The Physics of Explosives and Blast Helmets (image) American Institute of Physics Share Print E-Mail Caption Pressure contours show the effect of a front-facing blast at various times after detonating 1.5 kg of C4 explosives from a distance of three meters. Black represents 1.0 atmosphere of pressure, and red indicates pressures over 3.5 atmospheres. Credit NRL's Laboratory for Computational Physics and Fluid Dynamics Usage Restrictions none Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.