Under 9 g, you're going to have a very hard time moving your head sideways or backwards, seeing as it feels nine times as heavy as it actually is. When a passenger aircraft takes off and we are suddenly stuck to our seat – that's a force equaling approximately 2 g. Rollercoasters usually only go as far as 4 g.

Experiencing 9 g—nine times the force of Earth's gravity—is an extreme physical ordeal typically reserved for fighter pilots and astronauts. At 9 g, your body feels like it weighs nearly 2,000 pounds, making it impossible to lift your arms or even move your head. The most significant effect is on the cardiovascular system; the heart struggles to pump blood upward against the force, causing blood to pool in the lower extremities. This leads to G-LOC (G-induced Loss of Consciousness). Before passing out, a person usually experiences "tunnel vision" and "grey-out" as oxygen leaves the retinas. To survive this, pilots perform a "G-strain" maneuver—flexing the legs and core while taking short, sharp breaths to keep blood in the brain. The skin on your face is pulled taut against your skull, and breathing becomes a labored, crushing task. In 2026, advanced "G-suits" use inflatable bladders to help squeeze the lower body, but even with technology, 9 g remains the absolute limit of human physiological endurance.