Eddington number


Sir Arthur Eddington (Wikipedia article) was a astronomer and physicist famous for popularizing and explaining Einstein’s theory of general relativity to the English-speaking world.

But more importantly than that he was a early forerunner of stat-obsessed Strava nerds like myself. He was a cycling enthusiast who liked to log where he’d been and how far – in fact his cycling logs are still stored in the Wren Library at Trinity College in Cambridge ( this PhD thesis has a picture ). I can’t find a definitive original source, but he has internet-accredited with inventing the (cycling) Eddington number. This number, E, is the largest number such that you have cycled E miles on E separate days. Eddington’s own Eddington number is variously credited as being 87 or 84. Veloviewer naturally will figure out your own Eddington number for you and display it in an attractive way. Here’s mine:


So right now my Eddington number is 66. The “cliff edge” at 48 miles is because I cycle 48 miles a day a lot (my commute is 24 miles in each direction), but don’t cycle 49 miles on those days.

There’s nothing inherent about “miles” in defining an Eddington number. You can easily switch to counting the number of times you’ve done E kilometres on E days (an easier job) and VeloViewer will show you this to. Mine is currently 96, which makes is sounds like I’m just a few rides away from becoming a metric Eddington centurion. Alas whilst I have done 96 96km rides, I’ve only done 85 100km rides, so I still have 15 rides to do!

This is the damnable charm of the Eddington number. The reward (“the score”) you get only grows with the square-root of the effort (total miles done). You really have try hard! The Explorer Square challenge has exactly the same property – your max square score only grows with the square-root of the number of tiles you have visited.

Anyone any idea who the world record Eddington number owner is? I think it might probably be one of the amazing challengers for the HAMR Annual Mileage Record – Kurt Searvogel road 76,076 miles in a year in 2015. That’s 206 miles per day. So his 2015 Eddington number alone must surely be in excess of 200. Or perhaps Steve Abraham holds the record. Amanda Coker might sweep them away though … 230 miles EVERY DAY for a year?!!





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