2019年06月25日 10:33:09|来源:国际在线|编辑:飞度云指南
Today Emc^2 is Einsteins most famous equation but another thoery he published the same year is more important and more controversial ,今天Emc^2是爱因斯坦最著名的方程式,但另一个他同年出版的理论更重要而且更有争议,the special theory of relativity.那就是特殊相对论。When Einstein was a teenager he enjoyed imagining what it would be like to ride a beam of light.当爱因斯坦还是一名青年的时候,他喜欢想象,就像驾驭着一束光一样。Now he returns to this daydream and changes his life.现在他返回到这个白日梦而那改变了他的生活。In the spring of 1905 Einstein was writing on a bus and he looked back at the famous clock tower that dominates Bern Switzerland .在1905年春天爱因斯坦在一辆公共汽车上写作时他回头看到著名的钟塔占瑞士伯尔尼的主导地位。And he imagine what happens if that bus racing at the speed of light.而他想象如果那辆公共汽车以光的速度行驶会发生什么。In his imagination Einstein looks back at the clock tower and what he sees is astonishing.在他的想象里爱因斯坦回头看着钟楼而且他所看到的令人震惊。As he reaches the speed of light the ends of the clock appear frozen in time .他达到了光速,时钟的两端开始将时间凝固住。Einstein later writes the storm broken in my mind.爱因斯坦后来写道暴风雨在我心中激荡。All of sudden all of sudden everything everything can gush in forward.突然间所有的一切一切滔滔不绝突然向前。Einstein knows that back to the clock tower time is passing normally.爱因斯坦知道回到钟楼的时间是正常通过。But on Einsteins light speed bus as he reaches the speed of light,但对于爱因斯坦而言,光速公交车使他达到光速,the light from the clock can no longe catch up to him .从时钟而来的光已经无法赶上他。The faster he races through the space the slower he moves through time.他穿越空间的越快,他通过的时间就越慢。This special insights sparks the birth of Einstein special theory of relativity which says that space and time are deeply connected.这种特殊的见解点亮了爱因斯坦的相对论说法,时间和空间都是紧密联系的。In fact they are one in the same,实际上它们是相同的,a flexible fabric called space time.一个被称为空间时间的柔性织物。注:听力文本来源于普特201205/182161Sublimation升华现象Sublimation on this moment of science.今天我们的节目要讲的是:升华现象。Pop quiz, everybody put away your books, and keep your eyes on your own radio.各位,请放下你们手中的书本,专心听收音机,我们来做一个突击测验。You fill the ice tray up to the rim and put it in the freezer. The ice that results will be用水将冰格填得满满的,漫过冰格的边缘,然后再将冰格放到冰箱的制冷室里,最后结成的冰会:a. at the rim b. over the rim c. under the rim. Answer? It depends.a. 刚好齐边 b. 边缘以上 c. 边缘以下 是?要看情况而定。I know, you hate that. But it does depend —it depends on how long you wait before checking on the ice again. My guess would be that most folks chose answer b: over the rim. That is correct, if you checked on the ice trays after only a couple hours. Thats because water expands when it turns into ice, as you know if you ever put a soda bottle in the freezer and came back to find it exploded all over the fish sticks.我明白,你们不喜欢这样的。但是,实际情况确实如此——取决于你要过多长时间去查看。我猜,很多人都会选择b选项:边缘以上。如果你在放入制冷室仅两个小时之后去查看的话,这个就是正确的。这是因为水在变成冰的时候会膨胀。就像大家所知道的,如果将一瓶汽水放在制冷室中,回头去看的时候会发现,汽水已经炸开了,整个制冷室中到处都是汽水。But if you were to leave the ice tray untouched for a couple of months, you might find the ice to be under the rim, or lower than the water was.但是,如果你将冰格放在制冷室中,好几个月都不动它的话,你会发现,冰在边缘以下,或是低于你之前装的水的高度。Huh? Didnt we just say water expands when it freezes? Initially, yes. But frozen water can do something else as well: it can sublimate. To sublimate is to go from one state to another without passing through the usual intermediary state.哈?我们刚刚不是才说了水在变成冰的时候会膨胀吗?最开始的时候,会。但是冷冻之后的水也会有其他的变化:升华。升华也就是物质不经中间状态直接从一个状态转变成另一个状态。By adding heat, ice can be melted into liquid water, which can be evaporated. Thats three states: solid, liquid, gas. But given enough time, ice can also turn into a gas without melting first! When your ice cubes seem to have shrunk, its because they are sublimating: the frozen water is slowly evaporating off the cubes, without ever actually melting.通过加热,冰可以化成液态水,液态水可以被蒸发为水蒸气。这是三个状态:固态,液态,气态。但是,如果时间足够的话,冰可以在不被融化的情况下转变为气态。如果你的冰“缩水”了,那是因为被升华了:在没有被融化的情况下,固态水以非常缓慢的速度在蒸发着。Will this work in any freezer? Next time.这种现象在任何的制冷器中都会出现吗?下次再谈。 /201208/194828

It might look like just another compact car.它看起来像另一款乘用车。What workers at Greatwall Automobile vehicle plant of Bulgaria are putting together, is Chinas foothold in the European market.中国长城汽车在保加利亚的汽车生产线已投入生产,厂里工人们正组装的车就是中国进军欧洲市场的立足点。Greatwall is the first Chinese auto-company to manufacture vehicles in the European Union.长城是中国第一家进入欧洲的自主车企。The stated yield plan is bringing new employment opportunity to the town of Lavage. Ivan Kusalarff is a team leader.这个木已沉舟的项目将会为洛维奇市带来新的就业机会。Ivan Kusalarff负责这个项目。He studied engineering in Sweden, but immediately jump that opportunity to help build auto-industry in his home country.他早年在瑞典修工程学,听说这个机会后,便立即回国投身兴建这项汽车产业。I wouldve probably stayed there if I havent heard about this career opportunity because its not just a job opportunity,如果没有碰到这个机会,我可能还呆在瑞典。在我看来,这不仅仅只是一个工作机会。most of us here for to a long-run, were not just here to buy some time, earn some money and then go home.大多数人来这里是从长远考虑,而不是为了消磨时光,赚点钱就回家。The plant is a joint-venture between Greatwall Motors, one of the Chinas largest auto-makers and Turks, Bulgarian industry company.这个汽车生产线由中国最大的汽车公司--长城汽车公司与保加利亚利特克斯公司合作建设。Greatwall recently started its production for now, its cars are available here in Bulgaria and Macedonia.该汽车组装厂已经正式投入生产,在保加利亚和马其顿的市场均有售。Very soon, they want to expand first southeast of Europe, and then to the entire continent.不久,长城汽车计划开拓东南欧市场,接着便是整个欧洲大陆市场。They hope to become a player in what is very competitive automobile markets.他们希望在这个竞争力强的汽车市场占有一席之地。Management acknowledges Greatwalls main selling point is the low price, but says that does not come the expense of quality.管理层了解长城汽车的主要卖点是价格低,也强调低价并不影响车的质量。We make fine products of great qualities, the marketing director says that I can ensure you that products we make are not inferior to those of other producers, European, Japanese, and others.市场总监说道,我们打造的是高品质的轿车。我向你们保,我们的汽车不会比产于欧洲,日本或其他任何地方的汽车档次低。The car plant is the most visible Chinese investment in Bulgaria, but not be only one, companies from China are investing in algricuture and red ruber energy here.这个汽车组装厂是中国在保加利亚造势最大的投资,但并不是唯一的,还有其它中国企业在这里投资农业和新型能源。But Bulgarian government says Chinese investment in the country increased by 40 million euros last year. Leading experts believe China sees Bulgaria as a gateway to the EU.保加利亚政府表示去年来自中国的投资金额增长了4000万欧元,在专家看来保加利亚是中国进军欧洲的大门。Not have political prejudice against emerging market ecomony because were emerging market economy.我们不会对新兴的市场经济怀有政治偏见,因为我们也注重发展新兴市场。So thats one big reason. And of course, in terms of labor cost, in terms of land price, energy prices in Bulgaria is the cheaper.这是很重要的一条原因。当然就运营成本而言,保加利亚的劳动成本,地价和能源成本较低。The workers at the Greatwall car plant want to prove they can produce quality at low cost.长城汽车生产线的工人想要明他们能够生产出性价比高的汽车。The future of this Chinese investment could depend on whether or not they succeed .他们的成败会决定中国企业在欧洲的未来。201205/181489

Science and Technology Animal obesity The fat cat cometh科技 动物肥胖 肥猫报到It is not just human beings that are getting fatter. Animals are, too不只人类正在变胖,动物亦然IN THEIR attempts to explain the global epidemic of obesity, researchers have often taken to fingering culprits beyond peoples direct control. It is now believed that increased levels of stress, climate change and even artificial light at night may contribute to expanding waistlines. However, if such factors affect humans, they ought, in principle, to have similarly nefarious effects on other creatures. This should hold especially true for species that are physiologically similar to people and live in proximity to them. Pet owners have long fretted that this may, indeed, be happening.在试图解释全球流行的肥胖时,研究人员往往指陈人们无法直接控制的元凶。人们现在认为,压力水平上升、气候变化、甚至连夜晚的人工照明都有助于扩大腰围。但是,如果这些因素影响人类,那么按理说它们对其它生物应该有同样的恶果。这种影响对那些在生理上与人类相似且靠近人群生活的物种应该尤其成真。宠物的主人们对此早就苦恼不已,的确这种影响有可能发生。Of course, anecdotal evidence carries little weight, so a group of researchers led by Yann Klimentidis, of the University of Alabama, decided to check whether animal obesity rates do in fact mirror the worrying trend among people. They published their findings this week in the Proceedings of the Royal Society.当然,道听途说不足为据,所以美国阿拉巴马大学的一组研究人员在扬?克利曼泰迪斯的领导下,决定核对核对动物的肥胖率是否跟人们的担忧趋势确实相符。他们在本周的《英国皇家学会会刊》上发表了他们的研究结果。Dr Klimentidis and his team set about their task by scouring online repositories of scientific papers, contacting fellow researchers and even petitioning pet-food companies for data on changes in animals bodyweights over the decades. They limited their search to mammals, whose bodies work much like humans do—and, specifically, to those mammals living with or around people in the rich world.克利曼泰迪丝士和他的小组着手完成任务,他们搜索网上的科学论文库、联系其它同道研究人员、甚至向宠物食品公司请阅近几十年来动物体重的变化数据。他们把搜索锁定在哺乳动物上,因为哺乳动物的身体跟人类的身体功能非常相似——而且特别把搜索锁定在那些富裕国家里与人共同生活或在人周边生活的哺乳动物上。The trawl threw up information on more than 20,000 animals from 24 distinct populations covering eight species. These included cats, dogs, mice, rats and several types of monkey. Some were bred in highly controlled research environments. Others lived in peoples homes or in the wild. None had their food intake artificially limited or, as with livestock, ramped up.这次搜罗从24个不同的群落中找出了八个物种2万余只动物的信息。这些物种包括猫、、小鼠、大鼠和几种猴。有些是在严格控制的研究环境下饲养的。其它的生活在人的家中或在野外生存。它们的食物摄入量均未人为限制或是象喂牲畜一样加料。For each population, Dr Klimentidis looked at the animals weight at an age corresponding to 35 human years. Middle adulthood was chosen to ensure the data were not fudged by the effects of either early development or old-age withering. Any animals that died within a year of this mid-life physical were also excluded.对于每个群落,克利曼泰迪斯士都调查了年纪相当于人类35岁的动物的体重。选择成年中期是为了确保数据既不受早期发育的影响也不受老年萎缩的影响而掺假。任何在这个中期体检年内死亡的动物也被排除。He then proceeded to calculate each populations average weight, as well as its obesity rate, for every decade of available data. The obesity rates were based on a bespoke indicator akin to the body-mass index that is used to gauge (roughly) whether a person is too rotund. This ploy permitted comparison between species in which weights have different meanings. (Nutritionists employ similar tricks to establish what is a healthy body-mass index for children in different age groups.)接着,他计算出每个群落的平均体重以及肥胖率,每十年取一个可用的数据。肥胖率的计算按预定的指标为基础上进行,预定指标类似于用来衡量(大约)一个人是否太圆的身体-质量指数。这项工作允许在体重意义不同的物种之间进行比较。(营养学家采用类似手法来确定不同年龄段儿童的健康身体质量指标是多少。)Subsequent number-crunching revealed a statistically significant increase in bodyweight in 11 of the 24 populations. The weights of the other 13 rose too, though not to an extent that was significant for any of the individual groups. Nevertheless, the fact that all of these insignificant changes were upward was, itself, statistically significant. Moreover, the obesity-rate indices followed a similar pattern. Dr Klimentidis reckons the odds of his data having come about by chance are about one in 10m for the weight gain and three in 1m for the rise in obesity.随后的数字处理揭示了24个群落中有11个体重显着增加。其它13个群落的体重也有增加,不过达不到对于任何个别群体来说都显著的程度。然而,这些微不足道的变化是向上增的这一事实本身就很显著。此外,肥胖率指数遵循了类似的模式。克利曼泰迪斯士估计,他的数据偶然出现的几率在体重增加方面大约是1000万分之一左右,在肥胖率上升方面大约是100万分之三。Most intriguingly, perhaps, the laboratory animals showed more pronounced gains than those living outside a lab. This is strange because the sorts of lab animals the researchers looked at tend to be given lots of food and left to nibble at leisure. This practice has not changed for decades. That the animals put on weight nonetheless suggests the phenomenon cannot be caused solely by pet owners appeasing their Garfields, or feral rats rummaging through refuse composed of ever larger quantities of calorie-rich processed food. Dr Klimentidis is unable to pinpoint any single mechanism that could account for his results. But this does not stop his data from lending exculpatory explanations for fat tummies more credence.或许最有趣的是,实验室动物比非实验室动物表现出更为明显的体重增加。这很奇怪,因为研究人员观察的各种实验室动物往往被给予大量食物,且让它们在闲暇时一点一点蚕食。这种做法几十年来都没有改变。尽管这样动物还在发胖,这说明发胖现象不可能是单由宠物的主人安抚他们的加菲猫引起的,或者单由野生鼠完全不吃大量富含高卡路里的加工食品引起的。克利曼泰迪斯士无法查明任何一种可以解释其研究结果的单一机制。但是,这并不妨碍借用他的数据对大腹便便作出开脱罪责的解释,而不是把罪责归于餐桌。 /201301/222532

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