Astronomers Cannot Agree On How Fast the Universe is Expanding (economist.com) 37
Two fundamentally different methods for measuring the universe's expansion rate continue to produce incompatible results -- with direct observations of receding galaxies yielding approximately 73 kilometers per second per megaparsec and cosmic microwave background radiation analysis producing closer to 67 km/s/mpc.
The discrepancy, known as the Hubble tension, has strengthened annually for the past decadem, according to Duke University astronomer Dan Scolnic. The persistent disagreement prevents calculation of the universe's precise age or size. The Lambda-CDM model, which holds that dark energy and dark matter comprise 95% of the universe while visible matter constitutes just 5%, assumes dark energy's nature has remained constant since the Big Bang.
Some theorists propose dark energy's potency changes over time, while others suggest the Milky Way sits within a comparatively empty region of space. A June study using gravitational lensing of quasar light, bypassing traditional distance measurements, matched the higher value. New telescopes including the Vera Rubin Observatory and Nancy Grace Roman Space Telescope may provide additional data. Past improvements in measurement precision have only reinforced rather than resolved the tension.
The discrepancy, known as the Hubble tension, has strengthened annually for the past decadem, according to Duke University astronomer Dan Scolnic. The persistent disagreement prevents calculation of the universe's precise age or size. The Lambda-CDM model, which holds that dark energy and dark matter comprise 95% of the universe while visible matter constitutes just 5%, assumes dark energy's nature has remained constant since the Big Bang.
Some theorists propose dark energy's potency changes over time, while others suggest the Milky Way sits within a comparatively empty region of space. A June study using gravitational lensing of quasar light, bypassing traditional distance measurements, matched the higher value. New telescopes including the Vera Rubin Observatory and Nancy Grace Roman Space Telescope may provide additional data. Past improvements in measurement precision have only reinforced rather than resolved the tension.
News? (Score:3)
Grand Unified Theory of Silly Buggers (Score:3)
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At some point, the simplest explanation that accounts for all observed cosmological phenomena is that the universe is just messing with us.
The simulation did not expect any of the simulated lifeforms to develop observational powers good enough to find the discrepancies between some observable facts and others. We're an early iteration. The next reboot will see improved physics, allowing for better correlation between the observable CBM expansion rate and the distant galactic expansion rate. Perhaps our current hardware needs an upgrade to get full resolution of these observances?
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There is a philosophical question in there somewhere. If the simulated lifeforms survive from reboot to reboot, could they use observed differences in the physics from reboot to reboot to detect that they were, in fact, simulated life forms? To prevent that, wouldn't the current simulation software version require that experiments run in an earlier version of the simulation under the old physics continue to produce the same old contradictory answers?
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There is a philosophical question in there somewhere. If the simulated lifeforms survive from reboot to reboot, could they use observed differences in the physics from reboot to reboot to detect that they were, in fact, simulated life forms? To prevent that, wouldn't the current simulation software version require that experiments run in an earlier version of the simulation under the old physics continue to produce the same old contradictory answers?
In my fictional universe (writing a series of sci-fi novels) only one person in the entirety of existence is aware of the reboots, and carries memories between reboots. She has troubles convincing anyone else of the truth of it, and as a highly gifted thinker with a very scientific bent, is aggravated as all get out that her memories are seen as a form of insanity, rather than evidence of a repeatedly rebooting simulation.
In other words, I would think a rebooted simulation would not at all leave the simulat
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In the beginning, there was only God and Man. And they were both bored.
So Man said to God: "How about a little game ? I dare you to create a coherent universe that I can't understand."
To which God replied: "Hold my beer."
Alternate explaination (Score:3)
Perhaps we've been enclosed in a Slo-Time Envelope [fandom.com], which is preventing us from calculating things accurately. Perhaps a preventative measure by Judiciary Pag to protect the rest of the Universe from us -- and any future Make the Universe Great Again movement. :-)
Queue the idiots... (Score:4, Insightful)
Scientists are baffled! Researches are terrified! Physics is broken! FFS.
It's just the frayed edge of our current understanding. There's no reason to think that there's anything wrong with the vast majority of our current mental model. But to hear the Internet talk about it, we're all huddled in fear that we might be wrong. But in truth, the clearer it becomes that the discrepancy is real, the more interesting things get.
Know why classical quantum physics is relatively boring? Because it's just so darned right all the time. It's no fun to just confirm things every time you measure them. The fun starts with a raised eyebrow and, "Huh..." The current benchmark for alternative theories is that they are as right as the classical ones.
Why this article? Nothing new here,
Re: Queue the idiots... (Score:2)
Why is the vacuum energy density much smaller ("as many as 120 orders of magnitude") than a zero-point energy suggested by quantum field theory?
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I don't know. But that's not a problem.
If you're trying to put a man on the moon, Newtons laws are right "enough". In fact, they're extraordinarily right. More right than I've ever been.
And if you're measuring anything but the vacuum energy density, quantum theory agrees with measurement all the way to the uncertainty digit , and that's often ten or more digits down. It's fantastically right. Possibly the most right we've ever had.
There's the fringe again - and that's where it's interesting.
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*whoosh*
Clickbait Crap (Score:4, Insightful)
"Astronomers cannot agree on how fast the universe is expanding
This suggests cosmology might be wrong about something fundamental"
It's shit articles like this that only help to fuel the anti-science types. Yes, the difference between the expansion rate of the distant galaxies and the CMB is an important thing to sort out, but it has nothing to do with already established successful and important science. This doesn't make a whit of difference to the average person, except that "scientists cannot agree".
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The more important anomaly is the JWST observation of galaxies that formed when the Universe was "too young for those galaxies to form".
If you push back the age of the Universe to allow those galaxies to form then you push on the coefficients of expansion and those need to agree with theory which they do not under current theory.
Some theories are compatible but lack a Big Bang which is taken as an article of faith by most and need more observations to consider.
Scientists not agreeing *is* science. If the s
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The more important anomaly is the JWST observation of galaxies that formed when the Universe was "too young for those galaxies to form".
One problem is the scientists all assume the universe is approximate 13 billion years old because that is the age of the oldest things we can see at the edge of the universe. Unfortunately as the universe ages, more and more matter expands past the observable horizon and we will never see it. The universe could be 40 billion years old but we can only see matter to the 13 billion year horizon. At some point the very edges of the universe will be moving away from us faster than the speed of light and it wi
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is it really that big of a variance (Score:2)
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Re: is it really that big of a variance (Score:2)
Why can't you predict the vacuum energy density from quantum models?
Re: is it really that big of a variance (Score:1)
Universal agreement (Score:5, Funny)
So everyone agrees that it's 70 (+/- 3)
Huge Improvement (Score:3)
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I disagree!
Or they agree ... roughly (Score:4, Informative)
- 67 from CMB: z=1100; 13.8 billion year old photons
- 73 from Galaxies measured: z=0.1; 1.3 billion year old photons
In this perspective 67 ~= 73. If the number is changing, it is changing at a rate of less than +0.007 per million years. The numbers are close enough that the error bars on these numbers could be what is wrong, not the numbers. For instance: https://astronomynow.com/2025/... [astronomynow.com]
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The numbers are close enough that the error bars on these numbers could be what is wrong, not the numbers.
This idea doesn't fix anything. The issue is that early Hubble constant values, each of which is supported by multiple methods now, closely and consistently cluster around different values. Asserting "maybe everyone is way less accurate than they think for unknown reasons and the values are really the same" has no degree of plausibility as many unrelated types of measurements would have to break in exactly the same way and without being detectable. The old and late Universe values really are different to fi
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- matter density
- baryon density
- dark energy density
- curvature of the universe
- characteristic acoustic scale (CMB only)
- gravitaional lense distortions (CMB only)
- optical depth to reionization (CMB only)
-
Not astronomers cannot agree (Score:4, Insightful)
It is Eddies fault (Score:1)
Units: 70 km/s/Mpc equals 1/(14 billion years) (Score:2)
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67 km/s/mpc? Please use standard units. (Score:2)