I've been a long time fan of Neil deGrasse Tyson and included a section about his work in the Art of Explanation. What I appreciate is his role in making physics more understandable to non-scientists. He's a great explainer and someone who continues to have an impact.
While I've never studied physics or astrophysics, I have a fascination with the subject. Part of what fascinates me is the idea that physics often explains how the universe works. The laws of physics, for the most part, have stood the test of time, and understanding them means understanding the world around you. As an explainer, that's a strong foundation of fact to build upon.
Tyson hosts a long-running online show/podcast called StarTalk and a recent episode about color caught my eye, no pun intended. :) In the episode, the discussion turns to the color of an apple and the difference between the human eye's perception of the color vs. what it really is in terms of physics. Here's the show:
This reminds me of seeing telescopic photos of objects like the crab nebula. As a younger person I imagined what it would be like to see it in person. Then I learned that the images are representations and the human eye would not see what's in the image. This bothered me for a while. Why do we care about an image that's not a real representation? Is it just art?
Over time I discovered that I had it backward. The perception of the human eye is just that, a perception. Just because we see something, like the color of an apple or nebula, doesn't mean that's what it is in reality. We can ask: How would a red apple look to a dog, or a housefly? The image their brain produces seems like reality to them, just like it does to us. Who's to say our perception is the "right" one?
The only way to know what's "real" is by looking at it scientifically, the way a physicist would. As Neil deGrasse Tyson says in the video above, the color of the apple is really defined by what it's not.
