Galaxies Underestimated

[ripcord]

This discussion is interesting, even though I have little of import to add except to say that fields like cosmology and other hard sciences must suffer under the unfortunate reputational burden of vast swaths of academia. The average man has to wade through a constant stream of so called "scientific" mendacity from the pseudosciences, so it breeds an unfortunate contempt.

Take the field of psychology, for instance. What substantive truth has it produced since Skinner in the 1950s? More bologna than anything else.

Edit: I went back and read what I wrote. Wow. Maybe coming on just a tensy but too strong.

 

[PWMDMD]

This discussion is interesting, even though I have little of import to add except to say that fields like cosmology and other hard sciences must suffer under the unfortunate reputational burden of vast swaths of academia. The average man has to wade through a constant stream of so called "scientific" mendacity from the pseudosciences, so it breeds an unfortunate contempt.

Take the field of psychology, for instance. What substantive truth has it produced since Skinner in the 1950s? More bologna than anything else.

I don't know anything about psychology so you're on your own there but I think there's some truth to what your saying as far as perception. When people see weak research, politicized studies, or outright pseudoscience being presented as "science," it can erode trust in legitimate scientific fields.

The problem is that many people treat science as one giant category when, in reality, different fields have very different standards of evidence and predictive power. The solution isn't to distrust all science, but to get better at distinguishing strong evidence from weak evidence. Unfortunately, that requires some understanding of science.

There's no getting around the fact that you have to know quite a bit about technical topics to give meaningful opinions about it.

 

[MolaKule]

...As for the Big Bang being a "failing cosmological model," I'd ask failing relative to what? The model successfully predicted the expansion of the universe, the cosmic microwave background, the abundance of light elements, and many aspects of large-scale structure formation. You can certainly argue that it is incomplete, and I would agree. But incomplete and failing are not the same thing...

I think you are referring to the "Hot" BB model which was a computer simulation involving a major extrapolation back in time carried out by Robert Wagoner at Stanford circa 1973, using various assumptions and conjectures.

The model goes back to ~ t=0 for a temperature ~ T = 10^11 Kelvin.

Prior to the earlier Proton-antiproton pair production epoch we "run out of secure physics," as explained by M.S. Longair in, Theoretical concepts in physics.

So we go from a supposed system with constituents in equilibrium at t=0 to a highly non-equilibrium system in later epochs for t>0.

I think you have more faith in cosmic conjectures and assumptions than I so I will leave it there.

 

[stormgol]

M82. the Cigar Galaxy. a Starburst Galaxy. one of the weirdest and prettiest Galaxy.

 

[JimPghPA]

I don't think we have directly observed Dark Matter but only inferred it indirectly.

If there is dark matter then it seems by implication there should be dark stars and dark galaxies and dark Quasars, but how would we know since it has so far been unobservable?

Dark stars have been located.

 

[JimPghPA]

If they don't overlap ours, you will never know.

If they don't overlap ours "within an observable location", you will never know.

 

[MolaKule]

Dark stars have been located.

Some potential candidates have been noted but no verification as of yet.

 

[PWMDMD]

I think you are referring to the "Hot" BB model which was a computer simulation involving a major extrapolation back in time carried out by Robert Wagoner at Stanford circa 1973, using various assumptions and conjectures.

The model goes back to ~ t=0 for a temperature ~ T = 10^11 Kelvin.

Prior to the earlier Proton-antiproton pair production epoch we "run out of secure physics," as explained by M.S. Longair in, Theoretical concepts in physics.

So we go from a supposed system with constituents in equilibrium at t=0 to a highly non-equilibrium system in later epochs for t>0.

I think you have more faith in cosmic conjectures and assumptions than I so I will leave it there.

I don't think this is really a matter of faith.

Every scientific model rests on assumptions. The question is whether those assumptions lead to predictions that match observations. The Big Bang model has been remarkably successful in that regard, whether we're talking about cosmic expansion, the cosmic microwave background, or the abundance of light elements.

I also don't think anyone is claiming that our understanding remains secure all the way back to t = 0. In fact, every cosmologists I've ever read was quite explicit about where the physics becomes uncertain and where current theories break down. Acknowledging those limits isn't a weakness of the model - it's simply an honest assessment of what we know and don't know.

Where I think we may disagree is that I don't view "we run out of secure physics" as evidence against the portions of the model that are well-supported. It tells us there are unanswered questions at the earliest epochs, not that the later predictions and observations suddenly become invalid.

So I wouldn't say I have faith in the conjectures. I'd say I have confidence in the parts of the model that have survived repeated observational testing, while remaining open to the possibility that our understanding of the earliest moments of the universe may change substantially in the future. As for t=0, neither I, nor any other human being, knows what happened, but we do confidently know what happened at t>0.


I hope we find a theory of quantum gravity in my lifetime and that we do figure out what happened at t=0.

 

[Astro_Guy]

M82. the Cigar Galaxy. a Starburst Galaxy. one of the weirdest and prettiest Galaxy.

M81 and 82 are located about 2/3 of a degree apart and are usually the first group of glalaxies those of us in the northern hemisphere see.

 

[MolaKule]

I don't think this is really a matter of faith.

Everyone has a belief system that leads to a faith in something.

Where I think we may disagree is that I don't view "we run out of secure physics" as evidence against the portions of the model that are well-supported. It tells us there are unanswered questions at the earliest epochs, not that the later predictions and observations suddenly become invalid.

You are not disagreeing with me, but with Prof Longair whom I quoted, a very respected High Energy Astrophysicist who has 5 noted texts and 200 papers. who gave his honest assessment about the hot big bang theory without the benefits or inaccuracies of Ai. I have used his texts in various courses and greatly respect his writings, especially his, Theoretical concepts in physics.

https://www.phy.cam.ac.uk/profile/prof-malcolm-longair/

So I wouldn't say I have faith in the conjectures. I'd say I have confidence in the parts of the model that have survived repeated observational testing, while remaining open to the possibility that our understanding of the earliest moments of the universe may change substantially in the future. As for t=0, neither I, nor any other human being, knows what happened, but we do confidently know what happened at t>0.

I would submit that unless you have studied and understood Wagoner's and Longair's writing's, you would not know of the assumptions and conjectures involved in the hot BB theory. Assumptions, ad hoc postulations and conjectures are part of any hypothesis, and especially simulations.

I hope we find a theory of quantum gravity in my lifetime and that we do figure out what happened at t=0.

For those interested in the topic I suggest:

https://arxiv.org/pdf/gr-qc/0006061

https://arxiv.org/pdf/astro-ph/0505266

https://arxiv.org/pdf/gr-qc/0205121

Hossenfelder, Sabine (2011). "Experimental Search for Quantum Gravity". In Frignanni, V. R. (ed.). Classical and Quantum Gravity: Theory, Analysis and Applications. Nova Publishers. ISBN 978-1-61122-957-8.

Hossenfelder, Sabine (2 February 2017). "What Quantum Gravity Needs Is More Experiments". Nautilus.

Since there are at least 20 proposed theories for QG maybe one of those will rise to the top.

 

[PWMDMD]

Everyone has a belief system that leads to a faith in something.

You are not disagreeing with me, but with Prof Longair whom I quoted, a very respected High Energy Astrophysicist who has 5 noted texts and 200 papers. who gave his honest assessment about the hot big bang theory without the benefits or inaccuracies of Ai. I have used his texts in various courses and greatly respect his writings, especially his, Theoretical concepts in physics.

https://www.phy.cam.ac.uk/profile/prof-malcolm-longair/

I would submit that unless you have studied and understood Wagoner's and Longair's writing's, you would not know of the assumptions and conjectures involved in the hot BB theory. Assumptions, ad hoc postulations and conjectures are part of any hypothesis, and especially simulations.

For those interested in the topic I suggest:

https://arxiv.org/pdf/gr-qc/0006061

https://arxiv.org/pdf/astro-ph/0505266

https://arxiv.org/pdf/gr-qc/0205121

Hossenfelder, Sabine (2011). "Experimental Search for Quantum Gravity". In Frignanni, V. R. (ed.). Classical and Quantum Gravity: Theory, Analysis and Applications. Nova Publishers. ISBN 978-1-61122-957-8.

Hossenfelder, Sabine (2 February 2017). "What Quantum Gravity Needs Is More Experiments". Nautilus.

Since there at least 20 proposed theories for QG maybe one of those will rise to the top.

Carroll, Weinberg, Penrose, Greene, and Hossenfelder have all discussed the hot Big Bang extensively in their books. Carroll and Greene in particular devote significant attention to it in From Eternity to Here, The Big Picture, The Fabric of the Cosmos, The Hidden Reality, and Until the End of Time. They cover both the observational evidence supporting the model and the areas where our understanding remains incomplete.

My point all along has been that none of these authors reject the Big Bang model simply because our physics becomes unreliable as we approach the earliest moments of the universe. In fact, they are generally quite explicit about where confidence ends and speculation begins.

Acknowledging that we "run out of secure physics" near t=0 is not the same thing as concluding that the model's later successes are invalid. The uncertainty applies to the earliest epochs, not to the observations and predictions that have been repeatedly confirmed.

So while I don't know Longair's writings, based on what you've said about it, I don't see a conflict between Longair's statement and my position, which are just the positions of mostly Greene and Carrol. If anything, they seem entirely consistent. The existence of unanswered questions at t=0 does not negate the evidence supporting the portions of the model that are well established.

Good discussion - I do really appreciate your time.

On personal note - it's pretty freaking cool his contact information is at Cavendish Laboratory on JJ Thompson Ave!

 

[mr_boring]

So we lose a lot in the quibble of semantics. Maybe not semantics, per se, with the proper definition of semantics, but what we are doing in this thread is attempting to quantify the unquantifiable. There's a lot of "now now, this is what we say and what we 'know' and what we 'think' "

If the worlds most foremost expert in something calls something previously unquantifiable "Blargaspargard" then it shall be heretofore known as 'Blargaspargard".

We will NEVER understand this. It's like trying to understand the mind of God. We simply will never know. You don't have to believe in an omnipotent being to get what I'm saying here. This is beyond comprehension. Nobody was there. There is no literal concrete proof. There is conjecture, hypothesis, and other scientific terms ad nauseum which apply here.



Perhaps, if we make it another 3 centuries, there will be tech and know how and whatnot to definitively say that Blargaspargard is not right. Until then, it's Blargaspargard. Who's right? Yeah, yet to be determined.


Ya'll who are educated in this have forgotten more than I can comprehend. But, it's truly conjecture. Much like splitting an atom until it was actually observed.


Love the discussion.