## Guessing what humanity is doing right now

I sometimes like to amuse myself by attempting to use a few bits of data, a little commonsense and a small amount of math to estimate what people are doing right now. I’m sitting in Starbucks now with about 20 other people, most with their devices out. How many are writing a post, how many reading blogs, maybe even someone is reading mine (the odds of that seem to be about 1:20,000,000, about winning lottery odds).

When I took my first physics class I was exposed to exercises to make reasonable estimates of things that were hard to measure: how many ping-pong balls would fit in the room we’re in, how many cars on on Mass Ave between the bridge and Harvard Square, that sort of thing. One experiment we did, to demonstrate how easy crude equipment could yield a reasonable answer was to estimate Avogadro’s Number. It was a simple experiment of putting a drop of oleic acid on a tub of water sprinkled with talcum powder and watching the film force the powder out of the way and measuring the diameter of the crude circle, weighing many drops to estimate the volume of a drop, getting facts about the rough size of the molecules. Surprisingly each estimate was within an order of magnitude of the right answer and thanks to law of large numbers the mean was about within factor of three, IIRC, not too bad. In grad school in macroeconomics course we had to estimate GDP (which would be known by end of term) and the mean value was within 0.1%, not too bad for amateurs. This kind of exercise turned out to be very useful in many things I did later in life and it’s sad more people don’t learn this simple technique.

Of course my thinking switched to people instead of molecules and as adolescent fantasy naturally I tried to estimate how many people were having sex at the moment. It only takes a few facts and assumptions to get a sensible answer: how many people are there, estimate their age from some data and decide what fraction might be sexually active, divide by two, estimate the time sex takes as a fraction of the day, and voila you get an answer. Of course, this too could not be accurately measured as there was no Internet for all the folks to post what they were doing.

So how many people are at Starbucks right now? Fortunately the Net and Google makes this a lot easier than it was 40 years ago since I quickly found there were 19,763 Starbucks in 2011. Now 1/3 of the people are asleep right now, but most of those are in the part of the globe that has lower Starbucks density than this time zone, so let’s guess that 60% of the Starbucks are open right this minute, so that’s about 12,000 Starbucks (add 5% growth since 2011). Since I spend a lot of Sundays at Starbucks I’ll use the samples of the four I visit to estimate about 20 people each, so that’s 240,000 people. I’ll bet this guess is within an order of magnitude, so I can now say what 0.003% of humanity is doing right now. Now the only non-authoritative estimate I can find translates to about 900K/hour; since many are just in-and-out and relatively few stay in the store it seems my guess wasn’t too bad (if only 1/2 stay and average stay is 20 minutes, that’s 150K).

So how many people are clicking Publish right now. That’s a bit of a toughie. WordPress.com’s statistics (only about 1/300th of the blogosphere) indicates an average of about two posts per blogger (sounds very high to me, a lot of writing going on). I don’t believe that would apply to the entire quantity of blogs, which I’ll estimate from a few (and probably highly inaccurate) bits: various estimates I can quickly find, 156M, 164M, 173M, 184M, 450M, 1000M (one for every 7 people in the world, a little hard to believe), many of these are old numbers (none claim to be very accurate) so I think I’ll go on the low side and guess 200M. Now only 2/3 of humanity is awake and most are doing other things in their life, so I’ll assume only a hour/day of each blogger, so about so I’ll estimate 12M people are at their blogs and guessing that it takes an average of 30 minutes to write and a second to publish, I’d estimate about 600,000 are clicking publish right now.

You think you can do better, give it a try. Like how many cars are on I-80 or I-5? How many people are sitting in waiting rooms at airports? Like how many people using the bathroom? How much water has been used, in any geographical area you’d like, in the last hour? How many bowling balls will fit in 26-100? Pick anything to estimate and let me know what you compute. And show your work.