explain using physics terms
2007-03-06 06:47:14 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Physics
This phenomena is a byproduct of Thin Film Interference. Basically, the oil forms a thin film on the surface of the water. When the incident rays of light hit the oil, some rays are reflected off of the oil surface and some off of the water surface. However, since the refractive index of water is higher than that of oil, a phase change of the light incident on the water surface occurs, and these rays are reflected back in the same direction as that of the rays reflected from the oil.
Because the rays that are reflected are half a wavelength out of phasewith each other, destructive interference occurs for light of a certain wavelength. Because white light (sunlight) is made up of all the different wavelengths of visible light, when some of these wavelengths are removed (due to the destructive interference of the light waves) the light changes colour.
The colour that is normally observed is a purplish colour due to the light in the middle part (greenish-yellow) of the visible spectrum being removed, leaving the red and blue parts to mix together to leave the nice purple you see when looking at an oily puddle.
Hope that helped and didnt confuse you :)
2007-03-06 09:11:08 · answer #1 · answered by drumboy_14 2 · 0⤊ 0⤋
Oil in itself is not particularly colorful. You must be talking about oil on water. Oil (or just about any hydrocarbon or hydrophobic molecule) on water makes those beautiful patterns of rainbows due to the way the oil spreads out on the surface of water. It actually forms a monolayer on the water surface. It is this monolayer interacting with the water and the way light reflects. This creates the chaotic difraction and interference patterns you see on the puddles at gas stations.
2007-03-06 06:59:49 · answer #2 · answered by CurazyJ 2 · 0⤊ 0⤋
I assume you mean when it rains out and there's standing water and then there's oil on top of the water or mixed in, the oil APPEARS colorful. What really is happening is the light is refracted and being spread out so since it's white light the light is being spread out into the different wavelengths.
2007-03-06 07:01:24 · answer #3 · answered by smartdude474 2 · 0⤊ 0⤋