美国国家公共电台 NPR Researchers Show Parachutes Don't Work, But There's A Catch

 

SCOTT SIMON, HOST:

This just in - research published in a major medical journal concludes that a parachute is no more effective than an empty backpack. But before you leap to any conclusions, hear the whole story from NPR science correspondent Richard Harris.

RICHARD HARRIS, BYLINE¹: The gold standard for medical research is a study that randomly² assigns volunteers to try an intervention³ or to be in a control group. For some reason, nobody has ever done a randomized controlled trial of parachutes. In fact, medical researchers often use the parachute example when they argue they don't need to do a study because they're so sure they already know the answer. Dr. Robert Yeh at Harvard Medical School got a wicked idea one day. He and his colleagues would actually attempt the parachute study to make a few choice points about the potential pitfalls⁴ of research. They started by talking to their seatmates in airliners⁵.

ROBERT YEH: We'd strike up a conversation and say, you know, would you be willing to be randomized in a study where you had a 50 percent chance of jumping out of this airplane with versus⁶ without a parachute?

HARRIS: Did you get any takers?

YEH: (Laughter) For the most part, we did not on those commercial airlines.

HARRIS: And those who said yes were excluded for reasons of questionable⁷ mental health. They had much better success asking members of their own research teams, from Harvard, UCLA and the University of Michigan, about volunteering to participate in the experiment on other aircraft.

YEH: Either a small biplane - that was our group that - we went to Martha's Vineyard and did that, and the group in Michigan went and jumped out of a small helicopter in fact.

HARRIS: The 23 people who agreed to jump from the smaller aircraft represented quite a skewed sample, which was part of the point Yeh and his team were trying to make. Photos taken during the experiment show the volunteers were only too happy to take part.

YEH: I think people are for the most part laughing all the way down to the ground.

HARRIS: Right, which is about two feet or something.

YEH: Exactly right (laughter).

HARRIS: Oh, a minor⁸ detail here. The biplane and helicopter were parked, so it's not surprising that nobody suffered any injuries. It's literally⁹ true that parachutes offered no better protection for these jumpers than the backpacks.

YEH: And, of course, the top line of results would be that parachutes don't work. But, of course, that is a ludicrous result. The real answer is that that trial did not show a benefit because of the types of patients that were enrolled¹⁰.

HARRIS: If they had enrolled people at high risk for injury - that is, people up in the sky - the results would have been quite different, not to mention unethical. Their study is published in the traditionally lighthearted Christmas issue of the medical journal BMJ.

YEH: It's a little bit of a parable¹¹ to say that we have to look at the fine print. We have to understand the context in which research is designed and conducted to really properly interpret the results.

HARRIS: Emory University epidemiology professor Cecile Janssens says via Skype this is a real problem in science.

CECILE JANSSENS: I know that people often don't look detailed¹² enough into what is being investigated to know how they can interpret the results of a trial.

HARRIS: Janssens was delighted to come across the paper on Twitter. She says, like a lot of research, the results are accurate as far as they go.

JANSSENS: Results of this trial can only be generalized to situations where people jump out of an aircraft that's within a few feet above the ground.

HARRIS: She plans to give this paper to her students with a straight face and see how long it takes for them to get the deeper points about scientific methodology buried in this absurd experiment.

JANSSENS: It'll be unforgettable.

HARRIS: Yeh is pleased to see that the fun he has had with his colleagues is turning into a teaching tool.

YEH: And our greatest, I think, accomplishment¹³ from all of this is that we felt very good that we were able to cite Sir Isaac Newton in the paper.

HARRIS: Yes, I noticed that. It was in fact his original publication from - what was it? - 1687.

YEH: (Laughter) That's right.

HARRIS: Yes, gravity is a law. Mess with it at your own risk. Richard Harris, NPR News.

1 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

2 randomly   

adv.随便地，未加计划地

参考例句：

• Within the hot gas chamber, molecules are moving randomly in all directions. 在灼热的气体燃烧室内，分子在各个方向上作无规运动。 来自辞典例句
• Transformed cells are loosely attached, rounded and randomly oriented. 转化细胞则不大贴壁、圆缩并呈杂乱分布。 来自辞典例句

3 intervention   

n.介入，干涉，干预

参考例句：

• The government's intervention in this dispute will not help.政府对这场争论的干预不会起作用。
• Many people felt he would be hostile to the idea of foreign intervention.许多人觉得他会反对外来干预。

4 pitfalls   

（捕猎野兽用的）陷阱( pitfall的名词复数 )； 意想不到的困难，易犯的错误

参考例句：

• the potential pitfalls of buying a house 购买房屋可能遇到的圈套
• Several pitfalls remain in the way of an agreement. 在达成协议的进程中还有几个隐藏的困难。

5 airliners   

n.客机，班机( airliner的名词复数 )

参考例句：

• The fog grounded the airliners. 大雾迫使班机停飞。 来自《简明英汉词典》
• They placed very stable and accurate atomic clocks on regularly scheduled jet airliners. 他们将非常稳定、准确的原子钟装在定期飞行的喷气式班机上。 来自辞典例句

6 versus   

prep.以…为对手，对；与…相比之下

参考例句：

• The big match tonight is England versus Spain.今晚的大赛是英格兰对西班牙。
• The most exciting game was Harvard versus Yale.最富紧张刺激的球赛是哈佛队对耶鲁队。

7 questionable   

adj.可疑的，有问题的

参考例句：

• There are still a few questionable points in the case.这个案件还有几个疑点。
• Your argument is based on a set of questionable assumptions.你的论证建立在一套有问题的假设上。

8 minor   

adj.较小(少)的，较次要的；n.辅修学科；vi.辅修

参考例句：

• The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
• I gave him a minor share of my wealth.我把小部分财产给了他。

9 literally   

adv.照字面意义，逐字地；确实

参考例句：

• He translated the passage literally.他逐字逐句地翻译这段文字。
• Sometimes she would not sit down till she was literally faint.有时候，她不走到真正要昏厥了，决不肯坐下来。

10 enrolled   

adj.入学登记了的v.[亦作enrol]( enroll的过去式和过去分词 )；登记，招收，使入伍（或入会、入学等），参加，成为成员；记入名册；卷起，包起

参考例句：

• They have been studying hard from the moment they enrolled. 从入学时起，他们就一直努力学习。 来自《简明英汉词典》
• He enrolled with an employment agency for a teaching position. 他在职业介绍所登了记以谋求一个教师的职位。 来自《简明英汉词典》

11 parable   

n.寓言，比喻

参考例句：

• This is an ancient parable.这是一个古老的寓言。
• The minister preached a sermon on the parable of the lost sheep.牧师讲道时用了亡羊的比喻。

12 detailed   

adj.详细的，详尽的，极注意细节的，完全的

参考例句：

• He had made a detailed study of the terrain.他对地形作了缜密的研究。
• A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。

13 accomplishment   

n.完成，成就，（pl.）造诣，技能

参考例句：

• The series of paintings is quite an accomplishment.这一系列的绘画真是了不起的成就。
• Money will be crucial to the accomplishment of our objectives.要实现我们的目标，钱是至关重要的。