Humans always aspire to move faster, faster and faster. That’s why we moved from the knowledge of circle, to Newton’s law and farther in to relativity. From a wheel that “turned life” to the rocket that “revolutionized life”; today we stand at traveling faster than a sound could. But traveling faster than sound introduces the phenomenon of Sonic Boom and a bunch of challenges. Following video could provide you with an insight in to Sonic Boom.

Sound is a Longitudinal Wave and travels as rarefaction and compression. Longitudinal waves have the displacement of particles and propagation in the same direction. But sound is a mechanical wave and require a medium to propagate. This implies sound can’t travel in vacuum. Moreover, it has different speeds in different media. This arises from the fact that the different media have different density of particle arrangement and hence different degrees of freedom. Hence, sound travels faster in solids and slower in liquids and slowest in air . The speed of sound in air at sea level is 340.29m/s.

The question is what happens when you travel faster than sound? The problem seems simpler but it’s tougher than we think. The speed of an aircraft in relationship with speed of sound is given by Mach number. ie; 1Mach = Aircraft speed/Sound Speed. This comes from the concept of  Mach Cone we discussed so far in the above video. To realize how faster is 1 Mach , just imagine the speed at you hear the sound when someone speaks to you. To make an aircraft “n” times faster than this is really cumbersome. But humans always try their best to make impossible -possible.The experiments were already began in 20th century to make this concept practical . The Project ” Concord” , the joint venture of British and France was the successful in terms of engineering such an aircraft, but failed in terms of making business and winning hearts of people. The main issue was Sonic Boom. But there were a lot of other issues that hindered the concept development in to reality. The following video discusses Why Traveling Faster Than Sound Is not Easy?

But these issues doesn’t push the dream travel in to impossibility. There are alot of aircraft that travel five times faster than the sound . Mach 2 speed aircraft are now widely used in the field of Defense. And now we have achieved a speed of Mach 9, emphasizing the truth that Sonic Boom still makes commercial viability difficult. However, we have to move forward with our scientific temper of traveling faster and  soon sort out a solution.