'Bubbles' could imply something like space-time changes, and in face a couple of comments speculatively / hopefully read them like this: [1], [2]

But they're (sadly?) much simpler: Spitzer bubbles 'are formed by radiation and winds from massive stars, which carve out holes within surrounding dust clouds.'

So really just the blast radius!

-- https://www.spitzer.caltech.edu/image/ssc2013-05a1-bubbles-w...

I would _love_ it if either of both these comments were true, by the way. Space-time can be boring and restrictive. What if...? I love the idea of bubbles reflecting a smaller universe and what it might hint about FTL, for example, and I live in hope that we'll find abberations and abnormalities like this.

[1] https://news.ycombinator.com/item?id=43552920

[2] https://news.ycombinator.com/item?id=43552713