What is negative g-force?
If you accelerate downwards faster than the rate of natural freefall, you will experience what is known as a negative g-force. As you accelerate, the liquid in your body (the blood) moves slower than the solid parts of your body due to the inertia of the blood, often resulting in a feeling of weightlessness. An example would be travelling in a car accelerating over the crest of a hill, or riding on a rollercoaster that accelerates downwards. Negative g-forces can result in a ‘redout’, where the blood gathers in your head and everything has a slight red tinge, something pilots often experience in high-speed dives.