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Farewell to Arms 对扶手说再见 Good afternoon, this is your captain speaking. We are at cruising altitude and will be in flight for another three hours, so youd better get comfortable. That means figuring out who gets the arm rest you, or your n
A Stationary Satellite, part 2 A geostationary satellite orbitsthe planet at the same rate as the planet rotates, so the satellite is always over the same patch of ground. Cool! you say. Id like to have one of those about twenty feet over my house. S
A Stationary Satellite, part 1 Some of the best devices in science have been anticipated by science fiction writers years before they existed. Occasionally a writer comes up with an idea that can be put into practice within their lifetime! Such is th
What Are Reflexes? If youve ever blinked at a sudden light, jerked your hand away from something hot, or jumped at a loud noise, then you know that these are not actions we consciously plan. Rather, they happen involuntarily. Such sudden, unconscious
Everyone knows the story of the Titanic, the great ocean liner that struck an iceberg and sank to the bottom of the Atlantic. Less widely known is the icebergs story: where did it come from, and how did it get in the way of the ship? Although the vas
In the early 1800s, a French physician named Ren Laennec had a dilemma. He needed to listen to the heart sounds of a young woman with signs of heart disease. But the only method of listening to heart sounds known to Western medicine at the time was s
Airplane Contrails Have you ever seen a perfectly cloudless sky? Cloudlessthat isexcept for two or three long white lines smeared across the perfect blue sky by airplanes like smudges on a pane of glass. Why do airplanes sometimes leave contrails beh
Mans Best Friendin All Shapes and Sizes Scientists are making great strides in understanding the genes that allow such a wide range of shapes, sizes and personalities in different dog breeds. Did you know domestic dogs were bred from wolves about 15,
Why Frisbees Fly With a gentle flick of the wrist on a warm summer day, you can launch a frisbee on a long and graceful flight. Why do they fly so well? One reason is something called gyroscopic force. This is the tendency of a spinning object to mai
Who Believes in Vampires? 吸血鬼,傳說中永生不老的超自然不死生物。吸血鬼的典型形象和特征是:牙齒尖長,皮膚白皙,眼睛发红。吸血鬼害怕照射到陽光,在太陽下會烧起来变成灰。但是也认为
A Fresh Breath of Methane 很早很早以前地球有很微量的氧气,而且地表状况十分恶劣。大气主要是N2和Co2,后来通过复杂的变化,地球开始出现了厌氧型生物。在生命的作用下,地球的氧气开始不断
Cold Feet and Hot Wings 鸟通常只在休息或睡觉的时候才单脚站立。鸟类学家认为,他们这么做是为了减少能量的消耗,并把一只脚收到翅膀之下休息,通常他们会交替使用两只脚独立。披着一身羽
Small People 佛罗勒斯人(Homo floresiensis)是近年发现的一种史前人类,为人属的一种,主要特征是体型小,大脑小,因此也被化名作哈比人。 一般认为他们与现代人类曾经生活在一个时代。他们
Skinny Legs and All Why do horses have skinny legs? Find out on this Moment of Science. Why do horses have skinny legs? Okay, they arent entirely skinny its mostly the (1)bottom half, with a big muscle up at the top.Thats odd. Human legs are kind of
Understanding Abu Ghraib 阿布格莱布监狱始建于上个世纪70年代,在萨达姆时期是用来关押伊拉克平民的监狱,萨达姆政府曾在此关押过因涉嫌与1982年杜贾尔村针对萨达姆的未遂暗杀案有关的平民,
You Snooze or You Lose 几乎每个人在忙碌了一天之后,都要香香地睡上一觉。当然也有活了一辈子不 睡觉的人,但那是极个别的。人要睡觉是一种生理反应,是大脑神经活动的一部分, 是大脑皮质
Summer Breeze, Makes Me Feel Fine 风是大家最熟悉的自然现象,要了解风的形成必须了解包围着地球的大气的运动。大气的流动也像水流一样是从压力高处往压力低处流。太阳能正是形成大气压差的原
Better Than Barney 某天夜里,你一觉醒来发现电视机忘了关,节目却已播完,电视屏幕上嘶嘶地闪着雪花,也许你不会想到,再普通不过的雪花噪音竟包含来自137亿年前宇宙大爆炸的遗物微波背景
Fatherless Honeybee s How male honeybee s can be without fathers? The reason lies in whats called a haploidiploid system of sex determination. Approximate ly one-fifth of the animal kingdom, including ants and wasp s , use this system. What it boils
Acid Water Yal: What are you doing outside, Don? It's about to rain. Don: I'm setting out bottles. Y: I can see that. But why? D: For my new business venture. Bottled rainwater! Y: As in living plastic bottles out in the rain and then selling them as