Multiverse

[Siyatanush]

Do the forum members support the multi universe theory? Can you give your reason for whatever you believe to be true?

[Silvestru]

1 hour ago, Siyatanush said:

Do the forum members support the multi universe theory? Can you give your reason for whatever you believe to be true?

There is no observational evidence to support this idea. I wouldn't even begin to understand how you could test this.

For the moment the people who really believe this are relying more on faith than science.  

The closest thing to science that discusses this idea is https://en.wikipedia.org/wiki/String_theory and more specifically https://en.wikipedia.org/wiki/Introduction_to_M-theory but this is not the multiverse in it's common meaning but something different. 

[Siyatanush]

Is it not true that Stephen Hawking supported the idea of multiverse in his last paper?

[Silvestru]

34 minutes ago, Siyatanush said:

Is it not true that Stephen Hawking supported the idea of multiverse in his last paper?

Here is the paper you are citing: https://arxiv.org/pdf/1707.07702v2.pdf

Could you please extract the paragraph in which he supports the idea of multiverse? (Not where he mentions the word)

This paper became famous just because Stephen Hawking published it a few days before his death. Many physicist do not agree with the idea that there should be a multitude of universes as a consequence of inflation.

You should wait for the feedback from a more experienced member of this forum but from my perspective it's nothing ground-breaking. 

Maybe my comment sounds a bit harsh or arrogant. I am trying to say that the media, as always transformed and hyped what this paper is trying to say. So I go back to my initial statement that this multiverse theory that you or anyone else proposes is un-testable as of yet.

Edited December 11, 2018 by Silvestru

[Strange]

8 hours ago, Siyatanush said:

Do the forum members support the multi universe theory? Can you give your reason for whatever you believe to be true?

There is no evidence for this hypothesis. So I wouldn't spend (waste?) any time on it. (Unless you are an actual cosmologist or astrophysicist looking for that evidence ...)

 

[Phi for All]

Any belief given to the concept has a very low trustworthiness factor. As a scientific explanation for anything, it's more wishful thinking than anything else, at the present time. I prefer thinking in terms of trustworthiness, as opposed to seeking something that's "true". 

As a concept for fiction, it's very imaginative and opens up infinite possibilities for the writer. I wonder if the soap operas have latched onto the multiverse hypothesis. A character can only have so many evil twins in one universe....

[beecee]

11 hours ago, Siyatanush said:

Do the forum members support the multi universe theory? Can you give your reason for whatever you believe to be true?

Hi.....Firstly in actual fact, it isn't a scientific theory, [which is the highest accolade any scientific model can have] it is simply hypothetical. Secondly mostly all scientific theories and models start out as speculative and hypothetical, and to use a favourite terminology of mine, need to run the gauntlet before reaching theory stage. Thirdly as yet we cannot even say with any confidence how or why the BB happened, and noting that this theory [the BB] only goes back as far as 10-43 seconds after the initial event, of which we are ignorant. So you can see that evidence for any multiverse is  unlikely to be evident.

[Siyatanush]

14 hours ago, Silvestru said:

Here is the paper you are citing: https://arxiv.org/pdf/1707.07702v2.pdf

Could you please extract the paragraph in which he supports the idea of multiverse? (Not where he mentions the word)

This paper became famous just because Stephen Hawking published it a few days before his death. Many physicist do not agree with the idea that there should be a multitude of universes as a consequence of inflation.

You should wait for the feedback from a more experienced member of this forum but from my perspective it's nothing ground-breaking. 

Maybe my comment sounds a bit harsh or arrogant. I am trying to say that the media, as always transformed and hyped what this paper is trying to say. So I go back to my initial statement that this multiverse theory that you or anyone else proposes is un-testable as of yet.

I will revert soon.

10 hours ago, beecee said:

Hi.....Firstly in actual fact, it isn't a scientific theory, [which is the highest accolade any scientific model can have] it is simply hypothetical. Secondly mostly all scientific theories and models start out as speculative and hypothetical, and to use a favourite terminology of mine, need to run the gauntlet before reaching theory stage. Thirdly as yet we cannot even say with any confidence how or why the BB happened, and noting that this theory [the BB] only goes back as far as 10-43 seconds after the initial event, of which we are ignorant. So you can see that evidence for any multiverse is  unlikely to be evident.

Are you not a believer of the Big Bang theory?

Edited December 12, 2018 by Siyatanush
Grammar

[beecee]

3 hours ago, Siyatanush said:

Are you not a believer of the Big Bang theory?

The BB is supported by four main pillars of evidence....

[1] The observed expansion:[2] The predicted CMBR: [1] Abundance and nucleosynthesis of the lighter elements: [4] Large scale galactic structure:

The BB describes the evolution of space and time from t+10-43 seconds. 

I accept the BB as the most likely model describing how our universe evolved due to the preponderance of evidence.

Edited December 12, 2018 by beecee

[Silvestru]

3 hours ago, Siyatanush said:

I will revert soon.

Take your time, I will be here Siyatanush. If you have time you can go through the materials that we added above for a more constructive talk. Don't worry if you don't understand some things especially from the Hawking paper. (I had to read reviews and commentary on some sections as I could not understand few parts) 

Don't forget that we are not here to prove/disprove anything just to have an interesting chat.  

[Eise]

On 12/11/2018 at 8:09 AM, Siyatanush said:

Do the forum members support the multi universe theory?

I don't. But there are notable physicists who do. 

On 12/11/2018 at 8:09 AM, Siyatanush said:

Can you give your reason for whatever you believe to be true?

Science should explain what we can observe. In physics this means we observe events, and try to find the regularities and put them into 'laws of nature', which are then abstract descriptions of what factually happens. To say it in other words: the laws of nature are descriptions of causal relationships.

A very special example of this is a measurement. Our measurements are also caused by something. Say we have a method of measurement, M1. Now scientists must guess: what kind of phenomenon could cause measurements like M1? Here you must realise that our 'language equivalent' of causal relationships are sentences like 'if A happens, then M1 happens'. However, when that sentence is true, it does not mean that 'If M1 happens, then A has happened'. So we must test by other experiments to see if we find other causal relationships, e.g. 'if A happens, then M2' happens. So we measure according M2, and it is confirmed. That does not yet mean that we know A is true: maybe M3, another kind of measurement for A doesn't work out. So science can never be 100% sure.

But now for the multi-universe. It supposes that there are no causal relationships between the universes. So how can we hope to find measurements that prove that there are other universes? 

Then there are several kinds of 'multiverses': those that follow from the 'many worlds interpretation' of quantum mechanics, for which the above ('no causal relationship') is definitely true. Also, it is just an interpretation, the many worlds interpretation is empirically equivalent with other interpretations. 

Then there are those presupposed by string theory. The problem with string theory is that it does not lead necessarily to a universe like ours. Many different kinds of 'universes', with different laws of nature can be derived from it. So one way out is to postulate that all these different universes exist, and we happen to be in the one we actually observe. But again: such idea is not supported by any kind of measurement. Measurements occur, by definition, in our universe. So in my opinion, even if physicists do not like the standard model, because of its many parameters that only can be measured, but not derived from a more fundamental theory, we still must explain how our universe works. Theoretically, it is possible we find nothing that explains the standard model. It is just as nature is. Full stop. 

Edited December 12, 2018 by Eise

[Airbrush]

The multiverse idea is simply the next logical step in cosmic organization.  1 Solar systems, 2 galaxies, 3 galaxy clusters, 4 galaxy superclusters, then what comes next?  Big bangs separated by vast distances?  5 a multiverse of big bangs.  Then 6 a multi-multiverse of multiverses? 

If there was no multiverse then does that mean the big bang is the entire universe?

Edited December 13, 2018 by Airbrush

[QuantumT]

Hello, I'm new here. This is my first post.

This is a very interesting subject. I have wondered about the acceleration of our cosmic expansion for long, and to me a multiverse is what makes most sense. Surrounding universes pulling with their gravity from all sides. If not anything else, that acceleration could be the evidence we would demand, to accept a multiverse.

Please do not confuse the multiverse with the "quantum many worlds theory", which is completely different and totally unprovable. I see people mixing those up all the time.

[Siyatanush]

20 hours ago, Silvestru said:

Take your time, I will be here Siyatanush. If you have time you can go through the materials that we added above for a more constructive talk. Don't worry if you don't understand some things especially from the Hawking paper. (I had to read reviews and commentary on some sections as I could not understand few parts) 

Don't forget that we are not here to prove/disprove anything just to have an interesting chat.  

It will take me some time to understand what Hawking wrote. Thanks for your patience.

[Airbrush]

"...Proponents of one or more of the multiverse hypotheses include Hugh Everett,^[23] Brian Greene,^[24][25] Max Tegmark,^[26] Alan Guth,^[27] Andrei Linde,^[28] Michio Kaku,^[29] David Deutsch,^[30] Leonard Susskind,^[31] Alexander Vilenkin,^[32] Yasunori Nomura,^[33] Raj Pathria,^[34] Laura Mersini-Houghton,^[35][36] Neil deGrasse Tyson,^[37] Lawrence Krauss, Sean Carroll^[38] and Stephen Hawking.^[39]"

https://en.wikipedia.org/wiki/Multiverse