Today’s post is part of a special series here on Planet Pailly called Sciency Words. Each week, we take a closer look at an interesting science or science-related term to help us expand our scientific vocabularies together. Today’s term is:
I guess this isn’t a real scientific term, at least not yet. The authors of this paper are proposing this term to describe a problem people living on the Moon or Mars may have to deal with in the future. For colonists, many a sprained ankle or broken bone (or punctured spacesuit) will probably be blamed on the G-shortage illusion.
The human inner ear, which regulates our sense of balance, is sort of hardwired for Earth’s gravity. The inner ear expects you to feel 1 g of force—no more, no less—due to the planet’s gravity, and it uses that 1 g of force to figure out which way is down.
But imagine you’re a fighter pilot doing all kinds of crazy maneuvers in midair. Your inner ear has to do some math to keep track of where you are, and which was is the ground, so you don’t crash. Now if you happen to turn your head while simultaneously pulling a hard turn with your aircraft, your inner ear could make a serious miscalculation.
This is a form of spatial disorientation known as the G-excess illusion, because it happens when you’re experiencing excess G-forces. It’s a well documented and well understood phenomenon, and pilots who aren’t adequately prepared for it can end up making fatal errors while flying.
The G-shortage illusion is sort of the same thing, but it’s caused by the opposite reason. Imagine this time you’re an astronaut on the Moon or Mars or some other world with hypogravity. You take your first step. At the same moment, you happen to turn your head. Your inner ear gets confused, and as a result…
Until I started learning about hypogravity, I didn’t realize how often Apollo astronauts lost their balance and fell over while trying to explore the Moon’s surface. The G-shortage illusion in action, it seems. Fortunately no one was injured, and no one damaged their spacesuit… but they could have.
So dear readers, if any of your are planning to move to the Moon or Mars, tread carefully!
P.S.: While researching for this post, I found this article from Naval Aviation Newsvery interesting. It’s written by an artist who was hired by the Navy to do caricature drawings about various forms of spatial disorientation, like the G-excess illusion. Those drawings were then used as visual aids in flight safety training. If you’re interested in how art contributes to STEM, this article is worth a look.