Monday, July 12, 2004
Allison is coming home from Australia soon, so I thought I'd post another picture from the trip - this one's from Hong Kong. And I just got back from Hilton Head. Random impression - coming back from the beach at high noon, I'd wash off the salt water in the outdoor shower. With the sun shining down from overhead, the falling water droplets were dazzingly bright - they seemed to form centimeter-long sparks of pure light. Thinking about it now, the water droplets had fallen about a quarter of a meter, giving them a speed of v=(2*9.8*.25)^.5, about 2 meters per second. So if the eye was seeing in .1 second 'snapshots', then the streaks of light should be 20 centimeters long. Hmmm... They did flash in and out of the field of vision almost as fast as possible - say I was seeing .02 second glimmers, that would give 4 centimeter long streaks, which still seems a little long. I took a photograph of the shower in the sunlight, maybe that could help resolve the issue if the shutter speed is known. Still, the most hypnotic thing about watching it was that there were tiny refracted rainbows just barely visible at the ends of the falling water droplets - shards of red and yellow glinting at the edge of perception.