One of my other interests are roller coasters. What you created was what's called an 'inversion'. Inversions are where the roller coaster's train goes upside down. The inversion you made is called a 'zero-G roll'. There is another inversion that similar, called a 'barrel roll'. The 'zero-G roll' is intended to produce the feeling of weightlessness, or 0G's. 1G equals 1 times the force of gravity, which we are all currently experiencing. There is a significant difference between a zero-G roll and a barrel roll. In the barrel roll, the train rotates around the track. Meanwhile, in a zero-G roll, the track rotates around the train.