Antigravity

Riders often experience near-weightlessness as they approach the top of a pendulum ride. If the ride is the type that makes a complete 360-degree circle, they experience a feeling of complete weightlessness.

Feelings of weightlessness are not due to a decrease in forces of gravitation; people do not feel forces of gravity. What you feel is the force of a seat (or other external object) pushing on your body with a force to counteract gravity's downward pull. A 180-pound person at rest in his office chair experiences the seat pushing upwards on his body with a force of 180 pounds. Yet at the top of a pendulum ride, the same 180-pound person will feel less than this normal sensation of weight. At the very top of the pendulum ride, riders begin to fall out of their seats. Since a 180-pound person is no longer in full contact with his seat, the seat is no longer pushing on him with 180 pounds of force. Thus, the rider has a sensation of weighing less than his normal weight.