First Color

Well, I am firmly convinced that some of the most difficult metaphysical, existential and / or scientific questions often come from young children in the form of an innocent question.

Case in point:

This morning, getting out of the shower, I overhear Patch (age 5) talking to her mom downstairs: “What was the first color out?”

“What?” my wife asks.

“What was the first color out?”

I think I know where this is going, but I remaing quiet, listening.

“Do you mean what was the first color ever made?” my wife asks, clarifying.

“Yes,” Patch says. “What was the first color made?”

Hmmm – a very interesting question, and one that I think I can answer. (That is, if my physics memory doesn’t fail me.)

Let’s see … you’d have to go back to the Big Bang. Now, I don’t recall the specifics, but I do know that when the “explosion” first took place, the temperatures were so high that matter could not exist. The universe, for that briefest of brief periods, millionths of the first nanosecond, was pure energy. High energy energy. Energy, in the form of super-intense highly energetic gamma rays, the most naturally energetic of radiation on the electromagnetic spectrum.

Then, as time went on, fractionally of a second at first and then over slower and slower periods (hours, then days, then thousands of years, then million of years, etc.), as the universe expanded at the speed of light (and perhaps even faster, what’s known as “inflation”), the universe cooled.

As it cooled, as the temperatures dropped, the universe as we eventually see it gradually coalesced. Froze, so to speak.

Cooling temperatures allowed for lower energetic rays of electromagnetism. After gamma radiation, X-rays were able to form. After X-rays, as the universe cooled further (whether hours, days or millennia I don’t recall), and ultraviolet rays appeared. Finally, after more time elapsed, voilà! Electromagnetic radiation in the 400-700 nanometer wavelength range, or, as is more commonly known, visible light.

And since we’re moving from higher energy to lower energy as the universe cools, we want to know what is the highest energy wavelength of visible light.

The answer is violet.

So it is my contention that violet was “the first color.”

Now … how to explain that to a five-year-old?