The Cosmic Web just got a bit too cosmic

If you've seen my previous debunking of a really stupid internet meme, it'll come as no surprise to find that I think this article is a bunch of bollocks. Even if the authors are a Marie Curie astronomer and a neuroscientist, it's still bollocks.

Galaxies can group into enormous structures (called clusters, superclusters, and filaments) that stretch for hundreds of millions of light-years. The boundary between these structures and neighboring stretches of empty space called cosmic voids can be extremely complex. Gravity accelerates matter at these boundaries to speeds of thousands of kilometers per second, creating shock waves and turbulence in intergalactic gases. We have predicted that the void-filament boundary is one of the most complex volumes of the universe, as measured by the number of bits of information it takes to describe it. This got us to thinking: Is it more complex than the brain?

I've never heard of anyone describing such accelerations, but the statement is meaningless without describing what the velocity is measured relative to. Galaxies at the edges of voids aren't falling into filaments at thousands of kilometres per second, but of course they are moving at such speeds relative to very distant galaxies. Galaxies falling into clusters, on the other hand, do indeed reach local speeds > 1,000 km/s, but I never heard of this happening at the void-filament boundary. Clusters form very clear structures at the intersection points of multiple filaments, and are very distinct from other parts of the filaments.

It only gets worse from hereon in.

Here it is again : a comparison of the distribution of dark matter in the Universe (from numerical simulations, on the left), to a slice of the human cerebellum (right). Do these look the same to you ? Because they don't to me. Not even close. I mean, good grief. There are whacking great round lumps in the cerebellum image that aren't at all similar to anything in the simulation. The network structure of the dark matter is barely visible in the cerebellum : what paths there are are generally straighter but make sharper twists and turns. The dark matter network structure is visible because of enormous density variations which are not reflected in the brain. So :

The eye immediately grasps some similarity between images of the cosmic web and the brain.

No it fucking doesn't. This is wishful thinking writ large.

A stunning message emerges from the power spectrum graph in Figure 2 (below): The relative distribution of fluctuations in the two networks is remarkably similar, over several orders of magnitude.

A power spectrum doesn't convey the full details of the structure, any more than the standard deviation tells you about coherent formations. And the choice of features they choose to plot is completely arbitrary - it's a garbage comparison that's totally unjustified.

One of us has recently measured how difficult it is to predict how the cosmic network evolves, based on the digital evolution of a simulated universe. This estimate suggests that about 1 to 10 petabytes of data are needed to describe the evolution of the entire observable universe at the scale where its self-organization emerges (or at least of its simulated counterpart).

Whut ? I saw someone running an n-body universe simulation in realtime once. A small one, to be sure, but you don't need enormous amounts of data. It's going to be of the order of megabytes or perhaps kilobytes, not petabytes. The large scale structure emerges very naturally from gravity alone - yeah, you need much more horrendously complex physics for galaxies and stars and stuff, but not for the web. The only thing I can think they're referring to is storing the data "as is" at any step, which could be large, but you definitely don't need anything remotely like a petabyte to store something that's a much, much closer match to the structure of the brain.

It is truly a remarkable fact that the cosmic web is more similar to the human brain than it is to the interior of a galaxy; or that the neuronal network is more similar to the cosmic web than it is to the interior of a neuronal body. Despite extraordinary differences in substrate, physical mechanisms, and size, the human neuronal network and the cosmic web of galaxies, when considered with the tools of information theory, are strikingly similar. 

Does this fact tell us something profound about the physics of emergent phenomena in the two systems? Maybe. But we must take these findings with a grain of salt.

I wouldn't even call these "findings". They are nonsense statements. But suppose for the sake of argument that some similarity were to be objectively and correctly (for these are not at all the same thing) demonstrated. What would it mean ? What do you want us to do with that knowledge ? How does it change anything, knowing that the action of gravity can, under some conditions, produce something that resembles a structure produced by completely different biological processes ? In a word, so what ?

The Strange Similarity of Neuron and Galaxy Networks - Issue 74: Networks - Nautilus

Christof Koch, a leading researcher on consciousness and the human brain, has famously called the brain "the most complex object in the known universe." It's not hard to see why this might be true. With a hundred billion neurons and a hundred trillion connections, the brain is a dizzyingly complex object.