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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

#111

Post by mxkopy »

John Wheeler popularized the term "it from bit" and the idea of a participatory universe. The limits of human observation aside, it could be that the universe itself doesn't really know how it began. If a superheated plasma is indifferent to being in a 5 dimensional black hole as opposed to a state where only space exists, then, in a sense, there isn't any difference between the two explanations (given that the plasma is the entire universe).

There's this phenomenon in science where you think something is arbitrary, it could've happened in any number of ways. Then you do some digging and find out there is actually only one possible way for it to happen, none of the other ways make logical sense. And it's not a matter of initial state or anything, but of geometry or something.

Sometimes, after I put down the crack pipe, I wonder if there is only one possible way for the universe to exist, and knowing it isn't a matter of observation, but of abstraction, that irreal logical constructions are actually not abstract enough to explain the universe, etc.

Maybe a variable initial state doesn't make logical sense at the end of the day. Maybe the numbers we have to plug into the models to make them work are like pi or the zeros of the zeta function, maybe they just fall out of some result in group theory or sth idk

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

#112

Post by tsimionescu »

deepsquirrelnet wrote: post #88
tsimionescu wrote: post #64

Earlier quoted context omitted.

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…

> I’d be surprised if either scientists were trying to publish articles like that — or if they were, that they could pass peer review.

The article we're discussing itself even links to one such paper [0]. All of the others she mentions are also published works - Penrose's CCC [1], the ekpyrotic universe [2], Hawking's no-boundary state [3] etc.

> 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?

Sure, but this is a different thing. Many of these are adding elements to the existing theories, and then predict a new initial state given the modified evolution laws.

[0] https://link.springer.com/article/10.1007/s10714-021-02790-7

[1] https://arxiv.org/abs/1808.01740?context=astro-ph

[2] https://arxiv.org/abs/hep-th/0103239

[3] https://arxiv.org/abs/1707.07702

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

#114

Post by danwee »

erlend_sh wrote: post #7

What we do know is that the universe didn’t begin from nothing . It’s impossible for something to arise out of nothing, so there has always been something . Nothingness is the space that holds everything. From there it can be argued that the universe began with the adjacent possible of nothing.

Please, how can any human being be so absolute about anything? Modern humans emerged ~300K years ago (or at least that's what we know so far), so how on earth can we be sure about anything? Our science is nice and all, and can help us built amazing devices that save lives and allow us to explore... but all we have are models. Theories. Zero certainty.

If anything, science is all about: "I have no idea what this is, but I have a model that seems to explain certain scenarios. Let's stick with it until someone more intelligent than us provides a better model". We may be "sure" about certain "laws" (e.g,, thermodynamics, speed of light, etc.)... but I think it's a mistake to be so absolute about them.

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

#115

Post by ben_w »

barrysteve wrote: post #106
ben_w wrote: post #87

Earlier quoted context omitted.

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 th…

I mean gene unfolding, meterology, lhc, fusion, space research, ect have all been served tremendously by computing. Granted one could say they are temporarily less useful due to a local peak of optimization, buut that's a long way from throwing out all the sine waves and commiting to perfect metaphysics.

Take any or all of your examples, and add an extra variable:

   if (unix_time>>128) % 2 == 1 { explode(); }
Easy to code, unfalsifiable. Adds nothing to our understanding.

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

#117

Post by danwee »

734129837261 wrote: post #23

"We don't know how fire comes to life, and we will never know." "We don't know how to defend ourselves against beasts, and we'll never know." "We don't know how disease spreads, let's just hug it out, we'll never know." "We don't know how to fly like a bird, we'll never know." "We don't know how to land the booster of a rocket, we'll never know." "We don't know how to cure that form of cancer, and we'll never know."…

What seems arrogant to me is to think that we, as human beings, can know everything given time and space.

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

#118

Post by pixl97 »

Victerius wrote: post #58
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.

My pet theory: Something has always existed. There was no beginning. No origin. No first cause. No t=0. No start. It's always been there. What was before that? That. And that. And that. Always that. And the Second Law of Thermodynamics is not absolute and can be broken.

Understanding what time is and what time isn't can deeply affect ones view of the universe. Being stuck down here in a gravity well we think of time as a fundamental thing that ticks along the same for everyone. But when we start looking at things at cosmological scales even the idea of a t=0 starts to bend and break.

For example look at particle interactions. The vast majority of them you can play them forward and backwards and they look exactly the same. You wouldn't be able to tell which way the video is running. The only way we can tell there is an arrow of time is because at some point a field asymmetry occurred. In a universe where all fields are symmetrical the idea of time simply breaks down and has no meaning.

The history of the Universe channel touches on this in their latest video.

Linked the wrong video, this is the one I meant to link: https://www.youtube.com/watch?v=x9m0sz2sUfU

https://www.youtube.com/watch?v=XSCrSkK2HcQ

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

#119

Post by tsimionescu »

aliasxneo wrote: post #99
gcau wrote: post #74

Things like the big bang seem to be things after the beginning of the universe. In the same way, the issue with a god is "who created god, and who created that who created god...". If he's eternal, who/what made him eternal? We have the same problem in science, and I think any explanation/theory would have the same problem. Also, I dislike that when some physicists explain this they say, "sure, you can get something…

In the case of the Bible, it makes it explicitly clear that God is uncreated. Asking the question, "Who created an uncreated God?" doesn't make much sense in that case.

Of course, but then immediately leads to the question: if we admit that it is possible for God itself to be un-created, why can't the universe itself be uncreated as well?

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

#120

Post by amriksohata »

In Hindu scriptures there are many many universes that are bubbles perspiring from a particular form of Vishnu as he lies down. With each breath the universes are formed and destroyed, for us the time is very very slow but at his level he is literally breathing in and out and the bubbles come and go.
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