A research team from India’s Tata Institute of Fundamental Research and the University of Oxford reanalyzed the “Pantheon+” catalog — which compiles observational data from more than 1,700 Type Ia supernovae — after correcting for brightness variation caused by the age of the supernovae’s progenitor stars. The reanalysis found no evidence supporting the long-accepted theory of the “accelerating expansion of the universe,” and instead suggested the expansion may actually be decelerating. On 5ch’s Science News+ board, opinions were divided: some expressed hope that the very concept of dark energy might become unnecessary, while others cautioned that accelerating expansion is also supported by multiple independent observations beyond supernovae, so this result alone wouldn’t overturn it.
Reanalysis of supernova observation data suggests the possibility that “the universe’s expansion is not accelerating”
Conventional wisdom has held that “the universe continues to expand, and its expansion is speeding up.” However, when a research team from India’s Tata Institute of Fundamental Research and the UK’s University of Oxford used a catalog containing observational data from more than 1,700 supernovae to test whether evidence could be found to support the universe’s “accelerating expansion,” they found that the expansion may in fact “not be accelerating.”
Pantheon+ supernovae corrected for progenitor age indicate the universe is decelerating | Monthly Notices of the Royal Astronomical Society
Source: academic.oup.com / original article here
2AnonymousSep 21, 2026 22:27
So does that mean we don't need dark energy after all?
3AnonymousSep 21, 2026 22:36
Knew something was off.
No matter how you look at it, accelerating expansion never made sense.
4AnonymousSep 21, 2026 22:43
Accelerating expansion is energy being injected from outside.
5AnonymousSep 21, 2026 22:55
I've been saying this all along.
There was no Big Bang. Herschel was right. AI will prove it.
6AnonymousSep 21, 2026 22:56
Expansion's about to stop, and next it'll start collapsing back into a single point.
7AnonymousSep 21, 2026 23:01
Maybe it was never expanding in the first place.
8AnonymousSep 21, 2026 23:47
Re: #1
This has a whiff of crackpot science to it.
The accelerating expansion of the universe isn't based solely on Type Ia supernovae, you know.
Multiple independent observations besides supernovae also support accelerating expansion,
so unless you bring a hypothesis that's consistent with those too, this is too weak to actually disprove acceleration.
14AnonymousSep 22, 2026 06:36
Re: #8
It's not that expansion is accelerating — it's that we're shrinking relative to spacetime.
The universe's accelerating expansion is correct in a relative sense,
and matter contracting is also a correct apparent phenomenon.
9AnonymousSep 22, 2026 00:47
If you say Type Ia supernova brightness varies, you lose a major yardstick for measuring distances to celestial objects.
That's the bigger problem here.
10AnonymousSep 22, 2026 00:56
Cosmological models can explain all sorts of things,
but lately they've been failing to match the observational data more and more often.
11AnonymousSep 22, 2026 01:43
Things get weird once light reaches the edge of the universe, so it must be expanding faster than the speed of light.
12AnonymousSep 22, 2026 01:52
Quanta don't become real either unless there are two of them.
Spacetime too doesn't hold together without a certain degree of quantum entanglement — the Kasa-Takayanagi theory.
Going by this, the edge of the universe isn't infinite —
the edge of the universe only becomes real when there's some relationship between one thing and another.
25AnonymousSep 22, 2026 17:08
Re: #12
Sounds like a video game that doesn't render areas the player isn't looking at.
13AnonymousSep 22, 2026 02:25
Looking forward to observations from the Nancy Grace Roman Space Telescope.
15AnonymousSep 22, 2026 06:58
Well, if we no longer need dark energy, that'd tidy things up nicely.
16AnonymousSep 22, 2026 07:47
"Space is wild" is wild.
17AnonymousSep 22, 2026 10:44
Re: #14
I think that's an interesting idea, but what's it based on?
And how would you go about proving or disproving it?
33AnonymousSep 22, 2026 18:23
Re: #17
Proper time — the locally elapsed time — differs from place to place.
Time elapses differently for Earth, the solar system, and the galaxy.
18AnonymousSep 22, 2026 13:15
Well, if there's fluctuation on a cosmic scale, there'd be places that accelerate and places that contract.
20AnonymousSep 22, 2026 14:28
Are we headed for a Big Crunch?
21AnonymousSep 22, 2026 14:44
Previous observations showed expansion was indeed accelerating (became conventional wisdom)
↓
New observations show expansion isn't accelerating
↓
Expansion speed drops
↓
Expansion stops and contraction begins
↓
Contraction accelerates
↓
Big Crunch!
22AnonymousSep 22, 2026 15:10
So naturally our bodies too are overflowing with the dark force — dark energy and dark matter.
24AnonymousSep 22, 2026 16:56
Re: #22
Exactly right.
Whoever controls the dark force controls the world.
23AnonymousSep 22, 2026 15:14
If galaxies keep colliding and merging over and over, won't everything eventually get pulled into one giant gravitational galaxy?
Well, the distant galaxies we see now are their appearance from over 10 billion years ago, so we don't actually know what they look like now.
27AnonymousSep 22, 2026 18:09
It's a terrible game but I can't log out (´;ω;`)
28AnonymousSep 22, 2026 18:18
Term Out
29AnonymousSep 22, 2026 18:19
Sunburns
30AnonymousSep 22, 2026 18:20
Nanoha A's
37AnonymousSep 22, 2026 18:32
Dark Energy
38AnonymousSep 22, 2026 18:43
Muv-Luv Alternative
39AnonymousSep 22, 2026 18:44
Wasn't the Big Bang a state change produced by the expansion heat of an extremely high-temperature process that occurred with acceleration?
40AnonymousSep 22, 2026 18:44
Re: #33
I see.
What observational results specifically support that?
If there's a paper, I'd like to take a look.
41AnonymousSep 22, 2026 19:02
But still, the discovery and observation of the cosmic microwave background (CMB) is amazing when you think about it.
Seems like there's more progress to come.
42AnonymousSep 22, 2026 19:03
If the universe is in "sage mode" (net slang for the drained, come-down calm after climax), then I guess there's no helping it that I am too.
43AnonymousSep 22, 2026 19:32
The portion of the universe we can actually observe is just way too small relative to the whole thing.
44AnonymousSep 22, 2026 19:42
Re: #1
There's a theory that explains teleportation as: when you keep cramming atoms into a bag, atoms eventually pop out of the bag — that's the teleportation. If you reinterpret that a different way…
Say there are two bags — our universe and another universe — and in that other universe atoms are being generated in huge numbers, so when atoms slip through that bag's wall and move over to our side, that's what generates dark energy, which means dark matter is matter from the other side.
Our own universe is also generating atoms in huge numbers, so once the expansion speed of the outer wall of our universe is exceeded, the atoms of our world end up teleporting over to the other side — that's basically what it comes down to.
It ends up being a theory that requires parallel worlds to absolutely exist.
46AnonymousSep 22, 2026 19:52
To connect parallel worlds, I guess you'd need a spot where a zero-mass point on this side overlaps with a zero-mass point on the other side.
Even if a spot has zero mass on this side, if there's mass there on the other side, that mass on the other side becomes a wall and you'd get stranded on this side.
The same principle works in reverse too, so it's impassable either way.
Background and Key Points of This Discussion
The theory that the universe is expanding at an accelerating rate was proposed in 1998 based on observations of Type Ia supernovae, and it was the basis for the 2011 Nobel Prize in Physics. Since then, the ΛCDM model — in which dark energy accounts for just under 70% of the universe — has become entrenched as the standard theory. This new study reanalyzed the Pantheon+ catalog (over 1,700 supernovae) that underpins that evidence, correcting for brightness variation caused by the age of each supernova’s progenitor star; after correction, the data pointed to deceleration rather than acceleration. This is where opinions in the thread diverged: some, like commenter #8, took the cautious view that accelerating expansion is backed not just by supernovae but by multiple independent observations — including the cosmic microwave background (CMB) and gravitational lensing — so a reinterpretation of supernova data alone wouldn’t overturn it, while others welcomed the idea that we might no longer need to assume the existence of the unknown entity called dark energy, calling it a tidier picture. One point readers can easily misread is that this isn’t a case of “the accelerating expansion theory being definitively disproven” — it’s a single reanalysis result at this stage, and confirming it through follow-up studies and consistency checks against other observational methods is still needed.
※This article is excerpted and summarized from the 5ch (Science News+) thread “[Universe] Reanalysis of supernova observation data suggests the possibility that “the universe’s expansion is not accelerating”.”
