Sciencing Fiction Be Hard

I like my science fiction accurate. I mean, Star Trek is fantasy, Star Wars is a space opera, and Firefly is a space western. The Expanse, with a couple of exceptions (and excepting the protomolecule and all that jazz), is pretty accurate. That’s what I look for.

So…last week, my critique group was working on two characters in a lunar lava tube with limited suit oxygen. “But there are oxygen candles,” geeknerd me said. But chemistry, but physics, But real rocket engineers in the critique group.

To the internet I go, trying to figure out how heavy a candle needed to be to provide oxygen for one person for eight hours. and what would be the gas volume for oxygen and how would a space suit accommodate the extra pressure. To say nothing of heat production… Sometimes there are bunny trails, sometimes there are rabbit holes, and sometimes…dragon lairs. Oh, and don’t bother Chat-GPT: to the same prompt, I got two different answers:
1. Asked the same prompt and got two answers. “…The amount of oxygen…[is] around 1 to 2 pounds of oxygen per hour…,” and
2. “The total amount [is]…in the range of tens to hundreds of liters per hour…”

In other words, GIGO, one the first computer acronyms that I learned so many years ago.

Watching a Randal Munroe interview was cathartic. Fractal science questioning and answering are what he lives for. (And, also, harassing Commander Hadfield about how a T-Rex would fly on top of an apparent 737s.) Buy his books! What If 2 is brilliant!

Randall’s got more time than I to turn BTUs into thermal conductivity for surface regolith on the Lunar South Pole and how long the tether from the candle to the spike on the surface could be before the cable melted. The solution to all the above? Write out the oxygen candles and have the characters’ situations be more dire. It’s good to be a god. The surviving characters will thank me.

Cartoon Copyright (C) Randall Munroe,, used according to site guidelines.