How a Sonic Boom is created

Explaining how a sonic boom is caused in simple and easy to understand terms, is by looking at wakes left by boats in the water. When you toss a pebble into the water or into a pond, little waves are formed in concentric circles and then propagate away from the point of impact. If a boat for example travels through the water at 3 to 5 miles per hour, little waves will propagate in the same way both behind and ahead of the boat. The boat will travel through the waves.
If the boat travels faster through the water than the waves can propagate, the waves cannot get out of the way of the boat fast enough and this is how a wake is formed. The wake is a larger single wave caus3ed by the boat travelling faster. This wake is formed by the smaller waves initially formed when the boat was travelling slower. These little waves would have propagated in front of the boat but now it cannot because of the speed the boat travels at.
Now, when an airplane travels through the air, it produces sound waves instead of water waves. When an airplane travel at a speed slower than the speed of sound, the sound waves can propagate in front of the airplane. Speed of sound varies but is normally measured at 7oo miles per hour through air.
When a plane travels faster and breaks the sound barrier then the sonic boom is generated. The shock waves are formed which cannot stay ahead of the airplane. The sonic boom is the wake described earlier compared to a boat. The shock waves, which would have propagated in front of the airplane normally, are now combined together. At first, you will not be able to hear anything then you will hear the sonic boom the shock waves create.

Related News

Futuristic biplane design eliminates sonic boom

A throwback to early 20th Century aviation may hold the… more

What causes a sonic boom

You can learn a lot about sonic booms by looking… more