both passengers and cargo, so shipping times and costs could be drastically reduced. http://blogs.howstuffworks.com/2010/08/17/how-5000-mph-vactrains-work-aka-evacuated-tube-transport-could-completely-transform-global-transportation/ Travel through evacuated tubes allows supersonic speed without the penalty of sonic boom found with supersonic aircraft. As the speed of sound is increased by reduction in air pressure, even a partial vacuum would increase the speed of