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The United Nations refugee agency says this year has been the worst ever for migrants and refugees crossing the Mediterranean Sea into Europe. Despite the fact that far fewer migrants are trying to cross than the number who did in 2015, many more had
Time spent in zero G changes the body: Astronauts come home with bone loss and muscle weakness. But what happens in their heads? To find out, researchers examined MRIs of astronauts brains taken before and after flight. They looked at 12 astronauts w
Unit 95 Scientists Look Forward to the Past Can time travel really be done? Physicists think that travel into future is possible. Einstein's special theory of relativity, published in 1905, predicted that time should be elastic, stretching or shrinki
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
But our time traveling isnt yet over. There is still the question of how the first galaxies kindled the very first stars. We are on a journey visiting the Dark Ages, a time over 12.5 billion years ago. The sight is spectacular. The sky is ablaze with
Its extremely frustrating because this region, this time period holds within it, in some sense, the rose headstone of / galaxy formation. But there are clues as to what was happening inside those dense hydrogen clouds. Look back even further in time
Imagine the disc of our galaxy, if you just took a disc of stars and put it there, gravity would tend to make this disc collapse/ into itself and it would immediately just fall together. That is not what we see with the galaxy. Whats actually going o
All of the galaxies, all of the stars, and gas and dust and planets, and everything else that we can see with our greatest telescopes represent about half of one percent of whats actually/out there. The rest is invisible. It is mostly some mysterious
They were once thought to mark the outer limits, but today astronomers believe the Milky Way galaxy is much bigger than what we can see. To understand why, we will travel to the stars of the outer galactic disc. Far from our usual place in space, we
We are at a foundry here, and they are pouring molten iron from all machinery. And they are going to make parts for new machines out of that iron, so they are recycling yet, but all that iron was created and ejected into the cosmos by gigantic stars
查看译文 tips: 怎样阅读才是有质量的阅读了? 中英对照请点击【中英对照】查看译文请点击 【查看译文】进行核对。 Pens in Space Legend has it that NASA spent a million dollars developing a pressurized ballpo
黑洞是一种引力极强的天体,就连光也不能逃脱。当恒星的史瓦西半径小到一定程度时,就连垂直表面发射的光都无法逃逸了。这时恒星就变成了黑洞。说它黑,是指它就像宇宙中的无底洞,
地球是太阳系从内到外的第三颗行星,也是太阳系中直径、质量和密度最大的类地行星。它也经常被称作世界。英语的地球Earth一词来自于古英语及日耳曼语。地球已有44~46亿岁,有一颗天然