cameron_

Genetic tests can be used to determine paternity though?

https://en.wikipedia.org/wiki/DNA_paternity_testing

Maybe you are referring to a specific type of test?

This sounded very wrong to me, so I googled and apparently they had a setup where the reflected air from the sail caused a net flow in the opposite direction allowing them to move forwards. But that is less effective than just blowing the air straight backwards without a sail.