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

backreaction.blogspot.com

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

#81

Post by barrysteve »

vouaobrasil wrote: post #48

I think one thing that humans have not come to terms with is the possibility that some fundamental fields are essentially dead in terms of possible new discoveries that most people will care about. That doesn't mean that there's nothing left to do. There are minor details in some fields but they are more like engineering problems. Physics may be one of those fields and I certainly think math is as well. However, it's…

Depends what you mean by care about, because the majority of praised discoveries are an extra foot on the millipede. Precisely because we designed our universities and technologies that way.

You can nurture in systems and cultures that break open the fundamentals again if you so wish. Most people don't wish it, they are happy living out incremental improvement in the city and surrounds.

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

#82

Post by tsimionescu »

kevinventullo wrote: post #29

Maybe it stops being science and starts being math, but I don’t think that means we should discourage people from doing it. That said, I am sympathetic to an argument that we may not need to fund such inquiries. “We will never know” sounds overly pessimistic to me; I could imagine someone from the 10th century claiming we will never know the trillionth prime number.

I think that the evolution of physics has actually been a series of discoveries of new things that are impossible. We used to think that many things were possible if only we knew the right spell, or invoked the right god, or just worked hard enough.

Then as people studied nature more thoroughly and systematically, they started observing laws that simply can't be crossed - conservation of energy, conservation of momentum, the increase of entropy , the limited speed of causality, the uncertainty principle - to name some of the bigger ones. All of these have put limits on something we used to think of as unlimited.

There are many more non-existence proofs in math as well - so even in pure math, you can't escape this accumulation (probably the most famous such problem, one long attempted that ultimately proved impossible, is "squaring the circle", or in modern terms, the fact that pi^n is irrational for any rational n).

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

#83

Post by johndunne »

vouaobrasil wrote: post #48

I think one thing that humans have not come to terms with is the possibility that some fundamental fields are essentially dead in terms of possible new discoveries that most people will care about. That doesn't mean that there's nothing left to do. There are minor details in some fields but they are more like engineering problems. Physics may be one of those fields and I certainly think math is as well. However, it's…

I believe this sentiment is what a large cross section of the physics community was thinking prior to Einstein’s breakthroughs.

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

#84

Post by blooalien »

gibsonf1 wrote: post #33

What if it never began and has simply always existed? That is the likely scenario, as the moment you think about it beginning, you again face beginning from what? What was that called before the universe other than the universe?

> "What was that called before the universe other than the universe?"

If it was "before the universe" then it wasn't called anything, because there was nobody here to give it the name "universe"?

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

#85

Post by XorNot »

jahnu wrote: post #45
XorNot wrote: post #20

Earlier quoted context omitted.

I'm increasingly sceptical. She's not in research anymore but has found success running an "I know what I'm talking about" contrarian blog. If she was a software developer we'd rightly start to wonder about grand pronouncements coming from someone no longer practicing in the field. When your market doesn't exist if you actually agree with anyone, the incentives start to be questionable.

> She's not in research anymore What are you talking about? She is still publishing proper research papers as recently as this month! https://arxiv.org/search/?searchtype=author&query=Hossenfeld... Some people pick up weird ideas about her and I really wonder why.

So you're right - Research Fellow at Frankfurt Institute of Advanced Science [1]

However her broad ranging commentary which tends to take the tone of "this field should listen to me but doesn't" as is the case with this article (and a few others she's done such as about the LHC[2] or black-hole information loss[3]) leaves a sour taste in my mouth.

[1] https://www.fias.science/en/fellows/detail/hossenfelder-sabi...

[2] http://backreaction.blogspot.com/2020/10/particle-physicists...

[3] http://backreaction.blogspot.com/2022/04/i-stopped-working-o...

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

#87

Post by ben_w »

barrysteve wrote: post #70

Sabine likes to swing an axe into a tree. Her preaching gets tiresome fast though. She redefines science to require simplicity, when it simply doesn't require it. Many solved or solveable problems in science are ghastly complex and computers improved or solved them. The LHC is a most-obvious example for that category. Do I even need to point out the counter-arguments or are we just taking Sabine at her word.. This th…

Sabine, wearing her science communicator hat, necessarily has to simplify a lot. Everything of hers that I watch or read is simplified science (including her branded Brilliant course), and it has to be simplified for me to follow it because I'm a software engineer not a scientist and I can't yet do the tensor differential calculus of relativity nor the complex-valued calculus of quantum mechanics.

But even without that caveat, science has to be as simple as possible (and no simpler), because every extra equation or variable beyond the minimum is necessarily a worthless decoration adorning the core idea. Computers don't always let you brute force your way past that extra complexity, but even when they do, it never really helps to have it.

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

#88

Post by deepsquirrelnet »

tsimionescu wrote: post #64
jacquesm wrote: post #2

"The issue is that physicists can’t accept the scientifically honest answer: We don’t know, and leave it at that." This sentence jumped out for me. Is there some kind of crusade going on that I have missed the beginning of? This feels like a strange sentence in this piece and feels like a (misguided) attack.

I think she justifies the "attack" towards the end of the piece, where she talks about the many theories that purport to explain how the universe began. Her point is that you can always create a coherent mathematical model that "explains" this, but since it is logically impossible to check it, you're not proposing a scientific theory.

I don’t often go looking in Astronomy or cosmology journals, but I’d be surprised if either scientists were trying to publish articles like that — or if they were, that they could pass peer review.

On the other hand, if you are working on theories that can extend into the early universe, it’s not unimportant to try and figure out where the model breaks down. Maybe t=0 isn’t possible, but t=1s? 1ns? 1ps? How much can we feasibly describe?

I’d argue that not exploring the limits of models is also bad science. Knowing the limits is a fundamental part of communicating a model.

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

#90

Post by indymike »

chiefalchemist wrote: post #49

But isn't Webb calling the BBT into question? Even if we answer how it began there is still: 1) Why? 2) What was there before that? 3) And before that? 4( And before that? And so on. It's the rabbit hole only hallucinogens can fill.

> It's the rabbit hole only hallucinogens can fill.

I am stealing this.

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