Arthur T Knackerbracket has processed the following story:
Quasars are a subclass of active galactic nuclei (AGNs), extremely luminous galactic cores where gas and dust falling into a supermassive black hole emit electromagnetic radiation across the entire electromagnetic spectrum. The gas and dust become luminous as a result of the extreme gravitational and frictional forces exerted on them as they fall into the black hole.
Quasars are some of the most luminous objects in the known Universe, typically emitting thousands of times more light than the entire Milky Way. They are distinguished from other AGNs by their tremendous luminosity, and their enormous distances from Earth. As the speed of light is finite, objects observed from Earth are seen as they were when the light we see left them. The nearest quasars to Earth are still several hundred million light-years away, which means that they are observed now as they were several hundred million years ago. The absence of quasars closer to Earth does not mean that there were never quasars in our region of the Universe, but instead means that quasars existed when the universe was younger. The study of quasars provides fascinating insights into the evolution of the Universe.
[...] Hubble has also imaged quasar ghosts — ethereal green objects which mark the graves of these objects that flickered to life and then faded. These unusual structures orbit their host galaxies and glow in a bright and eerie green hue, and offer insights into the pasts of these galaxies.
(Score: 2) by bzipitidoo on Monday September 05 2022, @01:04AM (10 children)
I don't buy that supposition that the universe has transitioned from an era with quasars to one without. Why shouldn't conditions in the universe still support the formation of new quasars?
(Score: 2) by maxwell demon on Monday September 05 2022, @03:58AM (2 children)
Well, I'm no astrophysicist nor a cosmologist, thus I can only guess. But I guess the quasars just stopped being quasars because the black holes had already eaten most of the matter in their vicinity.
Remains the question why no new quasar galaxies are forming. But that seems plausible: Most of the material of which galaxies could form already is inside galaxies. And most of the remaining material got diluted due to the expansion of the universe, so at any spot the amount of matter available for forming galaxies decreases over time.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by StupendousMan on Monday September 05 2022, @04:22PM (1 child)
(Score: 2) by legont on Monday September 05 2022, @08:01PM
Let me add to it (and you correct me if I am wrong). Gas, which moves by Bernoulli principle, has much higher probability to fall into a black hole than stars. Note that gas fall into starts as well following the same principle. Once the process is mostly over, the black hole has no feed to speak of as well as stars.
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.
(Score: 0) by Anonymous Coward on Monday September 05 2022, @03:58AM
I suppose you'd need regions where new galaxies are forming to get them.
(Score: 0) by Anonymous Coward on Monday September 05 2022, @06:08AM
(Score: 2) by inertnet on Monday September 05 2022, @07:49AM (4 children)
Considering the expansion of the universe, I wouldn't rule out that quasars were more common when it was more densely packed.
Fictional: for a very long time I've had an idea for a story about the universe going from a big bang to a big crunch, resulting in another big bang, but of negative mass (to us). So the universe alternates between positive and negative mass. Imagine a collection of intelligent beings from the previous negative universe, who can't live in our current one, are trying to speed it up by causing quasars around the edges. They are at war with those that escaped the previous positive universe, who have entered our universe after it was safe and who are looking for intelligent races to join their fight. Scouts have already visited Earth in the past and tried to explain all this to our ancestors, which is why we now have religions that speak of heaven and hell (the upcoming negative universe). If we are found to be eligible, we will be invited to join this eternal war, else we will burn in hell forever.
(Score: 2) by Immerman on Monday September 05 2022, @06:42PM (3 children)
Just FYI, negative mass is completely mythical, and we have good reason to believe inherently impossible. Though antimatter could still be a good fit for your story - that's just a different spin on normal, positive-mass matter. Interesting only because of its rarity, and tendency to annihilate when it contacts "normal" matter.)
The physics: matter is not synonymous with mass. Mass is a property of energy: E=mc², or as originally expressed, m=E/c². Matter has mass because it's composed of an *incredibly* dense concentration of energy. To get negative mass you'd need negative energy, which given our current understanding is a nonsensical concept. It would mean you could suck all the energy out of a box, and then somehow continue sucking out even more energy. And if you can extract stuff that's not there, could I get you to extract a few $million from my checking account for me?
A big crunch would convert all the matter in the universe to energy - but the total quantity of energy, and thus total mass of the universe, would remain unchanged.
However, the incredible energy densities in a crunch would likely unify the fundamental forces again, and I don't think there's currently any particular reason to believe that the forces would separate out the same way again after a new big bang - which would mean completely different physics, and that things like atoms and photons from our universe couldn't exist in the new one. No reason you can't ignore that for the sake of a story though, right?
(Score: 2) by inertnet on Monday September 05 2022, @08:53PM (2 children)
I came up with this idea about 45 years ago, but have never written it down because I'm not a writer. I realized later that the laws of physics would make this an impossible story, but back then I thought it could make a great "mother of all science fiction". Even major religions could be made to fit in if prophets were just people who had met these inter-universal scouts. There would be lots of races, tech, wars, galaxy wide battles. It could have been huge, but I never got around to get it off the ground, or pitch it to someone who would be able to expand it all into a collection of books.
(Score: 2) by Immerman on Monday September 05 2022, @09:14PM (1 child)
You should give it a shot - the only way anyone ever becomes a writer is to write until they get good at it. Just like any other art. Practice alone isn't always enough to truly master a skill, but almost everyone sucks until they spend at least a few thousand hours developing basic competence.
And for storytelling, as with software, you'll never find anyone else to run with your ideas unless you're paying them handsomely. Few people acquire the skills unless they have their own ideas demanding to be made real - in which case they almost certainly spend their lives with far more ideas than they have time to create.
(Score: 2) by inertnet on Monday September 05 2022, @10:40PM
Thanks for those words, but the book I'm about to write won't be fiction. If all goes well I'll start writing down my 10 year long treasure hunt later this year. I really don't have the time to write thousands of pages of science fiction.