# The Eddington number in cycling

Sir Arthur Eddington (Wikipedia article) was an 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 accredited-by-the-internet 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 76. The "cliff edge" at 48 miles is because I cycle 48 miles a day a lot (my commute used to be 24 miles in each direction), but I don’t cycle 49 miles on those days.

There’s nothing inherent about using "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. I'm pleased to have an Eddington number of 108, so I'm a "metric centurion" but I love to be one for miles too. The number 76 makes is sounds like I'm not too far away. Alas whilst I have done 76 76 mile rides, I’ve only done 35 100 mile rides... I'm not even halfway!

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 to 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.

Veloviewer also makes Eddington-style statistics available for minutes in an activity, climbing and kudos. It's another must for "stat collecting" cyclist.