Human senses are fairly sophisticated. As we discussed in a previous article, our vision is pretty good compared to some animals, but inferior to others. What we see is only a tiny sliver of the electromagnetic spectrum, but we still managed to discover the rest of the spectrum using science and technology. What evolved into our visual spectrum, our rainbow, does make sense. What we call visible light is a lot of the wavelength radiation that the sun produces. But it certainly isn’t the entire picture, especially when you consider technology and other sources of radiation that aren’t the sun.
So let’s imagine some way that a human could see everything. Perhaps it’s a gene therapy that replaces the blue, green, and red photosensitive proteins in the retina with 10, 20, or 30 new proteins that are sensitive to the full range of the electromagnetic spectrum. Or, to continue on the theme of the previous article, perhaps a multispectral camera that is hooked up to a virtual reality headset.
However it’s done, that person can now see every form of EM radiation as interpreted by how humans normally interpret color. For the sake of simplicity, this system doesn’t account for polarization like some forms of animal vision do. This stretching of color perception is also on a logarithmic scale. So what would the world look like?
To begin with, they would be seeing a lot of green. What was once the entirety of the human visual spectrum is now represented by only a few shades of green. Similarly, many things would appear slightly yellowish too. If you’ve ever seen infrared footage, you know that many objects radiate heat in the form of infrared light. So this person’s breakfast would be a yellowish green color that became even more green as it cooled down. If the person used a microwave to warm up their food, he would experience a bright blast of yellowy orange.
Microwaves and radio waves could become particularly distracting, considering that they’re everywhere. But one of the things that makes them useful is that many materials are transparent to that kind of radiation. Still, this hypothetical vision can detect it, and it would appear mostly orange or red, depending on how long the wavelength was. Many of our everyday technologies, such as Wi-Fi, Bluetooth, and car radios, would appear as a bright flare of those colors when this person was looking directly at a radiation source.
We also can’t forget about ultraviolet radiation. Much of the extremely high-energy UV radiation that would appear slightly bluish to this person gets filtered out by the upper atmosphere. Ultraviolet light that makes it to the surface from the sun would also appear to be green; it would just be a few shades deeper, reflected from certain materials. If the individual’s perception were sharp enough, he or she might even see ultraviolet patterns that appear on some flowers, which only insects can detect.
Considering how disorienting this is likely to be, let’s say that this person injures himself, and needs to go to the hospital. This will give him an excellent opportunity to see x-rays, which to him appear to be firmly in the blue range of his modified vision. Unless this person otherwise works with high-energy radiation, it’s unlikely that he would commonly see this range of colors in his everyday life. A small amount of high-energy radiation comes from space and other terrestrial sources, but his sensitivity would need to be extreme to pick up this normal background level.
Another thing that would be distinctly lacking in this view of the world would be white, or even any shade of gray. Pale colors and grays come from the blending of essentially every color we can perceive at roughly equal levels. A large portion of the electromagnetic spectrum is encountered in our everyday lives, but it’s unlikely that many of them would be reflected or emitted from the same object at roughly equal levels. Pink would also not exist to this person. What we perceive as pink is simply materials that reflect or emit every color except green. And since infrared, visible, and ultraviolet radiation are the most common, green would be everywhere to this person.
Nighttime would certainly be very different. The intense greens of the day would shift slightly more toward the yellow as infrared became a more predominant form of light. People, animals, anything else warm like the sidewalk after a hot day would still appear very bright and vivid to this modified person.
The night sky would still be dark, again stars would not be white, but instead bright points of pure green. Maybe looking through a regular telescope would allow this person to see what some infrared and radio telescopes can see. And maybe the sky wouldn’t be black at all. If his eyes were sensitive enough, it would be a dark brown or even a rusty orange. The blast of yellowy orange he saw from his microwave oven this morning, now also appearing in the sky as the cosmic microwave background, a remnant of the Big Bang.
Knowing how different the world would seem, would you want to see everything?