Q:Hey Joe, I've just started my senior design project (textile design) and my main inspiration was your "How Bees Can See the Invisible" video. My theme is things in nature that cannot be seen with our naked eye from those ultraviolet altered photos showing us how bees see flowers to other microscopic images. I've gotten a few ideas and sources from your blog but I was wondering if you knew of anything else I could check out if you have the time? If not then thanks for all the inspiration already!
Oh, cool! So, first off, i”m really touched that one of my science videos could inspire some real-life creative work! Secondly, I freakin’ love this idea.
There are so many! Besides the bees and butterflies you mentioned, let’s see, we’ve got birds that can sense or “see” magnetic fields (fish and other animals can do that too, more here). We’ve got the fabled mantis shrimp and its chorus of a dozen photoreceptors (although mantis shrimp vision isn’t quite all it’s cracked up to be). Mantis shrimp can also see circularly polarized light, a skill they share with certain kinds of beetles, who may use it to detect friendly mates who would, to us, remain camouflaged in dense plant growth. Pit vipers can sense infrared like a slithery version of the Predator. There’s a fish with split eyes that can see above and beneath water simultaneously. Many insects have compound eyes, like flies and bees, who knows what that pixelated world looks like? Dung beetles are somehow able to track the stars for navigation, and there’s a whole host of animals with enhanced night vision, often thanks to a special tissue called tapetum lucidum. Dolphins "see" with sonar, and bats use echolocation (there are even moths with echolocation countermeasures!)
Then, of course, we have humans who can see beyond “normal vision.” There’s the still-controversial tetrachromats. Then we have aphakia and ultraviolet vision in humans, like Claude Monet. Even people with color deficiency, such as colorblindness, are seeing things in nature as they can not be seen by those of us with normal vision.
What about our space telescopes, that convert everything from radio waves to microwaves to X-rays into meaningful visual data? What about our various breeds of microscope, able to image proteins and individual atoms?
You know what my favorite part about all this is? Sure, we can’t see it with our own eyes, but for most of the electromagnetic spectrum, we are able to build eyes that can!
I know I’m missing some. Leave your favorites in the comments or reblogs!
Glasses That Can Reverse “Health-Blindness”
If you’re red-green colorblind, then chances are you see nothing, or close to nothing, within the left Ishihara test circle above (you can test yourself here). The image on the right? That’s red-green colorblindness effectively cured with just an inexpensive special pair of glasses.
This type of colorblindness, more common in males than females, results from a deficiency in either the red or green color receptors in the retina, the genes for which are on the X chromosome (hence the higher occurrence in males). If you’re a medical professional, this can be a dangerous condition. This is something that Mark Changizi calls “health-blindness”.
Changizi theorizes that our color vision, particularly our ability to discern reds (something your dog can’t do well), evolved so we could detect health, vigor, and emotions in our fellow primates. Oxygenated hemoglobin happens to reflect red light in wavelengths that fall precisely where our red receptors are most sensitive.
A doctor’s eyes are his or her most powerful tools. Red-green deficient medical personnel are less able to detect conditions like jaundice and low blood oxygenation because they simply don’t have access to the part of the electromagnetic spectrum that they need.
Not any more, it seems. Changizi’s 2ai labs has developed a special lens, called Oxy-Iso, that shifts those wavelengths into the visible. This wasn’t something they set out to do, but colorblind people who tested some of their vision-enhancing technology reported that there was something unexpected going on. While wearing the glasses, which don’t have any active electronics, they report being able to see what was previously invisible to them: pink skin and red blood.
In case you missed that part, these glasses open up an invisible part of the spectrum to colorblind people, and that could save lives. That’s amazing! Science is mighty stuff, eh?
Claude Monet’s Ultraviolet Eye
NEW VIDEO! How the famous painter was a bit like a honeybee, and what that teaches us about the science of vision.
This may be my favorite video of all my videos. I hope you enjoy. Also, I got to play with a Lite-Brite the size of a wall.
The Charles Darwin School For Dogs Who Never Evolved To See Red And Green Good And Want To Do Other Stuff Good Too
Dogs, even the ones termed “sight hounds” or “seeing-eye dogs”, don’t see well. Of course, they make up for this with one of the most masterfully evolved scent-capturing systems ever developed (AKA “their nose”, which is really a biological marvel).
Colin Schultz shares some great links to explanations of dog vision over at Smithsonian Smart News. In short, they see about 20/75 at best, and have only two color receptors in their eye compared to our three, which results in red and green not differentiating into much more than a gray-blah-blurry haze.
I plugged a photo of a red fire hydrant into WolframAlpha’s dog vision simulator to get a sense of what that must be like (although we really can’t tell exactly what it would be like, since we have people brains and they have dog brains and for all kinds of other scientific/philosophical reasons). It’s a good start though.
If you’d like to play with WolframAlpha’s dog vision simulator, head to their site and enter your query like this: “apply dog vision to image of a _______”
In other news, posts like this make me realize how much I miss my puppies while working in San Francisco for the summer :(
Well, that all depends on how you look at it …
Ambiguous image illusions seem to simultaneously point out limitations in our visual system (dependence on shapes, edges and previous experiences in interpreting what’s in our visual field) as well as its flexibility (because in the end, most of us can see both shapes).
Think about that while you explore the young lady/old lady, rabbit/duck and whale/kangaroo illusions above.
I wonder how these work for people who experience “face blindness”, the inability to recognize and identify faces. Radiolab explored that condition previously.
This GIF might break your brain a little:
Take a look at the sequence of images below (I recommend clicking through to enlarge, Tumblr Dashboard folks). Works best if you stare at the dot:
Color? Or black and white?
The rods and cones of your retina respond to the illumination (black-white) and color of a scene, respectively. But that input passes through one key information filter on the way to your visual cortex.
In a sense, your rods and cones take a wavelength survey of the visual field, measuring all the wavelengths they are capable of measuring. It’s the “opponent process” that begins to give color meaning. It’s not only how “red” something is, it’s also how “not green” it is. Likewise, a yellow tulip in the original image from above is intensely “not blue”.
When looking at the “blue” tulips, your blue photoreceptors get fatigued. This creates the illusion of yellow when the blue surplus is taken away.
Ouch. I need to close my eyes.
Beau Lotto: Optical illusions show how we see
One of the best TED talks I’ve seen in recent memory. Sit down and prepare to get a bit of a brain cramp as you are taken through a series of truly awesome optical illusions.
In the process, you will learn a bit about how we perceive the world. In a sense, these tricks show us how our eyes work, but more accurately it shows us how our brains make sense of all that visual information.
You begin with particular wavelengths of light, the purely physical thingness of things. You end with a perception of your surroundings, tricks and all. All the between bits are where the fun lives.
What IS an illusion???
The human eye is one of the most powerful machines on the planet: It’s like a 5000-megapixel camera that can run in bright light, near-darkness, and even underwater.
And yet our eyes an imperfect: What a camera sees that our eyes don’t. Complement with 100 ideas that changed photography.
Our eye is (and isn’t) like a camera, but our brain is certainly more than a roll of film. I mean, what mere roll of film could create a picture like the brush of Claude Monet, who near the end of his life could see into the ultraviolet?
Animal Eye Close-Ups
Jeepers creepers, where’d you get them peepers?
Aren’t eyes just great? It’s amazing to see how evolution has solved a single problem in such a myriad of ways. Actually, to be more accurate, it’s amazing to see that evolution has molded such diverse and intricate machinery from perhaps the same starting point.
That’s right. Although it’s long been thought that animal eyes evolved separately as many as 40 times, eyes most likely owe their varied existence all to one single gene. That gene is named Pax6, and it’s a master control switch for many of the things that end up becoming eyes in jellyfish, flies, snakes and even humans. It doesn’t make eyes on its own, but acts like the conductor during the symphony of development. The protein it makes looks like this:
Now that we are sequencing more and more genomes, and deciphering the precise DNA sequence of Pax6 in all of those diverse creatures, we are able to map out how that gene has changed over time. Like a game of molecular telephone, DNA sequences (usually) get more and more scrambled as they spread into new species. Follow the molecular breadcrumbs back far enough, and you can find out where you came from.
And for all those oodles of eyes, all gorgeous, intricate and exquisite, Pax6 might hold the key to seeing where vision began.
I’m continually amazed at the added beauty of the world when we are allowed to view it from a point beyond our usual sensory range.
Do you know why plants are green? It’s because they reflect green light more intensely than other colors. If anything, that kind of makes them not green. If it doesn’t contribute to photosynthesis, they have no use for it. And although we can’t see it with our limited vision, they also eschew the infrared.
Andrew Shurtleff has made a stunning time-lapse showcasing the world as viewed in near-infrared. The light-sensitive chips of digital cameras can sense these wavelengths outside human vision (near-infrared being about 800-2000 nm wavelengths compared to our 400-700 nm visual range). With the right kind of video editing, that infrared world comes alive like a planet painted from pure ice. The leafy material appears white due to its intense reflection of infrared light.
Infrared photography has been used for decades to study vegetation. Kodak’s infrared-sensitive Aerochrome film paints the plant world in an eerie dusting of pink that you’ll have to see to believe. And NASA, whose scientists use the entirety of the electromagnetic spectrum to paint pictures of our world and others in Pepto-pink, create amazing works of Earth as art using infrared filters:
(via Bad Astronomy)