007: Gravity
Lately I’ve been having some heavy thoughts about gravity. Not too long ago I binge watched all the episodes of “The Expanse,” on Prime Video. If not familiar, humans invent a really cool, high thrust space engine that allows for colonization into the expanse of the solar system. Once there, everything sucks, and everything goes horribly wrong. Apparently, the main form of entertainment is throwing people out of the airlock. That is until malevolent aliens open a stargate, and then comedy ensues, etc.
A key aspect of the show is humans living in different gravitational environments. In the show there are eclectic g-loads. There are natural gravitational environments like Earth (1 g), Moon (1/6 g), and Mars (1/3 g). Then there are artificial centrifugal gravity environments (≈1/3 g) like on Ceres, Eros, random asteroids, various rotating space stations, and rotating spaceships. Also, there is magnetic simulated gravity, which is basically embracing the microgravity environment (0 g), while wearing magnetic space boots. However, my favorite is thrust gravity.
Linear acceleration can create thrust induced artificial gravity. This may sound unrealistic to maintain, but it’s not that difficult. I have a patent for a propulsion system that can produce thrust gravity as a feature (see patent). Just saying.¹
Anyway, upon thinking about gravity as a variable, I see a pattern. Full gravity (1 g) seems to be good for the body and low or zero gravity seems to be really bad. Let me unpack that a little further. Brief moments of zero gravity can produce euphoria and a generally positive experience. However, if the microgravity is prolonged negative effects occur.
Astronauts on the ISS live and work in microgravity. Some have lost as much as 20% of their bone mass. It’s theorized that if humans stayed in microgravity for many generations, they could evolve to ultimately have no bones at all.²
Body changes can happen in just the first few days in microgravity. Things like face swelling, loss of taste and appetite, dizziness with a falling sensation, and a stuffy nose. After weeks or months, other changes happen, like a rash or eczema, possibly a fever blister, vision deterioration, maybe a cold, or allergies. This is because microgravity changes your immune system, and it can reactivate preexisting dormant viruses.²
In “The Expanse,” lower than full gravity environments also leave their mark. Residence of Mars and the Belt (Asteroid Belt) find it difficult or impossible to return to the Earth. This is because generations of biological changes have made it essentially a one-way trip.
Ironically, adaption to the space environment in this way could be paradoxically counterproductive to the ultimate goal of colonizing space. Earth-like exoplanets thus far tend to have a predicted Earth-like gravity. Thus, if through spacefaring the human body can’t return to Earth, that also precludes colonizing Earth-like exoplanets. In other words, it’s like winning the battle but losing the war.
I think gravity should be looked at differently. A little microgravity can be fun, but too much of it is really bad for your health. An analogue might be the difference between the staples of an entrée and dessert. It would be foolish to eat only dessert, all the time. Microgravity is like ice cream and cake, and full gravity is like meat and potatoes (apology to offended vegans). For maximum health, one should seek the maximum gravity (≤1 g). Thus, future space travel should be built around this doctrine. Simply, adapting to microgravity is a short-term thinking mistake.
References:
Conner, Paul H. (2017). Electron Propulsion Engine. U.S. Patent & Trademark Office. U.S. Patent No. 9,586,701. Retrieved from https://patentimages.storage.googleapis.com/0b/3b/bc/0e7fcfaa2f5b2e/US9586701.pdf.
LaMotte, Sandee. (2021). Your body in space. CNN. Retrieved from https://www.cnn.com/interactive/2021/08/world/human-body-in-space-quiz-scn/.