Sometimes there are some strange coincidences, well this week they have revolved around the 50 degree angle. First it was related to Jet's EE on irrigation and the relationship between the spread of water and the angle of the jet, the small droplets are affected more by the resistance than the large ones. Experiment showed that the optimum angle was 50 degrees. On the way to the climbing wall the farmer was spreading liquid manure from a tank, for maximum effect the nozzle should be 50 degrees the smell was bad so I didn't hang around. The climbing wall was set at 50 degrees. Strangely some moves were easier than when vertical since you climb out not up. The increase in PE from bottom to top is significantly reduced when you loser the board. There was something else that I can't remember, I will have to tink about it.