The Super Earths
01- K-11
02- Migrating Worlds
03- Gliese 581
04- Goldilocks
05- 51 Pegasi
06- Doppler Effect
07- Rhythmic Shift
08- Eccentric Giants
09- Transitters
10- Mu Arae
11- Intermediate World
12- Worlds Observed
13- Extra Solar Earths
14- Migrant Worlds
15- Accretion
16- Core Accretion
17- Disk Erosion
18- Planetary Embryos
19- The Protected Zone
20- Ecosphere
21- Ecosphere II
22- Beta Pictoris
23- Vanquishing Starlight
24- Red Edge / Earth Shine
25- Distant Continents
26- The Age of Stars

06 - Doppler Effect

Click here for enlarged diagram


If the star is moving toward the Earth the light is compressed and shifts to slightly shorter wavelengths. If the star is moving away from the Earth the light is stretched and shifts to slightly longer wavelengths. This is like the doppler effect in sound. Sound moving away from the listener is lower in pitch and sound moving toward the listener is higher in pitch because the soundwaves are respectively stretched or compressed.

Light waves are bluer in colour when compressed and redder when stretched.

  Alan Lambert 2011