Calculating the hypothetical travel time of the "Shot Heard Around the World" involves assuming a speed of 1000 meters per second, leading to an initial estimate of about 40 seconds to cover the Earth's circumference of 40,000 kilometers. However, this estimate does not account for the Earth's curvature or the bullet's trajectory, which would extend the actual travel time. Air resistance would further impact the speed and path of the bullet, making the journey longer. The phrase also serves as a metaphor for significant global events, emphasizing the spread of information rather than physical travel. Ultimately, the travel time would exceed 40 seconds due to these various factors.