|MadSci Network: Earth Sciences|
The lightning strike is virtually invisible until the built-up charge actually discharges. When this happens, the "speed" of the strike is something on the order of 1/3 the speed of light. This is still very fast, to the human eye very nearly instantaneous, beyond the speed of human reaction.
There are numerous accounts of people who have felt (and seen) their hair stand on end in the minutes preceeding a strike (an example can be seen here), and have moved to a safer place before the discharge. Alertness to the environment doubtless prevented injury in those cases.
June 22-28 is Lightning Safety Awareness Week. Check out the National Weather Service's
Lightning Safety Awareness Week pages. There are many web resources
about lightning. You might start with these previous
posts to the MadScientist Network at
Try the links in the MadSci Library for more information on Earth Sciences.