Bullshit. Tedious, bullshit. The only rational deifinition of a coastline is that it would be a rough average measurement, as nothing else is possible. Very large areas are washed away daily, and in other places the wind and tide deposit a wide variety of material that does in fact become dry land repleet with trees. The daily shift is likely as much as several miles in storm season. My advice is to put your maths, away, and go for a walk, and contemplate that which will not conform to any or in fact ALL compuational power that exists.