Monday, October 22, 2018

The Truth, the Whole Truth, and Nothing But the Truth

Science fiction writer Arthur C. Clarke once had a character in one of his stories (I wish I could remember which one, but I cannot - believe me, I've tried.) looking in awe at an ultraviolet (or maybe it was an X-ray) view of the Earth as seen from the Moon. Staring back and forth between the image and the actual Earth in the lunar sky above him, he finds himself lost in a philosophical reverie. Which is the Earth's "true" appearance, he wonders.

The fact is, they both would be. What we see with our eyes is indeed a valid picture of reality, but not the only one. Notice I did not say there were two realities - there is only One Truth - but rather there are two (in fact, many) ways of looking at that one reality.

Here is an image of Pluto taken by the New Horizons spacecraft, as seen in "natural color, that is, as it would appear to a hypothetical astronaut reproducing New Horizon's flight plan.

So. That's pretty much what you or I would see, were we ever lucky enough to travel so far. But here is the same image with "enhanced color". That is, the colors are true, but somewhat exaggerated to bring out fine detail.

Is that less real than the first image? Not really. All the person processing the image did was to compensate for the limitations of human eyesight. He hasn't added or subtracted any data - just enhanced it. All those colors were present in the first image. They were just too subtle for the eye to pick up without assistance.

But there are other wavelengths that human eyesight is totally incapable of ever seeing. We're just not constructed for it. But that does not mean those wavelengths are any less real. Below we have a view of Pluto in the infrared. The imager has selected colors that can be seen by us humans to represent those we cannot, and here is the product thereof.

And next is an image where the color scheme is completely arbitrary, each one representing a different type of surface mineral. Scientists use such "false color" images to see patterns which would otherwise be invisible to us.

And how about this image, showing the unlit, night side of Pluto, surrounded by its atmosphere?

But are such global images really the "truth"? Do we need to be close up to see what Pluto really looks like? After all, imagine you were looking at a picture of a person taken from a distance of one mile away. You might be able to make out that it was indeed a person (and not, say, a tree), but could you really say you knew what the person looked like?

Here is a relatively close up image of Pluto, showing its rugged terrain and mountains made of pure ice water.

And here is one of the closest, most detailed images taken by New Horizons, showing features as small as what would be individual buildings on the Earth. (As always, click on the image to get full resolution.)

At this point, you can either throw up your hands and say there is no "true" view of the planet Pluto, or...

... or, you can realize that Reality is damned complex, and the best we can ever do is tug at the edges of it. Now please don't get the totally false impression that somehow what we see with our own two eyes is somehow "not true". Far from it! It is as true as any of the other images we just perused. It's just not the Whole Truth.

No comments:

Post a Comment