New Effort To Clean Up Space Junk Reaches Orbit (轨道)

A demonstration mission to test an idea to clean up space debris (碎片) was launched Monday morning local time from the Baikonur Cosmodrome in Kazakhstan. Known as ELSA-d, the mission will     1     technology that could help capture space junk, the millions of pieces of orbital debris that float above Earth.

The more than 8,000 metric tons of debris threaten the loss of services we rely on for     2     life, including weather forecasting, telecommunications and GPS systems.

The spacecraft works by attempting to -attach itself to dead satellites and pushing them toward Earth to burn up in the     3    .

The mission, which will be run from the U.K., will carry out this catch and release process     4     over the course of six months. The goal is to prove the servicer satellite’s ability to track down and remove with its target in varying levels of     5    .

Space junk has been a growing problem for years as human-made objects such as old satellites and spacecraft parts build up in low Earth orbit until they     6    , deorbit, explode or crash with other objects, breaking into smaller pieces of waste.

According to a recent report by NASA, at least 26,000 of the millions of pieces of space junk are orbiting along at 17,500 mph, they could “destroy a satellite on impact”. More than 500,000 pieces are a “mission-ending threat” because of their ability to impact     7     systems, fuel tanks and spacecraft cabins.

The development of other cleanup technologies has been in progress for years. In 2016, Japan’s space agency sent a 700-meter chain into space to try to slow down and     8     space junk. In 2018, a device called RemoveDebris successfully cast a net around a copy satellite.

The European Space Agency also plans to send a(n)     9     robot into orbit in 2025, which the organization’s former director general has referred to as a space “vacuum cleaner”.

These efforts could prove     10     important as private space ventures like SpaceX continue to disorder low Earth orbit with a huge number of satellites.

Brain Training through Virtual Reality

Scientists have long sought to prevent sharp memories from dulling with age, but the problem remains persistent. Now new research suggests virtual reality might help older people recall facts and events based on     1     details.

The study involved 42 healthy older adults from the San Francisco Bay Area. Half spent a dozen hours over four weeks playing a virtual-reality game called Labyrinth; they wore headsets and walked in place,     2     virtual neighbourhoods while completing tasks. The other half, in the control group, used electronic tablets to play games that didn’t     3     finding positions or recalling details. After 15 sessions, the latter performed roughly the same as before on a long-term memory test based on picking out objects they had seen about an hour earlier. But the Labyrinth players’ scores rose, and they were less frequently tricked by objects that     4     the ones they had viewed.

Those     5     “brought them back up to the level of another group of younger adults who did the same memory tests,” says Peter Wais, the researcher who designed the VR game. The game likely stimulates the hippocampus — a brain area important for long-term memory. What the Wais’s team is trying to do is uniquely suited to VR,” says Meredith Thompson, who studies learning through VR games but was not involved in the new study. “VR can provide greater     6     than other games,” she says, adding that after this proof-of-concept study, “it would be great to actually     7     people over time and see what this type of game does for long-term memory.” Wais’s team is now investigating how long the     8     effects last and which elements of the training have the most impact.

It remains unclear how test performance in a laboratory setting might     9     to real-world situations. The outcome, needs to be repeated, ideally with a much larger group, before it’s treated as a strong     10    .

You’ll Often Walk Alone

There has been a quiet pandemic (流行病) developing while most people’s attention has been on Covid-19. The lockdown has worsened a problem that has been     1     in many developed nations for decades: loneliness.

Part of the problem     2     from contemporary employment. Globally, two in five office workers feel lonely at work. This rises to three in five in Britain. Gig-economy (零工经济) jobs can leave people with     3     incomes and without the companionship of colleagues. The pandemic has made it more difficult to make, and maintain, friendships, particularly for new employees. Even before the crisis, the hope that     4     offices would encourage greater camaraderie (友情) proved to be false. Many people find the chatter     5     and withdraw with noise-canceling headphones. They then email colleagues who are sitting only a few desks away.

Perhaps loneliness relates to human history. Mass urbanization is a relatively recent development; if the history of human existence was     6     into a single day, the Industrial Revolution did not occur until almost midnight. For much of that time, humans lived in small groups of hunter-gatherers; cities may just overwhelm the senses. Ms. Hertz points her finger at a recent development: social media. The internet has led too much cyber-bullying (although it has also been a source of companionship during the lockdown). And people     7     to their smart phones spend less time interacting socially.

Some changes in behavior are owing to     8     choice. Before the pandemic no one was stopping people going to church or taking part in sports. They     9     preferred to do other things. Indeed, one reason for the decline in communal activities is that men choose to be with their families rather than     10     to the bar; American fathers spend three times as much time with their children as they did in the 1960s. That is surely a welcome development. So recreating a communal society may be difficult.

Throughout the 20th century, Japanese towns and cities grew     1    . Today about 80 percent of the Japanese people live in urban areas. The growth of towns and cities, called urbanization (城市化), happens in two ways. One way is     2     rural-urban migration, when people move to the city from the country. As cities prosper and grow, industries and services that     3     many people both as workers and consumers grow to meet the     4     of the increasing population. New industries and services emerge to support the growing business, and the region experiences an upward spiral of growth.

The urban areas on the Japanese island of Honshu (本州岛) continue to grow     5     they attract more people, industries and business. These urban areas contain nearly two-thirds of Japan’s population and manufacturing. City suburbs are     6     in the rural spaces between the towns and cities, and Japan’s efficient and fast transportation system links them all.

Four     7     cities on Honshu-Tokyo Kawasaki (川崎), Chiba (千叶), and Yokohama (横滨) have grown together into one of Japan’s largest urban areas. Two other large urban areas have     8     on Honshu. The area around the city of Nagoya (名古屋) forms one, and the cities of Osaka (大阪)，Kyoto and Kobe (神户) from the other. At the     9     time, these three areas are growing toward one another to form one long, enormous urban area. A single urban system this large is called a megalopolis. This Japanese megalopolis on Honshu, stretching from Tokyo in the east     10     the way to Kobe in the west, is called the Tokaido (东海道) megalopolis.