Polite Dissent

Aquaman #21 continues the tale of the people of Sub Diego. It’s a fascinating premise, and one of the better Aquaman stories in recent memory. I’ve addressed certain issues of the storyline a few times before, but this latest issues brings up a few more questions.

The Delivery – A baby delivered to water-breathing parents is discovered to be an air-breather and has to be rushed to the surface to survive.

• Why is the doctor wearing gloves when he’s delivering the baby? Any contaminants are just going to float around in the water (and in fact a later panel shows floating blood).
• In some ways, it makes sense that the parents would not know their child was not a water breather until the delivery. Fetal circulation bypasses the lungs, so the baby’s lungs aren’t used until after delivery and there would be no telltale signs beforehand. However, you’d think they would have checked an ultrasound to look for gills.
• Did they cut the umbilical cord before racing the baby to the surface?

Pressure – Has it ever been established how deep Sub Diego is under the water? I’m just wondering about water pressure. For every 33 feet of depth, there is an additional atmosphere of pressure (additional to the regular one atmosphere at sea level). Thus if Sub Diego is at 100 feet, the water pressure is equal to four atmospheres, or four-times normal pressure.

Bends – I have seen some readers speculating that Atlanteans and the citizens of Sub Diego should be suffering from the Bends. Decompression sickness, better known as the Bends, is the result of nitrogen bubbles precipitating out of the blood. At high pressures, air bubbles easily dissolve in liquid (think of a closed 2-liter bottle of soda). As the pressure is reduced, these bubbles rapidly enlarge (open that 2-liter bottle). These enlarging nitrogen bubbles in the blood and organs are responsible for the symptoms of the Bends. The nitrogen gets into the blood by breathing air at high pressures. Since the citizens of Sub Diego have gills and not lungs, they are not breathing air but instead filtering oxygen out of the water. Nitrogen should not be an issue.

Light – There is not much light available underwater. Humans require sunlight to correctly make use of vitamin D. Rickets will be a concern.

Air bubbles – Since everyone in Sub Diego uses gills to get oxygen, why are they all breathing out air bubbles? Where did the air to make these bubbles come from? Similarly, how do the residents of Sub Diego talk? Air passing over the vocal cords causes gives rise to the sounds of speech. I guess water traveling over the cords could work in a similar way, but the carrying distance would be shorter and the tone changed. And in this panel it sure like like one of those gangsters is trying to smoke.

Hair – Here’s an interesting article regarding the hair of Atlanteans, looking at the subject from a physics and anthropology point of view. Good reading, though I think he’s wrong about the Bends.