[SaintSeiya84]

Because the universe did not originated in a Big Bang, that's just a theory that is becoming more and more disproved. The universe is infinite and eternal, in constant change? sure, but in no way it started 13500 million years ago.

[simonh]

Some thing can't become more disproved, either it's disproved or it isn't.

The timeline is certainly up for grabs, there are uncertainties in the various ways we measure or infer distances and the age of objects, but so far nothing that invalidates the overall scheme. Roger Penrose's idea of conformal cyclic cosmology is a plausible alternative, but even that still has an event in our past that looks an awful lot like a big bang. There are just too many observations any alternative theory needs to explain, like galactic red shift and the cosmic background radiation. If stars are infinitely old, how come they still have any hydrogen left?

It's always a good idea to keep an open mind though. What are the alternatives you think have legs?

[petsfed]

Do you have any citations for any of what you just said?

Also, the Big Bang "theory" is a theory in the technical sense, in that the overwhelming majority of evidence ever collected is at least neutral towards the Big Bang, to say nothing of the virtually incontrovertible evidence in support (esp. the cosmic microwave background radiation, redshift correlated with distance to virtually all extra-galactic objects, low metalicity in ultra-distant (read early) objects, etc etc etc). It could still be wrong, but we'd need some other theory that adequately explains all the available evidence, and makes several new, testable predictions that are also observed to be correct. The term "theory" is not used colloquially here as a fancy way to say "guess" or "idea" (those are, in the same technical sense, best called "conjectures" or (generously) "hypotheses"). It has a very narrow meaning here, and dismissing the Big Bang theory as "just" a theory really reveals your ignorance on the subject here.

[jiggawatts]

At the risk of engaging in a thread started by a likely troll: the Big Bang hypothesis has a few inconsistencies. For example, different distance candles disagree on the Hubble constant. Now JWST is finding unusually old galaxies. Etc…

I still lean towards the Big Bang as the most likely model, but it’s not as well established as, say, germ theory.

[petsfed]

Granted. And those inconsistencies are not new.

I actually had an idea in undergrad (20+ years ago) to probe Hubble Constant variation using quasar reverberation mapping and very-long-baseline-interferometry. Then the professor I was working with pointed out that the baseline I needed was something like 100,000 times earth's orbital diameter.

Back then, one of the sexier ideas was that the universe might have locally different fundamental constants, and that variation could reveal some information about the higher-dimensional "space" that the universe existed inside of. I've been out of that field for a long time though, so I've no idea what the cutting edge is. I just know that the Big Bang theory is still pretty safe.

There are plenty of things wrong in the theory, but none of the evidence suggests that "expansion from a singularity" is wrong, let alone "infinite and eternal" is right.

[coliveira]

In fact it makes little sense to talk about time before the big bang, because inside a singularity time moves infinitely slow. So the point is that, yes, the universe never really started because time didn't exist before the singularity. The universe only evolved to a different dimension, so to speak, and time as we know started to exist when the big bang occurred.

[_0w8t]

The question about existence of time before singularity does not have an answer, rather than affirmative no.

A singularity means that all timelines goes through it, but it is impossible to make continues extension of the timelines past the singularity in the current physical models. That literally means that anything is possible with the timeline prior that. The timeline can jump, be replaced by a set of random points, became a multidimensional surface, go back etc. It may even indeed disappear, but we do not know.

[klyrs]

I like to think that the Big Bang is the ultimate Great Filter. When civilization gets too advanced, they start building galaxy-sized colliders and smash charged supermassive black holes together to see what makes 'em tick...

But as a non-physicist I recognize that my "theories" are just for funsies and have less value than bellybutton lint.

[stevenhuang]

This is similar to the plot of Greg Egan's Schild's Ladder. Fantastic book.

> Twenty-thousand years in the future, Cass, a humanoid physicist from Earth, travels to an orbital station in the vicinity of the star Mimosa, and begins a series of experiments to test the extremities of the fictitious Sarumpaet rules – a set of fundamental equations in "Quantum Graph Theory", which holds that physical existence is a manifestation of complex constructions of mathematical graphs. However, the experiments unexpectedly create a bubble of something more stable than ordinary vacuum, dubbed "novo-vacuum", that expands outward at half the speed of light as ordinary vacuum collapses to this new state at the border, hinting at more general laws beyond the Sarumpaet rules. The local population is forced to flee to ever more distant star systems to escape the steadily approaching border, but since the expansion never slows, it is just a matter of time before the novo-vacuum encompasses any given region within the Local Group.

https://en.m.wikipedia.org/wiki/Schild's_Ladder

[drsnow]

How far away would one need to be in order to never come into contact with such a border growing at 1/2c?

[Larrikin]

This is certainly a troll thread, but have there been ANY experiments in the past few decades that push back against the big bang? Seems like it was hard to accept by many in the beginning but that the evidence is so overwhelming at this point. As someone who isn't a scientist and just listens to a lot of cosmology podcasts, even when they explore crazy theories I haven't heard of anything of an alternate theory in modern cosmology.

[leepowers]

The Big Bounce[1] hypothesis is a model that "suggests that we could be living at any point in an infinite sequence of universes". So while our current universe may not be infinite there may be some yet undiscovered infinite/eternal natural process that gives rise to universes.

Olber's Paradox[2] and the inability to reconcile it with our current astronomical observations seems to disprove that our current universe is itself infinite.

[1] https://en.wikipedia.org/wiki/Big_Bounce

[2] https://en.wikipedia.org/wiki/Olbers%27_paradox

[bottled_poe]

Space dust over intergalactic distances seems sufficient to explain Olbers’s Paradox?

[aw1621107]

Strictly speaking, Olber's Paradox is about an infinite, eternal/static, and homogeneous universe with an infinite number of stars; in such a case, the light the dust absorbs would cause the dust itself to start emitting light, which would make it visible [0]. I'm not sure to what extent this paradox applies outside that scenario (e.g., an infinite-but-changing universe)

[0]: https://www.scientificamerican.com/article/why-is-the-night-...

[bottled_poe]

Actually, probably just the standard expanding universe + light horizon.

[spiderice]

> 13500 million

Why word it like this instead of using 13.5 billion? Is this a common thing to do in astronomy? Or are you trying to make the claim of 13.5 billion years sounds more ridiculous? Genuine question.

[g___]

Probably because million is unambiguous. Billion sometimes refers to 10^12 rather than 10^9.

[pengaru]

That's just, like, your opinion, man...