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As light is travelling within the expanding universe does the wavelength of distant light change over long time periods or does it appear the same because our o
by mywacaday 7y ago
As light is travelling within the expanding universe does the wavelength of distant light change over long time periods or does it appear the same because our observations are expanding too(my head hurts)>
- jfengel 7y agoYes, the wavelength gets longer. That is, in fact, how we measure the distance: for a known frequency (say, the electrons jumping up and down in a hydrogen atom), we observe that this color is "redder" the further away an object is. The number "z" mentioned above is called the redshift because of that, and it's how we know the distances of the furthest objects.