Hummingbirds See the Light
/
an you imagine the unimaginable? Well, that’s a pointless question, isn’t it? It answers itself. If you tell me there’s something I can’t imagine, then by definition I can’t do it. So, what is this? A lame joke? Some kind of riddle?
I guess you could say it’s a mind game, but one based on reality. In other words, I’m talking about something that exists—but something we’ll never see.
But hummingbirds do.
olor is one of the joys of the world. We feel sorry for the “color blind”—how much those poor folks are missing! But in relative terms, every human is color blind because we all share a biological disadvantage.
In school, you probably learned about the “rods and cones” in your eyes. What you probably don’t remember is that there are more than 100 million of these cells. The cones mainly measure light and dark…and the rods track combinations of red, blue or green colors. How those rods are triggered by incoming light creates the full range of the color spectrum we know.
Most people called color blind see a drabber world, since the red and green cones essentially are reporting the same information to the brain.
Conversely, some lucky creatures on earth are “color rich”.
They have a fourth type of cone in the eye--one that sees ultraviolet light. This hardly seems fair, does it? After all, aren’t we supposed to be the highest life form? This is like being on a TV game show and asked to pick a prize behind either door #1, door #2 or door #3—only to find out later that the super-duper prize is actually behind a door #4…hidden offstage. No one even told you about.
So, this deficiency is something we really can’t imagine—or can we?
n the spirit of full disclosure, there are many creatures that have this fourth cone; birds, fish, even some mammals. But I’m going to focus on hummingbirds because I like them.
Recently, scientists put them to the test. They placed two feeders out in a wildflower meadow, one containing sugar water, and one plain water. (Hummingbirds are sugar addicts—another reason to like them.) Next to each feeder they placed an identical green LED bulb—identical, that is, to the scientists. Both looked like the same shade of green—they couldn’t see a difference. But one on the bulbs was designed to mix both green light and ultraviolet light.
Even after shifting everything around, mixing it all up—a dozen different experiments, including every variation the scientists could think of--the hummingbirds always spotted the UV+ green light, because they knew the sugar water would be there. The hummingbirds could see the light.
ell, OK, this is probably frustrating. Don’t you wish you could see what the hummingbirds do? Actually, we might be able to get close.
The first example is the color purple. It naturally mixes two colors—red and deep blue—from opposite ends of our visible color spectrum. It’s the widest spread that ROY G BIV has to offer. In this way, it approximates how UV rays mix with normal colors.
Throughout history, the color purple has been associated with royalty and power—Queen Elizabeth I ruled that no one except the royal family could wear it. Maybe on some level those kings and queens sensed a “specialness” in that color, something they felt befitted their specialness on earth.
The other, more concrete example comes courtesy of the black light…at one time an almost mandatory feature of discos and college dormitory rooms. In the dark, the black light illuminates some objects in almost other-worldly ways.
That includes some face paint and makeup…the spots on bananas…and scorpions in the desert at night that might be crawling up the side of your house. It creates colors that are frequently described as “fluorescent” or “neon”. But even here, it’s not quite the real thing. This is UV light being absorbed and reflected by the black light, at a somewhat different wavelength than what the sun actually produces.
o, I guess the answer to the original question is “no”—you can’t imagine what is unimaginable. Ben Carson of Princeton, one of the scientists who oversaw the hummingbird experiments described above, concluded,
"It is impossible to really know how the birds perceive these colors. (For example) is ultraviolet+red a mix of those colors, or an entirely new color? We can only speculate.”
For hummingbirds, no big deal. They know they’re special. After all, they’re the only birds that can fly backwards and upside down. Seeing more is a snap.
Even the crows and seagulls can only imagine how they do that.
Have a comment or thought on this? Just hit the Your Turn tab here or email us at mailbox@cascadereview.net to have your say.
