IT IS NOT much to look at: an anonymous suburban office building, wedged between a shopping mall and a car dealership. Yet the Defence Advanced Research Projects Agency, or DARPA, has had a hand in many of the most celebrated technologies of the age, from the internet to global positioning systems to radar-foiling stealth aircraft. Its boss, Arati Prabhakar, jokes about having invented fire.

挤在一座购物中心和一间汽车销售点之间，这座没有名牌的市郊办公楼并不起眼。但这正是美国国防高等研究计划署（简称DARPA）的所在地。该机构曾出力促成了当代很多最著名的技术，如互联网、全球定位系统以及可以躲开雷达的隐形飞机。该机构的负责人阿拉提•普拉哈卡尔（Arati Prabhakar）开玩笑说火就是他们发明的。

DARPA remains gamely engaged in research that to outsiders sounds like science fiction. Its Living Foundries programme, for example, is trying to work out how to use microbes to detect and repair worn or corroded materials. Blood Pharming aims to create a kit to grow blood from a culture for battlefield transfusions. ChemBots is investigating robots that can change their shape to squeeze through small openings and then reconstitute themselves on the other side.

DARPA依然坚持进行一些在外人眼里看来像是科幻故事的研究。例如，其“生物铸造厂”项目试图利用微生物来探测并维修损耗或是生锈的材料。“血农场”旨在创造出可以利用培养基制造血液的装置，以供战场输血之用。“化学机器人”则在研究可以改变外形挤过小洞，之后