Forty-two,” said Deep Thought, with infinite majesty and calm. - Douglas Adams

Generally, old media don't die. They just have to grow old gracefully. Guess what, we still have stone masons. They haven't been the primary purveyors of the written word for a while now of course, but they still have a role because you wouldn't want a TV screen on your headstone.

"Sir Isaac Newton, renowned inventor of the milled-edge coin and the catflap!" "The what?" said Richard.
"The catflap! A device of the utmost cunning, perspicuity and invention. It is a door within a door, you see, a ..."
"Yes," said Richard, "there was also the small matter of gravity."
"Gravity," said Dirk with a slightly dismissive shrug, "yes, there was that as well, I suppose. Though that, of course, was merely a discovery. It was there to be discovered." …
"You see?" he said dropping his cigarette butt, "They even keep it on at weekends. Someone was bound to notice sooner or later. But the catflap … ah, there is a very different matter. Invention, pure creative invention. It is a door within a door, you see."
"Is this when you're wearing the helmet?" "Especially when I'm wearing the helmet!"

POPULATION: None. It is known that there are an infinite number of worlds, simply because there is an infinite amount of space for them to be in. However, not every one of them is inhabited. Therefore, there must be a finite number of inhabited worlds. Any finite number divided by infinity is as near to nothing as makes no odds, so the average population of all the planets in the Universe can be said to be zero. From this it follows that the population of the whole Universe is also zero, and that any people you may meet from time to time are merely the products of a deranged imagination.