Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

We don't know how the universe began, and we will never know

backreaction.blogspot.com

Post reply on HN
Print view View original

361–370 of 610 posts

Re: We don't know how the universe began, and we will never know

#361

Post by tsimionescu »

superposeur wrote: post #133

I’m a big fan of the blog, but disagree with this entry. Her argument could be applied to the idea of the Big Bang itself: we can never receive light from any further back than the “surface of last scattering”, so the notion of a hotter prior epoch is an extrapolation. The extrapolation is a good one as it uses independently-tested laws of evolution, at least to the point these laws presumably break down, as she poin…

> Similarly, it’s entirely conceivable that we may find independent ways to test which of the proposed modifications of the evolution laws is correct, for instance by using data collected from binary mergers. Then, these modified laws would lead to a modified story of what happened near the Big Bang.

Sure, but you have to start from observations of the binary merger, not from what you'd like the Big Bang to be like, like most of these theories do. Starting from predictions about the origin of the universe is unlikely to produce good testable theories, since there is nothing to test there. You have to look at phenomena that are actually still happening in the universe to guide your research, and only then extrapolate.

Re: We don't know how the universe began, and we will never know

#362

Post by Inu »

IAmGraydon wrote: post #178

“We will never know” is such a contradictory statement. On the surface, it implies the limits of our knowledge while simultaneously indicating that the author possesses the omnipotence required to know what humans will learn throughout the entirety of our future. Add it to your list of things to never write.

Depends on the field, Gödel's theorems make claims of impossibility.

Re: We don't know how the universe began, and we will never know

#363

Post by UmbertoNoEco »

mtlmtlmtlmtl wrote: post #254

I honestly never cared for Hossenfelder's science communication. She's far too dismissive and dishonest in representing theoretical views she disagrees with. And I don't necessarily have the physics understanding to pick these biases out too easily. I think Sean Carroll for instance does a much better job at this when he interviews people whose views he disagrees with in his podcasts, which happens quite frequently.

agree but be aware carroll swings way way way way to the other extreme especially about the pet theories he happens to like: multiverses ; the everett interpretation of qm ;boltzmann's brains and so on

Re: We don't know how the universe began, and we will never know

#364

Post by bandyaboot »

twiss wrote: post #225
synu wrote: post #203

Earlier quoted context omitted.

I watched the video, and the sense I got was you don’t need to bother to read anything where scientists talk about having figured out what happened at the beginning of the universe because we can never know. This seems to explicitly exclude the possibility that there could ever be a discovery you might read about that would change that.

She explicitly says that the scientific method is insufficient to give an answer to this question. So reading anything written by scientists won't give a conclusive answer. I think it's implicitly hinted that you might as well read something by a religious person, or a philosopher, or anyone with a random theory, as none of the theories can be proven or disproven by the scientific method, and so all of their answers…

Honestly I find “it’s unknowable” to be a pretty satisfactory answer. Mostly because to me it points at something that seems almost obvious the more I’ve thought about it. Even if it were possible to see past the “Big Bang”, what possible reason is there to think that would be the end of the rabbit hole? As mind bending as it is to think that the trail is infinite, it’s even more mind bending to imagine that it’s not.

Re: We don't know how the universe began, and we will never know

#365

Post by green_on_black »

kosh2 wrote: post #337

The only thing that can maybe be understandable for us is an infinite universe. What was before 0? -1. What before that? -2. But how can we ever understand how out of a state of nothingness came something? That is where the science "ends" and the door to philosophy opens. Those are similar problems like "Why is there not nothing?", "Why are the laws of nature not different?" etc.

To add to your point, why should there be nothingness? Who is to say that 0 is before 1? There's 1/2 somewhere right? And 1/4 before that, etc.

It's not obvious that there "should" be nothing, rather than perpetual something. It's not obvious we should work with integers and not the reals. Or the rationals. Or the rationals without zero, which cannot exist as a denominator (in the common definition of the rationals). It's not obvious that we've ever detected zero. And why a line? Why not a circle? And even if a line, couldn't it be the limit of a circle whose radius tends to infinity? Etc.

Re: We don't know how the universe began, and we will never know

#366

Post by 0134340 »

DemocracyFTW2 wrote: post #191
IAmGraydon wrote: post #178

“We will never know” is such a contradictory statement. On the surface, it implies the limits of our knowledge while simultaneously indicating that the author possesses the omnipotence required to know what humans will learn throughout the entirety of our future. Add it to your list of things to never write.

That's a very narrow reading of it. There's always an implicit "to the best of our current knowledge" caveat with every sound scientific statement. And it's true, to the best of our current knowledge, we can never know what it's like inside a black hole or very close to the time our universe began because the physics that we know tells us no person or probe can ever go there and come back to tell. If you're no so gen…

That reminds me of her article, very narrow. She seems to imply scientists, or at least scientific theories, implicate certain universal origins when really they're implying "to the best of our current knowledge". I think most everyone that's scientifically literate, and you'd think it'd be common knowledge among most of HN crowd, knows that scientific theories of universal origins aren't certain but here we have a whole article of the 'well awkshually' party-pooping you're talking about. She does seem pretty certain about uncertainty though which tells the tale that she's not beyond the paradox either.

Re: We don't know how the universe began, and we will never know

#367

Post by lanstin »

bumbledraven wrote: post #240
coldtea wrote: post #217

Earlier quoted context omitted.

> On the surface, it implies the limits of our knowledge while simultaneously indicating that the author possesses the omnipotence required to know what humans will learn throughout the entirety of our future That's no contradiction though. A contradiction would be "I know everything about X" and at the same time "There's a limit to our knowledge of X". It's no contradiction to claim that there are limits to our know…

> in math we can even prove that some things can never be proven No we can't. We can only prove that certain formal systems cannot resolve certain statements. We might still invent other formal systems that are acceptable to us and that can resolve those statements.

And for those other systems, iF they embed arithmetic, we can effectively produce a statement that is visibly true and which that other system cannot prove.

Re: We don't know how the universe began, and we will never know

#368

Post by benreesman »

IAmGraydon wrote: post #178

“We will never know” is such a contradictory statement. On the surface, it implies the limits of our knowledge while simultaneously indicating that the author possesses the omnipotence required to know what humans will learn throughout the entirety of our future. Add it to your list of things to never write.

Hossenfelder is a polarizing figure. “Lost In Math” was a thought-provoking book in the tradition of the other string iconoclasts (Smolin, Woit, Rovelli, roughly “the Perimeter crowd”). “Three Roads to Quantum Gravity” was the last general audience book that Smolin did before he’d fucking had it and did “The Trouble with Physics”. Woit went straight for the jugular with “Not Even Wrong”.

These people have (for better or worse) burnt the ships with the people of their generation who write grants and sit on tenure committees.

Hossenfelder’s pivot to “wildly over-credentialed pop-sci YouTuber” is interesting. My gut flinch reaction is like, “you’re better than this”, but… I have not walked a mile in her shoes, and if this is an end-run around a corrupt job market for particle/high-energy people who won’t won’t get on board with The Landscape? Maybe more power to her.

I give that context so that people will know (my opinion on) the backstory for why she’s in an adversarial relationship with The Academy.

The “will never know” phrasing might be unfortunate. But the epistemological principle goes back to Hawking at least: “asking what happened before the Big Bang or where it came from is like asking what is north of the North Pole”.

It’s a fun thing to theorize about, but the Big Bang is almost definitionally “the bound on observable causality”. It’s not a statement about what we won’t ever know, it’s a statement about what’s knowable.

Re: We don't know how the universe began, and we will never know

#369

Post by 0134340 »

yibg wrote: post #265
IAmGraydon wrote: post #178

“We will never know” is such a contradictory statement. On the surface, it implies the limits of our knowledge while simultaneously indicating that the author possesses the omnipotence required to know what humans will learn throughout the entirety of our future. Add it to your list of things to never write.

I don’t know if the statement is correct in this case but in general saying “we will never know” about a subject which we have incomplete knowledge isn’t a contradiction. I can say, we will never know what the first human that got to North America had for lunch on their 20th birthday, and I think that’s as true as it could reasonably be. Sure maybe we’ll invent a time machine or some other technology in the future th…

Very few things about the origins of the universe can be stated as fact at this point so “we will never know” isn't a "fact" either. Implied certainty on either side seems pre-emptive.

Re: We don't know how the universe began, and we will never know

#370

Post by hota_mazi »

michaelsbradley wrote: post #294
hota_mazi wrote: post #226

Earlier quoted context omitted.

Faith is the justification that people give when they believe something for no good reason. You can believe anything based on faith, therefore, it's not a reliable path to truth. Only reason is. The faster our civilization gets rid of faith, the better off we'll be.

Fides et ratio was written to address that problematic way of thinking (what you just expressed). Maybe give it a read.

Could you outline what's problematic about it here?
Post reply on HN