Hi! I'm a high school student, aspiring to pursue a career in Astronautical Engineering. I always try and ponder on questions about everyday aerodynamics and physics. So, here's a question from you from an aspiring scholar. It is known that, at high velocities, pilots in super-sonic jet fighters, or just standard fighter jets that can achieve incredibly high speeds, experience an increased G-force pressing against them in the cockpit. Why does this happen? I've read it in many science-fiction novels as well, about how inertia and increased G-force due to great velocity can be, well, harmful to a human being. The main reason I ask this question is because I believe (I hope, at least) that one day we will be able to reach relativistic speeds with manned spacecraft to venture the stars. Would such forces act the same way in space? And if so, would there be a way to balance the forces without affecting the motion of the spacecraft? A force field of a sort, maybe? I thank you in advance for your insight, Alexander Needleman.