The counter space in my kitchen is at a premium. It’s valuable real estate, and every square inch matters. So when a new espresso machine arrives at my door, I always have to play a high-stakes game of countertop appliance Tetris to figure out how everything will fit—or who needs to get banished into a cupboard. When the De’Longhi Specialista Arte Evo rolled into my kitchen, I was ready to make tough decisions.
From the box’s size, I was sure the rice cooker or the food processor would have to be exiled. When I got the De’Longhi out of its box, though, my appliances breathed a sigh of relief. This is a svelte espresso machine, and it fits perfectly without sending any of my favorite appliances to a pantry gulag. Things were off to a good start, and it only got better—mostly.
Slim and Consistent
The first couple of shots I pull out of any espresso machine will usually require some finagling. When an espresso machine has an internal burr grinder, that’s just one other thing I have to dial in from scratch. By the second shot, I was happy with what I was getting out of the Specialista.
The espresso poured into the cup in two streams of luxurious caramel-gold liquid, the crema gathering on top in an even layer. I changed the settings and pulled more tester shots to see how it performed with different grind consistencies and amounts for testing purposes, but by that second shot, I knew I’d found the sweet spot.
Photograph: Jaina Grey
Something I always like about De’Longhi espresso machines is the knobs. A lot of different models from the company up and down the price spectrum have really good knobs. The ones here are a joy to use. They’re raised from the surface of the control panel, and the outward face has the signature concentric circles of machined steel; the sides are adorned with textured metal accents. One controls the amount of coffee to grind, and the other toggles between brewing modes.
When you turn the grind knob, there’s a little resistance, just enough to feel like you have very fine control. The mode knob has a satisfying click when you switch from one mode to another. How much you enjoy using a device is important, and these little details make the Specialista Arte Evo feel good to use.
The Specialista Arte Evo comes in at a delightfully narrow 11.2 inches, sparing quite a bit of my counter space—especially since this is taking the place of two appliances, an espresso machine and a coffee grinder. There are smaller espresso machines—the new KitchenAid Semi-Automatic Espresso Machine is about as narrow as the Specialista—but most that have a built-in grinder are a little wider.
Photograph: Jaina Grey
Some Assembly Required
The Specialista’s built-in conical burr grinder can grind coffee fine enough for espresso and coarse enough for drip or other brewing methods, so it’s capable of replacing a stand-alone grinder. There is one little quirk, though. The portafilter can’t slot into place underneath the grinder unless you attach the “grinding and tamping guide.” This component is a short cylinder of plastic that locks onto the portafilter to guide the grounds directly into the basket and help direct the tamp down onto the grounds.
It’s weird. The guide doesn’t feel as high-quality as other parts of the Specialista, almost like a cheap 3D-printed plastic. If you try to slot the portafilter underneath the grinder without the guide, you have to hold it there the whole time, and the grinder will likely spill some grounds into the drip tray. It feels like the grinding and tamping guide was added as a fix to the issue of the grounds spilling out.
Matson told me that he finds wearing a headset to be too cumbersome when you’re working out. In particular, parents told him that they can’t check out with VR because they need to know what’s going on around them. However, I prefer to not have any distractions, mainly because I’m horrible at exercise and will take any excuse not to do it.
High-endurance athletes may find Saga’s offerings a bit slim, too. Matson says the company plans to ship the bikes with three to four trails in the system, each about 20 kilometers long. This is not very many rides, and those rides are not very long. By way of contrast, NordicTrack has an extensive library of rides of all lengths, levels, and programs, which also increase resistance and move up and down as you ride. Other bikes integrate with Zwift, the immensely popular online cycling platform, or collect intensely granular data that allows you to improve your fitness.
Photograph: Saga Holographic
As of yet, HoloBike doesn’t do any of those things. The augmented technology, however, certainly makes what you’re seeing seem more real. And in some circumstances, not being real is a bonus. If all the trails are virtually generated, I’d love to have the ability to safely traverse places I wouldn’t otherwise go, like the streets of Mumbai, or even something entirely fictional, like a delivery route from Paperboy, or Elliott’s big take-off from E.T.
It would be cool if there were a possibility for users to design or contribute trails, too. I joked to Matson that they should make some version of a trail that goes all the way around the world, so you could circumnavigate the globe over the course of a year’s worth of rides, only to have him suggest creating a little onscreen pedal boat for when you’re crossing the Atlantic. With the HoloBike, the world really is entirely open and limitless. That’s enormously exciting.
That being said, the bike’s starting price tag on Kickstarter is $2,599, with expected delivery in the winter of 2024-2025. That’s comparable to other video-enabled stationary exercise bikes, but a lot to shell out for potential. If I’m going to ride a bike, I need something that approximates the feeling of the open road a little more closely, and for a little bit longer.
If you’re in the market for a mini PC then you really should be taking a look at what Minisforum has to offer.
The Chinese company produces a range of affordable, well-specced devices, such as its latest release, the UM790 XTX. This is a more powerful alternative to the UM780 XTX which Minisforum currently refers to as “The king of the Mini PC”.
Although the company first announced the UM790 XTX towards the end of last year, it has only just now gone on sale in China. The new device comes with a Ryzen 9 7940HS processor that can be pushed up to 70W TDP – 25 watts more than AMD’s default. The UM780 XTX, in comparison, comes with a Ryzen 7 7840HS CPU.
With or without RAM and storage
Elsewhere, the UM790 XTX is equipped with a decent selection of ports. On one side there’s a USB4 (Alt PD) port, two USB 3.2 Gen2 Type-A ports, and an audio jack. The other side offers another USB4 port, another two USB 3.2 Type A ports, HDMI, Display Port, and two RJ45 2.5G network ports. There’s also an OCulink port so you can connect pro GPU cards to the device.
UM790 XTX also comes with upgraded active cooling (from 65w to 70w) to ensure optimal operating temperatures even under heavy loads. It also has a magnetic top cover with a replaceable backlight etched sheet and RGB lighting.
The mini PC can be purchased without memory and storage for CNY 3,299 ($455), or you can choose a model with 16GB /32GB/64GB of DDR5-5600 RAM and a 512GB/1TB/2TB SSD with pricing starting from CNY 3,999 ($552).
At the moment the UM790 XTX is only available to buy in China, but Minisforum sells most of its mini PCs globally, including the UM780 XTX, so it’s likely only a matter of time before it becomes more widely available.
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Electrons in stacked sheets of staggered graphene collectively act as though they have fractional charges at ultralow temperatures.Credit: Ramon Andrade 3DCiencia/Science Photo Library
Two teams have observed that electrons, which usually have a charge of −1, can behave as if they had fractional charges (such as −2/3) — and do so without being nudged by an external magnetic field. It’s the first time this ‘fractional quantum anomalous Hall effect’ has been observed experimentally, and physicists are scratching their heads over exactly how it works. It’s a fundamental discovery that might also someday have practical applications: fractionally charged particles are a key requirement for a certain type of quantum computer. “I don’t know anyone who’s not excited about this,” says condensed-matter physicist Pablo Jarillo-Herrero.
Japanese tits (Parus minor) flutter their wings to invite their mate to enter the nest first. Scientists who observed eight breeding pairs of wild tits noticed that when one of the birds sat in front of the next box and fluttered its wings, the other would go in first. It’s the first documented evidence of birds using a symbolic gesture: one that has a specific meaning (like waving ‘goodbye’) but isn’t simply pointing at an object of interest. “It implies that birds have a level of understanding of symbolism that probably a lot of people wouldn’t have given them credit for before,” says ornithologist Mike Webster.
Offering researchers more money or time doesn’t seem to push them towards higher-risk, higher-reward projects. A survey asked more than 4,000 US-based academics how various hypothetical grants would influence their research strategy. Only tenured professors were willing to pursue riskier research with longer-running grants. And respondents were very unwilling to take less money in exchange for a longer grant. The results seem to suggest that “fairly reasonable changes in the structure of one particular individual grant don’t do enough to change the overall incentive structure”, says Carl Bergstrom, a biologist who has studied science-funding models.
The number of satellites and other space debris in low-Earth orbit (a) is on track to exceed 100,000 in the next ten years as SpaceX, OneWeb, GuoWang and Amazon plan to launch around 65,000 satellites (b). Policymakers must come up with a plan for space sustainability, argues a group of astronomers. (Nature Sustainability | 10 min read) (A. Williams et al./Nature Sustainability)
You might have heard this one before: astronomer Fred Hoyle coined the phrase ‘Big Bang’ to make fun of a theory of the Universe’s origins that he disliked. Wrong, writes historian Helge Kragh. Hoyle did originate the catchy term — in a 1949 popular-science talk for BBC radio — but it was never intended as ridicule. And most people, including Hoyle, pretty much ignored it for decades afterwards. In 1965, the discovery of the cosmic microwave background signalled the triumph of the theory, ‘Big Bang’ made it into a New York Times headline, and the term snowballed into the popular lexicon.
Climate forecasting powered by artificial-intelligence (AI) algorithms could replace the equation-based systems that guide global policy. Some scientists are developing AI emulators that produce the same results as conventional models but do so much faster, using less energy. Others are hoping that AI systems can pick up on hidden patterns in climate data to make better predictions. Hybrids could embed machine-learning components inside physics-based models to gain better performance while being more trustworthy than models built entirely from AI. “I think the holy grail really is to use machine learning or AI tools to learn how to represent small-scale processes,” says climate scientist Tapio Schneider.
Nature artist and scientific illustrator Zoe Keller says she is particularly drawn to “less charismatic” species such as snakes, amphibians, invertebrates, bats and fungi. (Nautilus | 6 min read)
Tonight, I’ll be keeping an eye on Corona Borealis, a constellation that is home to a white dwarf star. Once every 80 years or so, the white dwarf blows off the material it has syphoned off from a nearby red giant star in a spectacular cosmic explosion visible to the naked eye — and it’s expected to take place sometime before September.
Help to keep this newsletter on a stable trajectory by sending your feedback to [email protected].
Electrons in stacked sheets of staggered graphene collectively act as though they have fractional charges at ultra-low temperatures.Credit: Ramon Andrade 3DCiencia/Science Photo Library
Minneapolis, Minnesota
Last May, a team led by physicists at the University of Washington in Seattle observed something peculiar. When the scientists ran an electrical current across two atom-thin sheets of molybdenum ditelluride (MoTe2), the electrons acted in concert, like particles with fractional charges. Resistance measurements showed that, rather than the usual charge of –1, the electrons behaved similar to particles with charges of –2/3 or –3/5, for instance. What was truly odd was that the electrons did this entirely because of the innate properties of the material, without any external magnetic field coaxing them. The researchers published the results a few months later, in August1.
Strange topological materials are popping up everywhere physicists look
That same month, this phenomenon, known as the fractional quantum anomalous Hall effect (FQAHE), was also observed in a completely different material. A team led by Long Ju, a condensed-matter physicist at the Massachusetts Institute of Technology (MIT) in Cambridge, saw the effect when they sandwiched five layers of graphene between sheets of boron nitride. They published their results in February this year2 — and physicists are still buzzing about it.
At the American Physical Society (APS) March Meeting, held in Minneapolis, Minnesota, from 3 to 8 March, Ju presented the team’s findings, which haven’t yet been replicated by other researchers. Attendees, including Raquel Queiroz, a theoretical physicist at Columbia University in New York City, said that they thought the results were convincing, but were scratching their heads over the discovery. “There is a lot we don’t understand,” Queiroz says. Figuring out the exact mechanism of the FQAHE in the layered graphene will be “a lot of work ahead of theorists”, she adds.
Although the FQAHE might have practical applications down the line — fractionally charged particles are a key requirement for a certain type of quantum computer — the findings are capturing physicists’ imagination because they are fundamentally new discoveries about how electrons behave.
“I don’t know anyone who’s not excited about this,” says Pablo Jarillo-Herrero, a condensed-matter physicist at MIT who was not involved with the studies. “I think the question is whether you’re so excited that you switch all your research and start working on it, or if you’re just very excited.”
Strange maths
Strange behaviour by electrons isn’t new.
In some materials, usually at temperatures near absolute zero, electrical resistance becomes quantized. Specifically it’s the material’s transverse resistance that does this. (An electrical current encounters opposition to its flow in both the same direction as the current — called longitudinal resistance — and in the perpendicular direction — what’s called transverse resistance.)
Quantized ‘steps’ in the transverse resistance occur at multiples of electron charge: 1, 2, 3 and so on. These plateaus are the result of a strange phenomenon: the electrons maintain the same transverse resistance even as charge density increases. That’s a little like vehicles on a highway moving at the same speed, even with more traffic. This is known as the quantum Hall effect.
In a different set of materials, with less disorder, the transverse resistance can even display plateaus at fractions of electron charge: 2/5, 3/7 and 4/9, for example. The plateaus take these values because the electrons collectively act like particles with fractional charges — hence the fractional quantum Hall effect (FQHE).
Key to both phenomena is a strong external magnetic field, which prevents electrons from crashing into each other and enables them to interact.
(Left to right) Long Ju, Zhengguang Lu, Yuxuan Yao and Tonghang Hang are all part of the team at MIT that demonstrated the FQAHE in layered graphene.Credit: Jixiang Yang
The FQHE, discovered in 1982, revealed the richness of electron behaviour. No longer could physicists think of electrons as single particles; in delicate quantum arrangements, the electrons could lose their individuality and act together to create fractionally charged particles. “I think people don’t appreciate how different [the fractional] is from the integer quantum Hall effect,” says Ashvin Vishwanath, a theoretical physicist at Harvard University in Cambridge. “It’s a new world.”
Over the next few decades, theoretical physicists came up with models to explain the FQHE and predict its effects. During their exploration, a tantalizing possibility appeared: perhaps a material could exhibit resistance plateaus without any external magnetic field. The effect, now dubbed the quantum anomalous Hall effect — ‘anomalous’, for the lack of a magnetic field — was finally observed in thin ferromagnetic films by a team at Tsinghua University in Beijing, in 20123.
Carbon copy
Roughly a decade later, the University of Washington team reported the FQAHE for the first time1, in a specially designed 2D material: two sheets of MoTe2 stacked on top of one another and offset by a twist.
This arrangement of MoTe2 is known as a moiré material. Originally used to refer to a patterned textile, the term has been appropriated by physicists to describe the patterns in 2D materials created from atom-thin lattices when they are stacked and then twisted, or staggered atop one another. The slight offset between atoms in different layers of the material shifts the hills and valleys of its electric potential. And it effectively acts like a powerful magnetic field, taking the place of the one needed in the quantum Hall effect and the FQHE.
Xiaodong Xu, a condensed-matter physicist at the University of Washington, talked about the MoTe2 discovery at the APS meeting. Theory hinted that the FQAHE would appear in the material at about a 1.4º twist angle. “We spent a year on it, and we didn’t see anything,” Xu told Nature.
Source: Adapted from Ref. 2.
Then, the researchers tried a larger angle — a twist of about 4º. Immediately, they began seeing signs of the effect. Eventually, they measured the electrical resistance and spotted the signature plateaus of the FQAHE. Soon after, a team led by researchers at Shanghai Jiao Tong University in China replicated the results4.
Meanwhile at MIT, Ju was perfecting his technique, sandwiching graphene between layers of boron nitride. Similar to graphene, the sheets of boron nitride that Ju’s team used were a mesh of atoms linked together in a hexagonal pattern. Its lattice has a slightly different size than graphene; the mismatch creates a moiré pattern (see ‘Anomalous behaviour’).
Last month, Ju published a report2 about seeing the characteristic plateaus. “It is a really amazing result,” Xu says. “I’m very happy to see there’s a second system.” Since then, Ju says that he’s also seen the effect when using four and six layers of graphene.
Both moiré systems have their pros and cons. MoTe2 exhibited the effect at a few Kelvin, as opposed to 0.1 Kelvin for the layered graphene sandwich. (Low temperatures are required to minimize disorder in the systems.) But graphene is a cleaner and higher-quality material that is easier to measure. Experimentalists are now trying to replicate the results in graphene and find other materials that behave similarly.
Moiré than bargained for
Theorists are relatively comfortable with the MoTe2 results, for which the FQAHE was partly predicted. But Ju’s layered graphene moiré was a shock to the community, and researchers are still struggling to explain how the effect happens. “There’s no universal consensus on what the correct theory is,” Vishwanath says. “But they all agree that it’s not the standard mechanism.” Vishwanath and his colleagues posted a preprint proposing a theory that the moiré pattern might not be that important to the FQAHE5.
Welcome anyons! Physicists find best evidence yet for long-sought 2D structures
One reason to doubt the importance of the moiré is the location of the electrons in the material: most of the activity is in the topmost layer of graphene, far away from the moiré pattern between the graphene and boron nitride at the bottom of the sandwich that is supposed to most strongly influence the electrons. But B. Andrei Bernevig, a theoretical physicist at Princeton University in New Jersey, and a co-author of another preprint proposing a mechanism for the FQAHE in the layered graphene6, urges caution about theory-based calculations, because they rely on currently unverified assumptions. He says that the moiré pattern probably matters, but less than it does in MoTe2.
For theorists, the uncertainty is exciting. “There are people who would say that everything has been seen in the quantum Hall effect,” Vishwanath says. But these experiments, especially the one using the layered graphene moiré, show that there are still more mysteries to uncover.
The worm-like caecilian Siphonops annulatus is the first amphibian described to produce ‘milk’ for offspring hatched outside its body.Credit: Carlos Jared
An egg-laying amphibian found in Brazil nourishes its newly hatched young with a fatty, milk-like substance, according to a study published today in Science1.
Lactation is considered a key characteristic of mammals. But a handful of other animals — including birds, fish, insects and even spiders — can produce nutrient-rich liquid for their offspring.
That list also includes caecilians, a group of around 200 limbless, worm-like amphibian species found in tropical regions, most of which live underground and are functionally blind. Around 20 species are known to feed unborn offspring — hatched inside the reproductive system — a type of milk. But the Science study is the first time scientists have described an egg-laying amphibian doing this for offspring hatched outside its body.
The liquid is “functionally similar” to mammalian milk, says study co-author Carlos Jared, a naturalist at the Butantan Institute in São Paulo, Brazil.
An unusual diet
In the 2000s, researchers showed that in some caecilians, the young hatched with teeth and that they fed on a nutrient-rich layer of their mother’s skin2 around every seven days. “It sounded a little strange — babies eating just once a week,” says Marta Antoniazzi, a naturalist also at the Butantan Institute. “That wouldn’t be sufficient for the babies to develop as they do.”
Antoniazzi, Jared and their colleagues wanted to investigate these young amphibians’ bizarre feeding habits in more detail, so they collected 16 nesting caecilians of the species Siphonops annulatus and their young at cacao plantations in the Atlantic Forest in Brazil. The researchers then filmed the animals and analysed more than 200 hours of their behaviour.
The footage revealed that as well as munching on their mother’s skin, S. annulatus young could get their mother to eject a fat- and carbohydrate-rich liquid from her cloaca — the combined rear opening for the reproductive and digestive systems — by making high-pitched clicking noises. The young would also stick their heads into the cloaca to feed.
The finding that S. annulatus is “both a skin feeder and now a milk producer is pretty amazing”, says Marvalee Wake, an evolutionary biologist at the University of California, Berkeley. It is probably just one of the caecilians’ many biological quirks. “Most species have not been studied at this level of detail,” says Wake. “So, who knows what else they’re doing.”
