In a classroom off the lobby, we receive a couple of hours’ instruction. Swee Weng Fan, a former flight surgeon for the Singapore air force, softly talks us through the basics of Newtonian physics and human physiology, explaining that our bodies are mostly water, run through by a circulatory system that keeps it functioning. Then we segue to how Newton’s discoveries—rest and velocity, acceleration, equal and opposite force—can quickly conspire to disrupt that system in terrible ways. When G-forces pull the blood from a pilot’s head and pool it at the feet, for instance, they upset the flow of oxygen to the brain. The result is G-force–induced loss of consciousness, or G-LOC. The eyes roll back, the body spasms, the pilot passes out—there’s even a bit of dreaming, Swee tells us. The warning signs include tunnel vision and temporary blindness. It will be our job this afternoon to resist G-LOC with an “anti–G-strain maneuver.” By tensing the legs, butt, and other major muscles below the heart, and by taking quick, deep breaths, Swee says, it’s possible to push blood back up into the head and not pass out, even as the centrifuge whirls us in circles at a steady 6 Gs.