Space is completely and absolutely silent because there is no sound in the vacuum.
The vacuum of space has no atmosphere to carry sound waves, so it is indeed silent. However, this statement oversimplifies: space isn't a perfect vacuum but contains plasma and gas, especially near stars and galaxies. These media can carry waves called plasma waves or Alfven waves. Additionally, sophisticated instruments detect radio waves and other electromagnetic radiation. The traditional statement 'space is silent' is accurate for conventional sound but misleading about space's actual character.
Reception
Sources
- NASA: Space and Sound PRIMARY
- Physics Classroom: Wave Propagation REFERENCE