Webb telescope spots super old, massive galaxies
colorado.edu
colorado.edu
We don’t know.
That’s point of building it!
Or, more accurately, you can think about it as a different set of priorities.
For instance, someone might want to spend a ten billion dollars of tax money to survey all the ball pits across the world, and accurately count the number of balls in each at precisely the same moment, just to have that knowledge "for its own sake." Is it myopic not to care about that?
A lot of people meet some of their needs for mysticism and meaning with astronomy, but it's also perfectly valid not to use it that way, and instead see it as blurry pictures of places that aren't even theoretically possible to interact with in any way.
Not necessarily. For one, I'm not talking about being able to articulate some argument for its value, I'm talking about agreeing with that value. To put it bluntly, not sharing that value isn't some kind of personal failure, though a lot of people here seem to mistakenly treat it that way.
> techniques developed for the collection and analysis of such vast datasets find their way back into more quotidian applications.
Which is different from knowledge "for its own sake." Townies with and without imagination will get behind aspects of the techniques, data, products and byproducts that resonate with them. NASA has plenty of examples.
https://www.scientificamerican.com/article/experts-doubt-the...
Neat article, they were asking all the right questions. Calculating how long a coal body could burn, and a mechanism/quantity required to refuel it based on the mass of the solar system
A year or two back I was at a lecture about hummingbirds and the shockingly weird ways they fly and during the Q&A some lady kept asking 'but what's the point of this? Why does it matter?' leaving the lecturer (and everyone else) deeply confused.
> that shouldn’t exist
Articles should be more careful. It isn't that much longer to say "that aren't predicted by current models".
For those like me who don't know what LISA is: https://en.wikipedia.org/wiki/Laser_Interferometer_Space_Ant...
Seems like an amazing project
If you're going to quote, I would suggest to do it fully.
One interpretation is that these are older (more red shifted), larger (more stars) galaxies. But that's just one explanation. A pretty good one, but still, it could also be something totally mundane and boring. Remember FTL neutrinos?
I'll be ecstatic if the existing model of the universe needs a massive update based on this new data. But it's important to search as hard as we can for answers that aren't the one we really want to see.
There have been proposed models for why this occurs (WIMPs, etc.) but none have been convincing from a scientific perspective, mainly due to the inherent lack of observations which can justify such models.
Can you suggest an equally terse title that would avoid problems such as "position[ing] scientific theories as normative rather than descriptive" and "mak[ing] refinement look like failure"?
I think you're assigning far too much wrongdoing to this perceived sleight here, I wouldn't even think that saying "our current understanding makes this look impossible" is a way of saying we shouldn't celebrate change and improved understanding, I would instead go the opposite way and think how interesting it is to find things outside our understanding
"Shouldn't exist" is cargo cult psuedoscience terminology.
To me it implies that the model has more weight than the universe.
I think it demonstrates a sloppy framing of the topic.
I find the entire thing extremely unphysical because of that. Why should just this one thing violate that? Just photons, nothing else? Are gravitational waves also stretched? Why can't we duplicate the effect in a lab?
[1] https://en.wikipedia.org/wiki/Timeline_of_the_early_universe...
Science can predict if it will rain tomorrow: "[a] seven-day forecast can accurately predict the weather about 80 percent of the time and a five-day forecast can accurately predict the weather approximately 90 percent of the time." [2]
Feel free to hubristically read articles such as Cosmic Evolution of Viscous QCD Epoch in Causal Eckart Frame [3] and tell us all where they are wrong. An introductory article into cosmology and inflationary theory [4].
[1] https://en.wikipedia.org/wiki/Maxwell%27s_equations#Macrosco...
[2] https://scijinks.gov/forecast-reliability
[3] https://inspirehep.net/files/b54851f57716f3e8fb650bc1c057ba1...
These agree to within a relatively small range. If the number were substantially different, it would imply that something deeply fundamental (and probably several deeply fundamental things) was wrong.
It's much more likely that our understanding of galaxy formation is wrong. That's much less fundamental, and much harder to observe.
It's just like debugging code. You start with the obvious stuff. It's much more likely that the error is in your program, for example, and not in the compiler. That's not proof, but you'd be foolish to start anywhere else.
> in 2008 and 2009, Hossenfelder in [17] and [18] builds her own bimetric model involving negative mass, from a Lagrangian derivation where she produces a system of two coupled field equations. [...] Actually, although sharing many similarities, having the same kind of coupled field equations regarding negative mass, a fundamental difference remains between Hossenfelder’s bimetric theory and the Janus Cosmological Model.
> Indeed, Hossenfelder doubts that the second entity can have an important effect on the distribution of standard matter, qualifying the gravitational coupling between the two species as “extremely weak”. This is because “for symmetry reason” she considers that the absolute values of the mass density of the two populations should be of the same order of magnitude. Such hypothesis leads to a global zero field configuration, which does not fit with observations, as she notices. Then, examination of possible fluctuations seems to be her main concern. Not perceiving that a profound dissymmetry is on the contrary the key to the interpretation of many phenomena, including the acceleration of the cosmic expansion, she will not develop her model further during the following decade, focusing instead on other research topics.
> Nonetheless, Hossenfelder points out a “smoking gun signal” that could highlight the existence of invisible negative mass in the universe, through the detection of diffracted light rays caused by diverging lensing, an effect previously predicted in [13]. We indeed showed from 1995 that photons emitted by high redshift galaxies (z > 7) are diffracted by the presence of invisible conglomerates of negative mass on their path. This reduces the apparent magnitude of such galaxies, making them appear as dwarf, which is consistent with observations.
> Another feature of the scenario becomes clear from the pre- viously discussed example of the Schwarzschild metric. If there was a localized source of negative energy, it would act as a gravitational lens - but unlike usual matter this would be a diverging lens since it would repel our (usual) photons. Such a lensing event would typically lower the luminosity of the source, an effect that could potentially add up over distance if the distribution of such sources is substantial. The detection of a diffractive lensing event could serve as a smoking gun signal for the here proposed scenario.
Source: http://www.ptep-online.com/2019/PP-56-09.PDF
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A Bi-Metric Theory with Exchange Symmetry (Sabine Hossenfelder)
> Another feature of the scenario becomes clear from the previously discussed example of the Schwarzschild metric. If there was a localized source of negative energy, it would act as a gravitational lens - but unlike usual matter this would be a diverging lens since it would repel our (usual) photons. Such a lensing event would typically lower the luminosity of the source, an effect that could potentially add up over distance if the distribution of such sources is substantial. The detection of a diffractive lensing event could serve as a smoking gun signal for the here proposed scenario.
Source: https://arxiv.org/pdf/0807.2838.pdf
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On the concept of apparent mass in two-sided/bi-metric universes:
https://januscosmologicalmodel.com/negativemass#conjugatecur...
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From last week's thread about black holes without a singularity:
I took away the premise just fine without getting hung up on elementary grammar.
Although in this case it looks like the automated modding of the title.
The timeline is certainly up for grabs, there are uncertainties in the various ways we measure or infer distances and the age of objects, but so far nothing that invalidates the overall scheme. Roger Penrose's idea of conformal cyclic cosmology is a plausible alternative, but even that still has an event in our past that looks an awful lot like a big bang. There are just too many observations any alternative theory needs to explain, like galactic red shift and the cosmic background radiation. If stars are infinitely old, how come they still have any hydrogen left?
It's always a good idea to keep an open mind though. What are the alternatives you think have legs?
Also, the Big Bang "theory" is a theory in the technical sense, in that the overwhelming majority of evidence ever collected is at least neutral towards the Big Bang, to say nothing of the virtually incontrovertible evidence in support (esp. the cosmic microwave background radiation, redshift correlated with distance to virtually all extra-galactic objects, low metalicity in ultra-distant (read early) objects, etc etc etc). It could still be wrong, but we'd need some other theory that adequately explains all the available evidence, and makes several new, testable predictions that are also observed to be correct. The term "theory" is not used colloquially here as a fancy way to say "guess" or "idea" (those are, in the same technical sense, best called "conjectures" or (generously) "hypotheses"). It has a very narrow meaning here, and dismissing the Big Bang theory as "just" a theory really reveals your ignorance on the subject here.
I still lean towards the Big Bang as the most likely model, but it’s not as well established as, say, germ theory.
I actually had an idea in undergrad (20+ years ago) to probe Hubble Constant variation using quasar reverberation mapping and very-long-baseline-interferometry. Then the professor I was working with pointed out that the baseline I needed was something like 100,000 times earth's orbital diameter.
Back then, one of the sexier ideas was that the universe might have locally different fundamental constants, and that variation could reveal some information about the higher-dimensional "space" that the universe existed inside of. I've been out of that field for a long time though, so I've no idea what the cutting edge is. I just know that the Big Bang theory is still pretty safe.
There are plenty of things wrong in the theory, but none of the evidence suggests that "expansion from a singularity" is wrong, let alone "infinite and eternal" is right.
A singularity means that all timelines goes through it, but it is impossible to make continues extension of the timelines past the singularity in the current physical models. That literally means that anything is possible with the timeline prior that. The timeline can jump, be replaced by a set of random points, became a multidimensional surface, go back etc. It may even indeed disappear, but we do not know.
But as a non-physicist I recognize that my "theories" are just for funsies and have less value than bellybutton lint.
> Twenty-thousand years in the future, Cass, a humanoid physicist from Earth, travels to an orbital station in the vicinity of the star Mimosa, and begins a series of experiments to test the extremities of the fictitious Sarumpaet rules – a set of fundamental equations in "Quantum Graph Theory", which holds that physical existence is a manifestation of complex constructions of mathematical graphs. However, the experiments unexpectedly create a bubble of something more stable than ordinary vacuum, dubbed "novo-vacuum", that expands outward at half the speed of light as ordinary vacuum collapses to this new state at the border, hinting at more general laws beyond the Sarumpaet rules. The local population is forced to flee to ever more distant star systems to escape the steadily approaching border, but since the expansion never slows, it is just a matter of time before the novo-vacuum encompasses any given region within the Local Group.
Olber's Paradox[2] and the inability to reconcile it with our current astronomical observations seems to disprove that our current universe is itself infinite.
[0]: https://www.scientificamerican.com/article/why-is-the-night-...
Why word it like this instead of using 13.5 billion? Is this a common thing to do in astronomy? Or are you trying to make the claim of 13.5 billion years sounds more ridiculous? Genuine question.