At 06:55 PM 8/24/2011, Jed Rothwell wrote:
Here is an interesting footnote to history. I believe the speed of sound was not established with this much precision until later. This was done by assuming for simplicity that the speed of light is close to infinite over short distances, and firing a cannon. The time delay from the flash to the sound of the explosion gave the speed of sound. This was done in 1826 at Lake Geneva to establish a value to within 1% of the modern figure. I don't know how they recorded it. I guess by pressing buttons to start and stop a timer. You would think this would mainly record human reaction time but I suppose it depends on how far away the cannon was.
The reaction time would affect both start and stop timing, probably about equally. Only if the interval were short such that variation in reaction time would be a major chunk of it would reaction time be a serious problem.
