Every day, from sunrise to sunset, we witness innumerable events that happen in nature. Since thousands of years, humans have been intrigued by the beauty and clock-like precision of the day and night cycle. This curiosity and the desire to know the secrets of nature resulted in a huge body of knowledge, called physics. Later, physics led to scientific and industrial revolutions in Europe and North America, which eventually spread to rest of the world. Since then, physics has continued to touch human lives in numerous ways.