Viewing profile — astroH

a lot better...we can excite these atoms in a lab and simply measure what comes out. often times don't even need a model because spectroscopy can be fully empirical for many transi…

And so you have proved my point. The observations presented in this article can be made consistent with both...as such one should think about stronger tests of both LCDM and MOND.

Again, LCDM and galaxy formation are two different things. "...and we didn't see what we were expecting at all..." It depends on who you ask. There were many pre-JWST models that d…

This is a misrepresentation of what I am saying. By no means am I casting an aspersion on JWST. I am casting an aspersion on this particular observation as a test of MOND and LCDM.…

In my opinion, this article is misleading at best. "...scans of ancient galaxies gathered by the JWST seem to contradict the commonly accepted predictions of the most widely accept…

So I think it is fair to say they did exist. If we believe in Big Bang Nucleosynthesis then heavy elements had to come from somewhere making the first generation of stars (whatever…

Multiple generations is perhaps an overstatement. The first oxygen in the Universe came from what we call Population III stars which is the first generation of stars to form after …

I wouldn't say it's too damaging yet. There is a general trend where these early galaxies are brighter than we had thought by simply extrapolating models that were built prior to J…

It's a lot less sophisticated than that. They take images in multiple filters. In the context of JWST of order 10 filters (sometimes more sometimes less). Source extraction is then…

While in general, 'metal' means all elements except for hydrogen and helium, in this specific case, 'metal' really means oxygen. They are using the measurement of the [O III] 4363 …

Indeed, but we define their "metallicity" (mass fraction of elements heaver than helium) typically by the gas that they formed from. And the key point is that since they form from …

These systems are very far away because you are looking more than 13 billion years back in time. The argument is JWST has a small field of view and these Pop III stars are like fla…

I think this is perfect! If only we can convince the author of the article...

Unfortunately not. These stars have no elements heavier than hydrogen and helium so you wouldn't be able to create a rocky planet that's habitable. Furthermore their lifetimes are …

As an expert in this space, I can confidently tell you that nothing about this observation is conclusive about the presence of the "First Stars" or what we call "Pop. III" Stars. B…

So MOND does predict more galaxies at high redshift however it also predicts earlier reionization than LCDM which it turns out not to be true and the mass function of clusters is n…

I have to say, this article is exceptionally disappointing. As someone who works in this space, there are numerous misleading depictions about the state of the field. Almost any re…

I think this is perhaps the wrong way to think about it. 50 million years represents ~14% of the age of the Universe (at 350 Myr) so it's really quite a big jump. Considering stars…

A lot of the work on distant galaxies is not being done with gravitational lensing. The idea is that you use massive objects in the foreground, like galaxy clusters, to focus light…

Echoing previous responses, it depends on what you want to learn. Gravity on large scales is fairly well understood (or at least many astrophysicists believe this to be the case). …

Couldn't agree more. Moreover, given that a huge part of the value of the degree is related to the prestige of the University, bad-mouthing your own institution only serves to redu…

Could you elaborate a bit more on this? I have thought about employing NNs in this way for quite a while but the thing I never wrapped my head around was ensuring how it generalize…

Modified gravity is still being actively explored and I would argue taken very seriously but not in the context of dark matter, rather in the context of dark energy. So in a sense,…

The best evidence for dark matter is arguably the CMB. The strengths of the individual peaks are highly suggestive of dark matter, in particular the third peak. Furthermore, most M…

Nebula isn't a physician-ordered test, nor does it come with the bioinformatics pipeline needed for rare conditions or genetic counseling. It's quite simply a different product for…