What is your argument against this?

[Johnny Blade]

That looks like a clear downward trend to me, yes.

There's a lot of uncertainty due to different methods, and another problem is the mass class also strongly affects metallicity. Ideally we'd want to tr ack metallicity with redshift for a specific galaxy mass class. They do this in Zahid et al. 2021:
Skærmbillede 2024-08-03 135747.png

Notice the mass-metallicity relation decreases obviously with redshift. The blue curve is redshift z=0.08, yellow curve (which is below blue) z=0.29, and so on, with the red curve (highest redshift) also showing lowest metallicities. So yes, there's a clear and obvious correlation when controlling for the mass-metallicity relation.

Yes, there's a mass-metallicity relation too, in addition to a redshift-metallicity relation. You need to control for mass, which the website you linked doesn't do.

Do you still believe metallicity is a good way to determine age?

I would say there's an obvious correlation for specific mass classes, yes.

So I'm not so sure yet why you think any of this means what you think it means. Best I can figure is that our galaxy has a higher mass than about 85% of all known galaxies. And it also has a metallicity thats higher than about 85% of known galaxies. This has been known for some time now. So of course, to find more galaxies, we have to look farther out into space. And almost all of the new galaxies we find will have less mass and less metal than the milky way.

So considering we have observed at the most, 5% of the knowable universe (I don't know where they get that number from. Maybe you can help me.) and further considering the morphology of galaxies we find (galaxy bars ect), It looks like the trend is that we will just find all kinds of different galaxies, everywhere, relative to our own high mass and high metal galaxy.

[Rumraket]

The Milky way galaxy is among the top 15% on terms of mass? Okay, and?

So considering we have observed at the most, 5% of the knowable universe (I don't know where they get that number from. Maybe you can help me.) and further considering the morphology of galaxies we find (galaxy bars ect), It looks like the trend is that we will just find all kinds of different galaxies, everywhere, relative to our own high mass and high metal galaxy.

The trend we have is that metallicity correlates inversely with redshift, as predicted by big bang cosmology.

Since the further away we look, the further back in time we look, the more time has there been for space to expand and light to be shifted towards longer wavelengths. And so since the universe is predicted to have once consisted almost entirely of hydrogen and helium, then the first stars would have consisted of only that.
And these stars and subsequent generations of them would have been producing all the elements heavier than helium, and so the more time have passed since that the more heavy elements have had time to build up. So since the closer to our own milky way, the closer to the present in time we look, the higher the metallicity on average.

The logic here seems perfectly straightforward and comprehensible to me. Close to the milky way, closer to the present. Closer to the present, longer since the big bang. More time, more time for metallicity to build up.

This trend hasn't been falsified or overturned that I am aware of. The situation in cosmology with the JWST is, to my mind, like we had a model that was created to fit observations we had from previous generations of telescopes, and it predicted a decreasing trend of, say, 0.9x (to just pick some number out of a hat to make a point). But a better telescope now tells us the trend is probably closer to 0.92x. Whoah, how will big bang cosmology survive?

If you read the pop-sci press you come away with the fatuous picture that astronomers and cosmologists are "surprised", "nobody expected this", "this galaxy shouldn't be possible", heads are exploding everywhere, textbooks have to be rewritten, and everything we use to think we knew is false so make-believe is just as reasonable as, well, all of modern science. Etc. etc.

It's ridiculous of course. This kind of reporting on the science is driven by bad incentives. Attention-grabbing, career-advancement, attracting researchers and grad-students to your institutions/university, generating hype and interest, attracting grants and funding, etc. The scientists themselves are often totally complicit in hyping, dramatizing, and overselling their results.

Meanwhile the truth is actually much better summarzied as something along the lines that "the best current model didn't entirely accurately predict the rate of star formation very close to the big bang, and possibly models that predicted a top-heavy initial mass function were correct all along." But that sounds much less shocking, doesn't it?