Cosmic Expansion - Spectroscopy Experiment

[Farahday]

Astronomers tend to presume that between any given source and observer, all light travels the same distance at the same speed. But light bends in the presence of gravity. Observe a simple prism and you will note the red wavelength bends less than violet. Forget stars and planets, how many mass-laden particles are there in 15 billion light years of space?

Light at lower wavelengths has a more distant trajectory from source to observer when it is repeatedly exposed to micro gravity and would take longer to traverse the distance. Is it possible that 'wavelength lag' alters the elemental absorption markers toward the red end of the scale?

Any suggestions how to set up an experiment?

 

[Valerie Park]

One way to test this hypothesis would be to use a spectrograph and observe the same star or other source of light at different distances. By comparing the intensity of different wavelengths of light at different distances, it should be possible to detect any discrepancies between the red and violet ends of the spectrum. This could then be used to calculate how much the light has been affected by gravity over the course of its journey.