1. Light waves from an object speeding away from you will stretch into longer wavelengths.
2. Light waves from an object speeding toward you will have shorter wavelengths.
3. That " light echo " was still observable, and the new study was based on analyzing the wavelengths of light from that.
4. wavelengths的意思
4. Astronomers used the telescope to break down the wavelengths of light in the quasar to figure out what was in the space dust.