this post was submitted on 01 Oct 2025

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The strongest evidence for a Universe before the Big Bang (bigthink.com)

submitted 4 days ago by Delta_V@lemmy.world to c/space@mander.xyz

25 comments fedilink hide all child comments

...Earlier this century, some very strong evidence arrived showing that there was a Universe before the Big Bang, demonstrating that the Big Bang wasn’t truly the start of it all...

...The differences between a Universe that began with a hot Big Bang and a Universe that had an inflationary phase that precedes and sets up the hot Big Bang are subtle, but tremendously important...

...in a Universe that underwent a period of inflation prior to the start of the hot Big Bang, we’d expect there to be density fluctuations on all scales, including on scales larger than the speed of light, which could have allowed a signal to travel since the start of the hot Big Bang...

Although later fluctuations superimpose themselves atop the older, earlier, larger-scale fluctuations, inflation allows us to start the Universe off with ultra-large-scale fluctuations that shouldn’t exist in the Universe if it began with a Big Bang singularity without inflation.

...At any moment in the Universe’s history, there’s a limit to how far a signal that’s been traveling at the speed of light since the start of the hot Big Bang could’ve traveled, and that scale sets what’s known as the cosmic horizon...scales that are greater than the horizon, known as super-horizon scales, are beyond the limit of what could’ve been caused by physical signals generated at or since the start of the hot Big Bang.

...When we look at the final (2018-era) Planck TE cross-correlation data, below, the results are breathtaking...As you can clearly see, there can be no doubt that there truly are super-horizon fluctuations within the Universe, as the significance of this signal is overwhelming. The fact that we see super-horizon fluctuations, and that we see them not merely from reionization but as they are predicted to exist from inflation, is a slam dunk: the non-inflationary, singular Big Bang model does not match up with the Universe we observe.

top 25 comments

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[–] TheBat@lemmy.world 30 points 4 days ago (5 children)

Can someone dumb this down for us idiots?

[–] yakko@feddit.uk 32 points 4 days ago (1 children)

They're looking at the way the balloon filled up and they think it might look pre-owned based on how it filled up

[–] MrNesser@lemmy.world 25 points 4 days ago (3 children)

Typical we got a 2nd hand universe

[–] yakko@feddit.uk 11 points 4 days ago

Refurbished! That's environmentally sound, you know

[–] harrys_balzac@lemmy.dbzer0.com 3 points 4 days ago

With anxiety and idiots

[–] ThrowawayPermanente@sh.itjust.works 4 points 4 days ago

For the price I'm not complaining

[–] RunawayFixer@lemmy.world 11 points 4 days ago (1 children)

The old theory was that all matter was concentrated into a single singularity, and then the big bang happened.

These newer measurements show that there is stuff outside of the area affected by the expanding big bang, indicating that there was already stuff floating around before the big bang happened, and that the big bang happened more gradual.

To make a stupid analogy: the old theory is a cracker exploding in vacuum, while the newer theory says it's more likely that the cracker exploded when someone was holding it in their fist, with the fist surrounded by a room filled with air. And now our powers of observation have become so good, that we can observe the air where it hasn't been disturbed yet by the expanding explosion.

[–] Karjalan@lemmy.world 2 points 3 days ago (1 children)

I thought that, in the old theory, the vacuum was also created on the big firecracker?

[–] RunawayFixer@lemmy.world 1 points 3 days ago* (last edited 3 days ago)

That's an older old theory I think: the big bang birthing time and space. Some newer old theories say that there was already something before the big bang.

https://www.scientificamerican.com/article/the-myth-of-the-beginning-of-time-2006-02/ "String theory suggests that the BIG BANG was not the origin of the universe but simply the outcome of a preexisting state".

[–] primrosepathspeedrun@anarchist.nexus 9 points 4 days ago* (last edited 3 days ago) (3 children)

Theres stuff farther out than it should be possible for stuff to have gone in the amount of time since the big bang.
So there was something before that. Or FTL is possible– it's not.

Edit: so everything i said is at most locally true/true for us.

[–] bjoern_tantau@swg-empire.de 7 points 4 days ago (2 children)

They'd rather consider a universe before the Big Bang before they get rid of λCDM.

[–] raunz@mander.xyz 8 points 4 days ago

ΛCDM actually 🤓

[–] Envy@fedia.io 7 points 4 days ago

New nerd rock band name

[–] JcbAzPx@lemmy.world 6 points 4 days ago

Or, more likely, we have the wrong date for the beginning of the universe.

[–] gasgiant@lemmy.ml 5 points 4 days ago (1 children)

Except that this says there are things that exist and have been measured on super scales which exceed the speed of light.

Unless I'm not understanding it correctly there is something faster than light it is just beyond the boundary of the universe so we could never achieve it as we can't exceed the speed of light within the universe to get to it.

[–] primrosepathspeedrun@anarchist.nexus 2 points 4 days ago (1 children)

Wait so c really is just a local thing?

[–] GreyEyedGhost@lemmy.ca 5 points 4 days ago (1 children)

Not so much that things can go faster than c, but that on a large enough scale, the universe can expand faster than c. What this means is, beyond a certain distance, the only way it's possible to travel to or even observe some points is if we have FTL capability. This is effectively the edge of the universe, which is a local phenomenon - someone at our edge of the universe could very well see farther away than we can, but they also wouldn't be able to see past us in the other direction (assuming some models are correct).

[–] primrosepathspeedrun@anarchist.nexus 3 points 4 days ago (1 children)

Oh that's much cooler. So is there a way to break out?

[–] GreyEyedGhost@lemmy.ca 3 points 3 days ago

There's no evidence we can go FTL. The closest we have is the Alcubierre drive, which requires an incredible amount of matter with negative mass.

[–] brian@lemmy.ca 6 points 4 days ago

Light moves fast, some shit moving faster than it cause stretchy-spacey-something, determined to be from before the big bang to make it work, and we can see the results I guess

I dunno tho, I'm just making it up and hoping I'm close

[–] justOnePersistentKbinPlease@fedia.io 2 points 4 days ago

Only going to touch on the article since I am not a physicist and yet: I suspect the article is bunk, because it seems to be trying to separate the big bang and inflation theory into competing theories.

General layman understanding of things in a nutshell. this may be completely wrong, and is likely full of "Lies-To-Children"

Everything compressed into singularity.
Big bang, everything is super hot plasma.
Faster than light expansion of the universe. Too hot to make anything out with the tools we have.
Things cool and the inflation stops being completely insane, the base fluctuations remaining from the big bang result in inequal distribution of matter, the first supermassive stars and their accretion discs form.
Those stars die and form into the supermassive black holes that form the seeds of all galaxies.
Because of whatever Dark Energy is, something related to a lack matter in space, the space between clusters of galaxies and clusters of clusters of galaxies, the rate of inflation of universe starts increasing and things start moving apart.

[–] sp3ctr4l@lemmy.dbzer0.com 8 points 4 days ago* (last edited 4 days ago)

My personal, unqualified, non expert, favorite explanation for this and other recently observed data that seems to be fucking with the general universe origin/history consenus lately:

Black hole cosmology.

We, us, our universe, is the result of the creation of a black hole in some... other universe, and ... yeah, basically; worm holes? No.

White holes?

Yes, and what they look like is entire new universes.

So, if true, that means it really is turtles all the way down, we are somewhere in some multiverse, a nested series of universes spawning black holes which spawn universe which spawn black holes... and there is absolutely no way of knowing anything about when that all 'started', or 'where' we are in that system.

Our universe is functionally some other universe's pocket dimension, but there's no way to retrieve what goes into that pocket.

But uh yeah, if this is the case, it could potentially explain some of these anomalies we (astronomers and astrophysicists) are more recently noticing.

[–] RunawayFixer@lemmy.world 6 points 4 days ago (1 children)

Personally I believe that everything has a beginning and an end, except time and space, which are going to be infinite. For that reason, I think it's more likely that our universe just goes on to infinity, and that we can only watch back X billions of years because of event horizon phenomena.

But even if our universe was born with a big bang and thus finite, that doesn't mean that it was the only big bang ever. If big bangs are a thing, then there's going to be a infinite amount of them happening in the infinity of time and space, each one filling their humongous little corner of space with uncountable galaxies. We might not be able to see/detect stuff further away than what we call the universe, but that doesn't mean that there is nothing outside of our universe.

[–] YiddishMcSquidish@lemmy.today -1 points 4 days ago (1 children)

What if the Milky Way is actually the literal center of the universe, and that's why everything is red shifting so uniformly? And we are still in the initial expansion of the universe.

[–] RunawayFixer@lemmy.world 3 points 4 days ago

It's the same old fallacy that people have been making since time immemorial: Our tribe is the chosen tribe and the world is as big as what we know of it.

Or much later, once smart people figured out that we were living on a planet, the assumption was made that our planet was the center of everything, with the sun rotating around the earth: Geocentrism.

And then when they figured out that that probably wasn't the case, there came a theory that everything in space evolved the sun: Heliocentrism.

So now that we know that both geocentrism and heliocentrism were incorrect hypothesises, we're just going to make the same mistake and assume that the milky way is the center of everything? Our horizon may have moved, but we're no smarter than those Greek philosophers who thought that the earth was the center of everything.