How Blast Waves Ambush the Brain It’s not just flying shrapnel and brute force that cause concussions on the battlefield. Pressure waves may also play a role. Here’s how An explosion begins with a powerful pulse of hot compressed gas that radiates outward, generating a wave of pressure that can travel up to 1,500 mph. The bigger the bomb, the faster and more forceful the wave. A vacuum of air trails this initial wave, creating a violent suction force that can shear organs. But little is known about how blast waves damage the brain. Shock waves rattle the head but may also compress the torso, transferring energy to blood vessels. One theory is that the oscillating waves travel through the bloodstream and into the brain, where they twist and kill neurons over time. Eric Hagerman is a contributing editor for Popular Science.