時差N小時:鉆石的年齡(上)

You walk into a fancy party. What is the oldest thingthere? No, not your in-laws, or even yourgrandparents. It will be a diamond someone iswearing. It’s not completely clear how naturaldiamonds are formed, and although it is known theyare made from carbon, scientists are not sure howcarbon gets to the extreme depths at whichdiamonds are made. Diamonds are formed very deepin the earth. The optimum depth for theirformation is about 120 miles beneath the surface,in the molten mantle. The temperature andpressure necessary for diamonds to crystallize are mind boggling: the temperature must beover 2,000 degrees Fahrenheit, and the pressure must be at least 690,000 pounds per squareinch. To put that pressure in perspective, a 150 pound person exerts only about 3 pounds persquare inch.

你走進一個高檔的聚會。那里什么東西是最古老的?不，不是你的in-law，或是你的祖父母。而是有人戴得鉆石。人們尚未完全清楚天然鉆石是如何形成的，雖然知道它是由碳構(gòu)成的，科學家們還不確定碳是如何到達鉆石形成的極端深度。鉆石是在地球很深的位置形成的。其形成的最佳深度是在地表之下約120英里，在熔化的地幔曾。鉆石結(jié)晶所需的溫度和壓力是超乎想象的，溫度必須超過2000華氏度，每平方英寸壓力必須至少達到69萬磅。為了正確地看待這種壓力，一個150磅的人每平方英寸施壓大約只有3磅。