（77, Ir, Iridium, 铱，192.22）
Don’t Look to the Skies!
不要看天！

I stared out into the cloudless blue Cretaceous sky. “I don’t see anything coming.”
我凝视着白垩纪那万里无云的蓝色天空。“我什么都没看到。”
“I wanted to get here early,” Rachel said. “There’ll be more time travelers soon, though. The last day of the Age of Dinosaurs has got to be a hot-ticket destination.”
“我想最好还是早点到这儿，”瑞秋说。“不过，很快会有更多的时间旅行者的。恐龙时代的最后一天肯定是个热门的打卡处。”
“No, I mean I don’t see any sign of the Chicxulub impactor?the comet or meteor or whatever it is that’s supposed to be about to smash into the Earth. Shouldn’t we be able to see it from here?”
“不，我的意思是我看不到希克苏鲁伯撞击物体的任何迹象——不管那是彗星还是流星，或者任何可能撞击到地球的东西，都看不到。我们不是应该能正从这里看到它吗？”
Rachel squinted into the sky. “You’d think. It certainly is a mystery.”
瑞秋斜视着天空。“你就想吧。这的确是个谜。”
“So how do we know we came to the right time?”
“那我们怎么知道我们到了正确的时间呢？”
“Stratigraphy, old son. Way back in the twentieth century Alvarez pÈre et fils realized that a thin boundary of clay marking the boundary between the Cretaceous and the Tertiary was unnaturally rich in iridium, no matter where in the world you examined it. Iridium is a lot more common in comets and asteroids than it is on Earth. So they postulated something big hit the planet, burned the forests, and killed the dinos?probably in the long nuclear winter afterwards.”
“地层学，小子。追溯到20世纪，阿尔瓦雷茨发现，白垩纪和第三纪之间那层薄薄的黏土层富含铱，无论您在世界上哪个地方考察，都有铱。在彗星和小行星中，铱比在地球上普遍得多。因此，他们推测出有什么巨大的物体撞上了地球，烧毁了森林，可能正是之后漫长的核冬天灭绝了恐龙。”
“Sounds dangerous.”
“听起来很危险。”
“No need to worry. We’ll only be here long enough to snap a few photos. We’ll cut out before the destruction actually reaches us.”
“不用担心。我们在这待不了多久，就拍几张照片而已。我们会在灾难真正到达之前就辙的。”
“Good. Hey! Isn’t iridium the same stuff that’s used to power our time machines? You don’t suppose??”
“好。嘿！铱不是用在我们的时间机器里提供能量吗？你猜会不会？”
“No, no, of course not,” Rachel said dismissively. “Oh, yes, certainly,there’s a chance of chronodestablization. But it’s very slight. Only one in ten thousand jaunts destabilizes. That’s certainly a risk worth taking.”
“不，不，当然不是，”瑞秋不屑一顾地说。 “哦，是的，当然，有可能发生时序不稳定问题。但这概率非常小。只有万分之一而已。这绝对是值得冒的风险。”
“Yeah, but if it did, it would go off with the force of an atom bomb. That’s what they told me in orientation, anyway.”
“是的，但是如果时序不稳定的情况发生了，会爆发出原子弹般的能量的。无论如何，这就是我在接受培训的时候他们告诉我的。”
“Yes, but a single bomb wouldn’t destroy the whole ecosystem! It would take?”
“是的，但是一颗炸弹不会破坏整个生态系统！对吧？”
Her eyes bugged out. Time travelers were popping into existence everywhere. On the hilltops, by the banks of the rivers, in the mangrove swamps?everywhere. From every age possessing time travel they came in the hundreds, the thousands, the millions.? God knows how many there were in the entire world. More, possibly, than there were dinosaurs.
她的眼睛忽然睁开了。时光旅行者们纷纷冒了出来。山顶上，河边，红树林里……全都是。从有时间旅行的时代开始，他们有几百，上千，上万。天知道到底有多少。可能比恐龙还多。
To every side of us light flashed into the sky and flashed and flashed and flashed, as one out of every ten thousand time machines destabilized and expressed itself as a thermonuclear explosion.
在我们每个方向的天空，有有光在闪烁着，闪烁着，闪烁着，每万台机器中就有一个不稳定的，核爆于此。