I was born in 1948. I can’t recall a world before television, but I know I must have experienced one. I do, dimly, recall the arrival of a piece of brown wooden furniture with sturdy Bakelite knobs and a screen no larger than the screen on this Powerbook.

Initially there was nothing on it but “snow,” and then the nightly advent of a targetlike device called “the test pattern,” which people actually gathered to watch.

Today I think about the test pattern as I surf the Web. I imagine that the World Wide Web and its modest wonders are no more than the test pattern for whatever the 21st century will regard as its equivalent medium.