Author: peterjang73

The search for planets outside our Solar System – exoplanets – is one of the most rapidly growing fields in astronomy. Over the past few decades, more than 5,000 exoplanets have been detected and astronomers now estimate that on average there is at least one planet per star in our galaxy.

Many current research efforts aim at detecting Earth-like planets suitable for life. These endeavours focus on so-called “main sequence” stars like our Sun – stars which are powered by fusing hydrogen atoms into helium in their cores, and remain stable for billions of years. More than 90% of all known exoplanets so far have been detected around main-sequence stars.

As part of an international team of astronomers, we studied a star that looks much like our Sun will in billions of years’ time, and found it has a planet which by all rights it should have devoured. In research published today in Nature, we lay out the puzzle of this planet’s existence – and propose some possible solutions.

A glimpse into our future: red giant stars

Just like humans, stars undergo changes as they age. Once a star has used up all its hydrogen in the core, the core of the star shrinks and the outer envelope expands as the star cools.

In this “red giant” phase of evolution, stars can grow to more than 100 times their original size. When this happens to our Sun, in about 5 billion years, we expect it will grow so large it will engulf Mercury, Venus, and possibly Earth.

Eventually, the core becomes hot enough for the star to begin fusing helium. At this stage the star shrinks back to about 10 times its original size, and continues stable burning for tens of millions of years.

We know of hundreds of planets orbiting red giant stars. One of these is called 8 Ursae Minoris b, a planet with around the mass of Jupiter in an orbit that keeps it only about half as far from its star as Earth is from the Sun.

The planet was discovered in 2015 by a team of Korean astronomers using the “Doppler wobble” technique, which measures the gravitational pull of the planet on the star. In 2019, the International Astronomical Union dubbed the star Baekdu and the planet Halla, after the tallest mountains on the Korean peninsula.

A planet that should not be there

Analysis of new data about Baekdu collected by NASA’s Transiting Exoplanet Survey Satellite (TESS) space telescope has yielded a surprising discovery. Unlike other red giants we have found hosting exoplanets on close-in orbits, Baekdu has already started fusing helium in its core.

Using the techniques of asteroseismology, which studies waves inside stars, we can determine what material a star is burning. For Baekdu, the frequencies of the waves unambiguously showed it has commenced burning helium in its core.

The discovery was puzzling: if Baekdu is burning helium, it should have been much bigger in the past – so big it should have engulfed the planet Halla. How is it possible Halla survived?

As is often the case in scientific research, the first course of action was to rule out the most trivial explanation: that Halla never really existed.

Indeed, some apparent discoveries of planets orbiting red giants using the Doppler wobble technique have later been shown to be illusions created by long-term variations in the behaviour of the star itself.

However, follow-up observations ruled out such a false-positive scenario for Halla. The Doppler signal from Baekdu has remained stable over the last 13 years, and close study of other indicators showed no other possible explanation for the signal. Halla is real – which returns us to the question of how it survived engulfment.

Two stars become one: a possible survival scenario

Having confirmed the existence of the planet, we arrived at two scenarios which could explain the situation we see with Baekdu and Halla.

At least half of all stars in our galaxy did not form in isolation like our Sun, but are part of binary systems. If Baekdu once was a binary star, Halla may have never faced the danger of engulfment.

A merger of these two stars may have prevented the expansion of either star to a size large enough to engulf planet Halla. If one star became a red giant on its own, it would have engulfed Halla – however, if it merged with a companion star it would jump straight to the helium-burning phase without getting big enough to reach the planet.

Alternatively, Halla may be a relatively newborn planet. The violent collision between the two stars may have produced a cloud of gas and dust from which the planet could have formed. In other words, the planet Halla may be a recently born “second generation” planet.

Whichever explanation is correct, the discovery of a close-in planet orbiting a helium-burning red giant star demonstrates that nature finds ways for exoplanets to appear in places where we might least expect them.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Gaming giant Valve has responded to reports that it is rejecting games from Steam that contain content created with artificial intelligence. Specifically, some developers have reported that Valve is blocking games from Steam if the developers cannot prove they have the underlying asset rights.

Valve reacted to this with a public statement shared with GameSpot. The company said it believes AI will have a role to play in the future of game development. At the same time, Valve said the “legal uncertainty” surrounding AI might prove to be a sticking point in the near future as AI evolves.

“We are continuing to learn about AI, the ways it can be used in game development, and how to factor it in to our process for reviewing games submitted for distribution on Steam,” Valve said. “Our priority, as always, is to try to ship as many of the titles we receive as we can. The introduction of AI can sometimes make it harder to show a developer has sufficient rights in using AI to create assets, including images, text, and music. In particular, there is some legal uncertainty relating to data used to train AI models. It is the developer’s responsibility to make sure they have the appropriate rights to ship their game.”

Valve said AI is a “constantly evolving” piece of technology, and it is not attempting to discourage the use of it on Steam. In fact, Valve said it is now “working through” how to incorporate AI into the existing Steam review policies, and right now, this means some games have been blocked.

“Stated plainly, our review process is a reflection of current copyright law and policies, not an added layer of our opinion. As these laws and policies evolve over time, so will our process,” Valve said. “We welcome and encourage innovation, and AI technology is bound to create new and exciting experiences in gaming. While developers can use these AI technologies in their work with appropriate commercial licenses, they can not infringe on existing copyrights.”

Finally, Valve said it doesn’t normally refund app submission payments, but in this case–for titles involving the use of AI–developers can be refunded as Valve works through its review process.

AI has been a major topic in the wider technology space and video games specifically in recent times. Microsoft partnered up with ChatGPT and reportedly invested $10 billion into the AI company. Microsoft Gaming CEO Phil Spencer believes AI will be a positive, additive force in gaming. Strauss Zelnick, the head of GTA parent company Take-Two, believes in AI as well, but he doesn’t think a rival developer could use it to make a genuine GTA competitor anytime soon. PUBG creator Brendan Greene’s new game, meanwhile, is using advanced machine-learning to create massive and realistic open worlds.

Outside of the video game space, Hollywood writers are now on strike due in part to concerns about AI and what role the technology could play in scriptwriting.

Got a news tip or want to contact us directly? Email news@gamespot.com

• A SpaceX-backed startup’s electric flying became the first to get approval for flight tests.
• Alef Aeronautics is already taking pre-orders for the car that will start at $300,000.
• Alef CEO Jim Dukhovny previously told CNBC he expected the car to be available in 2025.

A fully electric flying car that’ll cost about $300,000 just won approval to start testing on the road – and in the air. 

Alef Aeronautics, a Californian automaker, said in a press release it had received a Special Airworthiness Certification from the Federal Aviation Administration (FAA) for the Model A. 

It’s the first such approval for a flight-capable car, according to the startup, which has been backed by the likes of SpaceX.

Alef CEO Jim Dukhovny said: “It allows us to move closer to bringing people an environmentally friendly and faster commute, saving individuals and companies hours each week. This is one small step for planes, one giant step for cars.”

Due to evolving FAA restrictions tied to the unprecedented capabilities of flying cars, Alef said its certification limits the locations and purpose for which it is permitted to fly.

The company aimed to produce the first flying car with both street driving and vertical take-off capabilities. It’s designed to fit within existing urban infrastructure for driving and parking.

The flying car is able to take off vertically or horizontally, and can carry up to two people. It’s expected to have a road range of 200 miles and a flying range of 110 miles.

Buyers can pay a $150 deposit to join the general queue, or $1,500 to get priority access when deliveries start. 

About 440 people paid deposits in the final three months of 2022, Alef said in January.

In December, Dukhovny told CNBC Make It that customers could expect to see their cars in the sky by 2025.

Alef wasn’t the only flying car and air taxi company to make a major regulatory breakthrough in recent days.

On Wednesday, shares in flying taxi comapny Joby Aviation soared 44% after it also received a Special Airworthiness Certificate from the FAA.  

In a small seaside town in northeast Japan, factory workers are disassembling old batteries from the world’s first mass-market electric cars and preparing them for a second life. Reusing batteries could help the auto industry live up to its promise to make a truly green transition. But it’s time-consuming and, for now, unprofitable.

Early models of Nissan Motor Co.’s all-electric Leaf, which first went on sale almost 13 years ago, have started to reach the end of their life spans. In an effort to make the end of the cars’ lives as green as their operation was, their used batteries are collected at Nissan dealerships in the US and Japan and sent to the factory in Namie, Fukushima, a town devastated in 2011 by a tsunami and a nuclear disaster.

Engineers at the plant, operated by 4R Energy Co. — Nissan’s joint venture with trading house Sumitomo Corp. — spend hours on each battery pack before shipping them out, mostly to be used again in another electric vehicle but sometimes to be repurposed in other devices, such as backup generators.

Collecting and reusing EV batteries keeps them from being discarded in landfills, where they might release toxins, or from being melted and pulled apart for their metals, which can be hazardous when done improperly. It also would reduce the industry’s reliance on the mining of costly rare-earth elements such as lithium and cobalt and cut down on the carbon emissions involved in making EV batteries — the dark side of the green car business.

Moreover, creating a bigger market for used batteries could boost the secondhand market for electric cars as well, by extending their life span and bolstering their resale value, which would hasten their adoption, says Yutaka Horie, the president of 4R Energy. “For EVs to proliferate, it needs to get easier for customers to buy and sell,” Horie said as he gave a tour of the factory that opened in 2018 with local government support. Namie officials have been trying to attract industries to the area after it lost 90% of its population in the evacuations following the Fukushima disaster.

With all the nuclear reactors in the area now decommissioned, officials are seeking to host businesses dealing with renewable energy and other new technologies. Because the project would help fulfill Nissan’s goal to make EVs more sustainable and popular, profitability was never an urgent priority. But 4R hopes that with time, it will become a profitable business on its own.

At first glance, the factory doesn’t look very cutting-edge. Robots and other automation equipment, a common sight at most car factories these days, aren’t noticeable. Instead, most of the work is done manually by its nine, mostly local engineers.

A reused EV battery can cost about half the price of a new one, according to Bloomberg Intelligence analyst Tatsuo Yoshida. He says what sets Nissan apart from other EV makers is that its 4R subsidiary is concentrating on reusing batteries as opposed to recycling them. Reusing entails swapping out deteriorated cells with healthy ones to extend the life of an aged but still-working battery. When recycling a battery, its rare-earth metals and other useful parts are extracted and used to produce something new.

At 4R’s plant in Namie, the process starts by slicing open the battery packs to evaluate their condition. Each pack weighs 300 kilograms (661 pounds) and contains 48 modules, each consisting of two batteries. Once the insides are exposed, they’re plugged into a computer for an initial assessment.

Workers put the packs through a stress test in a sealed room they call the sauna, repeatedly exposing them to extremely high and low temperatures. This provides data on the extent of deterioration and the remaining range in each battery. “This data is everything,” Horie says, motioning toward the sauna.

The data, together with background information on previous owners—which sometimes can include everything from their geographies to driving history—offer insights on how EV batteries degrade over time under different environments, laying the groundwork for future improvements in battery development, he says.

This data-heavy, labor-intensive approach stands in sharp contrast to the recycling method being pursued by automakers such as Tesla and BYD, which break down end-of-life batteries and extract their raw minerals to reuse in completely new batteries. While both methods keep used batteries from ending up in the junkyard, 4R Energy’s extensive testing allows it to salvage more of what remains, meaning there’s less waste. But partly because of the data collection, the process is far more time-consuming.

Battery recycling might be easier to scale up as volume grows, but both recycling and reuse will have a role to play in the future, says BloombergNEF analyst Colin McKerracher. “Battery repurposing is often more time-consuming than recycling, but allows the company to reuse more of the battery materials,” he says.

4R won’t disclose financial details, except to say that it believes greater scale will eventually help it turn a profit. Horie says 4R’s intake has been doubling annually since 2018, and it now receives “thousands of batteries” every year. It also now has storage capacity for 2,000 batteries across three locations in Fukushima. But even with such growth, it’s unclear whether 4R will reach the scale required to turn a profit.

Nissan’s Leaf never quite took off with drivers, selling only 646,000 cars since production began in 2010. Early adopters of environmentally conscious vehicles instead went for hybrids such as the Toyota Prius, and attention in recent years has shifted to Tesla’s sleeker all-electric models.

4R Energy currently only handles old Leaf batteries, but it’s planning to expand its scale by working with other Nissan models including the Sakura, a newer EV popular in Japan. It’s also trying to turn the old batteries into a greater variety of equipment, including power storage units for wind, solar and other renewable energy.

Tooru Futami, who worked at 4R Energy following a career at Nissan developing the Leaf, says the batteries being made today have better range and longer life spans than old ones do, making it hard for used batteries to compete. But he believes this advantage will shrink over time, as long-range batteries join the recycling stream and improvements in battery performance plateau. “Over time, that gap will narrow,” says Futami, now a research fellow at the mobile gaming and e-commerce company DeNa Co. in Tokyo.

The Leaf was the front-runner, but batteries from the first Teslas and other early EVs are also nearing the end of their use, meaning battery recycling and refurbishing is just starting to take off. A recent surge in EV sales means more growth ahead. As many as 77 million EVs could be on the road by 2025, with 229 million by 2030, according to projections by BNEF.

Even in Japan, where EVs accounted for only 1.7% of passenger cars sold last year, the ground is shifting. In February, Nissan said, it will introduce 27 EV models. And Toyota Motor Corp., after years spent focusing on hybrids and gasoline cars, plans to rapidly expand EV production in the next few years.

The Japanese carmakers are still trailing far behind Tesla and others in EVs, despite their early start in the environmentally friendly category. These days, Chinese manufacturers dominate the EV battery supply chain, from mining to assembly, and their recycling capacity is also growing. Analysts say 4R Energy will eventually feel more competitive pressure.

“4R is the front-runner in Japan, but there are dozens like them in China,” says Hideki Kidohshi, a senior specialist in energy and transportation at the Japan Research Institute. He says it’s not realistic to expect financial viability for the company’s efforts right away, anyway. “It’s not about whether this business makes sense now,” he says. “It’s about lowering costs in preparation for future growth.”

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