This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Astronomers use standard candles to measuring distances. The Doppler Effect is a change in the observed frequency of light due to relative motion. Only the motion along the line-of-sight matters. The frequency of sound waves increases as a source approaches the observer, and decreases as it recedes . Approaching sources Spectral lines shifted to higher frequencies => short wavelengths. Spectrum is blueshifted Receding sources Lines move to lower frequencies => longer wavelength Spectrum is redshifted The Doppler effect is very important because it is the only way of measuring the motions of distant objects....
View Full Document
- Spring '08