Ananya Bhattacharya
Mon, March 20, 2023

Picture of the missing cylinder

Thai authorities found a radioactive cylinder that was reported missing earlier this month. The bad news is that the object was no longer intact.

The steel tube containing Caesium-137 went missing from a power plant in the Prachin Buri province, where it was used for ash measurements. It was found after authorities detected radioactive readings at Prachin Buri’s largest steel foundry on Sunday (Mar. 19), Bangkok’s English-language daily The Nation Thailand reported, citing provincial governor Ronnarong Nakornjinda.

Officials were hopeful the tube would be found untouched–much like in the case of a cylinder Caesium-137 drum that was misplaced and found six days later on an outback highway in Australia in January. If opened, the salt-like material inside could easily scatter and pose severe health risks from rashes and burns in the short-term to high risk of cancer in the long-run, the Office of Atoms for Peace secretary Permsuk Sutchaphiwat had warned earlier.

Unfortunately, that scenario now appears to be a reality. The readings came from scrap metal that had already been compressed into cubes ready to be smelted on Sunday evening.

Operations at the foundry have been halted, and all employees have been asked to leave. The authorities have also set up a perimeter to stop outsiders from entering. Workers at the now-shut metal plant will undergo urine tests and be monitored for signs of radiation exposure, Opas Karnkawinpong, permanent secretary of the Ministry of Public Health, told reporters on Monday, as Bloomberg reported.

Thai citizens want to know more about the radioactive tube

The Thai government did not provide a timeline of when the case was smelted, nor did it share details of how much radioactive material was released.

Enraged citizens are tweeting about the mishandling of information dissemination, saying the government isn’t giving them enough information in a timely manner. The government has tried to abate fears by saying it found “no radioactive contamination” in the area, and no cases of radiation have been reported at any clinics or hospitals.

Thailand’s missing Caesium-137 tube, by the digits

30 years: The long half life of Caesium-137. (Half life measures the time taken for the radioactivity of an isotope to fall to half its original value.)

300 years: How long Caesium-137 can remain in the environment

25 kilograms: Size of the Caesium-137 cylinder that went missing.

50,000 baht ($1,450): Cash reward for anyone who could provide information about the cylinder, offered by Kittiphan Chitpentham, a representative of the National Power Supply Public Co.

100,000 baht ($2,936): The fine, along with a maximum one year in prison, that the power plant operator—National Power Plant 5A Co.—will have to face if it is found guilty of delayed reporting of missing radioactive material. It was thought to have gone missing in mid-February but only reported to be hunted down starting March 10.

Throwback: Missing cobalt-60 in Thailand

In 2000, workers stole cobalt-60 cylinders from discarded X-ray machines. A garbage scavenger then sold it to a scrap dealer, who broke the tube, scattering parts in the junkyard. Five workers at the scrapyard and four waste collectors ended up in hospital with radiation sickness. More than 1,800 people in the area were exposed to harmful radiation.

Offering some respite, deputy secretary general Pennapa Kanchana says that this time’s missing cylinder is far less radioactive than the incident in 2000.