When Apple cut its expectation benefit for the last quarter of 2018 because of slow sales of iPhones, markets were shocked. The company’s share price, which had been sliding for months, fell by a further 10% on January 3rd, the day after the news came out. Apple’s suppliers’ shares were also hit. But Apple’s pain is humans’ gain. The fact that these magical devices are now so popular is something to be celebrated.

Nearly 4bn of the 5.5bn adults on the planet now have one smartphone. They connect billions of people to the internet’s huge amount of information and services. Phones make markets more efficient and inspire growth. Yes, they can be used for wasting time and spreading disinformation. But the good far outweighs the bad. They might be the most effective tool of development in existence.

Actually this slowdown is the result of market saturation (饱和). After a decade of rapid taking-in, there is much less opportunity to sell handsets to first-time buyers as so few of them are left. And replacement cycles are becoming longer as new models offer only insignificant improvements. For all but the craziest fans, the slowing pace of upgrades comes as a welcome relief.

Does that mean innovation (创新) is slowing? No. The latest phones contain amazingly clever technology such as 3D face-scanners and cameras assisted by artificial intelligence. Moreover, smartphones also provide a foundation for extra innovations, like mobile payments and video streaming, and for future ones, such as controlling “smart” home equipment or robotaxis.

As computers become smaller, still more personal and closer to people’s bodies, many scientists believe that wearable devices will be the next big thing. Even so, finding another product with the range of the smartphone is a tall order. The recent slowing of smartphone sales is bad news for the industry, obviously. But for the rest of humans it is a welcome sign that a transformative technology has become almost universal.

Beneath the surface of a gemstone, on the tiny level of atoms and molecules（分子）, lie clues (线索) to its origin. At this year’s meeting of the Geological Society of America in Minneapolis, Catherine McManus reported on a technique that uses lasers (激光) to clarify these clues and identify a stone’s homeland. McManus directs scientific research at Materialytics, in Killeen, Texas. The company is developing the technique. “With enough data, we could identify which country, which mining place, even the individual mine a gemstone comes from,” McManus told Science News.

Some gemstones, including many diamonds, come from war-torn countries. Sales of those “blood minerals” may encourage violent civil wars where innocent people are injured or killed. In an effort to reduce the trade in blood minerals, the U.S. government passed law in July 2010 that requires companies that sell gemstones to determine the origins of their stones.

To figure out where gemstones come from, McManus and her team focus a powerful laser on a small sample of the gemstone. The technique is called laser-induced breakdown spectroscopy. Just as heat can turn ice into water or water into steam, energy from the laser changes the state of matter of the stone. The laser changes a miniscule part of the gemstone into plasma, a gas state of matter in which tiny particles（微粒）called electrons separate from atoms.

The plasma, which is superhot, produces a light pattern. (The science of analyzing this kind of light pattern is called spectroscopy.) Different elements（元素）produce different patterns, but McManus and her team say that gemstones from the same area produce similar patterns. Materialytics has already collected patterns from thousands of gemstones, including more than 200 from diamonds. They can compare the light pattern from an unknown gemstone to patterns they do know and look for a match. The light pattern acts like a signature, telling the researchers the origin of the gemstone.

In a small test, the laser technique correctly identified the origins of 95 out of every 100 diamonds. For gemstones like emeralds and rubies, the technique proved successful for 98 out of every 100 stones. The scientists need to collect and analyze more samples, including those from war-torn countries, before the tool is ready for commercial use.

Scientists like Barbara Dutrow, a mineralogist from Louisiana State University in Baton Rouge, find the technique exciting. “This is a basic new tool that could provide a better fingerprint of a material from a particular locality,” she told Science News.

Cities, covering less than 2% of the Earth’s surface, are major contributors to climate change, consuming almost 80% of the world’s energy and producing more than 60% of greenhouse gas emissions. Fortunately, net zero emissions (净零排放) by 2050, a target set at the COP26 conference, could be achieved faster using digital twins cities, according to a recent research.

Looking and behaving identically in their real-world physical environments, digital twins can help track, manage and reduce environmental damage rapidly. These replicas (复制品) link to networks of sensors that collect data from buildings, transport, air quality, and energy use, to see where emissions can be cut and efficiency improved. Similar technologies have been in use since NASA’s Apollo moon mission in 1969, where computers and machine replicas were used to test and monitor spacecraft.

Research shows that digital twins can save cities more than $ 280 billion globally by 2030 through more efficient urban planning. Digital twin provider Cityzenith believes that net zero deadlines could be achieved 15 years earlier if the world’s 100 biggest cities use the technology to decarbonize. “They are the perfect tool for managing and speeding up the energy transformation,” said CEO Michael Jansen. “We could get to net zero globally by 2035.”

Over the past decades, big tech companies around the world, including GE Digital and Siemens, have developed software for replicating cities, including a district of Berlin, the island nation of Singapore, and the entire city of Shanghai in China. In the US, the Digital Twin Consortium is working to standardize how digital twins are built and share data. Technology company MX3D built the world’s first 3D-printed stainless steel bridge and co-created its digital twin. CEO Gijs van der Velden believes twins will give us precise control over the built environment.

Recently, OpenAI also made advances in this field. On February 15, the company revealed its latest groundbreaking tech—Sora to the world. Sora is a text-to-video generative AI model. It can generate videos that matches the text prompt (文本提示) given to it in a few seconds. Experts believe Sora is likely to be applied in science and national defence in the future.