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mosesbp

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I’m glad this kind of work is getting highlighted on HN, but this is an extremely misleading title, to the point of being outright false. As often happens, this appears to be due to PR titles being controlled by non-specialists, not the study authors.

While the work the authors do is important, in no sense does the tool they produced actually run a simulation.

A simulation implies a physical model and usually partial differential equations that are often solved on supercomputers, but here the neural network is rather interpolating some fixed simulation output in a purely data-driven way.

The simulations have not gotten faster due to neural networks, cosmologists have just gotten better at using them. Which is great!

Edit: see the sub-comment in the thread by crazygringo for the lead author’s take

Your link seems unrelated to the topic of this article? I gave the line items for the research conducted in the OP.

A good faith reading of your comment leads me to guess you might take issue with a small number of unrelated NSF CAREER awards going to research you don’t find worthwhile (such as those alluded to in your link). But the vast majority of CAREER awards fund what I would imagine you would consider “real science” [1], like the content of OP.

So please do not tune out!

[1] You can count them here in the list of all CAREER awards: https://www.nsf.gov/awardsearch/advancedSearchResult?PIId=&P...

If you think this is cool/valuable, I just want to point out that this work is being paid for by the DOE Office of Science (BES division), uses the NSF National High Magnetic Field Laboratory, and is using money from an NSF CAREER award (“Acknowledgments” section under “Funding” in the actual paper [1]). The former is facing a cut of 14% [2] (The Office of Science overall is seeing a similar cut), the second is facing a 40% cut [3], and the latter appears to be destroyed entirely (no money requested) [4] in documents released by these agencies for FY2026 (executive budget).

This research is also supported by Chinese funding agencies, who I imagine will not be engaging such senseless hamstringing of their national scientific organs…

[1] https://www.science.org/doi/10.1126/sciadv.adr6202

[2] See page 5 of https://www.energy.gov/sites/default/files/2025-07/doe-fy-20...

[3] See page “Facilities - 5” of https://nsf-gov-resources.nsf.gov/files/00-NSF-FY26-CJ-Entir...

[4] See page “Summary Tables - 1” of the link in [3].

Making progress on these key issues in galaxy evolution and black hole growth is exactly the kind of research that will not happen (or at minimum be extremely limited) under the current administration’s grant cancellations, funding cuts, and staffing reductions at the NSF and NASA, the two of which account for almost all of US astronomy research funding.

Thanks for this earlier article. From there it seems that the most staff losses are at Goddard, which is largely focused on science, not launch capabilities. So this unfortunately seems to fit into the larger “anti-science” push of the administration (e.g. the almost entirely senseless cuts at the NSF, NIH) more than it has to do with launch activities. Another dark day for US physics research…

Does anyone have access to a copy of the NASA statement on this that was shared with the media? It makes a big difference where in NASA these people were employed - this is the difference between slimming down an engineering division or cancelling one launch project and the total destruction of a smaller program for physics, which may have a much longer-term impact on US science.

This is already how astronomy, and specifically cosmology, research works in the US (and most other places). Data is made public within a short period of obtaining it on a schedule (usually less than a couple years) that is set before data is taken.

It is far from clear that the Chinese government supports this type of open data sharing.

Here is the preprint [1].

From a quick glance, the authors look only at a small (relative to the overall size of the universe) region of space and study the emission from the gas between galaxies (specifically, the WHIM [2]). It would seem challenging to draw major conclusions based on this study - and the authors themselves conclude higher quality data of the type they are using is needed.

Some context:

This missing gas or "missing baryons" problem is a very old one [3]. See here [4] for a nice review (Section 4 mentions the missing baryons problem, which really is localized to the cosmologically "recent" universe - we know where the gas was when the universe was older.) It increasingly seems like the missing baryons problem can be resolved by gas living in the WHIM between galaxies. This recent paper [5] argues using Fast Radio Burst data that, in principle, this problem can be solved this way.

[1] https://arxiv.org/pdf/2506.14917

[2] The charmingly named "Warm-hot intergalactic medium" - https://arxiv.org/pdf/astro-ph/0007217

[3] "Baryons" is cosmology jargon for ordinary matter - gas and plasma.

[4] https://arxiv.org/pdf/1512.00086

[5] https://arxiv.org/abs/2409.16952