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posted by Fnord666 on Thursday August 20 2020, @10:52PM   Printer-friendly
from the get-one-while-it's-hot dept.

The Universe Has Made Almost All the Stars It Will Ever Make:

But there's a big puzzle here. Exactly what puts a cap on the number of stars the universe has made and will ever make? This question has long been a subject of intense astrophysical debate, particularly in relation to the stellar composition of individual galaxies. For example, our current cosmological paradigm (or at least the one that most scientists subscribe to) is that we live in a universe dominated by dark matter, and in a dark matter universe the biggest galaxies should have formed the most recently,4 being assembled by the hierarchical, gravitationally driven merger of smaller systems. Yet if you examine very large, massive galaxies you find that they tend to be composed of older stars, suggesting that they've already sat around in their dotage for a very long time.

To try to explain this, astronomers invoke the idea of "quenching," where something acts to suppress or shut down the formation of new stars across galaxies. Not surprisingly, you need a pretty potent mechanism to quench anything on these scales, and among the most plausible culprits are the supermassive black holes that exist at the core of most galaxies and which can flood the space around them with photons and particles emitted from material as it screeches toward their event horizons. That outward transfer of energy can, quite literally, blow away the interstellar gas that would otherwise cool and clump into new stars.

The precise details of how this might work are certainly not yet fully understood. But there are new tantalizing clues in the fact that the masses of supermassive black holes appear to correlate with the mass of stars contained in their host galaxies.5 That is pretty shocking because even a supermassive black hole a billion times the mass of our sun only occupies a volume similar to that of our solar system. So somehow a galaxy that spans tens of thousands of light-years is intimately related to what is, in effect, a microscopic dot at its center.


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  • (Score: 2) by Bot on Friday August 21 2020, @07:13AM (3 children)

    by Bot (3902) on Friday August 21 2020, @07:13AM (#1039805) Journal

    Logically following GP post, "not being an astrophysicist" should be enough cred.

    TFA is basically saying that the pretty big bang theory says X but we observed Y so we made up the assumption Z according to whom the as yet unprovable title of the article stems.

    OK a little brick of logical knowledge that will be used to develop the theory further. Personally if I had a career there I would pursue less epicyclist stuff but who knows maybe I could not even choose.

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  • (Score: 2) by Pslytely Psycho on Saturday August 22 2020, @03:13AM (2 children)

    by Pslytely Psycho (1218) on Saturday August 22 2020, @03:13AM (#1040258)

    Ah, but there was no logic nor evidence presented. Just a childish rant that attacks without reason and without even the slightest argument supporting objecting to "extrapolating nonsense" with an example of what they consider to be nonsense and why.

    Of course in this insane age, I guess name calling like a five year old trying to get attention now counts as a reasoned, logical argument.

    A good many theories are unproven and many may sound absurd on their surface, that's kind of the point, you falsify with evidence. At one time the thought of exceeding 25mph (40.2kph) was believed to be fatal, and human spaceflight or a heliocentric solar system a flight of fancy or blasphemy. Evidence is what changed peoples minds. If you have to resort to name calling, then there are only a few possibilities.

    a: troll

    b: ignorant troll

    c: totally fucking ignorant troll

    d: compensation for very laughable sexual equipment

    e: needs a medication refill

    f: needs a hug

    g: way over the legal limit to drive

    h: is actually five years old

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    • (Score: 2) by maxwell demon on Saturday August 22 2020, @05:55AM

      by maxwell demon (1608) on Saturday August 22 2020, @05:55AM (#1040292) Journal

      Ah, but there was no logic nor evidence presented.

      Of course not. Logic and evidence is what scientists use, and the OP clearly didn't want to give the impression to secretly be a scientist. ;-)

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    • (Score: 2) by Bot on Saturday August 22 2020, @03:27PM

      by Bot (3902) on Saturday August 22 2020, @03:27PM (#1040415) Journal

      You are right in principle except the theory being "therefore there is some undetected AND POTENTIALLY UNDETECTABLE matter which makes the equations great again" is not easily falsifiable.

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