There are 1.3 million km of railroads in the world. At 200km/h, a trolley could travel them in little over 270 days.
Rearrange them in a circle and, providing everyone is cooperating for the sake of philosophy, there’s plenty of time to tie 8 billion people to the rails and run them over.
Except, given finite resources, the tracks would run out before having enough space for 8 billion tied-up people.
There are 1.3 million km of railroads in the world. At 200km/h, a trolley could travel them in little over 270 days.
Rearrange them in a circle and, providing everyone is cooperating for the sake of philosophy, there’s plenty of time to tie 8 billion people to the rails and run them over.