Astronomers puzzled by little red galaxies that seem impossibly dense | Hacker News Reader

Astronomers puzzled by little red galaxies that seem impossibly dense

newscientist.com

90 pointsjandrewrogers61 comments

Is this what a group of type III civilizations look like on the Kardashev scale? Back when the universe was hot and dense and it was still fun?

Well, the universe is very heterogeneous, you see. There's still plenty of hot, dense, and fun to go around, you just have to look in the right places!

Colder is actually better and more fun. You see, the theoretical lower limit for how much energy your super-computer takes to run is given by temperature, and thus on a larger scale by the temperature of the background radiation in your part of the cosmos. See https://en.wikipedia.org/wiki/Landauer%27s_principle

“Red galaxies? On a Friday night? They’re so hot and dense and full of obnoxious Level III civilizations, nobody goes there anymore.”

This is what happens once you start down the road of making Paperclips…

"It looks like you're telling a transhumanist parable. Would you like help?"

https://www.decisionproblem.com/paperclips/index2.html#-game

Too soon.

occam's razor says probably not

Says who? Have you considered the alternatives?

Maybe that's another Great filter in Drake's equation - civilizations dumb enough to go full scale in crypto mining and 'AI' to generate cute cat pictures with nobody to stop for a second and think a bit. Those last few tokens will take half of universe's energy to mine, lets hope we are on the other side.

The preprint version of the main paper being discussed: https://www.arxiv.org/abs/2408.07745

"We stress, however, that the canonical interpretation of AGNs causing the broad Hβ lines also remains viable."

What’s the layperson’s interpretation of this?

They're trying to figure out how fast the galaxy is rotating by looking at the redshift from the stars. Some are moving towards us and others away. That spreads out the distinctive frequency of hydrogen emissions.

They think it's broader than the conventional explanation (active galactic nuclei) can explain. But it can't be ruled out.

They have offered an interesting hypothesis (all those stars packed into a small space) but this other, perhaps more conventional, explanation for the observations is not ruled out.

Must be heck of a night sky on one of those planets

They might be too early for planets, at least rocky ones. I'm not exactly sure of the timeline for these stars, but planets require at least a generation or two of stars and novas to fuse heavy elements, and we're probably looking at some of the earliest stars formed (assuming it they are actually stars, not entirely clear yet).

Also, if they're not sure how the stars themselves can survive being so close to each other, stable planetary orbits are probably right out. :D

Man isn't that just so freaking cool. Matter comes together forms some kind of mechanical system to produce new materials which come together and form a new system and so on. Some how a few principles which all matter follows gets reproduced again and again at higher and higher scales.

Is there a fun/good read on astronomy?

Most likely the same principle that formed earth and life will form else where even if slightly different

https://astrobites.org/

I wonder how close we are talking.

"close" in astronomical terms tends to be rather a long way away,

My personal hope is that they’re white holes that have been heavily red shifted… probably gonna be something way less exciting but none the less interesting.

> it was missing other key features seen with black holes, such as X-rays and radio waves. There were also other features, such as a peak in the light’s brightness at certain frequencies, that suggested it came from stars

Amateur speculation:

A dense group of stars tightly circling an early forming supermassive black hole? The stars would be able to (mostly) block the radio and x-rays.

Space is big, really big, even if it looks small. I doubt you would be able to block enough but that is just armchair guessing. Things like reemission might also help?

“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.”

— Douglas Adams

I hope this quote has made its way into the academic literature in some way.

Can those be just globular clusters in their 'bright' phase? Globular clusters are not even mentioned in that article, which is weird.

I'm gonna guess that the prominent astronomers at several top-notch universities mentioned have heard of globular clusters, and that the reason it's not mentioned is it's not relevant.

Why? How do the astronomers know that its many stars, how did they rule out its the normal amount but brighter?

Which aspect of the answer do you want? You can write a textbook on such a broad question; how we determine the mass of a galaxy, its composition, its distance, etc.

JWST is seeing brand new things; globular clusters are so well documented as to be part of the original Messier catalog that predates the United States.

The answer is not rocket science. JWST saw something, scientists made an interpretation, there should be an explanation "why" somewhere. And you won't need to write a textbook on that because you can cite prior work.

There is no solid/proven explanation right now. Only hypotheses to be tested. It’s a new phenomenon they’re working to understand.

It's unfortunate that during "professional development" we collectively appear to unlearn saying "no". Or, more widely, learn to avoid using simple direct language. It's not limited to scientists :-(

I think it's because the implication of any such question is how/why did they exclude.... It's like when you ask somebody, did you have a nice day? If they respond "yes" or "no", that's breaking the unstated rules of conversation.

And I would add that perceived competence does not preclude elementary solutions or problems. We're all humans, and humans are entirely prone to silliness, regardless of our credentials. NASA lost a near billion dollar Mars orbiter [1] because nobody, of the thousands of highly credentialed people that worked on that project, bothered to ask, 'Did anybody make sure that all components are using the same measurement system (metric vs customary), run a sim, or at least sanity check the data we're getting back?' Because surprisingly, the answer there would have been "no."

[1] - https://en.wikipedia.org/wiki/Mars_Climate_Orbiter

Assuming that all their light is coming from stars, they have far too much stellar mass (with stellar masses similar to the Milky Way) to be the progenitors of today's globular clusters.

In globular clusters stars tend to have similar age in terms of main sequence progression. If most of the stars approach their brightest phase, the cluster will be extremely bright relative to its mass.

Such a mass-to-light ratio is accounted for when computing a stellar mass.

I've read the paper, those objects have all properties of AGNs, but since having AGNs so early doesn't fit current mainstream, authors try very hard to come up with a different explanation.

“Unlock this article”

Please stop linking to paywalls ffs.

https://news.ycombinator.com/item?id=10178989

Waybackinator and web.archive.org don’t work, the latter also shows the paywall.

You can only post it with workarounds.

Furthermore it might also be legal to shit in your living room; I would however still consider it bad form.

And then people complain about clickbait. If you want good science journalism then you ought to be willing to pay for it. Otherwise it will be funded by adverts, and that means maximising clicks, and that means clickbait headlines.

archive.ps or whatever the domain is now.

Plug: I made <https://waybackinator.com/>. You can just append a URL to the URL path to get a link to the most recent archive snapshot, if there is one. It uses the wayback machine's API.

Example:

1. https://www.newscientist.com/article/2445967-astronomers-puz...

2. https://waybackinator.com/https://www.newscientist.com/artic...

3. "That URL is not available via the internet archive API."

Oh well.

If it's just for The Wayback Machine, you can prepend https://web.archive.org/web/ to the URL; no need for the waybackinator indirection.

I've made a bookmark of the URL https://web.archive.org/web/%s in Firefox, and assigned the "wm" keyword to it, so I only have to prepend that.

LPT: you can right click on any search box and select "Set a keyword to this search" (or whatever it is exactly in English).

Archive.today is the master domain which should redirect to the best one for one's location:

https://en.wikipedia.org/wiki/Archive.today

How does that work?

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