There is rarely time to write about every cool science story that comes in our way. This year we're again hosting a special series of Twelve Days of Christmas posts highlighting a science story that fell through the cracks every day from December 25th to January 5th in 2020. Today: Experiments on synchronization in a network of violin players have shown that people can drown out distractions and misunderstandings in order to stay in sync better.
An August 2020 study published in Nature Communications uses a model of violin synchronization in a network of violin players and shows that there are ways to drown out distractions and misunderstandings.
An unusual experiment involving 16 violinists trying to sync their playing using noise-canceling headphones yielded some fascinating results, according to an August 2020 article published in Nature Communications. The study concluded that human networks differ fundamentally from other networks because of our ability to make decisions about synchronized behavior. This could lead to better models of complex human behavior, with applications in fields as diverse as economics, epidemiology, politics, traffic management and the spread of misinformation.
So far, there have been studies on synchronization in human behavior, particularly with regard to bridge dynamics. For example, as we have reported, people who walk on a bridge that is beginning to shift instinctively adjust their stride to match the swaying motion of the bridge as it wobbles sideways. This is known to anyone who has tried walking on a fast moving train and had to find a firm footing when the train wobbled from side to side. A bridge, however, exacerbates the problem and leads to additional small lateral oscillations that increase the swaying. The result is a positive feedback loop (the technical term is "synchronous lateral excitation").
Get a large enough crowd to adjust their stride to match the movement of the bridge, and the swaying can get dangerously strong, as the Millennium Bridge did when it opened in June 2000. Approximately 90,000 people crossed the bridge on opening day, with around 2,000 people crossing it at any one time, and the movement of the crowd caused significant tremors and fluctuations.
Over time, the pedestrians accidentally synchronized with each other and made the bridge wobble even more. The spontaneous synchronicity of the crowd was similar to the highly synchronized blinking of fireflies or the firing of neurons in the brain. The Londoners called it "Wobbly Bridge". Officials closed it after just two days, and the bridge remained closed for the next two years until appropriate changes could be made to stop the swaying.
The phenomenon was also seen among stockbrokers, according to a 2011 study which found that traders' daily instant messaging patterns are closely related to their level of synchronous trading. Bottom line: "The higher the synchronous trading the traders are, the less likely they are to lose money at the end of the day," the authors wrote. Cornell University applied mathematician Steven Strogatz performed synchronization experiments with crickets in soundproof boxes.
Moti Fridman – physicist at Bar Ilan University in Israel and co-author of the paper for violin players – also has a longstanding interest in synchronization, having published studies on synchronized large laser networks and, on a smaller scale, the unusual coupling explains why rubbing the rim of a wine glass creates a tone and vibrations in other wine glasses. For violin studies, he worked with Elad Shniderman, a music student at Stony Brook University in New York, and colleagues from Bar-Ilan and the Weizman Institute of Science.
Enlarge /. 16 violinists took part in a network experiment in which they were connected to a computer system and only heard the sound received from the computer.
For the most part, previous studies have involved simple networks in which every person (or node) is connected to every other person. In a more complex network, the number of connections between each person can vary, and there can also be delayed messages between them that can prevent transition to a synchronized state. As Fridman et al. In her paper, she wrote: "Research on network connections or coupling has mainly focused on all-to-do coupling, while current social networks and human interactions are often based on complex coupling configurations."
The participating violinists put on noise-canceling headphones and began playing the same musical phrase repeatedly without looking at or listening to the other players. They could only rely on what they heard through headphones connected to a computer system. The researchers then introduced intermittent delays in signals between coupled violinists, varying the delays and combinations of violinists. It is called a "frustrated situation," and most network models assume that in such a frustrated state, each node tries to strike a balance between all of the different inputs.
Instead, Fridman et al. found that players responded by adjusting their playing, speeding up or slowing down their pace to better synchronize with their fellow violinists. "Human networks behave differently than any other network we've ever measured," Fridman told the Jerusalem Post. "In a state of frustration, they don't look for a 'middle' but ignore one of the inputs. This is a critical phenomenon that changes the dynamics of the network. Human networks can change their internal structure in the right order to achieve a better solution than is possible in existing models. "
It is similar to a phenomenon known as the "cocktail party effect": the ability of humans to pick a thread of conversation amid the cacophony of chatter in a crowded room. However, the effect has not yet been taken into account in studies on network synchronization. The next step is to run the experiment online and try to sync hundreds and thousands of violinists over the internet.
Developing better models of complex human behavior would have implications in a variety of areas, including better control of epidemics – which is particularly worrying given the ongoing coronavirus pandemic today – and preventing the spread of false information on social media (" fake news "). . "Our results also apply to any network in which every node in the network has decision-making options, such as autonomous cars or the introduction of AI into our highly connected world," Fridman told Inside Science. "Our model can predict the dynamics of such systems with high accuracy, beyond what was previously possible."
DOI: Nature Communications, 2020. 10.1038 / s41467-020-17540-7 (About DOIs).
Listing image by Chen Damari