Did Fick’s Law save Harrison Odjegba Okene?

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Diagram showing the divisions of the worlds oceans. (Image by K. Aainsqatsi)

Breathing Underwater and Staying Alive for Sixty Hours

Okene’s situation is different from these two bubbles in that his bubble is relatively simple. Unlike the bubble interface of the diving bell spider, which is curved, the surface of Okene’s “bubble” is flat. This means the air pressure inside the bubble is the same as the water (hydrostatic) pressure. At a depth of 30 meters, this is close to four atmospheres, or four times the pressure you are currently experiencing now. Does this mean that equal pressures between the bubble interface imply no gas transfer? Not quite. As you probably guessed, there is a bit more science to the story.

When the tugboat sank to a depth of 30 meters it ended up lying close to the oxygen-minimum area of the pelagic zone – not near the surface, nor near the bottom. Seymour tells us that, “Oxygen enters the ocean from the surface and is produced by phytoplankton in the photic zone (the zone where there is sufficient sunlight for photosynthesis to occur). The debris from this zone falls through the water and is consumed by microorganisms below the photic zone. This consumes the oxygen from the water, creating the oxygen minimum zone that is very low in oxygen from about 50 meters to about 200 meters.

So although there would be some oxygen dissolved in the water where Okene sank, it would be low. At this point things, get a little murky. As the partial pressures of all gases is extremely low in the water and high in the bubble, air is going to continuously diffuse across the water’s surface; a conclusion both Seymour and Shirtcliffe agree on. What happens after is where the two scientists depart.

Pressure and Oxygen: Dr. Shirtcliffe’s Theory

As the pressure inside the bubble is four times atmospheric pressure, the oxygen partial pressure will be four times normal. Shirtcliffe believes that oxygen and other gases will gradually be lost into the water until equilibrium is reached. As carbon dioxide and oxygen are more soluble, these will dissolve much faster than nitrogen. Oxygen will continue to dissolve into the water until the partial pressure is at 20% atmospheric pressure, just like the air we breathe on the surface.

Shirtcliffe explains that, “deep sea divers have to be supplied with gas containing much less than normal so that the pressure of the oxygen in their tanks is only one-fifth atmosphere.” At this point he believes that the bubble will be stabilized by the less soluble nitrogen gas. According to this theory, Okene would be fine until the not -so-soluble nitrogen escapes and the bubble collapses. Just as with the diving bell spider, any oxygen he uses will be replaced by what is already dissolved in the water. At this point, the surrounding water is saturated with oxygen, acting as a reservoir for oxygen and a place for the carbon dioxide to go.

Something else could have worked in Okene’s favor as well. Even though there is a very low concentration of oxygen in the water, it isn’t all dissolved away throughout the boat as the movement of dissolved gas through the liquid is slow. Any dissolved gases remain close by. Any oxygen used will be there to return as he uses it.

Oxygen and Nitrogen: Dr. Seymour’s Theory

It is at this point that Dr. Seymour disagrees. He says, “both oxygen and nitrogen in the bubble and at 4 atmospheres, it would continually be above the partial pressure of dissolved oxygen and nitrogen, so the bubble would never stop losing gas to the water. It would eventually dissolve completely.” In Seymour’s paper, he shows that the presence of a body inside the bubble increases the pressure inside the bubble and oxygen consumption hastens its collapse.

Bubble size and respiration rate are important factors. We can only guess what could happen as the actual size of the room is unknown. Water currents could also slowly pull oxygen rich water away from the room. Both scientists agree there is much we do not know but we can hazard a guess on Okene’s metabolic rate.

Surviving the Cold

Seymour notes that Okene was found in freezing water. A human under those conditions would have the highest metabolic rate possible – nearly equivalent to someone doing heavy exercise. This will increase the oxygen consumed in the tiny office. Seymour points out that when Okene was ‘found’ he is shown nearly naked and quite alert; not something you would expect from someone trapped underwater for sixty hours. Less clothing means that Okene won’t be able to retain any body heat, and is danger of hypothermia. He says, “I do not believe that a man could survive 60 hours in near freezing water. This is the major problem. The second is thirst, but not food. I suspect a hoax here, but I am a sceptic.”

Did Science Save Harrison Okene?

So the big question is, “Can science explain Okene’s sixty hour survival in what should have been a watery tomb?” That is difficult to say. As there are so many variables we don’t know or can account for. We do not know the size of the room, for example, nor do we know whether water was flowing around inside the boat.

Is Okene’s survival a miracle of science? We simply cannot tell but we must open ourselves up to another possibility.

Could it be a miraculous hoax?

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