Hi, I'm sure you've had so many of these posts over the time of this board's creation, but alas, I've been having something of a debate with a friend of mine regarding lightning. My point is that lightning cannot strike precisely the same point twice because: 1 - No two things in existence are ever precisely the same. No two bolts of lightning can be the same since the things the causes of the two lightning bolts have to be different. They would only be exactly the same bolt if time-travel was possible. 2 - Even if the same lightning bolt was caused twice, then the point would have changed. The point that was hit by bolt A couldn't be the same as the point that was hit by point B. The point continually changes through time. 3 - Even if points 1+2 are somehow proved wrong, we could never know that the same point was hit because we cannot measure anything precisely. The measurements go on forever because obviously you can take the measurement to a further decimal point. -------- His argument is that lightning doesn't take into account how it is formed, so theoretically, the same bolt could be re-created, and if a point exists, it can be measured. I really think I'm right here, and I'd like it if you could clarify one way or the other. I'm more a philosopher than a scientist so if anyone could tell me any way to make it clearer to my friend that he is wrong would also come in handy. Thanks. :) Glyn.