I really like the visualization as gel electrophoresis. What are axis? X is the letter, color/intensity is frequency, Y - I assume is the time? If Y is the ti

I really like the visualization as gel electrophoresis. What are axis? X is the letter, color/intensity is frequency, Y - I assume is the time? If Y is the time, I can imagine that there would be mostly times without any activity punctuated by brief blips where almost all the letters are lit up. Is it just that the time span is shorter than I expect, and that just shows a 30min interval or so? Is this just typing from one sitting? E is typically the most used letter in plain text, I'm surprised how infrequently this shows up.