ASTR 1010 1st EditionLecture 11Outline of Last Lecture I. Light & WavesA. Properties of WavesB. Light Wave Spectrum- DiagramOutline of Current LectureI. The Doppler EffectA. DiagramB. FormulaCurrent LectureI. The Doppler Effect- The Doppler Effect is a wave phenomenon where a detected wavelength is different from the source wavelength due to a relative radial motion between the source and the observer. Characteristics include:o When the source and/or observer move toward one another, the detectedwavelength is shorter than the source wavelength, so it has been “shifted”to a shorter wavelength (has higher frequency). o When the source and/or observer move away from one another, the detected wavelength is longer than the source wavelength, so it has been“shifted” to a longer wavelength (has lower frequency). o The greater the shift, the greater the relative speed between the source and observer.o The effect does not depend on the distance between the source and the observer.- Light that has been shifted to higher frequencies due to approach is called blueshifted light and light shifted to lower frequencies is called redshifted light.- To date, all distant galaxies show a redshift in the light they emit, meaning they are all moving away from the Milky Way and the Earth.A. DiagramB. Formula∆ λλ=vcλ=wavelengt hv =velocityc=speed of light(3.00 x 108m/s)∆=change (¿thiscase ,
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