The Hand-Off

In 1904, the American historian Henry Adams (the grandson of John Quincy Adams and the great-grandson of John Adams) postulated his own kind of Moore’s Law to describe the rapid progress of the previous centuries. World coal output, he noted, had roughly “doubled every ten years between 1840 and 1900, in the form of utilized power, for the ton of coal yielded three or four times as much power in 1900 as in 1840.” He used the improved marginal efficiency of coal as a proxy for technological and scientific progress, which he regarded as a potentially inexhaustible force. But he foresaw problems: