So you know the Channel Tunnel, yeah? Can I ask something about it? You know how it's under the ground, and then that ground is under water? Does that mean that the tunnel itself has to be SUPER strong in order to not collapse under the combined weight of the water and the ground? Or is it just as strong as a tunnel under the ground, the water on top making no difference? I guess this is a Physics question really.
I've been thinking a lot about the Channel Tunnel recently. It's pretty amazing.