'Hubble Tension' and the Nobel Prize Winner Who Wants to Replace Cosmology's Standard Model (msn.com) 59
Adam Riess won a Nobel Prize in Physics for helping discover that the universe's acceleration is expanding, remembers The Atlantic. But then theorists "proposed the existence of dark energy: a faint, repulsive force that pervades all of empty space... the final piece to what has since come to be called the 'standard model of cosmology.'"
Riess thinks instead we should just replace the standard model: When I visited Riess, back in January, he mentioned he was looking forward to a data release from the Dark Energy Spectroscopic Instrument, a new observatory on Kitt Peak, in Arizona's portion of the Sonoran Desert. DESI has 5,000 robotically controlled optic fibers. Every 20 minutes, each of them locks onto a different galaxy in the deep sky. This process is scheduled to continue for a total of five years, until millions of galaxies have been observed, enough to map cosmic expansion across time... DESI's first release, last year, gave some preliminary hints that dark energy was stronger in the early universe, and that its power then began to fade ever so slightly. On March 19, the team followed up with the larger set of data that Riess was awaiting. It was based on three years of observations, and the signal that it gave was stronger: Dark energy appeared to lose its kick several billion years ago.
This finding is not settled science, not even close. But if it holds up, a "wholesale revision" of the standard model would be required [says Colin Hill, a cosmologist at Columbia University. "The textbooks that I use in my class would need to be rewritten." And not only the textbooks — the idea that our universe will end in heat death has escaped the dull, technical world of academic textbooks. It has become one of our dominant secular eschatologies, and perhaps the best-known end-times story for the cosmos. And yet it could be badly wrong. If dark energy weakens all the way to zero, the universe may, at some point, stop expanding. It could come to rest in some static configuration of galaxies. Life, especially intelligent life, could go on for a much longer time than previously expected.
If dark energy continues to fade, as the DESI results suggest is happening, it may indeed go all the way to zero, and then turn negative. Instead of repelling galaxies, a negative dark energy would bring them together into a hot, dense singularity, much like the one that existed during the Big Bang. This could perhaps be part of some larger eternal cycle of creation and re-creation. Or maybe not. The point is that the deep future of the universe is wide open...
"Many new observations will come, not just from DESI, but also from the new Vera Rubin Observatory in the Atacama Desert, and other new telescopes in space. On data-release days for years to come, the standard model's champions and detractors will be feverishly refreshing their inboxes..." And Riess tells The Atlantic he's disappointed when complacent theorists just tell him "Yeah, that's a really hard problem."
He adds, "Sometimes, I feel like I am providing clues and killing time while we wait for the next Einstein to come along."
Riess thinks instead we should just replace the standard model: When I visited Riess, back in January, he mentioned he was looking forward to a data release from the Dark Energy Spectroscopic Instrument, a new observatory on Kitt Peak, in Arizona's portion of the Sonoran Desert. DESI has 5,000 robotically controlled optic fibers. Every 20 minutes, each of them locks onto a different galaxy in the deep sky. This process is scheduled to continue for a total of five years, until millions of galaxies have been observed, enough to map cosmic expansion across time... DESI's first release, last year, gave some preliminary hints that dark energy was stronger in the early universe, and that its power then began to fade ever so slightly. On March 19, the team followed up with the larger set of data that Riess was awaiting. It was based on three years of observations, and the signal that it gave was stronger: Dark energy appeared to lose its kick several billion years ago.
This finding is not settled science, not even close. But if it holds up, a "wholesale revision" of the standard model would be required [says Colin Hill, a cosmologist at Columbia University. "The textbooks that I use in my class would need to be rewritten." And not only the textbooks — the idea that our universe will end in heat death has escaped the dull, technical world of academic textbooks. It has become one of our dominant secular eschatologies, and perhaps the best-known end-times story for the cosmos. And yet it could be badly wrong. If dark energy weakens all the way to zero, the universe may, at some point, stop expanding. It could come to rest in some static configuration of galaxies. Life, especially intelligent life, could go on for a much longer time than previously expected.
If dark energy continues to fade, as the DESI results suggest is happening, it may indeed go all the way to zero, and then turn negative. Instead of repelling galaxies, a negative dark energy would bring them together into a hot, dense singularity, much like the one that existed during the Big Bang. This could perhaps be part of some larger eternal cycle of creation and re-creation. Or maybe not. The point is that the deep future of the universe is wide open...
"Many new observations will come, not just from DESI, but also from the new Vera Rubin Observatory in the Atacama Desert, and other new telescopes in space. On data-release days for years to come, the standard model's champions and detractors will be feverishly refreshing their inboxes..." And Riess tells The Atlantic he's disappointed when complacent theorists just tell him "Yeah, that's a really hard problem."
He adds, "Sometimes, I feel like I am providing clues and killing time while we wait for the next Einstein to come along."
Yes yes (Score:3, Insightful)
Yes I get it. The standard model sucks. It's dumb etc. etc. Except, none of the proposals to replace it make any sense and are worse than the standard model on multiple metrics.
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Yes, I get it. The Ptolemaic system sucks. It's dumb etc. etc. Except, none of the proposals to replace it make any sense and are worse than the Ptolemaic system on multiple metrics.
Re:Yes yes (Score:5, Informative)
Only when Isaac Newton published the Principia Mathematica, astronomers finally got a model that was easier to handle and more exact than the Ptolemian one.
Re: Yes yes (Score:2)
I mean, youâ(TM)re kinda proving his point too though. The point of this article is not that thereâ(TM)s a new model, itâ(TM)s that weâ(TM)ve entered that stage where thereâ(TM)s a clear need to come up with a better model, because itâ(TM)s become apparent that Î is not a constant. We only really entered this stage this year. Now we need to spend a while coming up with ideas that fit the data better and are still useful.
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"It does need to be replaced" is nice and dandy, but it begs the question "By what?" And this question is not sufficiently answered yet. Each of the candidates (MoND, TeVeS, STVG/MOG et.al.) has its own quirks and unmotivated postulates.
And with 40 years, you are new to the party. MoND is now 43 years old. And that classical cosmology (e.g. Einsteinian Cosmology) has its problems is known since about 90 years already.
You are just re-iterating what everyone
Kepler (Score:5, Interesting)
Didn't Kepler's laws and elliptical orbits make the Copernican model work?
Newton's Theory of Gravitation explains Kepler's laws, but for the measurement precision back-in-the-day, you didn't need higher-order perturbation terms to Keplerian ellipses?
Re:Kepler (Score:4, Interesting)
Kepler did put the Sun at the focus of ellipse (Score:3)
Take a look at one of the illustrations from "Astronomia Nova", which shows the orbit of a planet.
https://i.sstatic.net/8322a.jp... [sstatic.net]
Disclaimer: I'm an astronomer.
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Maybe next time you'll pick a site that doesn't forbid hotlinking.
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And the Oblate spheroid model of Earth is just a crutch for lazy people unable to accept the Geocentric flat Earth model is actually a plane mapped to a torus. The Earth is a donut.
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Dark energy decreasing over time is not something in the models, it is (ostensibly) something that is being measured. All Riess said is that, if true, the standard model needs to be corrected.
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IIUC, a *varying* dark energy is not explained by the models. A constant one is (as a parameter for curve fitting).
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Constant dark energy isn't "explained" by the models either. These things are parameters of the models and the current one uses the simplest parameters compatible with observations. As you say, as parameters for curve fitting.
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What you've said doesn't make sense.
Expanding space explains the expansion of the universe. Prior to the late 1990s it was sufficient to describe what cosmology had observed, and we expected that the expansion should be slowing down due to gravity. Then better observations showed that it was actually speeding up.
The "expanding balloon" thing is part of the current standard model of cosmology as it was part of its predecessor. Dark energy is someone actively blowing up the balloon.
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I dunno, the mathematical handwaving of timescape cosmology doesn't seem to me any worse than the cosmological constant evolution finetuning of the standard model.
I suspect there is an emotional element to preferring the more simplistic, thus therefore more amenable to pure math, model among cosmologists. They are mathematicians at heart.
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Yes there is: God-did-it!
An omnipotent magic being can do anything by definition. It's a theory so easy even a Republican can understand it.
Testable? Well, if you control your sexual urges and sing it kiss-up tunes you will allegedly find out after you check out. I volunteer certain politicians to test...
A new model needed? (Score:2, Insightful)
It's worth remembering just how complacent the late 19th century physicists were despite the obvious gaps in their models which Einstein and others use to build a radically different model. This time round the flaws are getting more obvious, but we lack a new hypothesis. Only when it comes along will we look back and say: 'How did anyone think "the standard model" was viable?'
The reality is that the scientific establishment has always settled in and enjoyed the perks of being the establishment. Admitting th
Re:A new model needed? (Score:5, Insightful)
Nice story, and wrong. Scientists are never complacent. The vast majority do not have what it takes to upend existing theory with something better because existing theory has many interlocking parts. That was true in the 19th century and is true now. We cannot all be Einsteins. So we do what we can. If that means building on existing models and theories, that's what we do. By doing that, we may be able to push them towards a more obvious revision that the next Einstein, or more likely a group because that's how physics is done these days, can see HOW to revise the theory and models.
Re:A new model needed? (Score:5, Informative)
Nice story, and wrong. Scientists are never complacent. The vast majority do not have what it takes to upend existing theory with something better because existing theory has many interlocking parts. That was true in the 19th century and is true now. We cannot all be Einsteins. So we do what we can. If that means building on existing models and theories, that's what we do. By doing that, we may be able to push them towards a more obvious revision that the next Einstein, or more likely a group because that's how physics is done these days, can see HOW to revise the theory and models.
Beat me to it. There is a weird popular culture meme that all scientists are these stodgy olde farts who are continuously "stunned" and "shocked","perplexed" or other inaccurate descriptive term whenever something new is observed.
When the proper word is excited. Yeah, we'll have scientists arguing their viewpoints, but that's how things work. You have a hypothesis, you argue it, and discuss back and forth, and if it works, you adopt it as a theory. Then if something new comes along, you work to fit it, and if it doesn't fit, you rinse and repeat until something does fit by coming up with new hypotheses and theories.
Some might think that scientists are pissed off about every new finding by the James Webb telescope by the headlines. The exact opposite is the truth. So while pop culture thinks scientists are all upset, in reality, these are the gravy days.
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The wonderful thing about science is it is one of the few areas where identifying the problem is valuable even if you haven't got a solution.
Engineer - Unless you got a better way this is good enough, we can be confident the thing won't fall over.
Scientist - (should be) fascinating you came up with a phenomena that does that match what my model predicts. Let's go figure out why.
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Try "the better physicists are never complacent". Most of the seem to always be complacent. And there's another large group that are complacent as long as the data fit the theory (i.e. they don't go looking for additional data to test the theories against). Even now when we KNOW that quantum theory is inconsistent with relativity, most physicists are complacent. The current theories are "good enough" for what they're working on, and they "don't sweat the small stuff".
Re: A new model needed? (Score:2)
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Einstein wasn't "Einstein" either. He was a great synthesizer who came along at the right time to put a bunch of existing stuff together in a nice package, explained well. He was not a lone genius who appeared out of nowhere to single handedly revolutionize physics. That's a myth invented because humans have a bias towards personality cults.
Most of the things pop science associates with Einstein are properly credited to others, some contemporary and some preceding him by many years. Some of them are concept
Hopeless article is hopeless, here's a better one: (Score:5, Informative)
To describe, in math, why this might be so we can use a simple addition to Einstein's General Relativity, one he considered adding himself for a time, that just "adds" energy out of nowhere continuously, dark energy, and that dark energy is just a constant everywhere. Which sounds weird, energy everywhere from nothing, that ends up acting like anti gravity over the whole universe? But this would cause the Universe to tear itself apart (over billions and billions of years) exactly like we see. So weird as it is, it seems like it's right.
Now after peering at the sky with enough telescopes it appears there might be, maybe, possibly, at the edge of all our abilities to see and calculate what we are seeing, a discrepancy. It seems as if maybe the universe isn't tearing itself apart at a constant rate. It seems like maybe, this "anti gravity" like dark energy thing, is slowing down over time. Maybe the energy doesn't come from nothing everywhere all the time, hooray? But we just needed to add one number to General Relativity to describe the previous dark energy using math, so how would we describe this new dark energy, how does it behave? And does it even exist, or are we messing up observations and how we calculate them somewhere along the way, and the old dark energy is just fine? We don't know, and astrophysicists are arguing over it and looking at the sky more to figure it out.
There, that's my best, coherent summary of what's going on. Nothing to do with "the standard model" which is a very important and completely different thing in physics, so it's a terrible phrase to use at all.
Re:Hopeless article is hopeless, here's a better o (Score:4, Interesting)
The answer to this that I like is that time moves faster within the voids than where mass is denser. This is consistent with relativity. Whether it's sufficient I've no idea, but the standard practice of smoothing everything out into a homogeneous blob is clearly wrong, it was just adopted to make calculation easier.
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The answer to this that I like is that time moves faster within the voids than where mass is denser.
Whether you like that theory or not is irrelevant. While it will remain a theory until actually tested and measured, it seems pretty clear that it is true. Time moves slower on the surface of the planet than where satellites orbit. Time clearly makes what would be 'straight' lines under most circumstances, into curved lines within gravity wells.
Time is very slow near a black hole. Time is "faster" here on the surface of the planet than near a black hole because the only gravitic influences here are the Sun
Re: Hopeless article is hopeless, here's a better (Score:2)
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There, that's my best, coherent summary of what's going on. Nothing to do with "the standard model" which is a very important and completely different thing in physics, so it's a terrible phrase to use at all.
Goods summary, thanks.
Instead of "the standard model", which, as a phrase, is used to describe the interactions of particle physics, I think they meant lambda-CDM, which is the current best model for cosmology, and hence could be described as "standard" (except the term has already been usurped by the particle physicists.)
The particle-physics standard model does play in, since if there is dark energy, this needs to be accounted for in the standard model. Mostly, however, the standard model needs to be modi
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That's why the summary says "the standard model of cosmology." Most of the commenters are too lazy to write all five words though.
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The real problem seems to be that it's very hard to test large-scale forces that are too weak to study locally. We can study gravity because we can actually test in a lab: a giant cement block slightly pulls at our measuring devices, for example. We can put materials in between to see if it blocks gravity, and change the material of the big block to measure any pull change. We can do some of these with Earth's gravity also.
So far none of the "Dark X" forces can be measured in a lab, and so we have to surmis
"Acceleration is expanding"? What? (Score:3)
"Acceleration is expanding" does not make sense.
Perhaps the expansion rate is accelerating?
I am an astrophysicist by education (although removed from science since I graduated long time ago), and the article as cited on Slashdot makes no sense to me. Is this just a small step in the understanding of dark energy and its impacts? Something totally new? A breakthrough of some sort? "We are in the process of getting new data and publishing more papers." Why is this news?
Re: "Acceleration is expanding"? What? (Score:3)
âoeExpansion is acceleratingâ is indeed the correct way to understand it. Not only that, but that acceleration is dropping over time. Itâ(TM)s a result that there have been vague hints of for a while, but that weâ(TM)re now at 4.2 sigma on. Not quite a âoeresultâ but getting pretty confident. Itâ(TM)s pretty high up on the scale of âoethis breaks everythingâ because pretty much the first assumption in lambda CDM is âoelambda is a constantâ.
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"Acceleration is expanding" does not make sense.
a c c e l e r a t i o n
What's so hard about that?
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I think the summary means to say "universe's expansion is accelerating" ?
...but the acceleration is decelerating.
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...but the acceleration is decelerating.
So, the jerk is negative?
Does anybody proofread these? (Score:2)
The universe's acceleration is expanding ? (Score:2)
Her Plan: (Score:1)
My theory is that God will grow tired of this universe and sell it as scrap to some snotty nosed kid who gives humans tails and dog-ears, and makes them shit through their belly button.
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My theory is that God will grow tired of this universe and sell it as scrap to some snotty nosed kid who gives humans tails and dog-ears, and makes them shit through their belly button.
I can see some advantages to that. Do we get fur? We should hold out for fur.
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Not near the equator or Louisiana, fur to friggen hot.
No stable equilibrium (Score:4, Informative)
"Heat death" is a thermodynamic concept, not a cosmological concept. It occurs because energy dissipates to maximize entropy. If the universe stops expanding it does not prevent heat death from happening: when stars burn up their fuel they stop glowing whether or not the universe is expanding.
Also wrong. A static configuration is unstable. Expand forever or collapse, those are the options.
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"Heat death" is a thermodynamic concept, not a cosmological concept. It occurs because energy dissipates to maximize entropy. If the universe stops expanding it does not prevent heat death from happening: when stars burn up their fuel they stop glowing whether or not the universe is expanding.
Actually this thermodynamic concept is just an assumption that cannot be challenged by scientists without loosing all their reputation. It is not accurate however, because if you manage to macroscopic sort the particles into high and low entropy particles, you can gain exergetic energy from a single energy pool.
This sorting is automatically true for example for any atmosphere (read gas in a gravitational field), and thus the whole idea of heat death is based on wrong assumptions.
No Maxwell's Demons [Re:No stable equilibrium] (Score:2)
You're basically saying that if you can make a Maxwell's Demon [auburn.edu], you can violate the second law of thermodynamics. This turns out not to be the case, although the reason it's not true is subtle. (In very very short summary, it is that acquiring the information to sort particles requires free energy, and this energy negates the entropy you can decrease in the sorting. But the devil (no pun intended) is in the details.)
This sorting is automatically true for example for any atmosphere (read gas in a gravitational field),
Gas in a gravitational field does not violate the second law of thermodynamics. If you drop
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Gas in a gravitational field does not violate the second law of thermodynamics. If you drop down in a gravitational potential well, you release energy.
Thats what I am questioning. In fact I have written a short article because to explain the situation that can be found at https://azouhr.github.io/2ndla... [github.io] .
Basically, whenever a particle is flying down (randomly) it increases speed and becomes warmer, and when rising, the speed is reduced and it becomes colder. This is exactly what you see in Atmospheres, where external radiation is not too high to change the behavior.
I would be more than happy if you were able to show me the error in that thoughts, ho
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Sorry, I don't have time to critique people who have alternative theories of physics; there's too many of them out there, and I've noticed that people who think they've invented new physics come up with newly revised theories faster than you can point of the flaws in their previous ones.
For the thermodynamics of adiabatic lapse in atmospheres, try, say, https://duckduckgo.com/?q=ther... [duckduckgo.com]
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Sorry, I don't have time to critique people who have alternative theories of physics; there's too many of them out there, and I've noticed that people who think they've invented new physics come up with newly revised theories faster than you can point of the flaws in their previous ones.
For the thermodynamics of adiabatic lapse in atmospheres, try, say, https://duckduckgo.com/?q=ther... [duckduckgo.com]
Thanks for your answer, its an answer I heard too often to complain about you.
Just note, that it is exactly this adiabatic lapse that confused me 30 years ago, and after investigating, I found no reasonable explanation in current science. In fact I found relevant issues in Boltzmanns "Vorlesungen über Gastheorie", and I found people who experimentally showed that this law is not universable applicable. I am aware of the term "alternative truth", but in that case, I would just say that it is the seco
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If you can make dark energy however strong you want you can come up with a static configuration. It's an inflection point though, so you've got to really, really want it.
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You can find a static solution, but not a stable solution.
A stable solution would need feedback.
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Yes. Static but not stable is what I intended by "you've got to really, really want it."
You could also come up with more or less plausible stable configurations if the strength of dark energy were related to the total energy of the universe, or to the size of the universe with something less than the constant per unit volume the cosmological constant model assumes.
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I think you're right, if the dark energy was inversely proportional to the size of the universe, that sounds like it would act like a feedback mechanism and would have a point of stability where if the universe shrinks, the dark energy tends to expand it, and it the universe expands, the dark energy tends to shrink it.
Models and measurements (Score:1)
One major issue with astronomy is that the only thing we can measure is light.
Turning that light into distance directly can only be done using parallax which only works for a few dozen light-years on very large objects.
Once you go beyond those objects, everything else relies on converting the received light into a distance via assumptions and some kind of model.
Some of the assumptions seem trivial, like the physics in space are the same as the physics on Earth.
But the idea that space is essentially the same