2020年经济学人 环球航海家马文·克里默(2)（在线收听）

To prepare himself he had done some hard study of oceanography and meteorology, in the gaps between teaching geography in the department he had founded at Glassboro State College, now Rowan University. And he had gone seafaring: first fishing on small outboards past the barrier islands off New Jersey, where he would venture out so far that his colleagues thought him either lost, or mad, and later sailing across the Atlantic to Ireland and Africa.

克里默在格拉斯伯勒州立学院自己创办的系教地理，即现在的罗文大学。为了做好准备，他抽出时间认真研究了海洋学和气象学。他还做过海员：起初是驾着小型舷外船在新泽西外的障壁岛捕鱼，他会冒险走得很远，以至于他的同事们认为他要么是迷路了，要么是疯了，之后他横渡大西洋到达爱尔兰和非洲。

It was on a voyage back from the Azores in 1974, when he had taken the dark-to-daylight watch and the compass-light kept failing, that he looked up and thought: why not? All he had to do at that moment was find Polaris, the Pole Star, put his shoulder in line with the keel, and steer straight on. It worked like a dream. Star-steering had intrigued him since childhood, when his farmer-father taught him to observe the different positions of the setting sun from the south-west corner of the barn.

1974年它在从亚速尔群岛返回的途中，他已经开始了从天黑到天亮的守望，罗盘的灯光也一直在减弱，所以他抬起头来想：为什么不呢？那时，他要做的事情就是找到北极星，使他的肩膀和船的龙骨维持在一条直线上，一直向前行驶。那就像做梦一样。自从孩童时期他就着迷于星球导航，那时，他的农民父亲教他从谷仓的西南角观察不同位置的夕阳。

On his voyage, a clear view of sunset or sunrise could tell him his position; but for latitude without a sextant he needed to make a geometry of the night sky, drawing an imaginary line between Polaris and his chosen navigation-star and watching where that star made its meridian transit. Finding a fixed point in the southern hemisphere was tricky until he learned to use Acrux and Gacrux, two of the brightest stars in the Southern Cross, as pointers to the southern celestial Pole. (Delta Orionis, right over the celestial Equator, was most useful for longitude.)

在航行中，如果能清楚地看到日出日落，他就能知道自己的位置；但在没有六分仪的情况下，他需要画出夜空的几何图形来得知纬度，在北极星和他选择的导航星之间画一条假想的线，观察这颗星在哪里越过子午线。在南半球找到一个固定的点是很棘手的，但他后来学会了用南十字星座中最亮的两颗恒星十字架二和十字架一作为指向南天极的指针。（位于天球赤道上方的参宿三对获取经度最有用。）