[kaon123]

Sorry, why can this not be a coincidence? I understand that the universe is smooth across large spaces similar to how a fog is smooth on larger spaces, and coarse on smaller ones.

But even then, given a large universe, why would this be mathematically impossible? If galaxies formed evenly everywhere, couldn't this have happened by coincidence? Which theory is violated here?

Sorry my knowledge is a limited "The great courses Cosmology" course from 2009

[andreareina]

It's not a hard violation, just that they are large enough and there are enough of them that you would not expect them to form in a universe that is otherwise described by the cosmological principle.

A random array of points can form a grid, but if you see a grid somewhere the natural assumption is that it wasn't formed by a random process.

[m3047]

Yet any arbitrary sequence (e.g. of bits) has an equal probability of occurring in a random bitstring. 111111 is equally likely as 100110 or 010101. Asked "which one is random?" most people would say the middle one (even people who know better, like me).

Personally I discount the likes of 111111 and 010101 because I know there are artificial processes which produce those sequences and so I discount them on that basis. Yet if you were training a machine to recognize "random" data you'd need to include one sample of each of the possible 2^6 sequences to train it on representative data.

There is another category of random / not random to be considered: self-similar data, where there is similar data in the same area or at different scales. Taken in total, all sequences in this "universe" may be nonetheless randomly distributed.

A taxonomy / review of sequences which we generate inordinately and what phenomena are affected is missing. Self-similar data always deserves a second look, although the cause can be a natural self-organizing principle (e.g. literal snowflakes).

[prmph]

Then why is life, which is more complex and structured, assumed to have arisen by chance?

If random processes can give birth to structure, then one can also argue that maybe this ring is a fluke.

Remember that randomness is not necessarily uniformity

[The_Colonel]

This structure is too large in relation to our observable universe for it to be explainable by a mere coincidence. It's 1.3bn light years in diameter, while the observable universe is 93bn light years in diameter.

This is also not the only such structure found, some other examples are even larger: https://en.wikipedia.org/wiki/List_of_largest_cosmic_structu...

[danparsonson]

> This structure is too large in relation to our observable universe for it to be explainable by a mere coincidence. It's 1.3bn light years in diameter, while the observable universe is 93bn light years in diameter.

Why is that important?

[simonh]

It should be possible to calculate them likelihood of distributions with a given degree of apparent structure. Not a given structure, but the degree of variance from a typical random distribution.

[belter]

https://expanse.fandom.com/wiki/Sol_gate