If we peer far enough into deep space, we should be able to see the filamentous, spidery large-scale structure of the Universe - the scientific opinion being that filaments and voids are the largest observable contiguous structures in the Universe.
But the Hubble UDF photos show galaxies scattered all over, right upto 13 billion light years away - a short time after the BB - with the said filamentary structures entirely undiscernable. Why so? If those filaments do exist - and are not a statistical deduction but an observable reality, the HUDF should bring them up. All the images I have seen of the filaments and voids are computer-simulated projections, never actual photographs.
If we’re inside a filament, how would we be able to see the larger structure from Hubble? Kind of like how we can’t see the arm structure of the Milky Way when we look at it, it just stretches across the sky.
No I do not, please enlighten me. When Hubble peers say 6 billion LY away, shouldn’t a filament, or a fragment of it, 9 billion LY away photobomb it? What, it’s not that simple?
And the bolded part is your misconception. The Hubble isn’t looking at a specific distance. It’s looking at everything between one inch away and forever away. The limitation on how far it can see is entirely how bright the stuff it’s pointed at happens to be. The things it sees that are farthest away are the ones that are (were) brightest. Other things at the same distance that are (were) dimmer are unseen.
It’s also the case that nearby things are seen as they were just a few years a ago. Whereas distant things are seen as they were millions or billions of years ago.
So we can’t take a picture *now *of how the large scale geometry is now. We can only take a picture now that shows different distance slices at different times in the past.
From that it’s not too difficult to compute a graphic of the structure. But we can’t take a picture of it.
Finally, the structure is pretty amorphous. It’s not like a lacework of solid rods and empty space. More like areas of really-empty space and areas of slightly-less-empty space.
Also, the universe is a lot like a sponge or a foam, with holes and walls. It is heterogeneous on the scale of the bubbles, but looking at larger scales, it seems pretty homogeneous (like looking at a piece of Styrofoam). Further, when looking outward with a telescope, all the bubbles and wall are piled up upon one another (like looking at an x-ray of a piece of Styrofoam).
The bubble-like nature of the universe first became apparent through careful measurement of distances of galaxies observed in a narrow slice.
I don’t know either, and the exact information I was looking for is hard to find, but here’s one sentence from the article on such a filament:
Now compare that to the HUD:
By my estimation, mind you I’m not an astrophyscisist, you’re complaining that a photo taken by a guy in Siberia shows trees spread evenly when you’ve read that the boreal forest is a band around the world.