Yes — that’s a very insightful way to put it.
We can define cosmic voids as the inter-galactic, inter-clusteric, and even inter-superclusteric spaces — but with a few clarifications and refinements.
✅ Accurate Reformulation:
Cosmic voids are:
Large-scale underdense regions of the universe, typically surrounded by galaxy filaments, clusters, or superclusters, and defined by their relative lack of galaxies, matter, and large-scale structure.
So your formulation works across different scales:
🌀 1.
Inter-galactic voids
- At smaller scales, there are spaces between galaxies, but these are not called “voids” in cosmology.
- These are just low-density intergalactic space — often filled with hot gas, dark matter, and the intergalactic medium (IGM).
- But not truly “void” — just sparse.
🌌 2.
Inter-clusteric voids
- This is getting closer.
- Voids at this scale are often tens of millions of light-years wide — between galaxy clusters, within the cosmic web.
- Most commonly studied voids fall into this category.
🌐 3.
Inter-superclusteric voids
- Yes, the largest cosmic voids, like the Boötes Void, span hundreds of millions of light-years and lie between massive structures such as superclusters.
- These are the most dramatic expressions of large-scale structure inhomogeneity.
- They reveal the spongy or web-like nature of the universe: voids surrounded by filaments and walls.
🧠 So can we define voids as “inter-everything”?
Yes — as long as we note that voids are defined by absence relative to their cosmic context, not by absolute emptiness.
Void = the space between:
- galaxies (on small scales),
- clusters (on mid-scales),
- superclusters (on vast cosmic scales).
But unlike mere gaps, voids have shape, dynamics, and cosmological significance:
- They expand faster than denser regions.
- They are cold spots in the CMB (via the ISW effect).
- They influence galaxy formation and large-scale flows.
✨ Final Formulation:
Cosmic voids are the liminal spaces between the luminous, the gravitationally entangled, the filamentously bound — they are the silent interludes between the symphonies of galaxies.
Would you like me to sketch a poetic-scientific diagram of the cosmic web, showing voids, filaments, clusters, and superclusters as a living cartography?
