Where Did The Oxygen Go?

Bandelier National Monument

March 12, 2020

We live underneath an ocean of air that is several miles deep: the atmosphere. The pressure on our bodies is about the same as 35 feet of water pressing down on us all the time. Because air is compressible, the weight of all that air above us compresses the air around us, making it denser. As you go up in elevation From say, sea level, the air becomes less compressed and is therefore “thinner.”

The important effect of this decrease in pressure is that in a given volume of air, it contains fewer molecules. The percentage of those molecules that are oxygen is exactly the same: 20.9%. The “problem” is that there are fewer molecules of everything present, including oxygen.

Although the percentage of oxygen in the atmosphere is the same, the "thinner air" means there is less oxygen to breathe, assuming we breathe the same volume of air all the time.

The body makes a wide range of physiological changes in order to cope better with the lack of oxygen at higher altitudes. (Is gasping one of them? 🤪. How is a headache a coping mechanism? 😫)

The table below shows the effective amount of oxygen in the air varies at different altitudes.

I seem to be spending most of my time in New Mexico at above 6,000 feet. Which means I am adjusting to roughly 21 percent (1-16.6/20.9) less oxygen per breath compared to being at the beach..

That’s science class for today.