Are you a roller coaster enthusiast?

If you are, you’ve probably noticed (when you weren’t screaming and closing your eyes) that the loops on these thrill rides are never circular.

And you’ve also probably noticed that vertical loops have an inverted teardrop shape instead of a complete circle.

The loops on coasters are built like this for a very specific reason.

The rails on roller coasters power the cars of the coaster toward the top of the loop from the bottom of the loop and help the cars get all the way around. This is called centripetal force. And the tighter the radius of a loop, the higher the speed will be through it.

If coasters were built with perfectly circular loops, there would be quite a few problems. First is gravitational force equivalent, commonly known as g-force. In perfectly circular loops, the g-forces that a human body would experience at the bottom of the loop would be unsafe.

The force needed to push it through a circular loop would cause this unsafe g-force as you approached the loop because the coaster cars would need that much extra power to make it through. So, basically, passengers could be harmed because the whole process would be unsafe for them.

So, until some crafty engineers come up with some new ways to create perfectly circular loops on roller coasters that will be safe enough for us to experience, we’ll be enjoying and screaming the way we have been on rides for years.