↩ Accueil

Vue normale

Reçu aujourd’hui — 25 décembre 2025

Concerns about ageing society ignore huge opportunities, says population expert

25 décembre 2025 à 13:00

Sarah Harper says society must create new ways of living and working amid potential ‘silver economy’

Concerns over an ageing population are overblown and society should learn to celebrate and capitalise on its “massive cohort of healthy, active, older, creative adults”, a leading population expert has said.

While pundits and pressure groups have raised concerns over falling fertility rates, highlighting the challenges for the economy and healthcare, others are more upbeat, arguing the rise of the “silver economy” brings new opportunities for growth.

Continue reading...

© Photograph: Maskot/Getty Images

© Photograph: Maskot/Getty Images

© Photograph: Maskot/Getty Images

Hundreds of thousands newly displaced as Islamic State insurgency expands in Mozambique

Rising numbers of people flee jihadists, as violence against civilians increases and foreign aid dwindles

More than 300,000 people have been displaced by an Islamic State insurgency in Mozambique since July, amid growing fears that authorities lack a workable plan to end the fighting.

With wars in Ukraine, Gaza and Sudan attracting more attention and foreign aid falling, the grinding conflict in Mozambique has been largely ignored or forgotten. More than 1 million people have been displaced, many of them two, three or even four times.

Continue reading...

© Photograph: Diego Menjibar Reynes/AFP/Getty Images

© Photograph: Diego Menjibar Reynes/AFP/Getty Images

© Photograph: Diego Menjibar Reynes/AFP/Getty Images

More than half a million pounds spent on influencers by UK government since 2024

25 décembre 2025 à 07:00

Figures from FoI request show increase in ministerial use of social media personalities to present campaigns

More than half a million pounds has been spent since 2024 on using social media influencers to promote UK government campaigns on subjects ranging from the environment to welfare.

The spending has included hiring 215 influencers since 2024, of which there were 126 in 2025 – an increase on the 89 hired in 2024 – and is seen as an attempt to use platforms such as TikTok to reach younger people.

Continue reading...

© Photograph: Simon Dawson/No 10 Downing Street

© Photograph: Simon Dawson/No 10 Downing Street

© Photograph: Simon Dawson/No 10 Downing Street

Reçu avant avant-hier

The Confederacy Goes on Trial, Along With Schools Named Jackson and Lee

23 décembre 2025 à 18:45
In an unusual trial, the N.A.A.C.P. has sought to show a school board’s “racist intent” by proving that the names of Robert E. Lee and Stonewall Jackson can’t be separated from white supremacy.

© Eze Amos for The New York Times

Stonewall Jackson High School was renamed Mountain View High School in 2020. The change was reversed by the Shenandoah County School Board in 2024.

May Britt, 91, Dies; Her Marriage to Sammy Davis Jr. Sparked Outrage

23 décembre 2025 à 16:36
She was a white actress, he was a popular Black entertainer, and their relationship elicited racist reactions in 1960, worrying John F. Kennedy’s presidential campaign.

© Hulton Archive/Getty Images

Ms. Britt and Mr. Davis at their wedding in November 1960. It was reported that the event had been delayed from October at the request of John F. Kennedy’s presidential campaign to avoid negative attention before the election.

Tell us: are you a UK centenarian or do you know one?

4 novembre 2025 à 11:55

We would like to hear from centenarians, their family and friends

The number of centenarians (aged 100 years and over) in the UK has doubled from 8,300 in 2004 to 16,600 in 2024, according to the Office for National Statistics.

Between 2004 and 2024, the number of male centenarians has tripled from 910 to 3,100. During the same period, the number of female centenarians almost doubled from 7,400 to 13,600.

Continue reading...

© Photograph: Pablo Garcia/The Guardian

© Photograph: Pablo Garcia/The Guardian

© Photograph: Pablo Garcia/The Guardian

Semiconductor laser pioneer Susumu Noda wins 2026 Rank Prize for Optoelectronics

2 décembre 2025 à 10:00

Susumu Noda of Kyoto University has won the 2026 Rank Prize for Optoelectronics for the development of the Photonic Crystal Surface Emitting Laser (PCSEL). For more than 25 years, Noda developed this new form of laser, which has potential applications in high-precision manufacturing as well as in LIDAR technologies.

Following the development of the laser in 1960, in more recent decades optical fibre lasers and semiconductor lasers have become competing technologies.

A semiconductor laser works by pumping an electrical current into a region where an n-doped (excess of electrons) and a p-doped (excess of “holes”) semiconductor material meet, causing electrons and holes to combine and release photons.

Semiconductors have several advantages in terms of their compactness, high “wallplug” efficiency, and ruggedness, but lack in other areas such as having a low brightness and functionality.

This means that conventional semiconductor lasers required external optical and mechanical elements to improve their performance, which results in large and impractical systems.

‘A great honour’

In the late 1990s, Noda began working on a new type of semiconductor laser that could challenge the performance of optical fibre lasers. These so-called PCSELs employ a photonic crystal layer  in between the semiconductor layers. Photonic crystals are nanostructured materials in which a periodic variation of the dielectric constant — formed, for example, by a lattice of holes — creates a photonic band-gap.

Noda and his research made a series of breakthrough in the technology such as demonstrating control of polarization and beam shape by tailoring the phonic crystal structure and expansion into blue–violet wavelengths.

The resulting PCSELs emit a high-quality, symmetric beam with narrow divergence and boast high brightness and high functionality while maintaining the benefits of conventional semiconductor lasers. In 2013, 0.2 W PCSELs became available and a few years later Watt-class PCSEL lasers became operational.

Noda says that it is “a great honour and a surprise” to receive the prize. “I am extremely happy to know that more than 25 years of research on photonic-crystal surface-emitting lasers has been recognized in this way,” he adds. “I do hope to continue to further develop the research and its social implementation.”

Susumu Noda received his BSc and then PhD in electronics from Kyoto University in 1982 and 1991, respectively. From 1984 he also worked at Mitsubishi Electric Corporation, before joining Kyoto University in 1988 where he is currently based.

Founded in 1972 by the British industrialist and philanthropist Lord J Arthur Rank, the Rank Prize is awarded biennially in nutrition and optoelectronics. The 2026 Rank Prize for Optoelectronics, which has a cash award of £100 000, will be awarded formally at an event held in June.

The post Semiconductor laser pioneer Susumu Noda wins 2026 Rank Prize for Optoelectronics appeared first on Physics World.

Tim Berners-Lee: why the inventor of the Web is ‘optimistic, idealistic and perhaps a little naïve’

29 octobre 2025 à 11:00

It’s rare to come across someone who’s been responsible for enabling a seismic shift in society that has affected almost everyone and everything. Tim Berners-Lee, who invented the World Wide Web, is one such person. His new memoir This is for Everyone unfolds the history and development of the Web and, in places, of the man himself.

Berners-Lee was born in London in 1955 to parents, originally from Birmingham, who met while working on the Ferranti Mark 1 computer and knew Alan Turing. Theirs was a creative, intellectual and slightly chaotic household. His mother could maintain a motorbike with fence wire and pliers, and was a crusader for equal rights in the workplace. His father – brilliant and absent minded – taught Berners-Lee about computers and queuing theory. A childhood of camping and model trains, it was, in Berners-Lee’s view, idyllic.

Berners-Lee had the good fortune to be supported by a series of teachers and managers who recognized his potential and unique way of working. He studied physics at the University of Oxford (his tutor “going with the flow” of Berners-Lee’s unconventional notation and ability to approach problems from oblique angles) and built his own computer. After graduating, he married and, following a couple of jobs, took a six-month placement at the CERN particle-physics lab in Geneva in 1985.

This placement set “a seed that sprouted into a tool that shook up the world”. Berners-Lee saw how difficult it was to share information stored in different languages in incompatible computer systems and how, in contrast, information flowed easily when researchers met over coffee, connected semi-randomly and talked. While at CERN, he therefore wrote a rough prototype for a program to link information in a type of web rather than a structured hierarchy.

Back at CERN, Tim Berners-Lee developed his vision of a “universal portal” to information

The placement ended and the program was ignored, but four years later Berners-Lee was back at CERN. Now divorced and soon to remarry, he developed his vision of a “universal portal” to information. It proved to be the perfect time. All the tools necessary to achieve the Web – the Internet, address labelling of computers, network cables, data protocols, the hypertext language that allowed cross-referencing of text and links on the same computer – had already been developed by others.

Berners-Lee saw the need for a user-friendly interface, using hypertext that could link to information on other computers across the world. His excitement was “uncontainable”, and according to his line manager “few of us if any could understand what he was talking about”. But Berners-Lee’s managers supported him and freed his time away from his actual job to become the world’s first web developer.

Having a vision was one thing, but getting others to share it was another. People at CERN only really started to use the Web properly once the lab’s internal phone book was made available on it. As a student at the time, I can confirm that it was much, much easier to use the Web than log on to CERN’s clunky IBM mainframe, where phone numbers had previously been stored.

Wider adoption relied on a set of volunteer developers, working with open-source software, to make browsers and platforms that were attractive and easy to use. CERN agreed to donate the intellectual property for web software to the public domain, which helped. But the path to today’s Web was not smooth: standards risked diverging and companies wanted to build applications that hindered information sharing.

Feeling that “the Web was outgrowing my institution” and “would be a distraction” to a lab whose core mission was physics, Berners-Lee moved to the Massachusetts Institute of Technology in 1994. There he founded the World Wide Web Consortium (W3C) to ensure consistent, accessible standards were followed by everyone as the Web developed into a global enterprise. The progression sounds straightforward although earlier accounts, such as James Gillies and Robert Caillau’s 2000 book How the Web Was Born, imply some rivalry between institutions that is glossed over here.

Initially inclined to advise people to share good things and not search for bad things, Berners-Lee had reckoned without the insidious power of “manipulative and coercive” algorithms on social networks

The rest is history, but not quite the history that Berners-Lee had in mind. By 1995 big business had discovered the possibilities of the Web to maximize influence and profit. Initially inclined to advise people to share good things and not search for bad things, Berners-Lee had reckoned without the insidious power of “manipulative and coercive” algorithms on social networks. Collaborative sites like Wikipedia are closer to his vision of an ideal Web; an emergent good arising from individual empowerment. The flip side of human nature seems to come as a surprise.

The rest of the book brings us up to date with Berners-Lee’s concerns (data, privacy, misuse of AI, toxic online culture), his hopes (the good use of AI), a third marriage and his move into a data-handling business. There are some big awards and an impressive amount of name dropping; he is excited by Order of Merit lunches with the Queen and by sitting next to Paul McCartney’s family at the opening ceremony to the London Olympics in 2012. A flick through the index reveals names ranging from Al Gore and Bono to Lucien Freud. These are not your average computing technology circles.

There are brief character studies to illustrate some of the main players, but don’t expect much insight into their lives. This goes for Berners-Lee too, who doesn’t step back to particularly reflect on those around him, or indeed his own motives beyond that vision of a Web for all enabling the best of humankind. He is firmly future focused.

Still, there is no-one more qualified to describe what the Web was intended for, its core philosophy, and what caused it to develop to where it is today. You’ll enjoy the book whether you want an insight into the inner workings that make your web browsing possible, relive old and forgotten browser names, or see how big tech wants to monetize and monopolize your online time. It is an easy read from an important voice.

The book ends with a passionate statement for what the future could be, with businesses and individuals working together to switch the Web from “the attention economy to the intention economy”. It’s a future where users are no longer distracted by social media and manipulated by attention-grabbing algorithms; instead, computers and services do what users want them to do, with the information that users want them to have.

Berners-Lee is still optimistic, still an incurable idealist, still driven by vision. And perhaps still a little naïve too in believing that everyone’s values will align this time.

  • 2025 Macmillan 400pp £25.00/$30.00hb

The post Tim Berners-Lee: why the inventor of the Web is ‘optimistic, idealistic and perhaps a little naïve’ appeared first on Physics World.

Influential theoretical physicist and Nobel laureate Chen-Ning Yang dies aged 103

21 octobre 2025 à 15:31

The Chinese particle physicist Chen-Ning Yang died on 18 October at the age of 103. Yang shared half of the 1957 Nobel Prize for Physics with Tsung-Dao Lee for their theoretical work that overturned the notion that parity is conserved in the weak force – one of the four fundamental forces of nature.

Born on 22 September 1922 in Hefei, China, Yang competed a BSc at the National Southwest Associated University in Kunming in 1942. After finishing an MSc in statistical physics at Tsinghua University two years later, in 1945 he moved to the University of Chicago in the US as part of a government-sponsored programme. He received his PhD in physics in 1948 working under the guidance of Edward Teller.

In 1949 Yang moved to the Institute for Advanced Study in Princeton, where he made pioneering contributions to quantum field theory, working together with Robert Mills. In 1953 they proposed the Yang-Mills theory, which became a cornerstone of the Standard Model of particle physics.

The ‘Wu experiment’

It was also at Princeton where Yang began a fruitful collaboration with Lee, who died last year aged 97. Their work on parity – a property of elementary particles that expresses their behaviour upon reflection in a mirror – led to the duo winning the Nobel prize.

In the early 1950s, physicists had been puzzled by the decays of two subatomic particles, known as tau and theta, which are identical except that the tau decays into three pions with a net parity of -1, while a theta particle decays into two pions with a net parity of +1.

There were two possible explanations: either the tau and theta are different particles or that parity in the weak interaction is not conserved with Yang and Lee proposing various ways to test their ideas (Phys. Rev. 104 254).

This “parity violation” was later proved experimentally by, among others, Chien-Shiung Wu at Columbia University. She carried out an experiment based on the radioactive decay of unstable cobalt-60 nuclei into nickel-60 – what became known as the “Wu experiment”. For their work, Yang, who was 35 at the time, shared the 1957 Nobel Prize for Physics with Lee.

Influential physicist

In 1965 Yang moved to Stony Brook University, becoming the first director of the newly founded Institute for Theoretical Physics, which is now known as the C N Yang Institute for Theoretical Physics. During this time he also contributed to advancing science and education in China, setting up the Committee on Educational Exchange with China – a programme that has sponsored some 100 Chinese scholars to study in the US.

In 1997, Yang returned to Beijing where he became an honorary director of the Centre for Advanced Study at Tsinghua University. He then retired from Stony Brook in 1999, becoming a professor at Tsinghua University. During his time in the US, Yang obtained US citizenship, but renounced it in 2015.

More recently, Yang was involved in debates over whether China should build the Circular Electron Positron Collider (CEPC) – a huge 100 km circumference underground collider that would study the Higgs boson in unprecedented detail and be a successor to CERN’s Large Hadron Collider. Yang took a sceptical view calling it “inappropriate” for a developing country that is still struggling with “more acute issues like economic development and environment protection”.

Yang also expressed concern that the science performed on the CEPC is just “guess” work and without guaranteed results. “I am not against the future of high-energy physics, but the timing is really bad for China to build such a super collider,” he noted in 2016. “Even if they see something with the machine, it’s not going to benefit the life of Chinese people any sooner.”

Lasting legacy

As well as the Nobel prize, Yang won many other awards such as the US National Medal of Science in 1986, the Einstein Medal in 1995, which is presented by the Albert Einstein Society in Bern, and the American Physical Society’s Lars Onsager Prize in 1990.

“The world has lost one of the most influential physicists of the modern era,” noted Stony Brook president Andrea Goldsmith in a statement. “His legacy will continue through his transformational impact on the field of physics and through the many colleagues and students influenced by his teaching, scholarship and mentorship.”

The post Influential theoretical physicist and Nobel laureate Chen-Ning Yang dies aged 103 appeared first on Physics World.

❌