Transcription:
By Jesse Squire @tracksuperfan · 1h
If I did my math right, those starting block speakers made a difference last night.
Without them, Lyles would have been at a disadvantage of 0.008 sec — how long the sound of the pistol takes to travel from lane 4 (Thompson) to lane 7 (Lylesh).
He won by 0.005.
[A picture showing starting blocks on the track with runners’ feet in them. Behind each starter block is a purple loudspeaker connected to wires leading out of frame.]
Does this assume the speakers are in series? (If that’s the right word.) Somehow I think someone’s thought of that.
Nah, electricity operates at near the speed of light, so its difference even across an entire stadium is negligible.
But if it were significant, you’d want them wired in parallel with equal wire length to each speaker, even though the closer ones don’t need that much wire.
You’d also want your transmitter to be physically on equal distance from the speakers. You always get a bit of current via the electromagnetic field, and it spreads throughout anything, not just wires.
Well, it also depends on whether that little current is enough to make a sound that the runner would be able to hear.
So he got the math wrong? Or rather used the wrong speed.
*Nvm I misread the original post.
They are more saying that using loudspeakers is better than a traditional starter pistol shooting a blank.
Since a starter pistol would be fired from either the inside, or outside of the track, the sound of it would take about .026 seconds (more than the .005 seconds) to reach the other side. This is estimating the air is around 20C.
With loudspeakers, as another user mentioned, you can theoretically ignore the length of wire as it would travel close to the speed of light. (~0.000000045 seconds using 99.9% Cu, if you are curious) Since the loudspeakers each are also an identical distance from their starting blocks, each of the athletes would hear the crack at the very same time.