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.
Ah, the good old days, when people used to talk to each other in public rather than looking at their phones or listening to headphones all the time. Except that's not been the case for awhile as XKCD demonstrates with a series of quotes from various publications dating back to 1871. This is from William Smith's Morley: Ancient and Modern published in 1886.
With the advent of cheap newspapers and superior means of locomotion... the dreamy quiet old days are over... for men now live think and work at express speed. They have their Mercury or Post laid on their breakfast table in the early morning, and if they are too hurried to snatch from it the news during that meal, they carry it off, to be sulkily read as they travel... leaving them no time to talk with the friend who may share the compartment with them... the hurry and bustle of modern life... lacks the quiet and repose of the period when our forefathers, the day's work done, took their ease...
In 1946, a young Stanley Kubrick worked as a photographer for Look magazine and took this shot of NYC subway commuters reading newspapers:
The more things change, etc. More of Kubrick's subway photography can be found here.
Today's XKCD must have taken Randall several years to draw...if you click and drag, it goes on forever. Or not quite forever, but Dan Catt did some figuring and:
Ok, so the XKCD map printed at 300dpi is around 46 foot / 14 meters wide, half that at magazine 600dpi quality.
Here's a better Google Maps-like way to explore the entire world.