I have this idea and I don't know how to process, explain or question it. I hope you can understand these images and help me formulating a good question.
This is like a gravitational train but it doesn't goes to the antipodes, just like a tunnel that cuts a slice of earth.
In this image I tried to express a straight path in a round surface. If I walk 1000 meters forward I will go to the shortest way and that way is a straight line. But if instead of walking, I dig a tunnel and, that path or way is still a straight line? Or from my point of view I will see that tunnel curved?
I'm really trying to figure out this. I don't have any scientific education and english is not my first language but I'm very curious and I'm hungry for knowledge :)