How the Earth Changed History Water World 神奇水世界（3-4）
Out there is a river valley that’s been carved into the rock. It’s been carved by running water, just flew down here smoothly off this rock bed and then cascaded down to the valley north there. Six thousand years ago, that was a big river. Satellite images reveal that the river bed I’m standing in [...]
How the Earth Changed History Water World 神奇水世界（1-2）
地球是我们赖以生存的家园，她为我们提供了生存所必需的物质——氧气和水。她用慈母般的温情哺育了一代又一代的人。当我们恣意地享受地球给予的一切时，是否已经了解地球了呢？地球的力量到底有多大！ Of all our planet’s forces, perhaps none has greater power over us than water. For me, water is the most magical force on earth. The presence of water shapes, renews and nourishes our planet. Oh, my God ! You get all wet there! It’s our planet’s lifeblood. It pumps through it continuously, delivering vital [...]
Sinkhole Swallows Hiker 死海岸边的致命沙洞
The Dead Sea is the lowest point on earth and runs more than 50 miles in length and stretches 11 miles across its wildest point, bordering Israel, The West Bank and Jordan. Large sections of the coast are fenced off and sign posted in Hebrew and English: Warning of sinkholes. The sea’s dropping water levels [...]
Sanaa 也门首都：萨纳
Day breaks in Sanaa, Yemen as the call to prayer rouses the inhabitants of this ancient city as it has for hundreds of years. This capital city, nestled at an elevation of over 7,000 feet in the Yemeni highland, is one of the oldest continually inhabited cities in the world. In the Medieval areas, towering [...]
Natural pools in Belize 伯利兹蓝洞
Why is this diver burrowing into the bottom of this mini lake.She is literally disappearing into the sand and gravel of the water’s floor.Only debris and the occasional bubbles from her breathing tank are visible. She is part of a project, largely funded by National Geographic, to dive into the sacred pools of the ancient [...]
Island paradise
Ever since man first began setting out for new lands by small boats heading over unknown horizons, he’s been searching for among other things, paradise. And paradise in the Tuamotus, a small archipelago in the Pacific about 200 miles northeast of Tahiti, means coconuts, digging clams, spear fishing and camping on the beach with the [...]
Smart power grids 智能电网
The United States has started the largest infrastructure project in human history, a complete top-to-bottom overhaul of our entire electrical supply grid, which is getting new intelligent devices at every step from the power company’s generators to the devices in our homes and making sure every component is secure from attack, while also elegant control [...]
Walking with tetrapods 世上最早的四足动物
Nature’s latest report from the world of paleontology challenges the assumptions made by everyone until now about when animals first walked the earth. This is footprint of early tetrapods. We have here, for example, digits, impressions, and something like their pads. This is important. I’ve been working personally in this field since the mid 1990s. [...]
Djerba Island
Djerba Island “花园岛”-杰尔巴岛 It’s Friday afternoon at a village bakery in Hara Kebira,this tiny Jewish community is preparing for the sabbat meal bringing pots of soup to be heated in the wood oven.Today’s customers are Jewish,but the baker here is Muslim.In much of the world,that’s a novelty.Here it’s daily life. “We work together.We do business [...]
Horseshoe Crabs and Humans 马蹄蟹与人类
马蹄蟹它有着马蹄状硬壳的身躯，还有一条细长的针状尾巴，别看它叫马蹄蟹，它可不是蟹类，它的学名是鲎（hòu），与蝎、蜘蛛以及已绝灭的三叶虫有亲缘关系。它的祖先出现在地质历史时期古生代的泥盆纪，当时恐龙尚未崛起，原始鱼类刚刚问世，随着时间的推移，与它同时代的动物或者进化、或者灭绝，而惟独只有鲎从4 亿多年前问世至今仍保留其原始而古老的相貌，所以鲎有“活化石”之称。 马蹄蟹为暖水性的底栖节肢动物，栖息于20－60米水深的砂质底浅海区，喜潜砂穴居，只露出剑尾。食性广，以动物为主，经常以底栖和埋木本的小型甲壳动物、小型软体动物、环节动物、星虫、海豆芽等为食，有时也吃一些有机碎屑。每年的五六月间，成千上万的马蹄蟹总会从大西洋深处爬上美国东南部的特拉华湾，在海岸交配、产卵。中国鲎在中国福建沿海从4月下旬至8月底均可繁殖。自立夏至处暑进入产卵盛期。大潮时多数雄鲎抱住雌鲎成对爬到砂滩上挖穴产卵。福州平潭每到农历六月，就有大量的鲎爬上岸，当地有民谚称：六月鲎，爬上灶。（参看百度百科关于马蹄蟹的更多资料） As the water is warm and tides grow high, horseshoe crabs leave the ocean floor and make their way to the shores and estuaries of the Atlantic Coast. Here in the sheltered waters of South Carolina, they suddenly emerge by the thousands in the spawning ritual they’ve performed for hundreds of millions [...]
本站空间赞助商
