Posted by wglb 10/26/2024
first brown dwarfs seen in other galaxies too
https://bsky.app/profile/philplait.bsky.social/post/3l7bssmh...
https://physics.stackexchange.com/questions/249679/gravother... https://en.wikipedia.org/wiki/Baryon_acoustic_oscillations
So you end up with this paradoxical situation where a "hot" mass starts to interact with a "cold" one and ends up making it even colder, so it collapses.
Of course then you get rocks sitting at a different internal temperature than the temperature of the overall cloud of rocks, and yes, over time that would reach an equilibrium. However, heat transfer in space, for large objects, is slow enough that this can be a very long time indeed.
Thinking some more about it, there are probably some ways to constrain the amount of time it takes for a past runaway to have occurred that rules this explanation out.
Using the official age of the universe we need to then form the quasar in a dense matter region and then speedrun a galaxy merger that ejects the relevant quasar out into sparse space, all of that in a few hundred million years only.
Using contemporary cosmology practices I suggest we add a Dark Age to everything observed. Yes the age of the quasar is 13 billion something years in the axis of regular time, but due to observations disagreeing with this timeline we can just keep adding years to any given observation in the Dark Age, complex time axis, until the problem is solved
AFAIK we have seen indirect evidence of their existence with Webb. They could explain some of this early structure.
> Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes.
> Comments should get more thoughtful and substantive, not less, as a topic gets more divisive.
> Please don't fulminate. Please don't sneer, including at the rest of the community.
Inflation has no influence on galaxy formation. Its duration was also a tiny fraction of a second, not years. It's also the first time I have heard it being associated with the term "dark age". The only actual "dark age" in cosmology in the common sense of the term is the period between reionization and first light by stars. Nothing to do with the quasars we are discussing here. It's really hard for me to read the comment in the way you suggest.
You can learn more about the problem from this physicist: https://www.youtube.com/watch?v=qS34oV-jv_A
> Inflation has no influence on galaxy formation.
That's completely not what I was talking about. I was saying that the era of rapid inflation that despite being postulated to be just a fraction of a second had immense impact on the shape of the universe can't be swept under the rug just because it's short and is already a kind of "Dark Time" when huge things were happening despite time barely passing.
You could equally sensibly postulate that 500 million years since the Big Bang there was a fraction of a second when galaxy formation underwent accelerated progress that aged them few billion years and that explains early black holes and such. Hopefully it won't come to that and more sensible explanation of what JWST sees will prevail.
It's true that "dark age" is not talked about in cosmology and is and invetion of the downvoted user. However when you think about it this naming analogy makes perfect sense when there seems to be missing mass it's called dark matter (which makes sense since it looks like the mass is there but it isn't shining), if there's missing energy it's called dark energy (despite the fact that we don't expect it to be shining in any way)... by extension when there's time missing we could call this problem dark time (witch is about as sensible name as dark energy) ... It's a case like scandal in Watergate hotel and then naming all scandals something-gate.
Angela collier's video is philosophically disingenuous (I do believe she believes what she says). You can't just lump a set of observations together and say it's not a hypothesis. The act of lumping those observations together implies the hypothesis that they share a casual unification.
"Observation" in the scientific vernacular carries added cachet because (barring fraud or miscalculation) it's irrefutable and more value neutral, versus a "hypothesis" which is designed to be refuted.
Calling the Dark Matter hypothesis an observation is a blatant attempt to inappropriately steal a sense of irrefutability. It's kind of terrifying that smart people are repeatedly using her video as a dunk
Irrefutability?
That doesn't sound scientific at all. Especially in the context of hypothesis that supposedly accounts for a set of observations unexplainable by status quo, while having zero predictive power so far.
The only irrefutable thing is that we observe something that behaves like gravitational attraction from the spots in space that don't seem to emit electromagnetic radiation. "Why is that?" is the Dark Matter problem or question. Anything said beyond that question on this subject is a hypothesis of some form of solution to that question. All of them equally useless so far.
> Irrefutability?
> That doesn't sound scientific at all
We're not talking about science here, we are talking about the philosophy of science.
At a trivial level it is still a hypothesis that each deviation from newtons laws (as in on a per galaxy basis) we observe has a common cause. But let's say that's quite trivial and it's an extremely easy hypothesis to accept.
There are levels to this. Are the deviations at the galaxy level caused by the same phenomenon as the deviations at the cluster level? Easy to believe, but still needs to be poked at. Slightly harder to believe out of hand than the previous
Is the ringing in the CMB caused by the same thing? If you don't admit that that is a harder sell (if even slightly) then that's dishonest.
By having grouped all of these distinct observations into one group of observations Angela has slyly implied they are all caused by the same thing, and introduced friction to exploring the possibility that they are not. That is scientifically irresponsible. Especially given, as you say, all the models suck.
Even this isn't commonly accepted hypothesis that explains the problem named Dark Matter. MOND postulates that while most of the observed effects have the same cause, that gravity works differently, it also states that smaller effects observed might have another source.
She's lumping all those observations because they are lumped by most physicists because they might potentially have a single cause and thus might be parts of singular problem. Maybe at some point Dark Matter problem will have to be split into several but we are not at that point of knowledge yet.
Physicists have always searched for theories of everything and I haven't seen where the friction introduced by that search prevented them from finding out how parts like quantum mechanics or gravity work even if they don't have any underlying common mechanism. On the contrary, idea that vastly different phenonmenons might have a single cause led to deep advancements and insights like in the case of Newtonian gravity.
Philosophy is BS. It doesn't matter. What matters if there's data available. Until there is, everything is open to ridicule because all ideas are ridiculous until some of them are shown to be true. Then the next generation learns about them at schools, integrates them into their intuition and they no longer see how ridiculous they are.
And there are many cases where you absolutely can't do that. For example, to fully explain how nuclei work, you must have both a strong AND weak nuclear force.
> Physicists have always searched for theories of everything
searching for theories of everything is arguably a big part of why physics is broken right now and hasn't made major progress outside of a few big experiments in decades
> Philosophy is BS. It doesn't matter. What matters if there's data available.
"What matters is if there's data available" is a philosophy of science. Look a lot of philosophy is BS, but you're peddling in the noncentral fallacy here. The philosophy of science is extremely important, and as a former working scientist I've seen so many scientists get caught up in their own fraud/self-delusion because they don't have a central philosophy of science to guide their efforts.
And, apparently, poor lonely black holes can evaporate over time?
Hawking temperature is inversely proportional to black hole size, so the bigger the hole the "colder" it is. The largest black holes will start evaporating very slowly once the CMB drops below their temperature.
A tiny micro black hole, if one were created, would evaporate almost instantly converting 100% of its mass into energy, basically a bomb. E.g. a 1kg micro black hole smaller than an electron would have a yield similar to a small hydrogen bomb, most of which would be released as ultra high energy gamma rays.
Black holes are awesome. In some ways they are the most extreme things in the universe, the extreme-est of extreme physics.
The mass-energy density required to create them is so far beyond anything humanly possible that trying to do so with, for example, hydrogen bombs would be not much better than trying to do it by squeezing really hard with your hand. It requires things like the first few milliseconds after the Big Bang (if primordial black holes exist) or collapsing massive stars. To give a sense of this density: a black hole with the mass of the Earth would be about the size of a marble (Schwartzchild radius). Inside of course there's either a true singularity or -- if certain theories of quantum gravity are correct -- a region of some kind of maximum-theoretical-density matter. (Some theories predict that true singularities don't exist.)
If somehow someday it were possible to create or control them, it would be possible to access energies far beyond fusion or even antimatter-driven reactions... think perfect direct mass-energy conversion with near 100% efficiency.
tl;dr there's a lot of dust around the quasar
Astronomy has a big problem with people overhyping their results
Exaggerate much… There is a lot of real oppression in this world. Disagreement over how to interpret astrophysical observations doesn’t enter into any of it.
That being said, when they were the best models we had they made sense to support.
That's how theories work?
And I would ask what alternatives to current dark matter and/or age of the universe you believe there are. Because I would argue it's not about thought police but more about using the best theories we have until they are proven incorrect.
That's genuinely basic science. If you don't understand that, then I'm not really sure what to do from there. (https://www.amnh.org/exhibitions/darwin/evolution-today/what...)
I have no idea what thermophlogistonics is, and there are no Google search results for it. But based on the aether theory, I can deduce it was just a sort of pre-Einstein theory of the universe.
You don't need to outsource your thinking to an external committee of glacially moving bureaucracy to decide for science to move forward by wholesale replacing one theory with another.
Thermophlogistonics is what we'd have today if we decided that the phlogiston theory is the way to go, we just need to decide that the Phlogiston is a Dark Particle we can't actually observe and then derive thermodynamics from experimental observation, followed by super gluing the two together as to not embarass the prestigious old guard that still believes in the perpetually unobserved phlogiston.
Are you saying that this exists today?
I feel like you want there to be some nefarious behind the scenes Snidely Whiplash sort of character keeping science held back, and that's just not the case.
We use the current theories and not phlogiston or whatever your straw man theory is because they're the best ones we have right now. They will change with new information.
It legitimately seems like you don't understand the basics of the scientific process.
“A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.” -Max Planck, physicist of some renown, prescient of this and many other comment threads
How law would work if it followed your patten of how science supposedly operate.
As for dark matter, repeat failure of observation in both man made experiments and inconsistencies in the cosmic distribution. If we called it the "ad hoc variable representing the will of the gods lightly pushing shit around" it would more accurately fit observations. Something spins too fast, arbitrary dial the will of god to keep shit together in that particular place.
Inconsistent with elsewhere? No problem the Gods will it differently there, maybe the average distribution of worshippers is lower in that galaxy? Contemporary evidence is the the same for both formulations of the dark mystery variable that forces observation to adhere to the fraying theory.
At some point the accumulated problems grow so large you don't need to be on a cosmologist payroll to recognize it for being legacy bullshit grandfathered into the present.
1) It's certainly not unheard of for theories have observational or experimental data appears that sends them back to the drawing board for reworking and do eventually get to a consistent state
2) Every other proposed theory to answer these questions ultimately ends up fitting the observational data we have even worse, or doesn't even attempt to explain it
3) Plenty of scientists are still poking at alternative theories and very few scientists love dark matter as an answer. They've just loved every proposed alternative less.
There's no shortage of dark matter detractors. It's just that none of them can come up with a better solution to answer questions about all the things that dark matter does answer. And no, just going "the gods did it" isn't better, because you can't use that as a theory to answer why some things are behaving the way they are, and we can with dark matter. And we do it quite often - far more often than we find weird things like these isolated quasars. But of course you don't get a front page hackernews article every time scientists apply science and things come out consistent with the existing science.
There's not some shadowy cabal of cosmologists doing everything in their power to keep the cult of dark matter alive. There's a bunch of experts who have seen the same arguments raised thousands of times with zero meaningful variation and have gotten tired of having to explain the same things over and over.
Sure. But when the socially dominant theory doesn’t fit observations, it’s called “a temporary setback that calls for some reworking”, and when a heterodox theory doesn’t fit observations, it’s called “falling flat on its face”, as you can see in another reply below. That’s not a healthy dynamic.
> There's not some shadowy cabal of cosmologists doing everything in their power to keep the cult of dark matter alive.
No… but curiously, you will get your comment flagged and removed on HN for making such a claim!
Because none of them get even close to explaining as much as dark matter does. This isn't complicated or a radical shift in standards - it's just requiring something be as good as the existing answer to get serious discussion. Pointing out that dark matter isn't perfect isn't an argument for things that are significantly less perfect than dark matter. There are massive gaps between dark matter and alternative theories. Something that worked as well as dark matter did and only struggled with a similar number of outliers wouldn't be said to fall flat on its face - but nothing is even in the same ballpark as it.
The more that can be explaining by an existing theory, the higher the bar is for any alternative theory to displace it. This is just how science has always worked.
>No… but curiously, you will get your comment flagged and removed on HN for making such a claim!
Because conspiracy theories with no evidence or grounding in reality don't make for intellectually stimulating discussion, I imagine.
Regarding your issues 1) applied to dark matter, reworked, patched, repatched. Still completely fails and are subject to more ongoing maintenance than a Boeing aircraft. 2) all other theories categorically rejected in a paragraph, while giving dark matter infinite retakes as in 1) is clearly a strong bias towards supporting the party line, not of science.
But if dark matter is 90% of the way there why would we bother with something that is 20% of the way there? Cosmologists and all sorts of physicists will still take to the time to read papers on MOND variation #2754 to see if it's actually making any headway. The problem is, it never really is. Maybe that'll change someday. Scientists are certainly giving it the chance to.
Dark matter is already held to a higher standard than all these other theories. Why should we lower the bar for them?
That stands on its own. That I don't provide a viable replacement is a refutation of absolutely nothing.