• Question: What is the sound barrier

    Asked by Jahi on 18 Dec 2024.
    • Photo: Rachel Edwards

      Rachel Edwards answered on 18 Dec 2024:

      It’s when you’re travelling faster than the speed of sound in air. Normally when we make sound, it spreads out into the air around us. But if we’re travelling faster than the sound waves, they can’t move out of our way – and you get a sonic boom because the pressure from the sound builds up.
      It’s really hard to go this fast though – there is a thing called air drag that slows you down normally, and it’s a lot stronger when you’re going at these speeds.

    • Photo: Caroline Roche

      Caroline Roche answered on 20 Dec 2024:

      As you approach travelling at the speed of sound (around 770mph) – the sound barrier – the drag experienced by an aircraft increases significantly (alongside other aerodynamic effects) and people once believed that it would be impossible to get past this ‘barrier’.
      If you go faster than the speed of sound, go supersonic, the high energy shock wave caused by this is known as a sonic boom. The sound of the boom actually follows the airplane so can be heard of large distances. It can also cause damage to windows and shake houses.

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