Recently, I was thinking about some details of a project I have had sitting in the back of my mind for years. Not sure if it is something I will ever pursue (there are multiple paths to that outcome), but I sometimes think about it.

The main point of contention is that I would need some amount of a gas which is benign to humans, which is not oxygen (as it also needs to be non-reactive). This means nothing like carbon dioxide or anything actually harmful. Ideally, something like nitrogen, but I think it is tricky to get that in a pure form on the consumer market. Helium is possible, but that seems like such a waste (it is a finite resource on Earth, and has lots of interesting uses beyond my musings or party balloons).

After some amount of thinking, and realizing that isolating something in a pure form is the tricky part, I started wondering about hydrogen. I don't think that humans react to it and I could extract it from water at a very high purity (I have done that once before - it was neat). Really, I probably only need something like 10 litres at 100 kilopascals so I could probably manage that, although I would have to build quite the apparatus to collect more than a few millilitres.

Then, I took a step back and realized that I need to find something interesting to do or make some more meaningful headway on my existing projects before I start musing about these more exotic ideas.

It reminds me of that time in high school when a teacher strike resulted in me spending time trying to figure out if I had access to any living tissues which could easily be shaped into a structure and fed such that it would be a living and self-healing building material.

Ah, the strange fancies of an idle mind,
...Nights