Final answer:
The delay between seeing and hearing fireworks explode is due to the difference in travel times for light and sound, with light traveling much faster than sound. Closer proximity allows for simultaneous perception of sound and light, while distance creates a noticeable delay for sound. In space, only light can be observed as sound cannot travel through a vacuum.
Step-by-step explanation:
When you observe two fireworks explode, and you hear the explosion of one as soon as you see it while observing a delay in sound for the other, this is due to the difference in travel times for light and sound. Light travels much faster than sound, at a speed of approximately 299,792 kilometers per second (speed of light), while sound travels through air at about 343 meters per second (speed of sound) at sea level and at a temperature of 20°C. If you are at a closer proximity to one firework, you may hear the explosion simultaneously with the light because the travel times for both light and sound are minimal. However, for the firework that is further away, you will see the light almost instantly, but there will be a noticeable delay before the sound reaches you as sound takes a significantly longer time to cover the same distance.
The concept also applies on a larger scale, such as observing a satellite explosion from the International Space Station. An astronaut on a spacewalk would see the explosion of a satellite immediately because light can travel through the vacuum of space, but they would not hear the explosion because sound cannot travel through the vacuum of space.