chennai scientists at iit madras have developed an algorithm that can help manage dense crowds using minimal manpower and prevent deadly stampedes in huge public gatherings like the kumbh mela and the hajjusing a computer simulation researchers can intelligently plan where to place police personnel to quickly quell disturbances in a crowd that could otherwise lead to panic and chaosthe research published in the journal physical review letters can also help design safe evacuation procedures for events and locations that witness high footfallcouple of years ago the elphinstone brigde tragedy took place in mumbai it was a very unfortunate event that we thought could have been prevented by understanding the physics of stampede said mahesh panchagnula a professor at indian institute of technology iit madrasif we know how these events start and how they propogate through a crowd there are ways of mitigating it he told ptithese kinds of stampedes have clear patterns in how they start we wanted to understand those early signs and figure out how you place the police people or what we call gamechangers who then direct the crowd in a way that would prevent stampede panchagnula saidthe ongoing kumbh mela a hindu pilgrimage at allahabad is one of the worlds largest religious gatherings up to two crore people taking a dip in the river on some days making the event a hot spot for mishaps that could put thousands at riskin 2013 at least 42 people died after a stampede broke out at the train station in allahabad during the festivalsimilarly mecca in saudi arabia islams holiest city is visited by millions of pilgrims every year in 2015 a stampede caused deaths of over 2000 pilgrims during the annual pilgrimage the deadliest hajj disaster in historysuch events call for better methods of crowd control the physics community has been looking at this problem for a while now researchers saidfor example they have investigated the idea of placing barriers at certain places that would make the flow of crowd easier it may sound counter intuitive but it works he saidit is all about streamlining the crowd it looks like you have placed barricades at certain places but it helps easing the crowd flow he addedthe research team which includes sumesh p thampi and ajinkya kulkarni analysed what happens when a dense crowd about 34 people per square metres fills into a confined spacethey said that in such gatherings the movement of the crowd resembles that of any fluid and hence laws of fluid dynamics can be applied to predict where disturbances can ariseif we look at the areal videos of people circumnavigating the kaaba in mecca it looks exactly like water swirling in a bucket panchagnula saidthe researchers tried to capture the simple rules that a person follows to navigate in a crowd in to a mathematical model the predictions of the model adhered well to experimental observations they saidlets say a gathering is set to take place in marina beach the police