The linked paper isn't clear, but it rather implies that the material density does not monotonically increase from light-emitting surface to the accreting (proto-)SMBH, but has a minimum somewhere between "core" and "surface". If it did increase monotonically, it'd be a TáO - an interesting alternative engine for stars (but probably not the Sun), I think.

But if the commentary from ScienceDirect explains how this object maintains that low-density zone, and isn't a TáO, then I've missed it. and I can't summon the enthusiasm to track down the original paper on ArXiv.

(I would have given this submission a "+" vote, but that option has been removed and replaced with a link to a help page anchor named "#i_use_noscript" which is true and somehow makes me a bad person. Your, and Slashdot's, loss. )

(With or without a cat-staffing job too.)

What is the normal result of forcing a dog to eat it's own vomit?

who set prices at retail. Or at least, printed them onto the shelf label. Do they send people - invisible people - running around the stores to change the labels ahead of me looking at them? I used to have that idea about how the TV worked - with tiny changing rooms in the cabinet - but I understand now that they work differently and the miniature actors go through a Rick'n'Morty-esque "portal" to their changing rooms, allowing for thinner TVs.

Or, does "retail" mean something different in EN_US?

A week or two ago I noticed that the "vote" buttons for submissions had been changed to link to some part of the "help" system, under the anchor "iusenoscript". Which means I can't vote for, or against, submissions. Which I used to do.

But, to be honest, I'm wasting less and less time here. The problem of it being American-centric is getting worse (and it has always been bad) ; the lunatic right-wingers that come with that are getting madder ; the stories are getting more boringly uniform - obsessing over AI, and it's coming collapse. I can't even bring myself to make the effort to submit some good astronomy stories.

Shrug. If it dies, it dies.

Unfortunately (?) Slashdot replaces the voting buttons with a link to a "I_use_Noscript" page, rather than registering a vote. Which, yes, I do. And if that offends the powers that be at Slashdot, tough shit. I'm not disabling it on your site, or anyone else's. Get over it.

It's more likely to get that engineering in America.

Asia in general and China in particular have had due respect for the lethality of respiratory viruses for a long time. I remember wondering about the Oriental habit of wearing respiratory masks in public places through the 2000s and 2010s - and it's largely down to their reasonable concerns about SARS (2004 to 2006) and then MERS (2012 to 2021).

No, I'd expect any lunatic gene engineering to take place in a Texas garage, performed by an anti-vaxx campaigner with delusional beliefs about how viruses spread. Because "Feee-dumb!"

(Yes, dear AC, you are being treated with contempt. It goes with being an AC.)

Sometimes the arguments last for decades.

And sometimes they're terminated by funerals.

The Sun, all stars, galaxies, formed by ordinary matter self gravitating into a volume where it's components interact with each other. With ordinary matter that implies a confining pressure produced by gravity, and a resisting pressure from the particles interacting with each other and not being able to share the same volume.

As a "RetiredChemist", you should recognise that situation from deriving the "Ideal Gas Laws" from Newtonian dynamics of particles and Van der Waal's expression for the volume of gas molecules (as opposed to the volume occupied by the gas under NTP, STP or whatever. REmember that lecture.

The thing about normal matter is that it's particles self-interact, leading to them having a consistent distribution of particle energies. And that means a gas of normal matter has a temperature, and it will radiate some of that energy away if it's temperature is greater than the ambient (currently 2.8-odd K ; the CMB temperature). Otherwise, it will collapse in volume under the influence of gravity - as you suggest - until it's internal temperature rises to the point that it starts to radiate it's thermal energy. Yadda, yadda, normal star formation theory, and on a bigger scale the same process for galaxies.

But with dark matter particles not (or very rarely) interacting (DM)particle on (DM)particle (and little from (DM)particle on (NormalM)particle), they just pass through your volume under consideration and out the other side, only responding to the gravitational force very slowly braking them as they ascend from the gravity well and into inter-galactic space. Then they slowly descend back into the middle of the galaxy, picking up speed from the gravitational field ... and pass through the middle of the galaxy without interacting with other DM (or NormalM) particles to shoot out the other side.

According to the -CDM model, DM does clump with matter - at the galaxy or galaxy-cluster scale. But it doesn't stick to other DM as well as "NormalM" does, so it hasn't (yet) condensed into dark galaxies etc.

Re-do your "Ideal gas law" calculations with a much smaller Van der Waals volume and much weaker electrostatic reaction between gas particles, and you too will reproduce the slowness of clustering. You could manage this when you were an undergraduate ; you can do it now.

You do realise that the first evidence for dark matter was found (and published) in the 1930s, well before anyone but Goddard's most optimistic liquid-fuelled rockets got off New Jersey potato fields.

No, you're an AC. You probably don't know that.

Your ignorance doesn't make it untrue.