New study on atomic nuclei overturns 70-year-old theory
Some atomic nuclei are not shaped like rugby balls, as a longstanding theory suggests, but are instead somewhat flattened, like almonds, according to a new study by Japanese scientists.
A team from the Riken national research institute and elsewhere published this new theory recently in an international science journal. The scientists said their research results, which overturn the last 70 years of established theory on atomic nuclei shapes, could be useful for discovering new elements.
The nucleus, located in the center of an atom, is composed of protons and neutrons. The shape of a nucleus is an essential characteristic that affects its stability.
Research on atomic nuclei shapes began in the 1930s. At first, nuclei were assumed to be round like soccer balls. However, experimental results were found that could not be explained by spherical nuclei.
During the 1950s, Aage Niels Bohr, Ben Roy Mottelson and Leo James Rainwater theorized that heavy atomic nuclei have ellipsoidal shapes—like rugby balls.
This went on to become an established theory, which earned the trio the Nobel Prize in Physics in 1975.
However, Takaharu Otsuka, a Riken senior visiting scientist who led the Japanese team, said he had his first doubts about the established theory 50 years ago, the same year that Bohr and others were awarded the Nobel Prize in Physics.
Otsuka was a graduate student of nuclear physics at the time.
He said that, no matter how hard he thought, he never understood why atomic nuclei had to be shaped like rugby balls with circular sections.
'It must be like that, since everybody says so,' he said he thought at the time.
But doubts lingered in his mind.
Otsuka began studying the subject in earnest sometime around 2010.
In the latest study, the team of Japanese scientists reworked the theory on the shapes of heavy atomic nuclei by focusing on quantum theory effects and the forces acting between protons and neutrons—neither of which were considered in the 1950s.
Their study showed that an almond-like nucleus shape, with elliptical sections perpendicular to the longest axis, allows the protons and neutrons in the nucleus to be bound together more strongly, making the nucleus more stable than a rugby ball-like nucleus shape with circular sections would.
Simulations using the Fugaku supercomputer also support the new theory, the physicists said.
'I want young people to cherish any doubts that they may have, because technological advances could allow those doubts to be verified one day,' said Otsuka.
About 300 types of atomic nuclei are stable and found naturally on Earth. Some 3,000 more types have been found to exist when created artificially.
Otsuka said he believes that more than 1,000 types of atomic nuclei likely have the deformed almond shape.
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Japan Times
41 minutes ago
- Japan Times
Japanese students struggle with description-type tests
The average correct answer rate was as low as 25.6% for description-type questions in the Japanese-language section of the fiscal 2025 national achievement test for junior high school third-graders, the education ministry has said. Among such questions, students seemed to struggle especially with those asking them to write their thoughts in a way that others can understand. The fiscal 2025 achievement test for elementary school sixth-graders and junior high school third-graders was held in April, with a total of some 1.9 million students participating from about 28,000 schools nationwide. This year, the ministry released test results by gender for the first time. Female students in both elementary school sixth grade and junior high school third grade gave more correct answers to Japanese-language questions than male students. More girls than boys in both grades said that they like, are good at or understand the subject well. In the mathematics and science segments of the national test, no significant gender gaps were seen in correct answer rates. However, fewer girls than boys said that they like, are good at or understand the subjects well. These tendencies in mathematics and science were also observed in the 2023 Trends in International Mathematics and Science Study. A ministry official said that the tendencies are believed to derive from multiple factors, including gender-related unconscious bias and biological differences between males and females. The average correct answer rate for each subject had been released earlier. Among elementary school sixth-graders, the correct answer rate came to 67.0% for Japanese language, 58.2% for mathematics, and 57.3% for science. Among junior high school third-graders, the rate was 54.6% for Japanese language and 48.8% for mathematics, while the average score in science was 505.
Asahi Shimbun
4 hours ago
- Asahi Shimbun
Miso produced in 1st fermentation attempt in space tasted 'nuttier'
Miso that has been returned to Earth after being fermented in space (Provided by Maggie Coblentz) In one small step for astronaut foods and one giant leap for Japanese cuisine, miso became the first successful fermentation in space, although it had a stronger flavor than paste produced on Earth. A scientific paper was published this past spring trumpeting the success aboard the International Space Station. The U.S. and European researchers who conducted the study chose miso, instead of cheese or wine, as the food item to be fermented. An interview with leading authors of the article showed their enthusiasm for the selection of the traditional Japanese condiment. 'I think 'surreal' is the word.' 'Yeah, it was crazy.' Maggie Coblentz, a research affiliate of space food with the Massachusetts Institute of Technology Media Lab, and Joshua Evans, a senior researcher of fermented foods with the Technical University of Denmark's Center for Biosustainability, sounded excited as they were interviewed. A group of scientists including Coblentz and Evans prepared a mixture of steamed soybeans, rice koji (boiled rice fermented with the Aspergillus oryzae fungus) and salt, and put several hundred grams of the paste in a transparent, semihermetic container. They sent the mixture aboard a rocket to the International Space Station in March 2020. The space facility is under 'microgravity,' equivalent to one-10,000th to one-one-millionth of the gravity on Earth. The paste was kept for about 30 days in a special box that can sense changes in temperature, humidity, off-gassing and other conditions. The container was returned safely to Earth, even though the power supply was disrupted a few times. The scientists said they had to overcome many hurdles during the experiment. They received a succession of inquiries from the ISS operator, including on the possible toxicity of the fermentation and on potential impact on other equipment aboard the ISS. They grappled with mountains of documents to clear the rigorous safety standards one by one. That was a single-shot test, wherein the experimental equipment couldn't have been repaired even if had succumbed to abnormalities in space. The researchers were told, ahead of the rocket lift-off, that a strange smell was coming from their equipment. They explained that was just the miso, giving off a beautiful aroma. CLOSE SHAVE OF 3 DAYS The rocket was launched around the time COVID-19 was raging across the globe. Evans said that, had the lift-off been scheduled for three days later, the experiment could have been rendered impossible by the pandemic-imposed lockdowns. Analysis of samples taken from the container of the miso raw materials showed they contained microbes of the same species that are found in miso fermented on Earth. The scientists concluded, on the basis of the taste, aromas and ingredients, that miso was present. Following peer-reviews and other procedures, their article was published in iScience, a U.S. science journal, in April to describe what they label as the first food fermentation experiment in space. Western media outlets covered the topic of the 'space miso' one after another. That is considered the first time that food was fermented aboard the ISS, even though a test culture of yeast cells, wine maturing, and other processes had taken place earlier in space. The researchers said the space miso contained more glutamic acid, an umami ingredient, than miso made from the same raw materials during the same period on Earth, and had a stronger 'nutty' and 'roasted' aroma. But lactic acid bacteria and yeasts, both of which are considered essential for Japanese miso production, were not found in the space miso. A chef who has lived in Japan used the space miso residue from the experiment to prepare miso soup, which members of the research team relished. 'Bringing it to space was really exciting for us to expand the creativity and the challenge of how to cook and prepare miso,' Evans said. 'It offered me the chance to view Earth as if I were seeing it from space by proxy.' FOOD DIVERSITY INSTEAD OF BIAS Coblentz stressed food diversity as she explained why she and her colleagues chose miso for the first fermentation project in space. Western food items account for the bulk of the space food offered aboard the ISS. 'Much of the research on fermented foods has tended to be predominantly in English,' Evans said. 'There can sometimes be a bias toward Western products such as bread, cheese and wine. Why not use that platform to showcase a greater diversity of products and traditions?' Since it is said that humans have a reduced sense of taste in outer space, nutritional efficacy is the major consideration in space food. 'Something like miso is really powerful because it's so concentrated in umami, protein, and flavor, and it is very versatile culinarily,' Evans said. 'It struck us as the ideal choice.' There are expectations the latest experiment will mark a step toward food diversification, which would make long-term stays in space closer to life on Earth in the future. In addition, the experiment will also be helpful for research on fermentation processes under microgravity. The experiment used rice koji spores, an essential ingredient for miso production, that were manufactured by Bio'c Co., a seed koji maker based in Toyohashi, Aichi Prefecture. Bio'c officials said they learned of the fact only upon reading the article. 'I find it a great honor that our product was used there,' said Bio'c President Yuichiro Murai. 'Miso is popular in Western countries, where, as I have been told, many people eat it without knowing that it has its origins in Japan. I hope we will take this opportunity to advertise the charms of miso.' SAKE BREWER IN WAITING Dassai Inc., a sake brewer based in Iwakuni, Yamaguchi Prefecture, is hoping to follow on the heels of the miso fermentation by making Japanese rice wine in space. The company has plans to send a set of raw materials and equipment, aboard a domestically produced H3 rocket, to the ISS's Japanese experiment module Kibo by the end of this fiscal year. The raw materials will be placed in a special device for fermentation into 'moromi' sake mash, which will be returned to Earth in refrigerated storage, where it will be used to make a commercial product, Dassai officials said. A 100-milliliter bottle of sake from the project was put on sale, through a preorder, to the tune of about 100 million yen ($670,000). The preorder slot has already been sold, company officials added. Dassai CEO Kazuhiro Sakurai said he felt heartened by the space miso experiment, as he has ambitions to brew sake on the moon in the future. 'The fermentation process in space marks a very big step,' Sakurai said. 'Humans will need pleasures and delights when they expand their sphere of living to outer space in the future. I hope that sake has a role to play there.' Takeo Koizumi, director of the nonprofit Fermentation Culture Promotion Agency, sounded skeptical about the authenticity of the space miso. 'It remains open to question whether that could be called a miso of the sort that Japanese usually have in mind,' he said, pointing out that yeasts and other microbes were not found in the space miso. But Koizumi sounded more upbeat as he added: 'The very fact the space miso became the talk of the town across the world is a positive note for the future of Japan's fermentation culture.'
Yomiuri Shimbun
21 hours ago
- Yomiuri Shimbun
Unverified Information on Tsunami Spreads on Social Media; Japan Govt Urges Caution over Misinformation
False footage and unverified information spread on social media following tsunami warnings issued by the Japan Meteorological Agency on Wednesday, prompting the government to urge people to remain cautious about such content. Footage showing a massive tsunami, taller than a high-rise building, crashing onto the Japanese coast was posted on X. The video, which appeared to be generated by the AI, had been viewed about 330,000 times as of 8 p.m. on Wednesday. A prophecy predicting that a disaster would occur on July 5 had been circulating in Japan and China. After tsunami warnings were issued, some people posted claims saying that the prophecy had come true. The Internal Affairs and Communications Ministry posted a message on X urging people to remain cautious about false information and misinformation, saying, 'There is a risk of unverified information being distributed on the internet, such as claims that have no scientific basis.'
