Whatever happens in the 21st century and beyond, it is likely we can't anticipate its scope. To illustrate, let's go not to the future, but to the past — about a century ago. No one in January 1900, not even Edison or Einstein, could have fully understood the sweep of change to come ... and we're talking about what was, in 1900, the immediate future. Consider the earth-shaking events of the first decade of the century: