Cloudy weather during the World War II led to a fateful shift in plans, sparing Kuroko from destruction and changing history. Nagasaki became the target instead, highlighting the immense impact of split-second decisions. This incident, akin to 'the butterfly effect,' continues to resonate with Kuroko's inhabitants, reminding us of history's delicate balance.

The butterfly effect, a part of chaos theory, states that predictions have limitations even in small, discrete systems. It was summarised by Edward Lorenz, the meteorologist who discovered it. He noted that a tiny change in the initial conditions had enormous long-term implications. By 1963, he had formulated enough ideas to publish an award-winning paper. For instance, when a butterfly flaps its wings in Cox's Bazar, that tiny change in air pressure could eventually cause a tornado in Florida. That means something minor, like a small mosquito bite, can have much more significant effects, such as putting someone's health in danger, called the butterfly effect.

The butterfly effect rests on the idea that the world is deeply interconnected; such a tiny occurrence can influence a much larger, complex system with enormous long-term implications.

Although chaos theory was the initial term, complexity science, or complex systems theory, is often used to describe chaotic behaviour. Around the world, people view the butterfly symbol as representing resolution, hope, and life. It also represents a state of naturalness and purity. But in reality, this theory teaches us that 'small things matter', and we are all 'connected to a bigger system'.

Our action now, today, would have been the result of a previous action, and this could, in turn, lead to future action. And with a small gesture, someone can change somebody's life.

E-mail: rubaiulmurshed@shomman.org