A Tale of Two Services

摘要

I have on my office wall a wonderful and thought-pro-voking visual map of world history, the Histomap of World History, published by Rand McNally, which graphically shows the rise and inevitable fall of various world civilizations in human history. Back in the year 800, the Assyrian Empire dominated the western world and looked like it would continue its supremacy for centuries to come. Then came the Roman Empire, the Mongolians, the Turks, the British Empire, Russia-each appearing invincible in its heyday until the rise of a stronger or more adaptive successor. Were I drawing a histomap of the world of online information (admittedly, a smaller slice of time), I would show some civilizations that came and went-NewsNet, anyone?-and some societies such as Dialog steadily plugging along since the earliest days.