4 . Meteorites (陨石) can offer clues about what the early solar system was like. But finding them is far from difficult. Now, some scientists are turning to drones (无人机) and machine learning to help spot freshly fallen meteorites much more efficiently. “A team of six people on a meteorite-hunting expedition can search about 200,000 square meters per day,” says Seamus Anderson, a planetary scientist in Australia.

Around 2016, Anderson began toying with the concept of using drones to take pictures of the g round to look for meteorites. That idea blossomed into a Ph.D. project. In 2022, he and his colleagues reported their first successful recovery of a meteorite spotted with a drone. They’ve since found four more meteorites at a different site. Drone-based searches are much faster than the standard search way. “You’re going from about 300 days of human effort down to about a dozen or so,” he says.

Anderson and his workmates have used drones to search for meteorites in remote parts of Western Australia and South Australia. The team is tipped off about a fall site by networks of ground-based cameras that track meteoroids flashing through the Earth’s atmosphere. The researchers have to do a series of fun but difficult work before the hunt. They pack a four-wheel drive vehicle with drone and computer equipment, battery charging stations, generators, fuel, food, camping equipment, tables, chairs and much more. The drive to the fall site can take more than a day, often on rough or nonexistent roads. Anderson says, “You hope you don’t pop a tire.”

After arriving, the team flies its primary drone at an altitude of about 20 meters. Its camera takes an image of the ground once every second, and the scientists download the data every 40 minutes or so when the drone lands to receive fresh batteries. A typical day of flying can net over 10,000 images, which are then divided digitally into 100 million or so smaller sections. Those “tiles”, each 2 meters on a side, are fed into a machine learning algorithm (算法) that has been trained to recognize meteorites based on images of real land rocks which are spray-painted black.

5 . Today, many people spend a lot of time reading online. Whether reading news or e-books, people are spending more time eyeballing (盯住) screens. While online reading opens up a great deal of knowledge to people, there are some disadvantages too, such as eyestrain, headaches, as well as difficulty in focusing on the text. Now a new reading system, Bionic Reading, developed by Swiss typographic designer Renato Casutt, can help people overcome these issues, and most importantly, it aims to help people read faster online and develop a more in-depth understanding of written content.

The reading system improve the reading process by guiding the eyes through text with artificial fixation points. To make it short: some parts of the words are displayed in bold (粗体). As a result, the reader only focuses on the highlighted letters and lets the brain center complete the rest. Your brain can “read” faster than your eyes, so by essentially reducing the number of letters your eye needs to look at, you can read faster while still preserving the full context.

Cassult discovered the system by accident. He was working on designing a book in a foreign language and realized he could read it if he sectioned it off. He worked for six years to develop Bionic Reading and is still working to adjust it.

A preliminary (初步的) study was conducted by the Swiss Institute InnoSuisee, but more research is needed before it can be definitively shown that the system improves reading. Some people with ADHD (多动症) prove that Bionic Reading helped them focus and comprehend what they are reading. Other people don’t seem to notice a big difference compared to regular text. There’s also no evidence to suggest Bionic Reading is any better than regular text. The best way to know if the Bionic Reader helps you read better online is to try it yourself.

8 . Biological fieldwork can mean trips to exotic places. The most common method is to send a few eager graduate students armed with camera traps and several weeks of spare time. But perhaps not for much longer. A paper published in Current Biology suggests an easier method: simply swabbing (擦拭) nearby leaves for DNA.

The DNA in question is called “environmental DNA” (eDNA for short). It refers to all the genetic information that animals leave behind as they go about their daily business: breathing, urinating, or interacting with their environment in any way.   In recent years, genesequencing (基因测序) technology has become quick and sensitive enough to pick out genetic sequences from particular animals including humans from this eDNA.

One way of doing so is simply to blow air through filters (过滤器), and then analyse them to see which animals live nearby. Drs Gogarten and Lynggaard wondered if there might be a simpler approach. Air-sampling systems can take days to do their work. Maintenance must be done, and filters must be changed. But given that eDNA is literally blowing around ecosystems, the searchers wondered if it might be collecting on leaves.

The leaves of many plants are waxy (蜡质的) and somewhat sticky. The researchers theorised that eDNA might end up stuck to leaves and that it could subsequently be collected by swabbing them. They tested their theory in the dense rain forests of Kibale National Park, in Uganda. Using simple cotton swabs, and wearing masks and gloves to prevent polluting the samples with their own DNA, they visited three areas of the park and collected eight swabs at each site, and then took them back to Copenhagen for analysis.

The swabs revealed the presence of 26 birds, 24 mammals, one amphibian and one fish, with each swab containing DNA from eight animals on average. More than half the samples were good enough to work out the precise species they came from.

Swabbing for animals, then, seems to work. Moreover, it is cheap, easy and fast. Graduate students will have to be content spending less time sample-hunting in distant parts of the world.

9 . The Great Barrier Reef is the result of millions of years of continental (大陆的) shifts, sea-level changes, and layers of coral (珊瑚) growth. The Reef was built over millennia (数千年) by coral attaching itself to existing dead coral, as it continued to reach toward the light. Like most living things, coral needs the sun to survive and generally lives in shallow waters, where enough sunlight can penetrate (穿透) the water. Sea levels began to rise at the end of the last most recent ice age, about 14,000 years ago. As a result, the previously exposed Reef was covered by water and the coral expanded along the length of the newly revived Reef.

Climate change is having a dangerous impact on this natural wonder. Although coral and algae (海藻) have evolved despite climate change, allowing them to survive, coral has begun producing products that are poisonous to the Reef and block the growth of algae. Additional concerns include the overwhelming amount of pollution and chemical runoff into the water which harms the already affected coral and reduces biodiversity.

The Great Barrier Reef is well known as one of the best diving destinations in the world. You can do your part to help scientists preserve the Reef’s ecosystem while visiting. By paying a visit to the Reef, visitors pay a reef tax that will be used for the management and conservation of the Reef. A lesser-known contribution visitors can make to Reef preservation is signing up for REEFSearch. After signing up, you’ll be sent a field guide that will teach you how to collect information that scientists can use to study the Reef’ s health. During each dive, using the information sent to you, you will look for key species, check for coral conditions, and make note of any garbage found near the Reef. These small contributions can ultimately have a large impact and save one of the great wonders of the world.

10 . Self-driving cars are hitting city streets like never before. In August the California Public Utilities Commission (CPUC) granted (授予) two companies, Cruise and Waymo, permits to run driverless robo-taxis 24/7 in San Francisco and to charge passengers for those rides. This was just the latest in a series of green lights that have allowed progressively more freedom for autonomous vehicles (AVs) in the city in recent years.

Almost immediately, Cruise was criticized for its vehicles behaving unpredictably. One blocked the road outside a large music festival, and another got stuck in wet concrete. The incidents have brought renewed attention to the potential difficulties of integrating self-driving cars into the urban environment.

Yet despite some ongoing opposition, self-driving car companies have continued to expand testing and operations to more US cities. Many supporters say these vehicles could offer a safer alternative to human drivers, make transportation accessible to more people, improve traffic flows around cities and decrease the environmental impact of cars. So far, though, most of those promised benefits remain squarely in a possible future. Meanwhile, here in the present, complications have become plainly apparent.

AVs, such as those operated by Cruise and Waymo, shouldn’t be confused with commercially available cars, such as electric cars, which come with some driver-assistance features. Unlike those vehicles, which require a human driver to oversee control at all times, robo-taxis run on the road without a person monitoring and managing each movement from behind a steering wheel (方向盘). This is made possible by a very detailed internal map.

Waymo and Cruise maintain that their AVs are safer than human drivers. Both companies have released data that they claim support this, yet some researchers have their doubts. “I actually think there is not yet enough data available to the public, including researchers like me, to be able to judge relative safety,” says Steven Shladover, an engineer at the University of California.