A 'Hubble Crisis'? New Measurement Confirms Universe is Expanding Too Fast for Current Models (phys.org) 87
"The universe is expanding faster than predicted by theoretical models," writes Phys.org, "and faster than can be explained by our current understanding of physics." There's now been new confirmation of this (published in The Astrophysical Journal Letters) by a team led by Dan Scolnic, an associate professor of physics at Duke University.
And this means the so-called Hubble tension "now turns into a crisis," said Dan Scolnic, who led the research team... This is saying, to some respect, that our model of cosmology might be broken." Measuring the universe requires a cosmic ladder, which is a succession of methods used to measure the distances to celestial objects, with each method, or "rung," relying on the previous for calibration. The ladder used by Scolnic was created by a separate team using data from the Dark Energy Spectroscopic Instrument (DESI), which is observing more than 100,000 galaxies every night from its vantage point at the Kitt Peak National Observatory. Scolnic recognized that this ladder could be anchored closer to Earth with a more precise distance to the Coma Cluster, one of the galaxy clusters nearest to us. "The DESI collaboration did the really hard part, their ladder was missing the first rung," said Scolnic. "I knew how to get it, and I knew that that would give us one of the most precise measurements of the Hubble constant we could get, so when their paper came out, I dropped absolutely everything and worked on this non-stop."
To get a precise distance to the Coma cluster, Scolnic and his collaborators used the light curves from 12 Type Ia supernovae within the cluster. Just like candles lighting a dark path, Type Ia supernovae have a predictable luminosity that correlates to their distance, making them reliable objects for distance calculations. The team arrived at a distance of about 320 million light-years, nearly in the center of the range of distances reported across 40 years of previous studies — a reassuring sign of its accuracy. "This measurement isn't biased by how we think the Hubble tension story will end," said Scolnic. "This cluster is in our backyard, it has been measured long before anyone knew how important it was going to be."
The results? "It matches the universe's expansion rate as other teams have recently measured it," writes Phys.org, "but not as our current understanding of physics predicts it. The longstanding question is: is the flaw in the measurements or in the models? Scolnic's team's new results add tremendous support to the emerging picture that the root of the Hubble tension lies in the models..."
And the article closes with this quote from Scolnic: "Ultimately, even though we're swapping out so many of the pieces, we all still get a very similar number. So, for me, this is as good of a confirmation as it's ever gotten. We're at a point where we're pressing really hard against the models we've been using for two and a half decades, and we're seeing that things aren't matching up," said Scolnic.
"This may be reshaping how we think about the universe, and it's exciting! There are still surprises left in cosmology, and who knows what discoveries will come next?"
And this means the so-called Hubble tension "now turns into a crisis," said Dan Scolnic, who led the research team... This is saying, to some respect, that our model of cosmology might be broken." Measuring the universe requires a cosmic ladder, which is a succession of methods used to measure the distances to celestial objects, with each method, or "rung," relying on the previous for calibration. The ladder used by Scolnic was created by a separate team using data from the Dark Energy Spectroscopic Instrument (DESI), which is observing more than 100,000 galaxies every night from its vantage point at the Kitt Peak National Observatory. Scolnic recognized that this ladder could be anchored closer to Earth with a more precise distance to the Coma Cluster, one of the galaxy clusters nearest to us. "The DESI collaboration did the really hard part, their ladder was missing the first rung," said Scolnic. "I knew how to get it, and I knew that that would give us one of the most precise measurements of the Hubble constant we could get, so when their paper came out, I dropped absolutely everything and worked on this non-stop."
To get a precise distance to the Coma cluster, Scolnic and his collaborators used the light curves from 12 Type Ia supernovae within the cluster. Just like candles lighting a dark path, Type Ia supernovae have a predictable luminosity that correlates to their distance, making them reliable objects for distance calculations. The team arrived at a distance of about 320 million light-years, nearly in the center of the range of distances reported across 40 years of previous studies — a reassuring sign of its accuracy. "This measurement isn't biased by how we think the Hubble tension story will end," said Scolnic. "This cluster is in our backyard, it has been measured long before anyone knew how important it was going to be."
The results? "It matches the universe's expansion rate as other teams have recently measured it," writes Phys.org, "but not as our current understanding of physics predicts it. The longstanding question is: is the flaw in the measurements or in the models? Scolnic's team's new results add tremendous support to the emerging picture that the root of the Hubble tension lies in the models..."
And the article closes with this quote from Scolnic: "Ultimately, even though we're swapping out so many of the pieces, we all still get a very similar number. So, for me, this is as good of a confirmation as it's ever gotten. We're at a point where we're pressing really hard against the models we've been using for two and a half decades, and we're seeing that things aren't matching up," said Scolnic.
"This may be reshaping how we think about the universe, and it's exciting! There are still surprises left in cosmology, and who knows what discoveries will come next?"
Re:I have a theory .. (Score:5, Insightful)
Eddies in the space time continuum (Score:2)
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Stop discriminating scientistically against alchemy!
Re:I have a theory too (Score:4, Funny)
I have a theory .. the expansion is caused by surface tension on a hyper-dimensional bubble.
My theory is that there are an infinite number of leprechauns pushing at the edge of the universe. As the size of the universe increases, the resistance becomes less and the leprechauns are thus able to increase the speed of expansion.
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At each push the number of leprechauns doubles. That works because infinity times 2 is still infinity.
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Human stupdity
and errr hmmm.. what was the..
Right yeah the leprechauns maybe, that must be it after all
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What's your hypothesis as to the cause of the deteriation in quality of slashdot commentards ?
Re: I have a theory .. (Score:2)
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...it could be demons. A dancing demon, no wait, something isn't right there.
Hey, look, it one sentence I made as much sense as you did in your whole post. And made a classical reference to boot!
In plain English (Score:5, Insightful)
Okay, if I understand the completely click-bait, topsy-turvy article writeup, the situation is this:
The current best guess for the expansion of the universe (by the Hubble constant) is not predicted by current models.
Astrophysicists were wondering if the flaw was in the models or the measurement methods. The current experiment shows that the measurement methods are accurate, indicating that it's the model that's wrong.
The universe is expanding. If you tally up all the gravitational attraction in the universe, you would expect the universe to expand, slow down, stop, and then collapse back into itself. (Or slow down less and less over time, reaching zero expansion in infinite time.)
However, the expansion is increasing over time. There is no explanation for this, so we assume "dark energy" is somehow involved.
This is different from "dark matter" that seems to show up in galaxies. About 83% of all matter in some galaxies (including our own) is dark matter, but about 70% of all matter in the universe is dark energy. Of the remaining 30%, 83% is dark matter in the galaxies, and 17% (of the 30%) is regular matter.
Re:In plain English (Score:5, Funny)
Re:In plain English (Score:5, Funny)
Re:In plain English (Score:5, Informative)
Some things in the universe move at a fraction of the speed of light. These are classified as radiation too.
Be careful, different uses of the word "radiation" mean different things. In most uses, including most of physics, anything moving outward ("rays") is radiation-- light, yes, but also beta rays (electrons), alphas, even neutrons.
In cosmology, however, there's a key difference: electromagnetic radiation, which moves at the speed of light by definition (*), shifts in wavelength proportional to the expansion of the universe, and hence loses energy as the universe expands. Matter, however, does not change in energy as the universe expands. So there's a significant difference there.
--
(* moves at the speed of light by definition, but unless it's moving through a perfect vacuum, this may be less than c, the speed of light in vacuum. For cosmological purposes, however, the vacuum between galaxies is so tenuous that there really isn't a difference.)
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The velocity factor (VF),[1] also called wave propagation speed or velocity of propagation (VoP or vP) of a transmission medium is the ratio of the speed at which a wavefront (of an electromagnetic signal, a radio signal, a light pulse in an optical fibre or a change of the electrical voltage on a copper wire) passes through the medium, to the speed of light in vacuum. For optical signals, the velocity factor is the reciprocal of the refractive index.
The speed of radio signals in vacuum, for example, is the
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OK, physicist mode on...
There are two, critically different velocities of electromagnetic radiation, and you conflated them.
First is the phase velocity, which is v_phi = frequency * wavelength (or v_phi = omega/k, where omega = 2 pi f, and k = 2 pi / wavelength), and is the velocity with which the wavefront of a monochromatic, continuous wave advances, and can be a number greater or less than the speed of light, since a continuous wave doesn't carry information. It can even go all the way to infinity in th
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Having a desk job, might as well be a plant.
Re:In plain English (Score:5, Insightful)
In plain English, when we accumulate data, our perception of the world can shift dramatically.
Examples:
1. Once enough data was accumulated, our view of the world changed from geocentric to heliocentric. ...
2. Once enough data was accumulated, our view of the world changed from one built on mathematical idealizations to one built on some "uglier things", like ellipses.
3. Once enough data was accumulated, our view of the world changed again, and we understood why these kinematic rules apply. Incidentally, we were able to explain nearly all things we saw, for a while
4. When our observations improved even more, we suddenly realized our world is a lot bigger than we thought.
5. When our observations improved further, we saw evidence that our ideas of "space" and "time" may not be valid when times are short and speeds are high
6. When our observations improved further, we saw that gravity can produce strange effect on space and time on its own
7.
You get the idea. This is more of the same. But don't worry, whatever we discover in the future will not impact the things we know already at the scales we know them. Just like quantum mechanics didn't make the rainbow vanish, or like Einsteinian interpretation didn't make falling off the 5th floor any different.
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Is physics wrong? Not that we've seen so far. (Score:2)
(5) and (6) were unfortunately wrong interpretations of observations and the world has been operating under a fantasy cosmological model ever since.
Items (5) and (6) are special relativity and general relativity respectively. So far, both have been well confirmed by multiple measurements.
Special relativity, in particular, has been so completely well confirmed that it's hard to believe it isn't accurate. Among other things, if special relativity is wrong then Maxwell's equations are wrong, and pretty much everything in modern electricity and magnetism wouldn't work. General relativity is much harder to test (you need very strong gravity for most of the
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This is the truth of science. Newton's work is accurate enough to be predictive in a lot of use cases, but strictly speaking, he was wrong. Einstein's work is more accurate, but Newton's formulas are easier to use. We don't throw out Newton's stuff just because it fails at Relativistic scales, we just only use it when the numbers have fewer digits. I have no doubt that eventually we'll develop something more accurate than Einstein's work, that explains the expansion of the universe and accounts for quantum
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It isn't surprising in the least, all accepted scientific models are approximations of reality that are correct within the uncertainty limits of the experiments we can make to verify them.
Even when there are philosophical differences in the approach to the model (e.g. Neo-Lorentzian vs. Einsteinian interpretation of gravity or the different interpretations of quantum mechanics), these tend to disagree where it is impossible to propose or hard to perform experiments that would produce definite results this w
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Seems God also gets sucked into fads and tries out new frameworks all the time.
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never met any gods, so I have no opinion on them
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Dark also can mean unknown. Darkest Africa meant unknown/unexplored, not lacking light. Same with the dark side of the Moon referencing the far side.
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They'll figure this out eventually, but the secret is that gravitational attraction simply shuts off past a certain distance. That's the only real flaw in their current model, it obviates the need for "dark" stuff, and it's a fair mistake to make, because it isn't logically contiguous with how everything else works. Once they find the formula for the max distance of gravitational attraction it will make the rest of the model work.
The aliens will punish me for posting this.
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the secret is that gravitational attraction simply shuts off past a certain distance
"Certain distance" measured from which point?
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I know what he's talking about, but he doesn't.
The MOND theories I've had the patience to check out are exercises in math that have no reasonable physics behind them.
As a result, they tend to take on just pieces of the problem and ignore any evidence that doesn't fit.
So, not holding my breath about any one of them replacing Newtonian gravity.
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Not quite sure what you mean by "decreasing in quantum steps", or, indeed, by the "decreasing" of gravity. It appears that you are not familiar with the formalism of quantization that is used to produce the quantum analogues of the classical theories. So the answer to your question is, no, there isn't really a quantization like the one you're thinking about, because it doesn't make sense, but it isn't easy to explain it here.
Try to read this https://en.wikipedia.org/wiki/... [wikipedia.org] and https://en.wikipedia.org/wik [wikipedia.org]
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For example, imagine a sphere in continuous space. Suppose you make a hole in the membrane with a knife. Now you have 1 hole. You can make another hole, now there are 2 holes. You can cut out as many holes as you like, as close together as you like, but the total number of holes is always going to be an integer. You
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Late reply, but would you help me understand why the membrane in your example is not discrete?
It seems to me that any membrane that actually exists in our universe must be made up of discrete components and is therefore discrete itself. To extend your example, I may continue slicing holes in a pattern until I am left with a one-atom wide but very long strip. This can still be considered the same membrane, just in a different shape. It still has length and width as required for a plane or membrane (for loose
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None of the forces we know about seem to be quantized in that way, and it would be rough on concepts like conservation of energy and momentum, so it's not likely gravity is. When someone says, for example, "electromagnetism is quantized" that means that the electromagnetic field has a minimum self-sustaining excitation which we call a photon. It doesn't mean the strength of the EM force comes in discrete values.
Old fashioned quantum mechanics describes force interactions as exchanges of virtual particles (n
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The original proposal for MOND was "what if F=ma isn't true when a is very small." That's not unreasonable, it's not dissimilar to what Einstein did with special relativity. Building on that, there are certainly MOND-style models that rigorously describe how that might happen. Basically, you just add some more fields.
The problem with MOND is that it's not the Occam's panacea Slashdot supporters think it is. Instead of adding new matter fields/particles you're adding new force fields/particles. Typically mor
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The original proposal of mond is not F=ma, but F=m*arbitrary shit*a, where "arbitrary shit" is precisely that, a convenient placeholder of a suitable function that is selected to fit any particular observation. It is completely unreasonable, as it fails to account for well-understood effects like gravitational lensing or mass distribution in large structures (e.g. the bullet cluster) at the ranges it claims to work. This is the problem of MOND, it is just an arbitrary mathematical that appeared to work befo
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doh: it is an arbitrary mathematical crutch
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That is certainly a good summary of the pop sci anti-MOND camp, pretty much the same as the pop sci anti-dark matter camp if you search and replace MOND for dark matter. Neither of which is really true.
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hint: waves travel further and faster the denser the medium.
Waves in fact travel less far and less fast the denser the medium (proportionally to the real and imaginary parts of the dielectric constant).
Re: In plain English (Score:2)
My pet hypothesis, based on a physics lecture I saw by a bona fide physicist at MIT, reference unfortunately lost, is that the red shift measurements are "wrong" because don't subtract out rotational forces
Universe could be rotating... but doesn't seem to (Score:3)
If the universe were rotating, at the large scale you would see asymmetry in pretty much all out observations, depending on whether you were looking along the axis of rotation, or toward the equator of rotation. For example, the cosmic background radiation is uniform to a factor of 1 part in 10^5 in all directions.
People discuss this-- Gamow, for example, asked the question in a paper in 1946. But, the answer seems to be no. See, https://www.livescience.com/65... [livescience.com]
There would also be other weirdness-- Gö
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>> If the universe were rotating
Rotating relative to what? It seems like this would imply that there is and 'exterior' to the universe within which it rotates.
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>> If the universe were rotating
Rotating relative to what? It seems like this would imply that there is and 'exterior' to the universe within which it rotates.
You would think that this is a hard problem, but it turns out that rotation, in General Relativity, is measurable without looking at any exterior framework. (True even on Earth: you can measure the rotation of the Earth with a Focault pendulum without looking at the stars).
Kurt Gödel found a solution to Einstein's field equations representing cosmology for a rotating universe. It's weird.
https://www.math.toronto.edu/c... [toronto.edu]
https://en.wikipedia.org/wiki/... [wikipedia.org]ödel_metric
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To be fair, Gödel was being Gödel and trying to come up with a weird solution.
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Based
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Astro physics -study of stars and the cosmos... Particle physics - study of tiny little things like electrons... he said physicists specialize into one category or another, very few physicists have deep knowledge of BOTH fields as he did ...
That's not true at all. If you study physics long enough (about 6 undergrad semesters or perhaps your first PhD year at the latest), you'll invariably come to a point where you study symmetries, and one of the first things you'll look at will be the cosmological phenomenon of baryon asymmetry (more matter than anti-matter in the visible world) and you will have to study the particle physics that try to explain how it came about and why. About that time, you'll bump into someone who has deep enough knowledg
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They'll figure this out eventually, but the secret is that gravitational attraction simply shuts off past a certain distance. That's the only real flaw in their current model, it obviates the need for "dark" stuff, and it's a fair mistake to make, because it isn't logically contiguous with how everything else works. Once they find the formula for the max distance of gravitational attraction it will make the rest of the model work.
Unfortunately, to explain away dark matter you need exactly the opposite: you need to say gravity doesn't drop toward zero past a certain distance.
This is how the MOND type theories work: suggesting that gravity gets stronger than expected at very very large distances.
The aliens will punish me for posting this.
No, but the people who pay attention to modern physics will.
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Crisis? What Crisis? (Score:3, Informative)
Just get Congress to write legislation that says creation was in 4004BC and the incoming president will sign it.
Problem solved.
Re:Crisis? What Crisis? (Score:4, Funny)
404 BC, universe beginning not found
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"Universal expansion is fake news! Riggers and wokesters are making up excuses to regulate space companies like Space X, where my good friend Leon invents money. I will stop this nonsense and nuke the Hubble and Spider Webb telescopes so riggers can't invent their fake science, so sad. I'll even nuke Jiiihna's scope before they even launch it. We'll make the Universe safe and static, like it was in the 1950's and how God intended it! Tintman Out!"
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The no fun chewing gum ... (Score:2)
Hubble Bubble -- the bubbles expand too fast.
(Note: The Pink flavor is discontinued 'cause of Red Dye #3.)
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some of us have been saying for decades that the model is wrong....
Unfortunately, so far no one was come up with a better one, although many many people have tried. And are continuing to try.
Flat-Earthers (Score:2)
...will have a great day when they hear about it.
someone smarter than me.... (Score:1)
...can explain how we have such confidence that "Type Ia supernovae have a predictable luminosity that correlates to their distance, making them reliable objects for distance calculations"?
It seems a great deal hinges on this assumption.
I understand that observed ones fit relatively well on a curve when we correct for luminosity but
A) not THAT perfectly
B) we haven't observed that many in stellar scales
C) even if it is a good "general rule" that makes it even more vulnerable to exceptions and frankly in gala
Crisis! (Score:1)
Oh, wait, it's just a scientific curiosity for us to learn from.
Ah (Score:1)
And once again the fools come out (Score:5, Insightful)
"Scientists say a part of our knowledge of physics isn't quite right and needs to be investigated if we want to improve our understanding... LOLZ, they're stupid idiots wrong about everything!"
If you don't want to be one of those idiots, I recommend at least reading the Wikipedia summary of a great essay on why people who say those things are themselves very wrong:
https://en.wikipedia.org/wiki/... [wikipedia.org]
Intriguing. (Score:3)
Our models would allow for the possibility that Dark Matter arose after the Big Bang, possibly a long time after, and that Dark Energy arose long after the CMBR.
Physicists have considered these as possible explanations for anomalies in the distribution of Dark Matter, and the existence of the Hubble Crisis.
If Dark Energy appears late, then you would indeed have two different values for the Hubble Constant. And our models of Dark Energy certainly allow that to be a possible explanation.
You'd have to explain the physics behind it appearing, and that may well end up an impossible hypothesis, but, for now, it would allow the universe to have different expansion epochs, played under different rules.
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Why not go on the idea that Dark Matter was always there, but radiation detection is just fundamentally limited as a way to detect it?
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https://www.symmetrymagazine.o... [symmetrymagazine.org]
The distribution and quantity in the primordial universe (the amount of dark matter was still increasing as the stellar era started) implies a later start.
It also simplifies some of the physics.
Completely understand this article (Score:4, Informative)
Update: The NEW Crisis in Cosmology https://www.youtube.com/watch?... [youtube.com]
NOTE PBS spacetime could go away if Trump cuts PBS funding.
Wrong title (Score:1)
How about "measurements show current models too slow."
Cuz. Ya know. If it's models vs reality, models lose.
Fundamental flaws that are made explains this (Score:3)
Humans use radiation of different wavelengths to observe the world and by extension design tools that use radiation to observe the universe. That by itself is a limitation. Picture a completely sealed room with no light of any kind, nothing in there that provides any sort of radiation. So, does the room not exist, because sight and radiation based sensors(tools) don't see anything? That is the flaw, humans use radiation to sense the world, and don't think in terms of, "if everyone was blind, what sort of senses would be needed to detect the world/universe around people?"
The potential for other senses to exist that we just can't comprehend, because humans don't have those senses ourselves is HUGE. Until we encounter a being that can communicate with us but has senses that we do not, that fundamental flaw will be lost on the overall scientific community. Even if there are other things out there that might warp "radiation" so we might have an idea that SOMETHING is there, too many just don't like the thought that, "humans just can't possibly have a direct way to "see" some things out there. The universe itself could be an infinite size, but without radiation that we can detect, our current scientific tools just won't be able to give us feedback about it.
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Unfortunately, your post is complete nonsense to the point it is more or less impossible to correct.
Proof We're In A Simulation (Score:2)
This confirms they're making room for a new DLC.
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Like Galileo, then Newton, then Einstein.
For example.