Brigham Young University celebrates 150 years with birthday science project

Instead of blowing out the birthday cake candles in a traditional way, Physics and Astronomy professor, Brian Anderson, helped blow them out with loudspeakers. 

Time reversal acoustics

BYU shared that Anderson and his team of students achieved the science project by using time reversal acoustics, a method Anderson teaches at the institution.  

First, the group recorded how sound travels from a distant source. Then, they played the recorded sounds backward, with the last sound played first. BYU explained that playing the first sound last creates focused sound waves back at the microphone’s original recording location.  

Anderson said that to blow out each candle, the group generated 180 decibels of sound at each candle’s position, about a thousand times louder than a rock concert.  

The experiment was conducted in a reverberation chamber.  

BYU explained while time reversal acoustics has many practical applications, such as destroying a kidney stone without invasive surgery, this time the technique was used for fun.