——好玩儿的字母（G）

上回玩儿字母还是在雪莱的春天（http://blog.sciencenet.cn/blog-279992-877598.html），然后就忘了——因为引出游戏的那本书（The Poetic Wreath）失踪了。前些天又看见它了。最近引力波沸腾，就玩儿小G吧。另外，旧文件里有段草稿写G的——那会儿刚在神保町的一家旧书店遇见了MTW的Gravitation——这是头一回在书店见它。那么老的书了，没想到书店还有；遗憾的是太沉了，没带它回家。草稿的题目叫“引力的彩虹”，可觉得太“熟”，才发现已经用那题目写过一回了（http://blog.sciencenet.cn/blog-279992-498355.html）。

The Poetic Wreath里面没有主题词Gravity，而见过的一些写引力的诗似乎都不够诗的想象。假如没有GR，谁能想到用几何来写引力？可见诗人的想象不如科学家的直觉。科学家如果改行写诗，诗人大概只好改行沏茶磨墨脱靴了。

见有诗人写引力子（Harley White, The Gravity of Gravity），说它像一匹五花马，但科学家们众说纷纭：

Gravitons, a gravitational source

Of controversy, are seen as a horse

Of a quite different color altogether.

But then scientists aren’t birds of a feather.

诗人接着还评论了引力假说，没有诗味，有几分空洞的道理：

Weak or strong, short or long, what is this thing

Called gravity? Wide hypotheses swing.

There are those who suppose that it’s this, others that.

Maybe someday, they all just might have it down pat.

更有诗味的是John Frederick Nims（http://www.poetryfoundation.org/poem/238744），他看准了引力的温柔，不像电磁力，没有暴戾的闪电，也不竖一道铁栅栏与人隔离，令人反感：

Mildest of all the powers of earth: no lightnings

For her — maniacal in the clouds. No need for

Signs with their skull and crossbones, chain-link gates:

Danger! Keep Out! High Gravity! she’s friendlier.

Won’t nurse — unlike the magnetic powers — repugnance;

Would reconcile, draw close: her passion’s love.

所以，引力是我们温柔多情的母亲（she’s our quiet mother, sensible）：

She taught our ways of walking. Her affection

Adjusted the morning grass, the sands of summer

Until our soles fit snug in each, walk easy.

Holding her hand, we’re safe. Should that hand fail,

The atmosphere we breathe would turn hysterical,

Hiss with tornadoes, spinning us from earth

Into the cold unbreathable desolations.

……