Responding to In Collaboration with Space

The “Hands Arts for Humans” (HA4H) livestream has started encouraging daily writing exercises. Common prompts are being shared. This has actually motivated/inspired me, so yay! See M’s Patreon or Vi’s Patreon if hand arts sound good, and hang out on the Discord with the hand-artist crowd.

I really like this prompt because it isn’t about The Work. It’s about our thoughts and feelings on things. And I do feel free to respond to prompts with just related thoughts and feelings, but I also feel better when I’m not bending the rules. I don’t know why. It’s probably about not wanting to feel/be persecuted for doing so, even if I’m confident that won’t happen.


What specific spaces intrigue you?

Let’s start with just a simple rotating space. I think there was a phase of my intellectual curiosity where certain concepts got permanently cemented as “slippery” or intriguing ones. “Standard deviation” was one. “Coriolis force” was another (and then centrifugal force, which I will adamantly defend as very real despite it not being an inertial force). Hell, let’s embed that, since the licensing and reference URLs explicitly allow it:

It’s a little weird to me how infrequently these have resurfaced in my life. Coriolis force in particular seemed to get thoroughly explored (as thoroughly as the vector product of the frame’s rotaton rate and the subject’s in-frame velocity can be, I guess) in an advanced dynamics course at university, which seems really late. It’s often misattributed as the cause of water swirling down drains specific directions, but it ain’t:

I’ll claim that’s an exhaustive proof-by-Youtube.

Anyway, that’s also come up while “CEO”ing (coaching) at International Space Settlement Design Competitions, which I regrettably don’t have the energy to do anymore for some reason. Spin things to “make gravity” with the centrifugal force! It turns out that’s an unusual concept, that I just came to accept at some point. And it adds complications! How do you dock with something that’s spinning? How do you turn it? Can part be spinning and part not be spinning? What if you spin parts in different directions? If you spin things really fast and figure out how big your thing needs to be for some amount of gravity, in what ways is that different than spinning it really slow and using a bigger thing for the same amount of gravity?

This video (why not put a bunch of Youtube videos in a post for once) sums up the ISSDC pretty well (I was judging, not CEOing that year, apparently). I guess it can’t be embedded. Not sure why.

These things kept coming up in my life in additional contexts and I finally came across the website I came across it while (I think I recall this clearly) wondering how fountains behave in a rotating frame. I had a glimmer of an idea. It turns out that Hall (who might run the website) had addressed the question as part of a more general thesis, The Architecture of Artificial-Gravity Environments for Long-Duration Space Habitation. Section 5.7 contains this beautiful illustration (at the bottom):

Figure 5.6: A fountain in artificial gravity. (Illustration by Tye-Yan "George" Yeh.)   from

Figure 5.6: A fountain in artificial gravity. (Illustration by Tye-Yan "George" Yeh.)


Note that the jet is narrow as it starts and spreads, so the axis is above the image and spinward is right. The jet is deflected spinward as it heads toward the center of the rotating frame because the center moves slower than things further toward the edge, and then once it’s falling again it gets directed anti-spinward for the same reasons—that’s Coriolis force! The jet curves down because it’s moving the same speed sideways as the floor and the spot on the floor is moving into its path (because it’s rotating!). That’s centrifugal force! Those two forces are the ones that arise in a frame rotating at a constant speed (and “Euler Force” appears if the rotation is changing, jeez Euler try not sticking your nose into something for once).

HOW COOL IS THAT THOUGH OMG PEOPLE COULD ACTUALLY LIVE IN A PLACE LIKE THIS though I have no idea what combination of spin rate and jet velocity it would take to make a fountain like the one shown and they may not be conducive to non-death

I feel like I had more thoughts on more spaces. I should’ve taken notes. But this took waaaaay longer than 10 minutes so oops!


Response to Connotations of Beauty