How long will Twitter be around? OCT 02 2013
The latest installment of XKCD's What If? column starts off by answering a question about how tall your Twitter timeline would be if it extended off the screen.
On my computer's monitor, the average tweet is about 2.4 centimeters high. This suggests that Jeph Jacques' tweet tower is 900 meters tall-taller than the tallest building-and still growing.
However, Jeph has nothing on @YOUGAKUDAN_00, who tweets many times per minute -- usually binary, but sometimes actual words. @YOUGAKUDAN_00 has accumulated 37 million tweets, enough to reach into low Earth orbit.
But then a more interesting question is explored...how long will Twitter last?
Suppose you're transported to an alternate universe. You open IMDb and load a random page, and the movie that comes up is The Land Before Time XXVII.
Based only on the title, how many Land Before Time movies do you think there are in this universe? Clearly there are at least 27, and probably more.
Allied troops faced a version of this problem in World War II. German tank parts had serial numbers, many of which were sequential (1, 2 ... N). Suppose they captured a random tank. If they determined it was Tank #27, then they can be sure that the Germans had made at least 27 tanks. It also told them there probably weren't millions of tanks; if there were, they would have been unlikely to get a two-digit serial number.