Scientists at the University of Lisbon might have resolved the 350-year-old mystery of the pendulum clocks that synchronize their swings over time.
Dutch scientist Christiaan Huygens invented the pendulum clock in 1656, but it was 10 years later when he noticed something odd on the clocks while he was staring at them from his bed: the clocks synchronize their swings over time, even if you start them on opposite directions.
The mysterious synchronization of swings, also known as the "odd kind of sympathy," has baffled scientists for centuries. That is, until scientists started analyzing the pendulum clocks and concluded that the clocks could be influencing each other's swings through sound pulses.
The researchers experimented with two pendulum clocks attached to an aluminum rail fixed on a wall.
"Nobody tested properly the idea of clocks hanging on the same wall," Henrique Oliveira, study co-author and a mathematician at the University of Lisbon and co-author, told Live Science.
Oliveira worked with Luís Melo, a physicist at the University of Lisbon, in developing a mathermatical model that would calculate the sound pulses that could travel through the wall from clock to clock. These pulses interferes with the swings of the pendulums, which caused them to synchronize their swings.
"We could verify that the energy transfer is through a sound pulse," Melo said, adding that the finding not only solves "an old, fundamental problem," but also provides an understanding of other types of oscillators, according to The Guardian.
The researchers plan to continue their study by analyzing the behavior of other oscillators, including the electronic oscillators used in microchips.
The study was published in the July 23 issue of Scientific Reports.
