On the gravity train you could get anywhere in the earth for 42 minutes

gravity train - this mode of transport exists only in theory, in which you can drive the distance between any two points on the planet. The shortest path between them - a straight line passing through the planet. Recall remake of "Total Recall" - this film just shows gravity train.

On Earth, a trip to the gravity train from any point A to any point B takes less than 42 minutes. However, this would be possible only if the planet is a perfect sphere with a uniform density. In our conditions there are several reasons why it is impossible to create a gravity train.

First, the train will have to pass through the center of the Earth, testing the influence of extremely high pressure - materials that can withstand such pressure, currently do not exist. Another problem - a very high temperature in the depths of the planet. Finally, in the tunnel that will be used to move the train, to be a vacuum, because the air due to friction will soon make the train unusable.

via factroom.ru