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Reçu aujourd’hui — 22 juillet 20256.5 📰 Sciences English

Tensions rise between US administration and science agencies

22 juillet 2025 à 17:56
Large group of people stood on grass outside a tall building holding a "75" sign
Stormy times Hundreds of staff at the National Science Foundation marked the agency’s 75th birthday in May with a group photo. (CC BY SA 4.0 Matthew Herron)

A total of 139 employees at the US Environmental Protection Agency (EPA) have been suspended after signing a “declaration of dissent” accusing Donald Trump’s administration of “undermining” the agency’s mission. The letter, dated 1 July, stated that the signatories “stand together against the current administration’s focus on harmful deregulation, mischaracterization of previous EPA activities, and disregard for scientific expertise”.

Addressed to EPA administrator Lee Zeldin, the letter was signed by a total of more than 400 EPA workers, of whom 170 put their names to the document, with the rest choosing to remain anonymous. Zeldin suspended the employees on 3 July, with EPA officials telling them to provide contact information so the agency could be in touch with them while they are on leave.

Copied to leaders of the US Senate and House of Representatives, the letter was organized by the Stand Up For Science pressure group. The letter states that “EPA employees join in solidarity with employees across the Federal government in opposing this administration’s policies, including those that undermine the EPA mission of protecting human health and the environment.”

The document lists five “primary concerns”, including the scientific consensus being ignored to benefit polluters, and undermining public trust by EPA workers being distracted from protecting public health and the environment through objective science-based policy.

The letter adds that the EPA’s progress in the US’s most vulnerable communities is being reversed through the cancellation of environmental justice programmes, while budget cuts to the Office of Research and Development, which helps support the agency’s rules on environmental protection and human health, mean it cannot meet the EPA’s science needs. The letter also points to a culture of fear at the EPA, with staff being forced to choose between their livelihood and well-being.

In response to the letter, Zeldin said he had a “ZERO tolerance policy for agency bureaucrats unlawfully undermining, sabotaging and undercutting the agenda of this administration”. An EPA statement, sent to Physics World, notes that the letter “contains information that misleads the public about agency business”, adding that the letter’s signatories “represent a small fraction of the thousands of [agency] employees”. On 18 July Zeldin then announced a plan to eliminate the EPA’s Office of Research and Development, which could lead to more than 1000 agency scientists being sacked.

Climate concerns

In late July, more than 280 NASA employees signed a similar declaration of dissent protesting against staff cuts at the agency as well as calling on the acting head of NASA not to make the budget cuts Trump proposed. Another example of the tension in US science took place in May when hundreds of staff from the National Science Foundation (NSF) gathered in front of NSF headquarters for a photo marking the agency’s 75th birthday. NSF officials, who had been criticized for seeking to cut the agency’s budget and staff, and slash the proportion of scientific grants’ costs allowed for ancillary expenses, refused to support the event with an official photographer.

Staff then used their own photographer, but they could only take a shot from a public space at the side of the building. In late June, the administration announced that the NSF will have to quit the building, which it has occupied since 2017. No new location for the headquarters has been announced, with NSF spokesperson Michelle Negrón declining to comment on the issue. The new tenant will be the Department of Housing and Urban Development.

The Department of Energy, meanwhile, has announced that it will hire three scientists who have expressed doubts about the scientific consensus on climate change – although details of the trio’s job descriptions remain unknown. They are Steven Koonin, a physicist at Stanford University’s Hoover Institution, along with atmospheric scientist John Christy, director of the Earth System Science Center at the University of Alabama in Huntsville, and Alabama meteorologist Roy Spencer.

The appointments come as the administration is taking steps to de-emphasize government research on climate and weather science. The proposed budget for financial year 2026 would close 10 labs belonging to the National Oceanic and Atmospheric Administration (NOAA). The NOAA’s National Weather Service has already lost 600 of its 4200 employees this year, while NASA has announced that it will no longer host the National Climate Assessment website globalchange.gov.

The post Tensions rise between US administration and science agencies appeared first on Physics World.

Making science go boom: Big Manny’s outreach journey

22 juillet 2025 à 15:00

When lockdown hit, school lab technician Emanual Wallace started posting videos of home science experiments on social media. Now, as Big Manny, he’s got over three million followers on Instagram and TikTok; won TikTok’s Education Creator of the Year 2024; and has created videos with celebrities like Prince William and Brian Cox. Taking his science communication beyond social media, he’s been on CBBC’s Blue Peter and Horrible Science; has made TV appearances on shows like This Morning and BBC Breakfast; and has even given talks at Buckingham Palace and the Houses of Parliament.

But he’s not stopped there. Wallace has also recently published a second book in his Science is Lit series, Awesome Electricity and Mad Magnets, which is filled with physics experiments that children can do at home. He talks to Sarah Tesh about becoming the new face of science communication, and where he hopes this whirlwind journey will go next.

'This Morning' TV show with Big Manny doing science experiments
Making science fun Big Manny (right) on ITV show This Morning with host Alison Hammond and Paddy McGuiness. (Courtesy: Ken McKay/ITV/Shutterstock)

What sparked your interest in science?

I’ve always been really curious. Ever since I was young, I had a lot of questions. I would, for example, open up my toys just so I could see what was inside and how they worked. Then when I was in year 8 I had a science teacher called Mr Carter, and in every lesson he was doing experiments, like exciting Bunsen burner ones. I would say that’s what ignited my passion for science. And naturally, I just gravitated towards science because it answered all the questions that I had.

Growing up, what were the kind of science shows that you were really interested in?

When I was about 11 the show that I used to love was How it’s Made? And there’s a science creator called Nile Red – he creates chemistry videos, and he inspired me a lot. I used to watch him when I was growing up and then I actually got to meet him as well. He’s from Canada so when he came over, he came to my house and we did some experiments. To be inspired by him and then to do experiments with him, that was brilliant. I also used to watch a lot of Brian Cox when I was younger, and David Attenborough – I still watch Attenborough’s shows now.

You worked in a school for a while after your degrees at the University of East London – what made you go down that path rather than, say, staying in academia or going into industry?

Well, my bachelor’s and master’s degrees are in biomedical science, and my aspiration was to become a biomedical scientist working in a hospital lab, analysing patient samples. When I came out of university, I thought that working as a science technician at a school would be a great stepping stone to working as a biomedical scientist because I needed to gain some experience within a lab setting. So, the school lab was my entry point, then I was going to go into a hospital lab, and then work as a biomedical scientist.

Big Manny's science book
Sparking interest Big Manny has now written his own series of children’s science books. (Courtesy: Penguin Books)

But my plans have changed a bit now. To become a registered biomedical scientist you need to do nine months in a hospital lab, and at the moment, I’m not sure if I can afford to take nine months off from my work doing content creation. I do still want to do it, but maybe in the future, who knows.

What prompted you to start making the videos on social media?

When I was working in schools, it was around the time of lockdown. There were school closures, so students were missing out on a lot of science – and science is a subject where to gain a full understanding, you can’t just read the textbook. You need to actually do the experiments so you can see the reactions in front of you, because then you’ll be more likely to retain the information.

I started to notice that students were struggling because of all the science that they had missed out on. They were doing a lot of Google classrooms and Zoom lessons, but it just wasn’t having the full impact. That’s when I took it upon myself to create science demonstration videos to help students catch up with everything they’d missed. Then the videos started to take off.

How do you come up with the experiments you feature in your videos?  If you’re hoping to help students, do you follow the school curriculum?

I would say right now there’s probably three main types of videos that I make. The first includes experiments that pertain to the national curriculum – the experiments that might come up in, say, the GCSE exams. I focus on those because that’s what’s going to be most beneficial to young people.

Secondly, I just do fun experiments. I might blow up some fruit or use fire or blow up a hydrogen balloon. Just something fun and visually engaging, something to get people excited and show them the power of science.

And then the third type of video that I make is where I’m trying to promote a certain message. For example, I did a video where I opened up a lithium battery, put it into water and we got an explosion, because I wanted to show people the dangers of not disposing of batteries correctly. I did another one where I showed people the effects of vaping on the lungs, and one where I melted down a knife and I turned it into a heart to persuade people to put down their knives and spread love instead.

Who would you say is your primary audience?

Well, I would say that my audience is quite broad. I get all ages watching my videos on social media, while my books are focused towards primary school children, aged 8 to 12 years. But I’ve noticed that those children’s parents are also interested in the experiments, and they might be in their 30s. So it’s quite a wide age range, and I try to cater for everyone.

In your videos, which of the sciences would you say is the easiest to demonstrate and which is the hardest?

I’d say that chemistry is definitely the easiest and most exciting because I can work with all the different elements and show how they react and interact with each other. I find that biology can sometimes be a bit tricky to demonstrate because, for example, a lot of biology involves the human body – things like organ systems, the circulatory system and the nervous system are all inside the body, while cells are so small we can’t really see them. But there’s a lot that I can do with physics because there’s forces, electricity, sound and light. So I would say chemistry is the easiest, then physics, and then biology is the hardest.

Do you have a favourite physics experiment that you do?

I would say my favourite physics experiment is the one with the Van de Graff generator. I love that one – how the static electricity makes your hair stand up and then you get a little electric shock, and you can see the little electric sparks. 

You’re becoming a big name in science communication – what does an average day look like for you now?

On an average day, I’m doing content creation. I will research some ideas, find some potential experiments that I might want to try. Then after that I will look at buying the chemicals and equipment that I need. From there, I’ll probably do some filming, which I normally just do in my garden. Straight after, I will edit all the clips together, add the voiceover, and put out the content on social media. One video can easily take the whole day – say about six or seven hours – especially if the experiment doesn’t go as planned and I need to tweak the method or pop out and get extra supplies.

In your videos you have a load of equipment and chemicals. Have you built up quite a laboratory of kit in your house now?

Yeah, I’ve got a lot of equipment. And some of it is restricted too, like there’s some heavily regulated substances. I had to apply for a licence to obtain certain chemicals because they can be used to make explosives, so I had to get clearance.

What are you hoping to achieve with your work?

I’ve got two main goals at the moment. One of them is bringing science to a live audience. Most people, they just see my content online, but I feel like if they see it in person and they see the experiments live, it could have an even bigger impact. I could excite even more people with science and get them interested. So that’s one thing that I’m focusing on at the moment, getting some live science events going.

I also want to do some longer-form videos because my current ones are quite short – they’re normally about a minute long. I realize that everyone learns in different ways. Some people like those short, bite-sized videos because they can gain a lot of information in a short space of time. But some people like a bit more detail – they like a more lengthy video where you flesh out scientific concepts. So that’s something that I would like to do in the form of a TV science show where I can present the science in more detail.

The post Making science go boom: Big Manny’s outreach journey appeared first on Physics World.

How SpaceX upended traditional launch markets – and what’s next

22 juillet 2025 à 14:52

Part 1 of this free report explores how SpaceX upended traditional launch markets by scaling reusability, slashing costs and normalizing frequent access to orbit. With more launches in 2024 than the rest of the world combined, the company has become a cornerstone of both commercial innovation and national security.

The post How SpaceX upended traditional launch markets – and what’s next appeared first on SpaceNews.

AST SpaceMobile seeks approval to give first responders a direct satellite link

22 juillet 2025 à 14:11
Illustration of an AST SpaceMobile BlueBird cell service satellite. Credit: AST SpaceMobile

AST SpaceMobile is seeking regulatory approval to provide direct-to-smartphone satellite connectivity for first responders in the United States, after reaching a deal to use the public safety spectrum AT&T operates.

The post AST SpaceMobile seeks approval to give first responders a direct satellite link appeared first on SpaceNews.

Spin-qubit control circuit stays cool

22 juillet 2025 à 12:00

Researchers in Australia say that they have created the first CMOS chip that can control the operation of multiple spin qubits at ultralow temperatures. Through an advanced approach to generating the voltage pulses needed to control the qubits, a team led by David Reilly at the University of Sydney showed that control circuits can be integrated with qubits in a heterogeneous chip architecture. The design is a promising step towards a scalable platform for quantum computing.

Before practical quantum computers can become a reality, scientists and engineers must work out how to integrate large numbers (potentially millions) of qubits together – while preserving the quantum information as it is processed and exchanged. This is currently very difficult because the quantum nature of qubits (called coherence) tends to be destroyed rapidly by heat and other environmental noise.

One potential candidate for integration are the silicon spin qubits, which have advantages that include their tiny size, their relatively long coherence times, and their compatibility with large-scale electronic control circuits.

To operate effectively, however, these systems need to be cooled to ultralow temperatures. “A decade or more ago we realized that developing cryogenic electronics would be essential to scaling-up quantum computers,” Reilly explains. “It has taken many design iterations and prototype chips to develop an approach to custom silicon that operates at 100 mK using only a few microwatts of power.”

Heat and noise

When integrating multiple spin qubits onto the same platform, each of them must be controlled and measured individually using integrated electronic circuits. These control systems not only generate heat, but also introduce electrical noise – both of which are especially destructive to quantum logic gates based on entanglement between pairs of qubits.

Recently, researchers have addressed this challenge by separating the hot, noisy control circuits from the delicate qubits they control. However, when the two systems are separated, long cables are needed to connect each qubit individually to the control system. This creates a dense network of interconnects that would prove extremely difficult and costly to scale up to connect millions of qubits.

For over a decade, Reilly’s team have worked towards a solution to this control problem. Now, they have shown that the voltage pulses needed to control spin qubits can be generated directly on a CMOS chip by moving small amounts of charge between closely spaced capacitors. This is effective at ultralow temperatures, allowing the on-board control of qubits.

CMOS chiplet

“We control spin qubits using a tightly integrated CMOS chiplet, addressing the interconnect bottleneck challenge that arises when the control is not integrated with qubits,” Reilly explains. “Via careful design, we show that the qubits hardly notice the switching of 100,000 transistors right next door.“

The result is a two-part chip architecture that, in principle, could host millions of silicon spin qubits. As a benchmark, Reilly’s created two-qubit entangling gates on their chip. When they cooled their chip to the millikelvin temperatures required by the qubits, its control circuits carried out the operation just as flawlessly as previous systems with separated control circuits.

While the architecture is still some way from integrating millions of qubits onto the same chip, the team believes that this goal is a step closer.

“This work now opens a path to scaling up spin qubits since control systems can now be tightly integrated,” Reilly says. “The complexity of the control platform has previously been a major barrier to reaching the scale where these machines can be used to solve interesting real-world problems.”

The research is described in Nature.

The post Spin-qubit control circuit stays cool appeared first on Physics World.

Reçu hier — 21 juillet 20256.5 📰 Sciences English

A cosmic void may help resolve the Hubble tension

21 juillet 2025 à 18:12

A large, low density region of space surrounding the Milky Way may explain one of the most puzzling discrepancies in modern cosmology. Known as the Hubble tension, the issue arises from conflicting measurements of how fast the universe is expanding. Now, a new study suggests that the presence of a local cosmic void could explain this mismatch, and significantly improves agreement with observations compared to the Standard Model of cosmology.

“Numerically, the local measurements of the expansion rate are 8% higher than expected from the early universe, which amounts to over six times the measurement uncertainty,” says Indranil Banik, a cosmologist at the University of Portsmouth and a collaborator on the study. “It is by far the most serious issue facing cosmology.”

The Hubble constant describes how fast the universe is expanding and it can be estimated in two main ways. One method involves looking far into the past by observing the cosmic microwave background (CMB). This is radiation that was created shortly after the Big Bang and permeates the universe to this day. The other method relies on the observation of relatively nearby objects, such as supernovae and galaxies, to measure how fast space is expanding in our own cosmic neighbourhood.

If the Standard Model of cosmology is correct, these two approaches should yield the same result. But, they do not. Instead, local measurements suggest the universe is expanding faster than the expansion given by early-universe data. Furthermore, this disagreement is too large to dismiss as experimental error.

Local skewing

One possible explanation is that something about our local environment is skewing the results. “The idea is that we are in a region of the universe that is about 20% less dense than average out to a distance of about one billion light years,” Banik explains. “There is actually a lot of evidence for a local void from number counts of various kinds of sources across nearly the whole electromagnetic spectrum, from radio to X-rays.”

Such a void would subtly affect how we interpret the redshifts of galaxies. This is the stretching of the wavelength of galactic light that reveals how quickly a galaxy is receding from us. In an underdense (of relatively low density) region, galaxies are effectively pulled outward by the gravity of surrounding denser areas. This motion adds to the redshift caused by the universe’s overall expansion, making the local expansion rate appear faster than it actually is.

“The origin of such a [void] would trace back to a modest underdensity in the early universe, believed to have arisen from quantum fluctuations in density when the universe was extremely young and dense,” says Banik. However, he adds, “A void as large and deep as observed is not consistent with the standard cosmological model. You would need structure to grow faster than it predicts on scales larger than about one hundred million light–years”.

Testing the theory

To evaluate whether the void model holds up against data, Banik and his collaborator Vasileios Kalaitzidis at the UK’s University of St Andrews compared it with one of cosmology’s most precise measurement tools: baryon acoustic oscillations (BAOs). These are subtle ripples in the distribution of galaxies that were created by sound waves in the early universe and then frozen into the large-scale structure of space as it cooled.

Because these ripples provide a characteristic distance scale, they can be used as a “standard ruler” to track how the universe has expanded over time. By comparing the apparent size of this ruler at observed a different distances, cosmologists can map the universe’s expansion history. Crucially, if our galaxy lies inside a void, that would alter how the ruler appears locally, in a way that can be tested.

The researchers compared the predictions of their model with twenty years of BAO observations, and the results are striking. “BAO observations over the last twenty years show the void model is about one hundred million times more likely than the Standard Model of cosmology without any local void,” says Banik. “Importantly, the parameters of all these models were fixed without considering BAO data, so we were really just testing the predictions of each model.”

What lies ahead

While the void model appears promising, Banik says that more data are needed. “Additional BAO observations at relatively short distances would help a lot because that is where a local void would have the greatest impact.” Other promising avenues include measuring galaxy velocities and refining galaxy number counts. “I would suggest that it can be essentially confirmed in the next five to ten years, since we are talking about the nearby universe after all.”

Banik is also analysing supernovae data to explore whether the Hubble tension disappears at greater distances. “We are testing if the Hubble tension vanishes in the high-redshift or more distant universe, since a local void would not have much effect that far out,” he says.

Despite the challenges, Banik remains optimistic. With improved surveys and more refined models, cosmologists may be closing in on a solution to the Hubble tension.

The research is described in Monthly Notices of the Royal Astronomical Society.

The post A cosmic void may help resolve the Hubble tension appeared first on Physics World.

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