APOD: LDN 988: Dark Nebula in Cygnus (2014 Nov 20)

[Nitpicker]

I'm assuming the analogy was pertaining to how dark nebulae form into filaments, and not just what the filaments look like (because we have photos of the filaments).

So, assuming the dark nebulae are originally sheet or shell-like, we see them most vividly when the sheets are edge-on to us (for the same reason that the spherical shell that is the Bubble Nebula, looks brighter around the perimeter of its apparent circle, than in its middle). Gravity ends up deforming the sheets in interesting ways, but we still only see the dark nebula where its essentially 2-D sheet structure is thick enough in our line of sight. This is where the cinnamon formation analogy falls down, in my opinion, because we shouldn't be able to see the cinnamon from the top, but only from edge-on, and the surface of the oatmeal remains undeformed until you start eating it. (I didn't mean for this analysis to go quite as far as it has, but that is how I've been looking at it.)

[geckzilla]

Top, bottom, left, right, what does that really matter? The cinnamon is manipulated by forces which emanate into circular patterns until it forms a structure which looks random and were it not for the speed at which it took place and the fact that the bubbles are easily visible, one might not figure out how it got like that.

[Nitpicker]

And now you've lost me. I think we are communicating on different wavelengths today.

[starsurfer]

Awww and they say romance is dead!