A new PR (personal record) as they say in track and field: a rise time measurement of about 40 picoseconds (40 trillionths of a second). This is slightly more than a 6x improvement over the previous PR of about 250 picoseconds (ie, about a quarter of a nanosecond which is of course a quarter of a billionth of a second).
In the image you can see that the voltage increases about 200 mV (4 vertical divisions upward at 50mV per division from the 10% line to the 90% line) in about 2 horizontal divisions (each horizontal division being 20 picoseconds) for a total elapsed time of approximately 40 picoseconds. I don't see any good way to get to a sub picosecond (less than a trillionth of a second) rise time, but it might be possible to squeeze out another 5 - 10 picoseconds with some further studying and fine tuning.
It would take 25 billion of these 40 picosecond increments to move a watch needle 1 second.
No big deal for the veterans here I realize but kind of fun for a guy who had not much of a clue about pulse generators and rise time measurements a couple years ago.