HISTORY OF SPECTRA INTERPRETATION

Since the red-shift effect is more of a sociological phenomena than an actual physical effect, it is more appropriately discussed in a historical context, we will concentrate on spectra, since this is where it all began :

HELIUM

At the turn of the century strange spectral lines were observed in the Sun's chromosphere, it couldn't be reproduced here on earth so it was attributed to a new element named Helium, this element was later discovered on earth.

CORONIUM

Another set of strange spectral lines was found in the sun's corona, again since it couldn't be reproduced experimentally a new element was invented: Coronium. It later turned out to be merely iron at very high temperatures.

NEBULIUM

Astronomers also tried to invent the element Nebulium based on a strange spectral line found at 501 nanometers in nebula. Again it turned out to be ordinary oxygen at low pressures, forbidden emission lines were successfully demonstrated in the laboratory several years later.

MYSTERIUM

In the mid-sixties astronomers discover another strange spectral line at 1.67 GHz radio wavelength. Its line intensities were all wrong, and one was so strong that they suspected it of belonging to a new molecule dubbed Mysterium. It turned out that the molecule was not new, but the ordinary OH molecule acting like a microwave laser or 'maser' which was demonstrated in the laboratory several years before.

These last four examples demonstrate that experiment always has the final word on astronomical theory, at least in a healthy scientific community. The cornerstone of science is a well controlled reproducible experiment.

There is a more detailed history of astronomical spectroscopy