We have opened countless doors to humanity before, and we have compiled for you the beauty of science, which is opening, that is noticed when the confusion on it is overcome, with different events. In this context, we both presented the hypnotic scenes we encountered when different scenarios took place, and briefly explained the behind-the-scenes of some of them.
If you played in the streets when you were a kid, you probably saw the oil residues on the ground, which is one of the hypnotic scenes we just mentioned, and compared it to a rainbow. Now we will explain why these residues appear colored, and even why certain colors are intense in certain places.
To get this colorful image, we need three ingredients: light, oil and water. So how do they interact with each other?
Oil residues from different vehicles and bicycles accumulate on the roads, although they are not visible most of the time. When it rains, the water and these residues interact with each other. At this point you can think of simple experiments where water and oil are put in the same container. As a result of this interaction, oil rises above water, as it has a lower density than water.
Since they do not mix with each other, an intermediate layer is formed between them. You can think of it as the thin line between them.
So what role does light play here?
When the rays come over the previous mixture, some of them are reflected directly from the uppermost oil surface. The remainder crosses the surface of the oil and is reflected from the interlayer that has just formed. However, this ray, whose direction has changed due to the layer with which it came into contact before, whose density is different from that of air and water, proceeds in a different direction.
The light we are talking about is white because it is sunlight. This means that it contains all colors:
However, different colors cannot bring their own colors to the surface due to the interaction of wavelengths. At this point, the synchronized rays can reach the surface and create their own colors. The thickness of the residue on the ground is the determining factor at this point. Since the thickness is not the same in all parts of these residues, different colors appear in different amounts in different parts.
For example, blues and purples stand out in the thicker spots, while reds, pinks and yellows stand out at the thinner spots.
Many reasons have been concocted in the past for how oil residues are formed. It was even said to the children that these remnants were a piece of the rainbow that had fallen, and it was circulating among them as a rumor.
Sources: The Naked Scientists, Science ABC, Science Young
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