Change causes mental fatigue

Getting high and coming back to earth repeatedly will crack you up. It’s true! The aviation industry calls this cracking up metal fatigue.

Surprisingly, metal fatigue does not come with age. It comes from what is called stress reversals. As you know, the air inside the aircraft is under greater pressure than the air outside. If it wasn’t, you would be rather uncomfortable, to say the least.

The problem is this. Every time the aircraft flies, its frame must expand and contract to accommodate the changes in air pressure. It is this expanding and contracting that causes metal fatigue. If the plane always flew at one constant height, then its metal would not get tired.

What does this tell us? It’s not stress that gives you mental fatigue. It is the ongoing stressing and relaxing that cracks you up.

Better to pick one state – stressed or relaxed – and then live with it.