The universe's expansion may actually have started to slow rather than accelerating at an ever-increasing rate as previously thought, a new study suggests.
"Remarkab...
If this gets confirmed, it will be a big deal. The fact that anything in cosmology is changing fast enough to be detected as different in a matter of decades is very strange and would mean we’re wrong about a lot of really significant things.
The fact that anything in cosmology is changing fast enough to be detected as different in a matter of decades is very strange and would mean we’re wrong about a lot of really significant things.
Totally. I wonder how much it is methods to measure being refined and new methods being discovered that show such different results.
Ah, it looks like a correction rather than an actual physical change in the value:
However, a team of astronomers at Yonsei University have now put forward new evidence that type Ia supernovae, long regarded as the universe’s “standard candles”, are in fact strongly affected by the age of their progenitor stars.
Even after luminosity standardisation, supernovae from younger stellar populations appear systematically fainter, while those from older populations appear brighter.
Based on a much larger host-galaxy sample of 300 galaxies, the new study confirmed this effect at extremely high significance (99.999% confidence), suggesting that the dimming of distant supernovae arises not only from cosmological effects but also from stellar astrophysics effects.
When this systematic bias was corrected, the supernova data no longer matched the standard ΛCDM cosmological model with a cosmological constant, researchers said.
Instead, it aligned far better with a new model favoured by the Dark Energy Spectroscopic Instrument (DESI) project, derived from baryonic acoustic oscillations (BAO) – effectively the sound of the Big Bang – and cosmic microwave background (CMB) data.
That’s somewhat less astonishing, but still a very big deal. I’ve always had an intuitive soft spot for Big Bounce cosmology–it’s just so neat and would wrap up so many things–and it would be cool if the evidence started supporting that.
The correcting of “standard candles” is a huge deal, but only to astronomy nerds. I never particularly liked the accelerated expansion of the universe and the required exotic explanations for it, but until now I was like :cant-prove-it:
It figures. Still, as the tools get sharper, the questions get weirder, I feel. when the data is getting more incontrovertible, the more responsibility we have to come up with valid explanations.
There’s a cosmological model in which the bounce actually takes place inside a supermassive black hole, and I know that some of the folks who like that view were excited about the James Webb results from last year that showed what appears to be a preferred axis of rotation for galaxies. I don’t know too much about the view though (I’m a lot more familiar with the small stuff than the big stuff).
If the Big Bounce happens faster than 10^100 years then there will still be black holes, and things falling into a black hole (such as the entire cosmos) would extend its lifespan.
Also, if the universe does eventually Bounce, new black holes will have opportunity to form. Hawking radiation only really starts to come into play when not even photons are hitting black holes any more.
If this gets confirmed, it will be a big deal. The fact that anything in cosmology is changing fast enough to be detected as different in a matter of decades is very strange and would mean we’re wrong about a lot of really significant things.
I think this is probably the safest conclusion we can make about the universe
I mean, I absolutely love that we are trying, but we are apes with lenses
Totally. I wonder how much it is methods to measure being refined and new methods being discovered that show such different results.
Ah, it looks like a correction rather than an actual physical change in the value:
That’s somewhat less astonishing, but still a very big deal. I’ve always had an intuitive soft spot for Big Bounce cosmology–it’s just so neat and would wrap up so many things–and it would be cool if the evidence started supporting that.
Yeah, it definitely makes more intuitive sense. Although the thought of possible eternal recurrence is horrifying.
The correcting of “standard candles” is a huge deal, but only to astronomy nerds. I never particularly liked the accelerated expansion of the universe and the required exotic explanations for it, but until now I was like :cant-prove-it:
It figures. Still, as the tools get sharper, the questions get weirder, I feel. when the data is getting more incontrovertible, the more responsibility we have to come up with valid explanations.
For me the big question is “what about black holes” in a Big Bounce scenario.
There’s a cosmological model in which the bounce actually takes place inside a supermassive black hole, and I know that some of the folks who like that view were excited about the James Webb results from last year that showed what appears to be a preferred axis of rotation for galaxies. I don’t know too much about the view though (I’m a lot more familiar with the small stuff than the big stuff).
… with strange aeons even black holes may die …
If the Big Bounce happens faster than 10^100 years then there will still be black holes, and things falling into a black hole (such as the entire cosmos) would extend its lifespan.
Also, if the universe does eventually Bounce, new black holes will have opportunity to form. Hawking radiation only really starts to come into play when not even photons are hitting black holes any more.