时差N小时 月球表面的记号为何不消失?(下)（在线收听）

Leave your Earth pan outside. Take the moon pan inside and place a cardboard box over the top of it, weighted down with something heavy.

把代表地球的平底锅放在户外，然后把代表月球的平底锅放在室内并在上面放上一个硬纸盒，再压上一些重物。

Wait a couple days and check again. The moon pan will look the same.

几天后再观察一遍，你会发现，代表月球的平底锅依旧如初。

More than likely, though, the Earth pan won’t. Maybe the wind blew the sand around. Maybe it rained or snowed.

而代表地球的平底锅却变化巨大，也许风把沙子吹得散落各处。也许被雨雪冲刷过。

The point is that Earth has an atmosphere, which results in wind, rain, rivers and streams, lots of motion.

关键就在于地球有一层大气，能够产生风、雨、河流、小溪等引起运动的事物。

Of course, Earth is also volcanically active: the ground shakes, lava pours out, continents rise and fall.

当然，地球的火山运动是非常活跃的，会引发地震、岩浆喷发、陆地沉降。

By comparison, nothing much ever happens on the moon–except for the impacts that give rise to those craters–even across billions of years.

相比之下，月球在数十亿年里基本不会产生这些现象（形成火山坑的撞击除外）。

So an impression on the moon can be a lasting impression indeed!

因此，你在月球上留下的印记会经久不衰的！