The history of the "0.10 sec" reaction time rule is rather interesting. As
technology improved and automatic timing was instituted the offical time
was started by the starter's pistol and the time was read off of a photo
at the finish line. (Hand times are faster because timers must "see" the
smoke before starting their watches but anticipate the finish line, that is
they have the watch stopping coincide with the torso hitting the finish
line. Experienced timers can come close to automatic times by "seeing"
the torso hit the finish line, then stopping the watch.) The Olympic
Committee tested all the world class sprinters to determine what a lower
bound for reaction times would be. I be;ieve that the qickest reaction
they measured was a Russian sprinter named Valery Borzov who
reacted in 0.14 seconds. They then set the lower bound to be 0.10 sec,
arguing that anybody who reacted faster than that had anticipated the
gun, that is "jumped the gun". The earlier comment justifies this decision
showing a range of reaction times the quickest of which was around
0.17 sec. I've viewed that start with stop action on my VCR and there is
no doubt that Christie clearly jumped. He comes off before the rest of
the pack of world class sprinters who seem to move in synchrony.
While one might wish to argue philosophically that as long as you move
after the gun you can not have jumped, I would disagree.
Additionally we should note that all the starting blocks have a speaker
in them now so the runners all receive the sound of the starter's pistol
simultaneousl
Craig Gunsul, Professor of Physics and Track N
gunsul@whitman.edu