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After so many decades of the buildup of high-speed clutter in the form of spent rocket stages, solid-rocket-motor slag, dead or dying satellites and the scattered fragments from antisatellite tests-all of which could damage or destroy other assets-low-Earth orbit is finally on the verge of becoming too crowded for comfort.
Finding ways to remove at least some of all that space junk should be a top global priority, says Donald Kessler, a retired NASA senior scientist for orbital debris research. “There is now agreement within the community that the debris environment has reached a‘tipping point’where debris would continue to increase even if all launches were stopped,” Kessler says. “It takes an Iridium-Cosmos-type collision to get everyone's attention. And we're overdue for something like that to happen .”
A new entrant in struggling with this worrisome state of affairs is the just launched ELSA-d mission demonstrated by Astroscale. ELSA-d is a two-satellite mission developed by Astroscale, a satellite services company: it consists of a “servicer” satellite designed to safely remove debris from orbit and a “client” one that disguises as space junk. The project aims to showcase a magnetic system that can capture stable and even tumbling objects, whether for disposal or servicing in orbit. Following a multiphase test agenda, the servicer and client will then deorbit together, disintegrating during their fiery plunge into Earth's atmosphere.
Although ELSA-d and other similar technology demonstrations are unquestionably positive developments for clearing orbital debris, they should not be mistaken for cure-alls. Despite their modest successes, such missions are falling short of addressing the dynamic dilemma at hand, and the proliferation of space junk continues essentially unabated.
There simply is no “perfect solution” to the problem of space junk, Kessler says. Removing large rocket bodies is a significantly different task than removing the equivalent mass of a lot more smaller objects, which are in a wide range of orbits, he observes. Meanwhile innovations by companies such as SpaceX are dramatically lowering launch costs, opening the floodgates for far more satellites to reach low-Earth orbit, where some will inevitably fail and become drifting, debris-generating hazards.
There is no doubt that active orbital debris removal is technically challenging, says Alice Gorman, a space archaeologist and space junk expert at Flinders University in Australia. “However, the big issue is that any successful technology that can remove an existing piece of debris can also be used as an antisatellite weapon,” she says. “This is a whole other can of worms that requires diplomacy and negotiation and, most importantly, trust at the international level.”
[A] To invent satellites that generate no space junk.
[B] To try to clear some of the space junk.
[C] To stop all launches before working out a solution.
[D] To reach an agreement on cleaning up space junk.
[A] we should have paid enough attention to space junk earlier
[B] we overreact to the Iridium-Cosmos-type collision
[C] it is really exciting to see the whole world focusing on the space
[D] it is time we attached attention to the debris in the space
[A] shows people have had great success in dealing with space junk
[B] is composed of two satellites with different functions
[C] is better than other comparable technology demonstrations
[D] can be counted on to address the dilemma at hand
[A] some of the orbital debris are either too big or too small to be captured
[B] companies are always innovating new ways to clean the orbital debris
[C] space junk keeps increasing because more satellites are launched
[D] the satellite launch technology is not mature yet
[A] satellites can also be used as weapons
[B] it is doubtless that all the orbital debris should be removed
[C] countries should work together to develop technologies
[D] solving the space junk problem requires a global effort
One of the biggest concerns in science is bias-that scientists themselves may influence the outcomes of experiments. Researchers have come up with all sorts of tactics to try to eliminate it, from having their colleagues repeat their work to the “double blinding” common in clinical trials, when even the experimenters do not know which patients are receiving an experimental drug and which are getting a sugar-pill placebo. But gathering the data and running an experiment is not the only part of the process that can go wrong. The methods chosen to analyse the data can also influence results.
A new paper, from a large team of researchers headed by Martin Schweinsberg, a psychologist at the European School of Management and Technology, in Berlin, helps shed light on why. Dr. Schweinsberg gathered 49 different researchers by advertising his project on social media. Each was handed a copy of a data set consisting of 3.9 million words of text from nearly 8,000 comments made on Edge.org, an online forum for chatty intellectuals. Dr. Schweinsberg asked his subjects to explore two seemingly straightforward hypotheses. The first was that a woman's tendency to participate would rise as the number of other women in a conversation increased. The second was that high-status participants would talk more than their low-status counterparts. Crucially, the researchers were asked to describe their analysis in detail by posting their methods and workflows to a website called DataExplained. That allowed Dr. Schweinsberg to see exactly what they were up to.
In the end, 37 analyses were deemed sufficiently detailed to include. As it turned out, no two analysts employed exactly the same methods, and none got the same results. Some 29% of analysts reported that high-status participants were more likely to contribute. But 21% reported the opposite. The remainder found no significant difference. Things were less finely balanced with the first hypothesis, with 64% reporting that women do indeed participate more, if plenty of other women are present. But 21% concluded that the opposite was true.
The differences arose because researchers chose different definitions of what they were studying and applied different techniques. When it came to defining how much women spoke, for instance, some analysts chose the number of words in each woman's comment. Others chose the number of characters.
Dr. Schweinsberg hopes that platforms such as DataExplained can help solve the problem. By allowing scientists to specify how they chose to perform their analysis, their decisions can be reviewed by others. It is probably not practical to check and re-check every result. But if many different analytical approaches point in the same direction, then scientists can be confident that their conclusion is the right one.
[A] The experiments cannot be repeated to verify the results.
[B] The subjects tend to have a lot of biases.
[C] It's actually difficult to realise “double blinding” in an experiment.
[D] There are many factors that can affect the results of an experiment.
[A] Its conclusions were approved by 49 researchers.
[B] The team could see the process of the subjects' analysis.
[C] It was conducted on social media.
[D] The subjects were chatty intellectuals.
[A] selecting the right subjects helps draw the right conclusions
[B] high-status participants tend to talk more than their low-status counterparts
[C] 64% of women tend to participate more when there are many other women around
[D] different definitions and techniques lead to different conclusions drawn by analysts
[A] Doubtful.
[B] Indifferent.
[C] Hopeful.
[D] Opposed.
[A] Data Don't Lie-But They Can Lead Scientists to Opposite Conclusions
[B] Scientists Should Allow Their Conclusions to Be Reviewed by Other Scientists
[C] Can We Still Trust Scientific Research?
[D] Should Science Rely More on Social Media?
There are two things to know this holiday season: Distracted driving will increase, and if your smartphone is loaded with apps, they can track just about every move you make. The confluence of these two seemingly different facts is that your phone knows that you are more likely to glance at a text, Facebook or Instagram while behind the wheel during the stretch between Thanksgiving and New Year's than you might be otherwise.
Why? Nobody can say for sure. But Matt Fiorentino, director of marketing at TrueMotion, is in a position to speculate. His company, which has a family of driving apps, just released statistics showing a 33 percent holiday jump in distracted driving. “People travel to see loved ones during the holidays. As they're driving, they want to provide updates on where they are,” Fiorentino said.
The National Safety Council issued a sobering estimate for the long Thanksgiving weekend this year: 433 people would die and an additional 49,400 would be seriously injured in car crashes. The final number isn't in for this Thanksgiving, but the NSC says that three years ago 355 people died on New Year's Day and 273 on Christmas Day. About a third of those who died had been drinking alcohol.
The tragedy of those statistics makes the TrueMotion projection of a 33 percent increase in distracted driving a cautionary one. TrueMotion collected the survey data from its safe-driving app. The app can be downloaded from an app store if the user agrees to abide by TrueMotion's terms. “Our technology can go into any mobile app to collect driving data,” Goldberg said.
Fiorentino added via email: “We only use smartphone sensor data to track driving behavior. We never see any content on the phone. So we don't see emails, Facebook messages, YouTube videos, etc.” He said that users opt in to allow their driving to be tracked by the app.
“ The TrueMotion Family app enables parents to see how their teens are driving —specifically distracted driving, speeding, and braking,” Fiorentino said. “We do not share TrueMotion Family users' information with law enforcement or insurers without their prior consent.” The app also found that people were far more likely to speed during the holiday period. The good news: While text messages increased, actual phone calls dropped by 45 percent when compared with the average weekday.
Your best bet to maintain your privacy and stay safe? Stay off your phone.
“Everyone wants a holiday to remember, but not for the wrong reasons,” said Deborah Hersman, a former National Transportation Safety Board chairman who now serves as the NSC's president. “Let's keep our holiday gatherings out of the emergency room.”
[A] listen to music
[B] kill the time
[C] chat with their beloved ones
[D] tell others their location
[A] 355 people died on Christmas Day three years ago.
[B] Drunk driving may increase the risk of death.
[C] Increasingly more people died during holidays.
[D] 433 people died during the Thanksgiving weekend this year.
[A] was widely used among people
[B] could be used in various occasions
[C] was popular among parents and teens
[D] could benefit both its developers and users
[A] speed up
[B] send messages
[C] drink wine
[D] make phone calls
[A] use safe mobile applications
[B] not drink alcohol before driving
[C] avoid long hours of driving
[D] limit your smartphone use
At the start of nearly every doctor's visit, chances are you will be asked to step on a scale and get your weight measured for that day's exam record. But many conversations around weight have become a hindrance, not a help, in the campaign to make people healthier. Doctors' recommendations to drop pounds are still extremely common, even though using body size as a one-size-fits-all index for health can obscure the complexity of an individual's particular physiology.
Many epidemiological studies have shown that heavier people are at higher risk for hypertension, diabetes and coronary disease. However, one intriguing report published in 2016 found that a higher body mass index (or BMI, the ratio of weight to height) “only moderately increased the risks for diabetes among healthy subjects” and that unhealthy thin people were twice as likely to get diabetes as healthy fat people. Clearly, there is more to the equation than weight. Although the association between excess weight and disease is very real, individual experience can vary greatly and depends on personal physiology and behavior.
Despite such findings, doctors routinely recommend dieting for weight loss as a means to “treat” poor health indicators such as high cholesterol and insomnia in obese patients-an approach with a poor success rate. The result: 95 to 98 percent of those who attempt to lose weight fail, and up to two thirds end up heavier than when they began. Spending years trapped in a cycle of losing weight, regaining it, then losing it again is associated with poorer cardiovascular health outcomes and contributes to hypertension, insulin resistance and high cholesterol.
Among the more insidious by-products of weight-centric health care are the increased stigma and shame experienced by the overweight. Research over the past two decades has shown that health professionals have negative attitudes toward obese people. Not only that but doctors' appointments with fat patients are shorter on average, and physicians routinely use negative words in their medical histories of such people. Some refuse to see these patients at all. Such biased practices keep people from regular annual exams and prevent the detection of serious conditions. And research suggests that the chronic stress of living with the shame of being a heavy person may underlie metabolic changes that increase the storage of fat, elevate blood pressure and drive up blood lipid levels.
It is time that doctors abandon the scale-centric health care practice and focus on behaviors that have proven positive outcomes for health. Lifestyle changes, such as enhancing one's nutrition by eating fruits, vegetables and whole grains, along with increased physical activity and smoking cessation, can improve blood pressure, blood lipid levels and insulin sensitivity-often independently of changes in body weight.
[A] people who weigh less are likely to be healthier than those who weigh more
[B] doctors tend to put too much emphasis on weight when giving advice
[C] there is no scientific basis for judging health by weight
[D] losing weight cannot make people regain their health
[A] there are multiple factors that can affect health
[B] the influence of weight on health can be ignored
[C] excess weight can do much harm to health
[D] BMI can comprehensively reflect a person's health status
[A] Neutral.
[B] Objective.
[C] Favourable.
[D] Critical.
[A] patients' underlying physical problems being ignored
[B] longer consultation time
[C] conflicts between doctors and patients
[D] shorter life expectancy of the patients
[A] treat all patients equally
[B] stop telling people to lose weight
[C] pay more attention to patients' mental health
[D] guide people to adopt a healthy lifestyle