Science fiction movies sometimes take place in space and contain scenes where things explode very loudly and brightly. Why is this realistic?

This could be considered realistic in the context of science fiction movies, as explosions in space would still produce light and sound. In reality, explosions in space would not produce any sound due to the lack of air molecules to transmit the sound waves. However, the intense light and energy released from an explosion can create a visually spectacular display, which is why explosions in space are often portrayed as being loud and bright in science fiction movies for dramatic effect. Additionally, incorporating explosions in space scenes can add excitement and intensity to the movie, making it more engaging for the audience.