Yes, so what it is is what it was, though what it was is a little different in content but not different in the true defined nature of science in its investigation of nature.
Originally Posted by Ken G
Using the scattering example, what it was... Newton and Clausius held that the blue sky was a result of light interference from water droplets (Newton) or water bubbles (Clausius). The intensity of the color of the sky, in their model, varied as the inverse square of the wavelength of light.
John Tyndall considered a scattering model due to large particles of moisture in the sky, but lacked a defined mechanism. Tyndall knew, however, that any model of explanation must include the fact that skylight is polarized.
John William Strutt (third Lord Rayleigh) in 1871, stirred by Tyndall and using Stokes and Maxwell ideas (though not the subsequent electromagnetic ones), deveoloped a mechanical model for scattering. Here it is, so skip it if you don't want the more nitty gritty.
Imagine a small particle -- one that is smaller than the wavelength of light that will be hitting it -- suspended in space and within the elastic aether. Since it was already known that light was a transverse wave at the time (mid-1800's), Strutt reasoned that the particle would begin to bobble (my word) but that the oscillating bobble action of the particle would only send secondary waves in directions that were not in the direction of the bobble action itself. In other words, the waves that would be generated in the direction of the bobble motion of the particle would be longitudnal waves, which are not light waves. The greates propogation likelihood would be in the direction of the incident light, coming or going, with declining likelihood as the angle approached the bobbling direction. Yet his theory did not address the actual observered saturation level of the blue from skylight. He assumed that multiple scattering did not take place, and, apparently, the computational tools necessity to resolve the differences did not exist until computers came along.
He used polarized light for simplification, then he addressed unpolarized light as the incident light and demonstrated how polarization is the necessary result from "scattering".
He then developed a mathematical model that showed, per his article, "the ratio of the amplitudes of the vibrations of the scattered and incident light varies inversely as the square of the wavelngth, and the intensity of the lights themselves as the inverse fourth power."
He also conducted experiements with light through prisms to determine the actual intensities of scattering to test his theory.
Maxwell praised this 1871 publication, which overturned Newton, Clasius, and others.
About 10 years later, and after Maxwell's em theory was strongly validated by Hertz creation of em waves that were also light waves, Strutt modified his theory to consider the particle to act as an oscillating dipole. But this did not change the propogation pattern much.