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

This portrayal of explosions in space is unrealistic because sound cannot travel in the vacuum of space. Sound waves rely on molecules to travel through, and since space is a vacuum, there are no molecules to carry sound waves. Therefore, explosions in space would not create any sound. Additionally, the bright fiery explosions seen in movies are often exaggerated for dramatic effect and may not accurately represent how explosions would look in the vacuum of space.