A large ridge of high pressure will keep us warm and dry for the rest of the week, with clear skies only marred by occasional smoky haze from the Rough Fire near Kings Canyon. Highs in the mid to upper 90s will carry us into the weekend, and we could see some high temperature records fall before things slightly cool at the end of the weekend.

Raindrob rainbow

So how do rainbows form? First the simple part: Sunlight, made up of the entire spectrum of visible light, can be broken down into its component colors by passing it through a prism. A raindrop can act as that prism. As the light enters the drop, the light is bent (refracted) and split into all the colors. These then reflect off the back of the drop, and when they pass through the front of the drop again, they are bent (refracted) still more.

rainbow physics

So raindrops act like prisms to split sunlight into its component colors. But the vector physics involved in creating the smooth, broad arc of colors can get very confusing. Without some pretty involved drawings that are out of the scope of this humble space, it is very tough to really explain how we can see a continuous span of color. But tomorrow I’ll take a stab.

 

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