Why the Earth Is Round？

Our never-thought to ask question for today is： Why is the earth round？ Why not a cube？ A cube？ No， thats silly. Is it？ Why？ Because…， because really big things like to be round for some reason. Exactly right. And that reason is gravity.

Think of it this way. Suppose the earth were a cube. Then some points on its surface would be farther away from the center than others. The corners， for example， would be much farther out than the rest.

Since gravity works equally on everything， there would be a tendency to pull those uneven places down. The surface would even itself out. The only geometrical object in which every point on the surface is the same distance from the center is a sphere. But wait a minute， Ive seen pictures of asteroids that have all sorts of crazy shapes. Why arent they round？ Only because they arent big enough for gravity to be a determining factor. If an asteroid were to suddenly become as big as a moon， it would indeed rearrange itself gradually into a sphere.

上期最佳譯文

廢寢忘食并不能有效提高成績！

哈佛大學一項關于“決心”的研究表明，“廢寢忘食”學習并不能學好。

人們認為，爭取優(yōu)秀的孩子為了追求高分，一般都要做出額外犧牲，比如睡得少，或者飲食不規(guī)律。

但是一項針對4 000名英國青少年的新研究表明，那些展現(xiàn)出決心、勇氣和堅持的學生一般會有更健康的生活方式。

哈佛大學教育研究生院的研究結果表明，“那些有決心的孩子更可能照顧好自己，培養(yǎng)健康的情感管理技能，而不是養(yǎng)成不利于健康的行為方式。”

之前已有研究表明，考試壓力過大對兒童的健康不利。凱洛格上個月發(fā)表的一項調查發(fā)現(xiàn)，年僅10歲的孩子就通過吸煙、吃糖果、喝能量飲料來備考。

哈佛大學教育研究生院的教員克里斯提娜·辛頓說：“研究結果表明，追求好成績的決心并不需要不惜一切代價來逼自己，而是要培養(yǎng)健康的情感管理技能，學會高效的學習方法?！?