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NASA

NASA-Inspired Airless Bicycle Tires Are Now Available (newatlas.com) 157

The Ohio-based Smart Tire Company has started a Kickstarter campaign for its shape memory airless bicycle tires that were created in partnership with NASA. New Atlas reports: At the heart of each Metl tire is a Slinky-like spring that runs all the way around the tire. That spring is made of a shape memory nickel-titanium alloy known as NiTinol, which is described as being strong like titanium yet also stretchy like rubber. Importantly, when NiTinol is placed under pressure, it initially deforms but then goes back to its original shape. This characteristic allows the Metl tire to gently compress and rebound, providing a smooth ride just like a pneumatic tire.

The spring is encased in a poly-rubber material which forms the tire's transparent sidewalls and replaceable tread. According to the company, this setup incorporates only half as much rubber as a regular tire. Additionally, while the tread may have to be replaced roughly every 5,000 to 8,000 miles (8,047 to 12,875 km), the main tire should reportedly last for the life of the bike. For this commercial introduction of the technology, the Smart Tire Company is offering a road/gravel tire in size choices of 700 x 32c, 35c and 38c. The 35c model is claimed to weigh 450 grams (16 oz), which is around the middle of the weight range for comparable pneumatic tires.

And we're told that while this first version of the tire will be of a fixed firmness, future models may allow users to increase the firmness by pumping in more air. So they'll be semi-pneumatic, but they will still never go completely flat. Assuming the Metl tires reach production, a pledge of $500 will get you a set of two -- getting them retreaded should cost about $10. Complete aluminum or carbon fiber Metl-clad wheelsets are also available for pledges of $1,300 and $2,300, respectively. Potential backers should note, estimated delivery isn't until next June.

NASA

Asteroid Behaving Unexpectedly After NASA's Deliberate DART Crash (bbc.co.uk) 36

One year ago NASA crashed its DART spacecraft into the asteroid "Dimorphos" (which orbits around a much larger asteroid named "Didymos"). The BBC calls the mission "part of an experiment to change the space rock's direction and test Earth's defences against asteroids in the future.

"However, a teacher and his class studying the rock have now discovered that since the collision, it has moved in a strange and unexpected way." [U]sing their school telescope, a team of children and their teacher Jonathan Swift at Thacher School in California have found that more than a month after the collision, Dimorphos' orbit continuously slowed after impact... which is unusual and unexpected. As reported in the New Scientist, the team presented their findings at a meeting of the American Astronomical Society.

After discovering the unusual behaviour of Dimorphos, it's likely that Nasa will have to factor in the high school's findings, if they ever launch another asteroid redirection mission in the future... One explanation for the asteroid's orbit continuing to change so long after the Dart collision is that material thrown up by the impact, including rocks several metres across, eventually fell back onto the surface of the asteroid, changing its orbit even more. The European Space Agency is launching a mission called Hera, which will arrive at Dimorphos in 2026 and could reveal more details as to what happened to the asteroid following the impact.

NASA

NASA's 'MOXIE' Experiment Successfully Generated 122 Grams of Oxygen on Mars (cnn.com) 70

CNN reports: The first experiment to produce oxygen on another planet has come to an end on Mars after exceeding NASA's initial goals and demonstrating capabilities that could help future astronauts explore the red planet. The microwave-size device called MOXIE, or Mars Oxygen In-Situ Resource Utilization Experiment, is on the Perseverance rover.

The experiment kicked off more than two years ago, a few months after the rover landed on Mars. Since then, MOXIE has generated 122 grams of oxygen, equal to what a small dog breathes in 10 hours, according to NASA. The instrument works by converting some of Mars' plentiful carbon dioxide into oxygen. During the peak of its efficiency, MOXIE produced 12 grams of oxygen an hour at 98% purity or better, which is twice as much as NASA's goals for the instrument. On August 7, MOXIE operated for the 16th and final time, having completed all its requirements...

Bigger and better versions of something such as MOXIE in the future could supply life support systems with breathable air and convert and store oxygen needed for rocket fuel used to launch on a return trip to Earth.

In a statement NASA applauded the performance of the MIT-created experiment. "When the first astronauts land on Mars, they may have the descendants of a microwave-oven-size device to thank for the air they breathe and the rocket propellant that gets them home...

"Rather than bringing large quantities of oxygen with them to Mars, future astronauts could live off the land, using materials they find on the planet's surface to survive."
Youtube

YouTube Under No Obligation To Host Anti-Vaccine Advocate's Videos, Court Says (arstechnica.com) 281

"12 people account for the lion's share of anti-vaccination propaganda posted to three of the leading social media outlets," NPR reported in 2021, citing a study from a London-based group opposed to online hate and disinformation."

But this week Ars Technica reports that one of those 12 "lost a lawsuit attempting to force YouTube to provide access to videos that were removed from the platform after YouTube banned his channels." Joseph Mercola had tried to argue that YouTube owed him more than $75,000 in damages for breaching its own user contract and denying him access to his videos. However, in an order dismissing Mercola's complaint, U.S. magistrate judge Laurel Beeler wrote that according to the contract Mercola signed, YouTube was "under no obligation to host" Mercola's content after terminating his channel in 2021 "for violating YouTube's Community Guidelines by posting medical misinformation about COVID-19 and vaccines."

"The court found no breach because 'there is no provision in the Terms of Service that requires YouTube to maintain particular content' or be a 'storage site for users' content,'" Beeler wrote. Because Mercola's contract with YouTube was found to be enforceable and "YouTube had the discretion to take down content that harmed its users," Beeler said that Mercola did not plausibly plead claims for breach of contract or unjust enrichment.

Mercola's complaint was dismissed without leave to amend.

Thanks to ArchieBunker (Slashdot reader #96,909) for sharing the article.
Moon

Can Japan's H2-A Rocket Deliver a Precision-Lander to the Moon? (msn.com) 9

The Washington Post reports: Japan launched a lunar mission Thursday, overcoming multiple failures and delays to become the fifth country to head to the moon — just weeks after India — in a global race to better understand Earth's closest neighbor... It is scheduled to enter the moon's orbit in three to four months and land early next year.

The rocket is carrying two space missions: a new X-ray telescope to help scientists better understand the origins of the universe and a lightweight high-precision moon lander that will serve as the basis for future moon landing technology. The telescope separated at 8:56 a.m., and the moon lander separated at 9:29 a.m...

Japan has made several attempts to reach the moon, including its Omotenashi project to land an ultrasmall probe. In November, Japan abandoned the project after failing to restore communications with the spacecraft. Earlier this year, Tokyo-based space company ispace also pulled the plug on the first Japanese private-sector attempt to land on the moon.

Japan's high-precision lander hopes to land within 328 feet (100 meters) of its target — which the article says it "much closer than conventional lunar landers, which usually have an accuracy of several kilometers."
NASA

NASA Admits 'At Current Cost Levels,' Its SLS Program is Unsustainable (arstechnica.com) 112

An anonymous reader shared this report from the senior space editor at Ars Technica: In a new report, the federal department charged with analyzing how efficiently U.S. taxpayer dollars are spent, the Government Accountability Office, says NASA lacks transparency on the true costs of its Space Launch System rocket program. Published on Thursday, the new report (see .pdf) examines the billions of dollars spent by NASA on the development of the massive rocket, which made a successful debut launch in late 2022 with the Artemis I mission. Surprisingly, as part of the reporting process, NASA officials admitted the rocket was too expensive to support its lunar exploration efforts as part of the Artemis program. "Senior NASA officials told GAO that at current cost levels, the SLS program is unaffordable," the new report states...

Moreover, the report indicates that NASA has not regularly updated its five-year production cost estimates for the rocket. The report also cites concerns about development costs of future hardware for NASA's big-ticket rocket program, including the Exploration Upper Stage. Another problem with NASA's cost estimates is that they do not appear to account for delays to Artemis missions. It is probable that the Artemis II mission, a crewed flight around the Moon, will launch no earlier than 2025. The Artemis III crewed landing will likely slip to at least 2026, if not more, with additional delays down the line...

NASA officials interviewed by the Government Accountability Office acknowledged that they were concerned about the costs of the SLS rocket. "NASA recognizes the need to improve the affordability of the SLS program and is taking steps to do so," the report states. "Senior agency officials have told us that at current cost levels the SLS program is unsustainable and exceeds what NASA officials believe will be available for its Artemis missions."

Medicine

Humanized Kidneys Grown Inside Pigs For the First Time 34

Scientists have grown humanized kidneys in pigs, raising the prospect of human organs being grown inside animals. The Guardian reports: The research involved creating human-pig chimeric embryos containing a combination of human and pig cells. When transferred into surrogate pig mothers, the developing embryos were shown to have kidneys that contained mostly human cells, marking the first time that scientists have grown a solid humanized organ inside another animal. The kidneys were not entirely human as they included vasculature and nerves made mostly from pig cells, meaning they could not be used for transplantation in their current form. It is not clear whether the challenge of making a wholly human organ would be achievable with current genetic engineering techniques.

Aside from the kidneys, the embryos were dominated by pig cells, with very few human cells in the brain or central nervous system. The potential for a humanized brain is a serious ethical concern for research involving hybrid embryos and one of the reasons for tight legal restrictions on research in many countries. [...] After being cultivated in the lab, the chimeric embryos were transferred to 13 surrogate sows. After either 25 or 28 days, the gestation was terminated and embryos were extracted and assessed. The embryos had structurally normal kidneys for their stage of development, showing the tubules that would eventually connect the kidney to the bladder, and were composed of 50-60% human cells. Very human neural cells were found in the brain and spinal cord.
The research has been published in the journal Cell Stem Cell.
Space

Starship Is Stacked and Ready To Make Its Second Launch Attempt (arstechnica.com) 89

SpaceX's Starship rocket is fully stacked and ready to launch again. According to Elon Musk, the company is just waiting for the Federal Aviation Administration (FAA) to approve the launch license. Ars Technica reports: That caveat is a big one because the Federal Aviation Administration is still reviewing paperwork and data from SpaceX about the first launch attempt of Starship in April 2023. That flight ended after about 90 seconds due to engine problems and other issues with the booster. The FAA has been reviewing data from that accident, including the environmental implications at the launch site and the delayed activation of the rocket's flight termination system. Following this accident, SpaceX prepared and submitted a "mishap investigation report" to the FAA. After reviewing the report, the FAA will identify corrective actions that the company must make ahead of its second test flight to ensure the safety of people, property, and wildlife near the South Texas launch site, which is surrounded by wetlands and the Gulf of Mexico. [...]

During the upcoming test flight, Starship will carry no payloads but will instead seek to demonstrate the performance of the booster's 33 Raptor rocket engines, stage separation, and ignition of Starship's six engines. Under a nominal flight, Starship will complete nearly three-quarters of an orbit around Earth before splashing down in the Pacific Ocean, north of the Hawaiian island of Kauai. The launch date is pending regulatory approval, but it is not expected to occur before the middle of September.

Medicine

Scientists Grow Whole Model of Human Embryo, Without Sperm Or Egg (bbc.com) 149

An anonymous reader quotes a report from the BBC: Scientists have grown an entity that closely resembles an early human embryo, without using sperm, eggs or a womb. The Weizmann Institute team say their "embryo model", made using stem cells, looks like a textbook example of a real 14-day-old embryo. It even released hormones that turned a pregnancy test positive in the lab. The ambition for embryo models is to provide an ethical way of understanding the earliest moments of our lives. This research, published in the journal Nature, is described by the Israeli team as the first "complete" embryo model for mimicking all the key structures that emerge in the early embryo.

Instead of a sperm and egg, the starting material was naive stem cells which were reprogrammed to gain the potential to become any type of tissue in the body. Chemicals were then used to coax these stem cells into becoming four types of cell found in the earliest stages of the human embryo: epiblast cells, which become the embryo proper (or foetus); trophoblast cells, which become the placenta; hypoblast cells, which become the supportive yolk sac; and extraembryonic mesoderm cells. A total of 120 of these cells were mixed in a precise ratio -- and then, the scientists step back and watch.

About 1% of the mixture began the journey of spontaneously assembling themselves into a structure that resembles, but is not identical to, a human embryo. The embryo models were allowed to grow and develop until they were comparable to an embryo 14 days after fertilization. In many countries, this is the legal cut-off for normal embryo research. The hope is embryo models can help scientists explain how different types of cell emerge, witness the earliest steps in building the body's organs or understand inherited or genetic diseases. Already, this study shows other parts of the embryo will not form unless the early placenta cells can surround it. There is even talk of improving in vitro fertilization (IVF) success rates by helping to understand why some embryos fail or using the models to test whether medicines are safe during pregnancy.

Earth

'Alarming' Scale of Marine Sand Dredging Laid Bare by New Data Platform (theguardian.com) 64

One million lorries of sand a day are being extracted from the world's oceans, posing a "significant" threat to marine life and coastal communities facing rising sea levels and storms, according to the first-ever global data platform to monitor the industry. From a report: The new data platform, developed by the UN Environment Programme (Unep), tracks and monitors dredging of sand in the marine environment by using the AIS (automatic identification systems) data from ships. Using data from 2012-19, Marine Sand Watch estimates the dredging industry is digging up 6bn tonnes of marine sand a year, a scale described as "alarming." The rate of extraction is growing globally, Unep said, and is approaching the natural rate of replenishment of 10bn to 16bn tonnes of sand flowing into the sea from rivers and needed to maintain coastal structure and ecosystems.

The platform has identified "hotspots" including the North Sea, south-east Asia and the east coast of the United States as areas of concern. In many places where extraction is more intense, including parts of Asia, marine sand is being extracted well beyond the rate at which it is being replenished from rivers. [...] Developed by GRID-Geneva, a centre for analytics within Unep, Marine Sand Watch has trained artificial intelligence to identify the movement of dredging vessels from its AIS data. It has data from 2012-19 from Global Fishing Watch, a company set up to track commercial fishing activities using AIS data from fishing vessels, but is working on more recent data.

Earth

It's Time To Put Oceans To the Test in the Climate Fight, Scientists Say (theverge.com) 98

More than 200 scientists have signed onto a letter pushing for "responsible" research into ways to trap planet-heating carbon dioxide in the world's oceans. They want to take urgent action on the climate crisis, while making sure they don't trigger any new problems by relying on oceans to help in the fight. From a report: Polluters have trashed the world's atmosphere with carbon dioxide emissions from fossil fuels. That blanket of pollution is already warming the planet and causing more extreme weather disasters. One way to keep climate change from getting worse is to take some of those historic emissions out of the atmosphere.

Oceans already do that for us, absorbing and holding around 50 times more carbon than the atmosphere. What if humans could supercharge that ability? That's what scientists want to better understand, along with any side effects that might come with messing with the chemistry of our oceans. Startups are already developing new technologies to sequester more CO2 in the sea. But there's still a lot we don't know about what impact that might have or what strategies might be most successful, the letter says.

Earth

Invasive Species Cost Humans $423 Billion Each Year and Threaten World's Diversity (theguardian.com) 57

Invasive species are costing the world at least $423bn every year and have become a leading threat to the diversity of life on Earth, according to a UN assessment. From a news report: From invasive mice that eat seabird chicks in their nests to non-native grasses that helped fuel and intensify last month's deadly fires in Hawaii, at least 3,500 harmful invasive species have been recorded globally in every region, spread by human travel and trade. Their impact is destructive for humans and wildlife, sometimes causing extinctions and permanently damaging the healthy functioning of an ecosystem.

Leading scientists say the threat posed by invasive species is under appreciated, underestimated and sometimes unacknowledged, with more than 37,000 alien species now known to be introduced around the world and about 200 establishing themselves each year. While not all will become invasive, experts say there are significant tools to mitigate their spread and impact, protecting and restoring ecosystems in the process.

"Invasive alien species are a major threat to biodiversity and can cause irreversible damage to nature, including local and global species extinctions, and also threaten human wellbeing," wrote Prof Helen Roy, Prof Anibal Pauchard and Prof Peter Stoett, who led the research. "It would be an extremely costly mistake to regard biological invasions only as someone else's problem," said Pauchard. "Although the specific species that inflict damage vary from place to place, these are risks and challenges with global roots but very local impacts facing people in every country, from all backgrounds and in every community -- even Antarctica is being affected."

Power

Scientists Finally Know Why Germany's Wild Boar Are Surprisingly Radioactive (msn.com) 54

An anonymous reader shared this report from the Washington Post: On April 26, 1986, the infamous explosion at a Chernobyl nuclear power plant unleashed large amounts of radiation into the atmosphere, an event that contaminated wildlife across country lines. The radiation levels seen in animals as a result has decreased in recent years — with the exception of one animal: the wild boar. For years, scientists questioned why levels of a radioactive isotope known as cesium-137 have remained surprisingly high in wild boars rooting around Germany and Austria, while decreasing in other deer and roe deer. In a new study released last week, a team of researchers finally solved this "wild boar paradox."

They uncovered that the main radioactive source is not the Chernobyl accident but nuclear weapons testing from the 1960s...

Radioactive cesium results from both nuclear weapons explosion and nuclear energy production. The element comes in different isotopic composition, cesium-135 and cesium-137, depending on the source. By analyzing the ratio of these amounts, the researchers can pinpoint the source of the radiation... In the nearly 50 collected meat samples, the team found 88 percent of the samples were above Germany's regulatory limits for radioactive cesium in food. Calculating the ratio of cesium isotopes in the samples, they found that nuclear weapons testing accounted for 10 to 68 percent of the contamination. Even if the Chernobyl accident had never happened, "some of the wild boars would actually still exceed the regulatory limits for food safety limits only because of the weapons tests today," said Georg Steinhauser, a radiochemist at TU Wien and author of the new study. "I think this is pretty mind-blowing because they were 60 years ago."

Steinhauser said the wild boars probably ingested the cesium from contaminated deer truffle mushrooms, which they dig up and eat during the winter when corn and acorns on the ground are scarce. Cesium seeps through the soil and is absorbed by the mushrooms, as if it were a nutrient. This also explains why observations show radioactivity levels in wild boar are higher in the winter. While cesium from both the nuclear weapons testing and the Chernobyl accident spread through the soil, Steinhauser said, the mushrooms appear to have fully absorbed the source from the nuclear weapons testing so far. Cesium seeps very slowly through the soil, sometimes only one millimeter per year, he said. Deer truffles, located between 20 and 40 centimeters, have already absorbed the "older" cesium from six decades ago. The "younger" cesium from Chernobyl has likely not fully integrated or is just now integrating at the soil depths where the mushrooms are located. But it could be bad news when the cesium from Chernobyl does reach the mushrooms — radioactivity levels could go up higher.

The study's author says his study isn't arguing for or against the use of nuclear energy — but does say that "it has to be done responsibly." He calls the study's results "a cautionary tale that we have to take good care of our environment," said Steinhauser. "Once released, a radioactive substance can never be unreleased again — and nature doesn't forget."
Space

How a Billion-Dollar Satellite Risks Upending the Space Insurance Industry (yahoo.com) 86

"Viasat Inc. has more than $1 billion of orbiting satellites in trouble," reports Bloomberg, "and space insurers are girding for market-rattling claims." The company's roughly $1 billion ViaSat-3 Americas satellite, central to expanding its fixed-broadband coverage and fending off rivals including Elon Musk's Starlink, suffered an unexpected problem as it deployed its antenna in orbit in April. Should Viasat declare it a total loss, industry executives estimate the claim would reach a record-breaking $420 million and, in turn, make it harder — and more expensive — for other satellite operators to get insurance... Viasat on Aug. 24 reported another stricken spacecraft, saying its Inmarsat-6 F2 satellite launched in February suffered a power problem. The failure may end the craft's useful life and result in a $350 million insurance claim, Space Intel Report said.

Viasat's troubles in orbit come a few years after big-name insurers like American International Group Inc. and Allianz SE have shuttered their space portfolios. That's left a smaller pool of providers to absorb the risks in the notoriously high-stakes $553 million market...

Following news of the Inmarsat-6 anomaly, Viasat and other industry participants "will likely experience significant challenges with obtaining insurance for future satellite launches," [investment banking firm] William Blair's Louie DiPalma said in an Aug. 25 note... In 2019, the total losses from satellite claims amounted to $788 million, which overwhelmed the total premiums for the year at $500 million, according to launch and satellite database Seradata. In the years that followed, big names like American International Group Inc., Swiss Re AG, and Allianz SE all closed the door on satellite insurance.

Earlier this month Viasat's CEO says before deciding whether they'll file a claim, "There's no consequences to us taking another couple or three months to get good measurements and then making those decisions."
Moon

Mission Accomplished, India Puts Moon Rover to 'Sleep' for 14 Days (reuters.com) 34

To complete one full rotation around its axis it takes the moon 655 hours. So a single "lunar day" is 13.64 earth days.

But sunset has finally come for India's Chandrayaan-3 spacecraft and its Pragyan rover, writes long-time Slashdot reader Geoffrey.landis , and the rover has switched off for the coming 655-hour night: With luck from the moon gods, it will wake up with the sunrise in 14 days. But, even if not, mission accomplished! It was designed for fourteen days of operation, the daylight period. In that time the rover accomplished just over a hundred meters (American units: one football field) of traverse, examining and chemically analyzing the surface.
"The Indian Express newspaper said the electronics on board the Indian moon mission werenâ(TM)t designed to withstand very low temperatures, less than -120 C (-184 F) during the nighttime on the moon," according to the Associated Press. But the rover's accomplishments already include making the first-ever measurements of the south pole's near-surface Lunar plasma, and confirming the presence of aluminum, calcium, chromium, titanium, manganese, and silicon. There's also sulphur, iron, oxygen and other elements on the moon, Reuters reports, citing a statement from the Indian Space Research Organisation (ISRO): The Pragyan rover from the Chandrayaan-3 spacecraft was "set into Sleep mode" but with batteries charged and receiver on, the ISRO said in a post on X, formerly Twitter, late on Saturday. "Hoping for a successful awakening for another set of assignments!" ISRO said. "Else, it will forever stay there as India's lunar ambassador."
Earlier this week the ISRO posted footage of the rover completing a near-pirouette to search for the safest route.

"The solar panel is oriented to receive the light at the next sunrise expected on September 22, 2023," the ISRO posted Saturday.
Biotech

A Biotech Company Says It Put Dopamine-Making Cells Into People's Brains 30

A biotech company has conducted a small-scale trial involving the implantation of lab-made neurons into the brains of 12 people with Parkinson's disease. The implanted neurons are designed to produce dopamine, which is deficient in Parkinson's patients, and early data suggests they may have survived and improved symptoms in some cases. MIT Technology Review reports: The study is one of the largest and most costly tests yet of embryonic-stem-cell technology, the controversial and much-hyped approach of using stem cells taken from IVF embryos to produce replacement tissue and body parts. The replacement neurons were manufactured using powerful stem cells originally sourced from a human embryo created an in vitro fertilization procedure. According to data presented by Henchliffe and others on August 28 at the International Congress for Parkinson's Disease and Movement Disorder in Copenhagen, there are also hints that the added cells had survived and were reducing patients' symptoms a year after the treatment.

These clues that the transplants helped came from brain scans that showed an increase in dopamine cells in the patients' brains as well as a decrease in "off time," or the number of hours per day the volunteers felt they were incapacitated by their symptoms. However, outside experts expressed caution in interpreting the findings, saying they seemed to show inconsistent effects -- some of which might be due to the placebo effect, not the treatment. Because researchers can't see the cells directly once they are in a person's head, they instead track their presence by giving people a radioactive precursor to dopamine and then watching its uptake in their brains in a PET scanner.
"It is encouraging that the trial has not led to any safety concerns and that there may be some benefits," says Roger Barker, who studies Parkinson's disease at the University of Cambridge. But Barker called the evidence the transplanted cells had survived "a bit disappointing."

He said the results were not so strong, adding that it's "still a bit too early to know" whether the transplanted cells took hold and repaired the patients' brains.
Education

CalTech To Accept Khan Academy Success As Option For Admission (latimes.com) 35

"Given that too many schools don't teach calculus, chemistry and physics, CalTech is allowing potential undergraduates to demonstrate their ability in these fields by using Khan Academy," writes Slashdot reader Bruce66423. Los Angeles Times reports: One of Caltech's alternative paths is taking Khan Academy's free, online classes and scoring 90% or higher on a certification test. Sal Khan, academy founder, said Caltech's action is a "huge deal" for equitable access to college. While Caltech is small -- only 2,400 students, about 40% of them undergraduates -- Khan said he hoped its prestigious reputation would encourage other institutions to examine their admission barriers and find creative solutions to ease them. The Pasadena-based institute, with a 3% admission rate last year, boasts 46 Nobel laureates and cutting-edge research in such fields as earthquake engineering, behavioral genetics, geochemistry, quantum information and aerospace. "You have one of the most academically rigorous schools on the planet that has arguably one of the highest bars for admission, saying that an alternative pathway that is free and accessible to anyone is now a means to meeting their requirements," said Khan, whose nonprofit offers free courses, test prep and tutoring to more than 152 million users. [...]

The impetus for the policy change began in February, when Pallie, the admissions director, and two Caltech colleagues attended a workshop on equity hosted by the National Assn. for College Admission Counseling. They were particularly struck by one speaker, Melodie Baker of Just Equations, a nonprofit that seeks to widen math opportunities. As Baker pointed out the lack of access to calculus for many students, Pallie and her team began to question Caltech's admission requirement for the course, along with physics and chemistry. Pallie and Jared Leadbetter, a professor of environmental microbiology who heads the faculty admissions committee, began to look into potential course alternatives. Pallie connected with Khan's team, which started a second nonprofit, Schoolhouse.world, during the pandemic in 2020 to offer free tutoring. Peer tutors on the platform certify they are qualified for their jobs by scoring at least 90% on the course exam and videotaping themselves explaining how they solved each problem on it. The video helps ensure that the students actually took the exam themselves and understand the material. That video feature gave Caltech assurances about the integrity of the alternative path.

Under the new process, students would take a calculus, physics or chemistry class offered by Khan Academy and use the Schoolhouse platform to certify their mastery of the content as tutors do with a 90% score or better on the exam and a videotaped explanation of their reasoning. Proof of certification is required within one week of the application deadline, which is in November for early action and January for regular decisions. Pallie and Leadbetter also wanted to test whether the Khan Academy courses are sufficiently rigorous. Several Caltech undergraduates took the courses to assess whether all concepts were covered in enough breadth and depth to pass the campus placement exams in those subjects. Miranda, a rising Caltech junior studying mechanical engineering, took the calculus course and gave it a thumbs-up, although she added that students would probably want to use additional textbooks and other study materials to deepen their preparation for Caltech.

Space

India Seeks To Top Its Moon Landing with Spacecraft To Study Sun (bloomberg.com) 18

Hot on the heels of its lunar landing success, India is readying to blast a probe even deeper into space to study the sun. From a report: The country's first solar observation mission, named Aditya-L1, is set to be launched from India's main spaceport on Sriharikota, an island off the southern state of Andhra Pradesh, at 11:50 a.m. local time on Saturday. The spacecraft is scheduled to spend 125 days traveling 1.5 million kilometers (932,000 miles) to its destination, a point in space where objects stay put and consume less fuel.

While arriving there would be an impressive achievement for ISRO, the Indian space agency, Aditya-L1 would have gone just a fraction of the 150 million km between Earth and the sun. For ISRO, success would be another major feat after India became the first country to land a spacecraft close to the lunar south pole in August. India has more ambitious projects in the works. A human spaceflight program aims to launch astronauts into orbit for the first time possibly by 2025, ISRO Chairman S Somanath said in an interview with news agency Asian News International. ISRO and NASA plan to cooperate on sending astronauts to the International Space Station and India is in discussions with Japan to work together on a mission.

Earth

Japan is Preparing For a Massive Earthquake (economist.com) 15

The centenary of the Great Kanto earthquake brings angst, and lessons for the world. From a report: Every year on September 1st, Japan's ministers trek by foot to the prime minister's office to take part in a crisis simulation. Across the country, local officials and schoolchildren drill for disasters. The date marks the Great Kanto earthquake, a 7.9-magnitude tremor that struck near the capital back in 1923. The ensuing disaster killed at least 105,000 people, including around 70,000 in Tokyo itself, destroyed 370,000 homes and changed the course of Japanese history.

This year's centenary of the disaster has occasioned much commemoration -- and angst. What will happen when the next Big One hits? Seismologists cannot predict earthquakes, but their statistical models, which are based on past patterns, can estimate the likelihood of one. The city government's experts reckon there is a 70% chance of a magnitude 7 or higher quake hitting the capital within the next 30 years. Far fewer people will probably die than during the disaster in 1923, thanks to better technology and planning: the worst case foresees some 6,000 deaths in the city. But millions of lives will be upended.

Another, similarly likely scenario could be much worse. A Nankai Trough earthquake, envisaged south of Kansai, Japan's industrial heartland, could trigger a tsunami; as many as 323,000 might be killed, according to an official estimate. Japan's approach to the risks of such catastrophes offers insights for a warming world facing more frequent disasters. Quakes of this size could "challenge the survival of Japan as a state" and send economic shock waves around the globe, says Fukuwa Nobuo of Nagoya University. After the next Tokyo quake, recovering basic city functions could take weeks and rebuilding the capital could take years; direct damage alone could run to as much as $75bn. One piece of research estimates that gdp would dip by 11% following a Nankai earthquake.

Science

Humanity's Ancestors Nearly Died Out, Genetic Study Suggests (nytimes.com) 64

Researchers in China have found evidence suggesting that 930,000 years ago, the ancestors of modern humans suffered a massive population crash. They point to a drastic change to the climate that occurred around that time as the cause. The New York Times: Our ancestors remained at low numbers -- fewer than 1,280 breeding individuals -- during a period known as a bottleneck. It lasted for over 100,000 years before the population rebounded. "About 98.7 percent of human ancestors were lost at the beginning of the bottleneck, thus threatening our ancestors with extinction," the scientists wrote. Their study was published on Thursday in the journal Science.

If the research holds up, it will have provocative implications. It raises the possibility that a climate-driven bottleneck helped split early humans into two evolutionary lineages -- one that eventually gave rise to Neanderthals, the other to modern humans. But outside experts said they were skeptical of the novel statistical methods that the researchers used for the study. "It is a bit like inferring the size of a stone that falls into the middle of the large lake from only the ripples that arrive at the shore some minutes later," said Stephan Schiffels, a population geneticist at Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

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