The Intergalactic Blues
On the planet Ivar, the insectile Queen was apoplectic. Until now, they’d trounced the primate invaders. The aliens couldn’t see in ultraviolet, which made them nearly blind in the dim blue light that filtered through Ivar’s reflective atmosphere. They were easy pickings, especially after dark.
She bobbed her antennae at the messenger, a cowering soldier-drone. What do you mean ‘you can’t locate them’?
The soldier-drone waved back, They’ve vanished! Gone invisible! But we found this. Perhaps it’s their secret weapon.
It transferred a plastic bottle into her mandibles. The Queen traced the alien symbols on the mystery object: SPF 50.
Cyanoderma is a bluish discoloration of the skin and mucous membranes. It can be caused by several things in the human body. Most commonly it’s associated with low oxygen levels in the body or in a specific area. You might see it in a person’s fingers if bad circulation’s a problem.
Cyanoderma’s almost always an indicator that something is seriously wrong and that an emergency room visit is in order. But interestingly, there’s another rare condition that causes cyanoderma: methemoglobinemia, which is a very rare genetic condition that makes people turn blue like Smurfs.
It works like this: your skin color is determined by a combination of factors. Melanin is a brownish-black pigment that serves as a natural sunblock, and people have greater or lesser amounts of it depending on their ancestry. Generally speaking, if your ancestors lived closer to the equator, you’ll have more melanin as it prevents skin cancer. If your ancestors lived closer to the poles, you’ll have less melanin since in the less sunny places of the world, maximizing Vitamin D production is more important than resisting cancer. Hemoglobin also influences skin color. It’s the red oxygen-carrying substance in our blood that’s also responsible for blushing.
People with methemoglobinemia have unusually high levels of methemoglobin, a specific type of hemoglobin. Unfortunately, this variety of hemoglobin tends to bind up extra oxygen in the blood without giving it back, which means the person’s whole body is a bit deficient in oxygen. Interestingly, people with this disorder are just deficient enough to turn blue without actually being harmed by the low oxygen levels. In one isolated community in Kentucky, this resulted in several generations of blue-skinned people living out their lives without any problems. Read the case study; it’s fascinating!
Today’s story came out of a long train of thought on cyanoderma. I was thinking about sunburns, and how sunscreen absorbs UV light. Under a black light, sunblock makes you look like you’re wearing thick, heavy camouflage paint. If humans confronted an alien species that could only see in the UV end of the spectrum, wouldn’t this be an excellent way of making ourselves invisible? We would essentially blend in with the blue!
It’s a compelling reason to follow your mom’s advice: always wear sunscreen. It just might keep the insectile Queen from seeing you.