Wavelengths of light from a distant galaxy are found to be 0.44% longer than the corresponding wavelengths measured in a terrestrial laboratory. What is the speed that the wave is approaching?

1 Answer
Ed Hitchcock
Feb 27, 2016

Light always travels at the speed of light, in a vacuum, #2.9979*10^8m/s#

Explanation:

When solving wave problems, the universal wave equation, #v=flamda#, is often used. And if this were a general wave problem an increased wavelength would correspond with an increased speed (or decreased frequency). But the speed of light remains the same in a vacuum, for any observer, the constant known as #c#.

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