In May 2021, a hole was found in a robotic arm aboard the International Space Station (ISS). The suspected culprit was a piece of rogue space junk. While thankfully no astronauts were injured, it has re-focussed attention on the growing problem of orbital debris.
How did we get here?
It’s easy to forget that just seven decades ago the Moon was the only thing orbiting the Earth. On 1 January 2021 there were 6,542 satellites in orbit. Tellingly, only just over half of them were active. That’s a lot of useless metal careering around the planet at 28,000 kph — ten times faster than a bullet.
How bad is the problem?
Very bad and getting worse. Estimates suggest there are currently half a million pieces of debris the size of a marble or larger and 100 million pieces of debris above one millimeter across. Yet only 27,000 pieces are actively tracked by the US Department of Defense.
What is Kessler syndrome?
It’s a catastrophic chain of events in which a satellite is shattered by a piece of space junk (or a collision with another satellite) and the resulting debris destroys more satellites creating more junk and so on in a never-ending cascade. It’s a domino effect – one piece falls and then takes the rest with it – and is named after NASA scientist Donald Kessler, who outlined the dangers back in 1978.
What can we do about it?
Better regulation of new launches would help, as right now it’s a bit of a free-for-all. There are existing regulations in place to try and mitigate the dangers, such as a 25-year de-orbit rule for missions in low-Earth orbit. However, ESA’s Space Debris Environment Report says that less than 60 per cent of those flying in low-Earth orbit currently stick to the rules.
Colin Stuart. Space Junk: Is it a disaster waiting to happen?
Internet: <www.sciencefocus.com> (adapted)
It can be concluded that in the beginning of the fourth paragraph, “It's” is the contracted form of it has
About ideas stated in the text above and the words used in it, judge the following items.
There are places in the world where wind power works well in freezing temperatures.
The underlined phrase in “orientations about course planning and delivery should not be meant to be prescriptive” (line 3)
Note that the text is predominantly written in the present tense. This can be explained by the fact that
In the fragment from the first paragraph “A number of authors have challenged longstanding cognitivist orientations of SLA”, the underlined term refers to cognitivist orientations which
Insomnia is the most common of all sleep complaints. Almost everyone has occasional sleepless nights, perhaps due to stress, heartburn or drinking too much caffeine or alcohol. Insomnia is a lack of sleep that occurs on a regular or frequent basis, often for no apparent reason.
How much sleep is enough varies. Although 7 1/2 hours of sleep is about average, some people do fine on 4 or 5 hours of sleep. Other people need 9 or 10 hours a night.
Inability to get a good night’s sleep can affect not only your energy level and mood but your health as well because sleep helps bolster your immune system. Fatigue, at any age, leads to diminished mental alertness and concentration. Lack of sleep is linked to accidents both on the road and on the job.
About one out of three people have insomnia sometime in their life. Sleeplessness may be temporary or chronic. You don’t necessarily have to live with sleepless nights. Some simple changes in your daily routine and habits may result in better sleep.
The text contains information on:
The World’s strangest laws
1. You can’t call a pig Napoleon in France.
2. It is illegal to die in the Houses of Parliament.
3. In Miami, Florida, you mustn’t skateboard in a police station.
4. In London, you don’t have to pay to take a flock of sheep across London Bridge.
5. In Florida, unmarried women can’t parachute on Sundays.
6. It’s illegal to play golf on the streets of New York.
7. In Kentucky the law still says that everyone must have a bath at least once a year.
8. In seventeenth-century Russia, you couldn’t grow a beard unless you paid a special tax.
9. In fifteenth-century England, it was illegal for men to wear a moustache.
10. In the USA in the eighteenth century, bars couldn’t sell soda water on Sundays.
From the book Practical Grammar John Hughes and Ceri Jones
According to the text, choose the correct alternative:
According to the text, “...stock the shelves...” (paragraph 3) is an example of
The lion and the four bulls
A lion used to walk about a field in which four bulls lived. Many times he tried to attack them, but whenever he came near, they turned their tails toward one another so that whichever way the lion tried to attack, he would have to face the horns of one of them.
At last, however, the bulls started arguing with each other, and each went off to a different part of the field by himself. Then the lion attacked them one by one and soon had killed all four.
Ann Arbor: The University of Michigan Press, 1996.p.138
The messsage of the text can be summarized as:
How facial recognition technology aids police
Police officers’ ability to recognize and locate individuals with a history of committing crime is vital to their work. In fact, it is so important that officers believe possessing it is fundamental to the craft of effective street policing, crime prevention and investigation. However, with the total police workforce falling by almost 20 percent since 2010 and recorded crime rising, police forces are turning to new technological solutions to help enhance their capability and capacity to monitor and track individuals about whom they have concerns.
One such technology is Automated Facial Recognition (known as AFR). This works by analyzing key facial features, generating a mathematical representation of them, and then comparing them against known faces in a database, to determine possible matches. While a number of UK and international police forces have been enthusiastically exploring the potential of AFR, some groups have spoken about its legal and ethical status. They are concerned that the technology significantly extends the reach and depth of surveillance by the state.
Until now, however, there has been no robust evidence about what AFR systems can and cannot deliver for policing. Although AFR has become increasingly familiar to the public through its use at airports to help manage passport checks, the environment in such settings is quite controlled. Applying similar procedures to street policing is far more complex. Individuals on the street will be moving and may not look directly towards the camera. Levels of lighting change, too, and the system will have to cope with the vagaries of the British weather.
As with all innovative policing technologies there are important legal and ethical concerns and issues that still need to be considered. But in order for these to be meaningfully debated and assessed by citizens, regulators and law-makers, we need a detailed understanding of precisely what the technology can realistically accomplish. Sound evidence, rather than references to science fiction technology --- as seen in films such as Minority Report --- is essential.
With this in mind, one of our conclusions is that in terms of describing how AFR is being applied in policing currently, it is more accurate to think of it as “assisted facial recognition,” as opposed to a fully automated system. Unlike border control functions -- where the facial recognition is more of an automated system -- when supporting street policing, the algorithm is not deciding whether there is a match between a person and what is stored in the database. Rather, the system makes suggestions to a police operator about possible similarities. It is then down to the operator to confirm or refute them.
By Bethan Davies, Andrew Dawson, Martin Innes (Source: https://gcn.com/articles/2018/11/30/facial-recognitionpolicing.aspx, accessed May 30th, 2020)
The authors conclude the text by stating that
The woman who caused the incident on Xiamen Air Flight MF8215 was
The overall purpose of the text is
Based on the previous text, judge the following item.
The sentence ‘The fish left, so the people left’ (last paragraph) shows how much the river determines people's lives in the community of Pixaim.
One of the purposes of the text is to confirm that the report determines the
Based on the text above, judge the following item.
In the first paragraph, the excerpt “that it refers to members of a public organization having the legal competence to maintain order and enforce the law” reinforces which meaning of the word “police” is condemned by police scholars.
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