【推荐3】Earth is experiencing its sixth mass extinction: somewhere between 30 and 159 species disappear every day, and more than 300 types of animals have died out since 1500. This is not good for the future of life on our planet, but what if we could make some of the extinct species come back to life? Thanks to ongoing advances in DNA recovery and cloning technology, de-extinction may soon be realized, and we may see Tasmanian Tigers, or Dodo Birds back into existence in the near future.

Some scientists are confident and optimistic about de-extinction. They think that the best reasons for de-extinction have more to do with ecology than tourism. “If this is always going to be a zoo animal, then stop,” says Ben Novak, the lead researcher at Revive & Restore—a foundation devoted to rescuing endangered and extinct species in San Francisco, California. “The goals have to be about ecological restoration and function.”

Take passenger pigeons for example. Their numbers reached nearly 5 billion at the start of the 19th century, and they played an important role in shaping the forests they inhabited(居住). After their extinction, the forests have never been the same. “The passenger pigeon is a very important ecological species if we want their original habitat back.” Novak says.

However, we need to think twice about Novak’s idea. Any new scientific initiative is bound to have risks, so is de-extinction. Although some assume that de-extinction may help the environment, we can’t be so sure. The de-extinct animals would now be strangers to their habitats. As the habitat is no longer what it was, the species role within the ecosystem may have also changed. This could be actually a threat to the other species within the environment as the de-extinct animals enter the area and compete for food sources. Once again we’re trying to force nature to act in a certain way, rather than letting it remain natural.

Many scientists also believe that priorities(优先权) would change within the conservation of currently endangered species. Would we still put in the effort to preserve living animals if we knew we could just magically bring them back from the dead? Douglas McCauley, an ecologist at University of California, Santa Barbara, stresses this worry. “Honestly, the thing that scares me most is that the public absorbs the misimpression that extinction is no longer scary. The general attitude becomes: Deforest, no worry, we can reforest. If we drive something extinct, no worry, we can de-extinct it.” said McCauley.

It seems that with the subject of de-extinction, we must look at our reasons for doing such a thing. Yes, we may, in the near future, be able to de-extinct the extinct species. But does that mean we should? Are the risks really worth it? Does it make sense to focus on the dead than the living? And who are we truly benefiting in the end?

Many people know that trash is a big problem on planet Earth. What many people don’t know is that trash has become a problem in outer space too.     1    

Statistically, there are more than 22,000 pieces of junk in space around the earth. And these are just the items that we can see from the surface of the earth by telescopes or radars.     2    

Objects, like bits of old space rockets or satellites, move around the planet at very high speeds, so fast that even a very small piece can break important satellites or become dangerous to people, particularly astronauts. If the tiniest piece of junk crashed into a spacecraft, it could damage the vehicle. That’s because the faster an object moves, the greater the impact if the object collides with something else.

To help minimize additional space junk, countries around the world have agreed to limit the time their space tools stay in orbit to 25 years. Each tool must be built to fall safely into the earth’s atmosphere, or the mass of gases that surround the earth, after that.       3    

Many scientists are also proposing different ways to clean up space junk. The Germans have been planning a space mission with robots that would collect pieces of space trash and bring them back to Earth so that they can be safely destroyed.

"In our opinion the problem is very challenging, and it's quite urgent as well," said Marco Castronuovo, an Italian Space Agency researcher who is working to solve the problem.       4     Many of these objects are tools that help people use their cell phones or computers.

"The time to act is now; as we go farther in time we will need to remove more and more fragments," he says.

【推荐3】According to the WHO, 90 percent of the world’s population lives in a place where they are exposed to unsafe levels of airborne pollutants, contributing to up to seven million deaths each year. If you live in a city, chances are that you’re part of that 90 percent, even if your city is relatively clean. That’s why cities worldwide have started embracing Internet of Things (IoT)solutions.

One of the best ways to fight pollution is to figure out where it’s worst and where it’s coming from. If you’ve ever made a habit of checking air quality around you, you may notice that there aren’t actually that many monitoring stations, and your closest one may not be that close. For pollution data to really be accurate and helpful, we need a lot more of it.

Luckily, IoT sensors and low-power wide-area networks are making it a lot easier to get and spread ultra-local data. Lampposts are one popular place to put them. For example, the Republic of Korea and Barcelona have already built out a network of pollution sensors in their streetlights. On the other hand, outfitting (配备) cars, bikes, and even people with pollution sensors provides valuable data on a smaller, more mobile scale.

Since pollutant levels can change dramatically even from one city block to another, having smaller-scale data is important for making a lot of decisions that, over time, might have a major influence on our health and behavior. It can influence where we decide to live, when we exercise, whether we bike to work, and, perhaps most importantly, what we can do about pollution in our area.

What all the Internet of Things can help us do on a personal level is use less energy. The data it provides, though, can be used to make big and small changes to the way we behave and build, and that is eventually where we’ll see benefits.

【推荐1】Apple and Google have teamed up to launch a mobile phone tool to follow the contacts of people infected with coronavirus (冠状病毒). The technology is a form of contact tracing, a method used to identify people who may have had contact with infected individuals in an attempt to prevent additional spread of disease. If a device user becomes infected with the virus and agrees to share that information, the record could be used to inform other people that the user could have infected.

Major technology companies—including Google and Facebook—have been denounced in recent years for not protecting user privacy. In some cases, companies have been accused of secretly selling user data. In the past, Apple chief Tim Cook has criticized Facebook and Google for putting profits ahead of user privacy.

However, now numerous technology companies and organizations have been seeking to develop tools to help fight COVID-19. Health and government officials have called for such technology to help fight the current crisis.

In announcing the new system, Apple and Google said its developers had built in “strong protections around user privacy.” The companies said the technology would not identify personal information or record user movements. It is designed to only catch data about when users’ phones have been near each other. Data will not be kept on company servers, Apple and Google added. The two companies also said they would “openly publish information” about their work for others to examine.

Pam Dixon is director of the not-for-profit World Privacy Forum. She told The Associated Press that after discussing the new system with a top Apple official, she is convinced that people’s privacy will be protected.

“I think they’ve taken care of some of the really big problems,” she said. Dixon notes that the companies are able to turn off the system when it is no longer needed. The government is not going to have identity information of those testing positive.