↩ Accueil

Vue normale

Oscar-winning computer scientist on the physics of computer animation

23 décembre 2025 à 15:03

This episode of the Physics World Weekly podcast features Pat Hanrahan, who studied nuclear engineering and biophysics before becoming a founding employee of Pixar Animation Studios. As well as winning three Academy Awards for his work on computer animation, Hanrahan won the Association for Computing Machinery’s A.M. Turing Award for his contributions to 3D computer graphics, or CGI.

Earlier this year, Hanrahan spoke to Physics World’s Margaret Harris at the Heidelberg Laureate Forum in Germany. He explains how he was introduced to computer graphics by his need to visualize the results of computer simulations of nervous systems. That initial interest led him to Pixar and his development of physically-based rendering, which uses the principles of physics to create realistic images.

Hanrahan explains that light interacts with different materials in very different ways, making detailed animations very challenging. Indeed, he says that creating realistic looking skin is particularly difficult – comparing it to the quest for a grand unified theory in physics.

He also talks about how having a background in physics has helped his career – citing his physicist’s knack for creating good models and then using them to solve problems.

The post Oscar-winning computer scientist on the physics of computer animation appeared first on Physics World.

Components of RNA among life’s building blocks found in NASA asteroid sample

12 décembre 2025 à 12:30

More molecules and compounds vital to the origin of life have been detected in asteroid samples delivered to Earth by NASA’s OSIRIS-REx mission. The discovery strengthens the case that not only did life’s building blocks originate in space, but that the ingredients of RNA, and perhaps RNA itself, were brought to our planet by asteroids.

Two new papers in Nature Geoscience and Nature Astronomy describe the discovery of the sugars ribose and glucose in the 120 g of samples returned from the near-Earth asteroid 101955 Bennu, as well as an unusual carbonaceous “gum” that holds important compounds for life. The findings complement the earlier discovery of amino acids and the nucleobases of RNA and DNA in the Bennu samples.

A third new paper, in Nature Astronomy, addresses the abundance of pre-solar grains, which is dust that originated from before the birth of our Solar System, such as dust from supernovae. Scientists led by Ann Nguyen of NASA’s Johnson Space Center found six times more dust direct from supernova explosions than is found, on average, in meteorites and other sampled asteroids. This could suggest differences in the concentration of different pre-solar dust grains in the disc of gas and dust that formed the Solar System.

Space gum

It’s the discovery of organic materials useful for life that steals the headlines, though. For example, the discovery of the space gum, which is essentially a hodgepodge chain of polymers, represents something never found in space before.

Scott Sandford of NASA’s Ames Research Center, co-lead author of the Nature Astronomy paper describing the gum discovery, tells Physics World: “The material we see in our samples is a bit of a molecular jumble. It’s carbonaceous, but much richer in nitrogen and, to a lesser extent, oxygen, than most of the organic compounds found in extraterrestrial materials.”

Sandford refers to the material as gum because of its pliability, bending and dimpling when pressure is applied, rather like chewing gum. And while much of its chemical functionality is replicated in similar materials on our planet, “I doubt it matches exactly with anything seen on Earth,” he says.

Initially, Sandford found the gum using an infrared microscope, nicknaming the dust grains containing the gum “Lasagna” and “Neapolitan” because the grains are layered. To extract them from the rock in the sample, Sandford went to Zack Gainsforth of the University of California, Berkeley, who specializes in analysing and extracting materials from samples like this.

Platinum scaffolding

Having welded a tungsten needle to the Neapolitan sample in order to lift it, the pair quickly realised that the grain was very delicate.

“When we tried to lift the sample it began to deform,” Gainsforth says. “Scott and I practically jumped out of our chairs and brainstormed what to do. After some discussion, we decided that we should add straps to give it enough mechanical rigidity to survive the lift.”

Microscopic particle of asteroid Bennu
Fragile sample A microscopic particle of asteroid Bennu is manipulated under a transmission electron microscope. To move the 30 µm fragment for further analysis, the researchers reinforced it with thin platinum strips (the L shape on the surface). (Courtesy: NASA/University of California, Berkeley)

By straps, Gainsforth is referring to micro-scale platinum scaffolding applied to the grain to reinforce its structure while they cut it away with an ion beam. Platinum is often used as a radiation shield to protect samples from an ion beam, “but how we used it was anything but standard,” says Gainsforth. “Scott and I made an on-the-fly decision to reinforce the samples based on how they were reacting to our machinations.”

With the sample extracted and reinforced, they used the ion beam cutter to shave it down until it was a thousand times thinner than a human hair, at which point it could be studied by electron microscopy and X-ray spectrometry. “It was a joy to watch Zack ‘micro-manipulate’ [the sample],” says Sandford.

The nitrogen in the gum was found to be in nitrogen heterocycles, which are the building blocks of nucleobases in DNA and RNA. This brings us to the other new discovery, reported in Nature Geoscience, of the sugars ribose and glucose in the Bennu samples, by a team led by Yoshihiro Furukawa of Tohoku University in Japan.

The ingredients of RNA

Glucose is the primary source of energy for life, while ribose is a key component of the sugar-phosphate backbone that connects the information-carrying nucleobases in RNA molecules. Furthermore, the discovery of ribose now means that everything required to assemble RNA molecules is present in the Bennu sample.

Notable by its absence, however, was deoxyribose, which is ribose minus one oxygen atom. Deoxyribose in DNA performs the same job as ribose in RNA, and Furukawa believes that its absence supports a popular hypothesis about the origin of life on Earth called RNA world. This describes how the first life could have used RNA instead of DNA to carry genetic information, catalyse biochemical reactions and self-replicate.

Intriguingly, the presence of all RNA’s ingredients on Bennu raises the possibility that RNA could have formed in space before being brought to Earth.

“Formation of RNA from its building blocks requires a dehydration reaction, which we can expect to have occurred both in ancient Bennu and on primordial Earth,” Furukawa tells Physics World.

However, RNA would be very hard to detect because of its expected low abundance in the samples, making identifying it very difficult. So until there’s information to the contrary, “the present finding means that the ingredients of RNA were delivered from space to the Earth,” says Furukawa.

Nevertheless, these discoveries are major milestones in the quest of astrobiologists and space chemists to understand the origin of life on Earth. Thanks to Bennu and the asteroid 162173 Ryugu, from which a sample was returned by the Japanese Aerospace Exploration Agency (JAXA) mission Hayabusa2, scientists are increasingly confident that the building blocks of life on Earth came from space.

The post Components of RNA among life’s building blocks found in NASA asteroid sample appeared first on Physics World.

So you want to install a wind turbine? Here’s what you need to know

8 décembre 2025 à 12:00

As a physicist in industry, I spend my days developing new types of photovoltaic (PV) panels. But I’m also keen to do something for the transition to green energy outside work, which is why I recently installed two PV panels on the balcony of my flat in Munich. Fitting them was great fun – and I can now enjoy sunny days even more knowing that each panel is generating electricity.

However, the panels, which each have a peak power of 440 W, don’t cover all my electricity needs, which prompted me to take an interest in a plan to build six wind turbines in a forest near me on the outskirts of Munich. Curious about the project, I particularly wanted to find out when the turbines will start generating electricity for the grid. So when I heard that a weekend cycle tour of the site was being organized to showcase it to local residents, I grabbed my bike and joined in.

As we cycle, I discover that the project – located in Forstenrieder Park – is the joint effort of four local councils and two “citizen-energy” groups, who’ve worked together for the last five years to plan and start building the six turbines. Each tower will be 166 m high and the rotor blades will be 80 m long, with the plan being for them to start operating in 2027.

I’ve never thought of Munich as a particularly windy city, but at the height at which the blades operate, there’s always a steady, reliable flow of wind

I’ve never thought of Munich as a particularly windy city. But tour leader Dieter Maier, who’s a climate adviser to Neuried council, explains that at the height at which the blades operate, there’s always a steady, reliable flow of wind. In fact, each turbine has a designed power output of 6.5 MW and will deliver a total of 10 GWh in energy over the course of a year.

Practical questions

Cycling around, I’m excited to think that a single turbine could end up providing the entire electricity demand for Neuried. But installing wind turbines involves much more than just the technicalities of generating electricity. How do you connect the turbines to the grid? How do you ensure planes don’t fly into the turbines? What about wildlife conservation and biodiversity?

At one point of our tour, we cycle round a 90-degree bend in the forest and I wonder how a huge, 80 m-long blade will be transported round that kind of tight angle? Trees will almost certainly have to be felled to get the blade in place, which sounds questionable for a supposedly green project. Fortunately, project leaders have been working with the local forest manager and conservationists, finding ways to help improve the local biodiversity despite the loss of trees.

As a representative of BUND (one of Germany’s biggest conservation charities) explains on the tour, a natural, or “unmanaged”, forest consists of a mix of areas with a higher or lower density of trees. But Forstenrieder Park has been a managed forest for well over a century and is mostly thick with trees. Clearing trees for the turbines will therefore allow conservationists to grow more of the bushes and plants that currently struggle to find space to flourish.

Small group of bikes at the edge of a large clearing in a forest
Cut and cover Trees in Forstenrieder Park have had to be chopped down to provide room for new wind turbines to be installed, but the open space will let conservationists grow plants and bushes to boost biodiversity. (Courtesy: Janina Moereke)

To avoid endangering birds and bats native to this forest, meanwhile, the turbines will be turned off when the animals are most active, which coincidentally corresponds to low wind periods in Munich. Insurance costs have to be factored in too. Thankfully, it’s quite unlikely that a turbine will burn down or get ice all over its blades, which means liability insurance costs are low. But vandalism is an ever-present worry.

In fact, at the end of our bike tour, we’re taken to a local wind turbine that is already up and running about 13 km further south of Forstenrieder Park. This turbine, I’m disappointed to discover, was vandalized back in 2024, which led to it being fenced off and video surveillance cameras being installed.

But for all the difficulties, I’m excited by the prospect of the wind turbines supporting the local energy needs. I can’t wait for the day when I’m on my balcony, solar panels at my side, sipping a cup of tea made with water boiled by electricity generated by the rotor blades I can see turning round and round on the horizon.

The post So you want to install a wind turbine? Here’s what you need to know appeared first on Physics World.

When is good enough ‘good enough’?

1 décembre 2025 à 12:00

Whether you’re running a business project, carrying out scientific research, or doing a spot of DIY around the house, knowing when something is “good enough” can be a tough question to answer. To me, “good enough” means something that is fit for purpose. It’s about striking a balance between the effort required to achieve perfection and the cost of not moving forward. It’s an essential mindset when perfection is either not needed or – as is often the case – not attainable.

When striving for good enough, the important thing to focus on is that your outcome should meet expectations, but not massively exceed them. Sounds simple, but how often have we heard people say things like they’re “polishing coal”, striving for “gold plated” or “trying to make a silk purse out of a sow’s ear”. It basically means they haven’t understood, defined or even accepted the requirements of the end goal.

Trouble is, as we go through school, college and university, we’re brought up to believe that we should strive for the best in whatever we study. Those with the highest grades, we’re told, will probably get the best opportunities and career openings. Unfortunately, this approach means we think we need to aim for perfection in everything in life, which is not always a good thing.

How to be good enough

So why is aiming for “good enough” a good thing to do? First, there’s the notion of “diminishing returns”. It takes a disproportionate amount of effort to achieve the final, small improvements that most people won’t even notice. Put simply, time can be wasted on unnecessary refinements, as embodied by the 80/20 rule (see box).

The 80/20 rule: the guiding principle of “good enough”

Also known as the Pareto principle – in honour of the Italian economist Vilfredo Pareto who first came up with the idea – the 80/20 rule states that for many outcomes, 80% of consequences or results come from 20% of the causes or effort. The principle helps to identify where to prioritize activities to boost productivity and get better results. It is a guideline, and the ratios can vary, but it can be applied to many things in both our professional and personal lives.

Examples from the world of business include the following:

Business sales: 80% of a company’s revenue might come from 20% of its customers.

Company productivity: 80% of your results may come from 20% of your daily tasks.

Software development: 80% of bugs could be caused by 20% of the code.

Quality control: 20% of defects may cause 80% of customer complaints.

Good enough also helps us to focus efforts. When a consumer or customer doesn’t know exactly what they want, or a product development route is uncertain, it can be better to deliver things in small chunks. Providing something basic but usable can be used to solicit feedback to help clarify requirements or make improvements or additions that can be incorporated into the next chunk. This is broadly along the lines of a “minimum viable product”.

Not seeking perfection reminds us too that solutions to problems are often uncertain. If it’s not clear how, or even if, something might work, a proof of concept (PoC) can instead be a good way to try something out. Progress can be made by solving a specific technical challenge, whether via a basic experiment, demonstration or short piece of research. A PoC should help avoid committing significant time and resource to something that will never work.

Aiming for “good enough” naturally leads us to the notion of “continuous improvement”. It’s a personal favourite of mine because it allows for things to be improved incrementally as we learn or get feedback, rather than producing something in one go and then forgetting about it. It helps keep things current and relevant and encourages a culture of constantly looking for a better way to do things.

Finally, when searching for good enough, don’t forget the idea of ballpark estimates. Making approximations sounds too simple to be effective, but sometimes a rough estimate is really all you need. If an approximate guess can inform and guide your next steps or determine whether further action will be necessary then go for it. 

The benefits of good enough

Being good enough doesn’t just lead to practical outcomes, it can benefit our personal well-being too. Our time, after all, is a precious commodity and we can’t magically increase this resource. The pursuit of perfection can lead to stagnation, and ultimately burnout, whereas achieving good enough allows us to move on in a timely fashion.

A good-enough approach will even make you less stressed. By getting things done sooner and achieving more, you’ll feel freer and happier about your work even if it means accepting imperfection. Mistakes and errors are inevitable in life, so don’t be afraid to make them; use them as learning opportunities, rather than seeing them as something bad. Remember – the person who never made a mistake never got out of bed.

Recognizing that you’ve done the best you can for now is also crucial for starting new projects and making progress. By accepting good enough you can build momentum, get more things done, and consistently take actions toward achieving your goals.

Finally, good enough is also about shared ownership. By inviting someone else to look at what you’ve done, you can significantly speed up the process. In my own career I’ve often found myself agonising over some obscure detail or feeling something is missing, only to have my quandary solved almost instantly simply by getting someone else involved – making me wish I’d asked them sooner.

Caveats and conclusions

Good enough comes with some caveats. Regulatory or legislative requirements means there will always be projects that have to reach a minimum standard, which will be your top priority. The precise nature of good enough will also depend on whether you’re making stuff (be it cars or computers) or dealing with intangible commodities such as software or services.

So what’s the conclusion? Well, in the interests of my own time, I’ve decided to apply the 80/20 rule and leave it to you to draw your own conclusion. As far as I’m concerned, I think this article has been good enough, but I’m sure you’ll let me know if it hasn’t. Consider it as a minimally viable product that I can update in a future column.

The post When is good enough ‘good enough’? appeared first on Physics World.

‘Caustic’ light patterns inspire new glass artwork

25 novembre 2025 à 18:00

UK artist Alison Stott has created a new glass and light artwork – entitled Naturally Focused – that is inspired by the work of theoretical physicist Michael Berry from the University of Bristol.

Stott, who recently competed an MA in glass at Arts University Plymouth, spent over two decades previously working in visual effects for film and television, where she focussed on creating photorealistic imagery.

Her studies touched on how complex phenomena can arise from seemingly simple set-ups, for example in a rotating glass sculpture lit by LEDs.

“My practice inhabits the spaces between art and science, glass and light, craft and experience,” notes Stott. “Working with molten glass lets me embrace chaos, indeterminacy, and materiality, and my work with caustics explores the co-creation of light, matter, and perception.”

The new artwork is based on “caustics” – the curved patterns that form when light is reflected or refracted by curved surfaces or objects

The focal point of the artwork is a hand-blown glass lens that was waterjet-cut into a circle and polished so that its internal structure and optical behaviour are clearly visible. The lens is suspended within stainless steel gyroscopic rings and held by a brass support and stainless stell backplate.

The rings can be tilted or rotated to “activate shifting field of caustic projections that ripple across” the artwork. Mathematical equations are also engraved onto the brass that describe the “singularities of light” that are visible on the glass surface.

The work is inspired by Berry’s research into the relationship between classical and quantum behaviour and how subtle geometric structures govern how waves and particles behave.

Berry recently won the 2025 Isaac Newton Medal and Prize, which is presented by the Institute of Physics, for his “profound contributions across mathematical and theoretical physics in a career spanning over 60 years”.

Stott says that working with Berry has pushed her understanding of caustics. “The more I learn about how these structures emerge and why they matter across physics, the more compelling they become,” notes Stott. “My aim is to let the phenomena speak for themselves, creating conditions where people can directly encounter physical behaviour and perhaps feel the same awe and wonder I do.”

The artwork will go on display at the University of Bristol following a ceremony to be held on 27 November.

The post ‘Caustic’ light patterns inspire new glass artwork appeared first on Physics World.

❌