Not long ago, the end seemed nigh. Humanity had never had a weapon it didn't use against itself, and the dawn of the atomic age meant civilization itself could be wiped out.
But in the 62 years since the bombings of Hiroshima and Nagasaki, many fingers have been on the nuclear button, and none pressed it. There's no telling what will happen if rogue regimes in North Korea or Iran get the bomb -- but if these trends hold, it seems life won't end as it began: with a big bang.
However, our advanced society could still collapse more quietly, with a mere whimper. We may, in fact, already be heading down that road. We wouldn't be the first society to simply fade away.
Across centuries, the Romans built a massive empire, stretching for thousands of miles. Rome built roads, a system to deliver water to a thirsty city, and encouraged intellectual development in its upper classes. Over time, though, the Romans forgot how to maintain the things they'd built. Their empire hollowed out and eventually collapsed, leaving humanity in the dark. It took centuries for scholars to relearn the things the Romans had known.
Now, take a look at modern-day America. We're undoubtedly more technologically advanced than ever before. But at the same time, we may well be forgetting the things that have made our advances possible.
Consider our infrastructure.
In 1883, the Brooklyn Bridge opened to much fanfare. At the time it carried pedestrians, horse-drawn carriages and trains across the East River. More than 100 years later, it remains a vital link, carrying thousands of cars every day. Think about that. When John Roebling started designing the bridge, he couldn't have imagined it would one day be used by automobiles, which hadn't been invented and are much heavier than horse carts. Yet his bridge was built solidly enough to handle this extra load, decade in and decade out.
Compare that with the 35W bridge in Minneapolis that collapsed earlier this month. That bridge was built just 40 years ago, specifically for interstate highway traffic. It should have been designed to deal with the steady pounding of thousands of cars and trucks. Yet it simply couldn't handle the load.
Our electrical grid is another example. In 2003 the northeast suffered through a massive blackout when the overloaded system failed. At the time, former energy secretary Bill Richardson observed that, "We're a superpower with a third-world electricity grid."
The blackout warned us that we need to increase supply to meet demand. But we haven't. Every year our demand for power increases -- there are ever more air conditioners to cool our homes, iPods and cell phones to charge, computers running constantly so they'll be ready at a moment's notice.