26th Mar, 2019

University of Southern Mississippi

Discussion

Started 20th Mar, 2019

Dear all,

in accordance with Friedmann-Lemaitre-Equation there are three different possibilities of space curvature which can be described mathematically and imparted graphically or analogously (Closed, Openend or Flat Universe). In the attached poster a fourth graphic representation is shown, which is however only graphically derived.

Is this sketch describable within Friedmann-Lemaitre-Equations? How can we interpret this sketch? A Universe that is truly infinite, although it has a defined start and a defined end point?

What would be a 3-Dimensional mathematical object to describe the plot (closed hypertorus, while closed means without a connection in the center?). And what numbers for curvature parameter k and density Parameter Ω make sense for this sketch?

I have created this plot purely graphically and wonder whether a mathematical interpretation of such a shaped space-time is possible, or whether it inevitably leads to paradoxes and is thus a graphic that can be drawn abstractly, but ultimately makes no mathematical sense.

Thank you!

I might add that my paper on a "Bipolar Model"...of hyperbolic space was rejected by Physics journals as being too mathematical and by Mathematics journals as being too physical. It primarily raises the question of what coordinates are "physical". This is not easy to answer. For example rotating coordinates are considered non-physical, but if you are in them, they are real and there is physics associated with them. As mentioned above, one needs to consider the matter distribution to make sense of them.

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20th Mar, 2019

In the "Closed Universe" and in the "Opened universe" you have put the geodesic views from the plane, in the "Flat universe" following that logic (which I do not know if it is the correct one) would be wrong, it would be a "triangle".

In the last figure, notice that it begins as two "Opened universe" reflected, and that in the part that expands to infinity join.

Therefore I would say that the figure you are looking for would be the "Opened universe" rotated, like an hourglass

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@Sergio Garcia Chimeno

Please note that the graph shows the size of the universe as a function of time, depending on the k and Ω parameters. While a closed universe reunites in one point (sometimes called Big Crunch), the open universe continues to grow. In the flat universe, however, growth is no longer recorded at some point due to the parameters, but there is an asymptotic approximation to a fixed size of the universe. This is at least the interpretation I was taught - and here the two-dimensional representation of a triangle - I think - would not be correct. But maybe I am wrong too.

Note that the fourth graphical representation says something strange if we accept that the x-axis represents time. So here we would have a universe that grows, then strikes backwards due to a too large exponential gradient - in this case into the temporal past (if x-axis is time). For me this is very difficult to understand and i wonder if there is anything mathematically to be read out of this graph, or if its just a nonsense plot.

Actually there is a common misunderstanding with the Friedmann-Lemaitre equations and the solutions for the Robertson-Walker metric. The point is that the parameters k and Ω define the metric, which is a local entity and does not imply the global structure of the space(time). Topologically, if k>0, the universe must be closed. But for k=0 or k<0, the universe can be either closed (and finite) or open (and infinite). For k=0 for example, a flat universe with periodic boundary conditions (aka torus) is not excluded. And for k<0 there exist several topologically distinct manifolds with constant curvature.

I am saying this because the commonly sketched 3 kinds of universes: closed 3-sphere, flat infinite space, and negatively curved 3-hypersphere is just not the complete picture.

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The other thing is: I do not understand the fourth picture. Where does the fourth option actually come from? I understand the graphics is meant to denote the timeline of the universe (bottom to top), but then I do not understand the fourth picture at all.

From what I said above, the parameter k defines the curvature of the RW metric. This by itself does not imply the global, topological properties of the universe. For this, additional input is needed, namely equations of state or in other words: models of matter. This then gives the "radius" as a function of a cosmological time parameter, and may lead to big bang, crunch, some periodicity maybe, ever expansion and so forth.

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Dear Oliver,

Thank you very much for the gainful answer.

To your question, where the fourth drawing did come from:

I just thought about how to graphically represent an entity that is infinitely extended in all directions, but is still a finite entity. The graphic thus has both a defined start and end point, but is nevertheless infinitely extended in all directions. As noted in the question, the derivation is purely graphical and I was just wondering if there is a mathematical interpretation of such a body.

I came up with the idea because the concepts of a closed universe as well as of an open universe were always coming towards me in my work, but they were then always closed **"or"** open. So the question for me was: Is there a description for a system that is open in all directions **"and"** closed with a defined start- and endpoint at the same time.

Aleksandar, I think you're going about this the wrong way, you can't just draw a picture then look for an equation that fits, you need to first propose a density profile (Robertson and Walker assumed homogeneous and isotropic) then from that work out the metric and finally calculate a graphical representation if that is feasible. The first three on your poster cover all the three possibilities of the Robertson-Walker metric so you need a different distribution of energy to start from. To work that backwards which is what I think you are trying to do, you first need to turn the picture into the equations for the metric. I would advise you look at a variety of existing metrics to see the form of what would be needed.

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Thank you for your comment. Basically I think you can draw a picture to see if there could turn out new thoughts or not. But of course there is no metric here. After the drawing I also did not find a corresponding formulation, so that I assume myself that it is a drawing that can be drawn, but nothing more.

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Aleksandar wrote:

Not so fast. Recall **Ringermacher's** discussion of oscillating accelerations (2015, 2017), and his earlier (2012) speculations about combining negatively curved (hyperbolic) regions of space ("voids") within an FRW universe.

Please keep going a little more!

Nigel

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Hi...

The FLRW metric is a solution of the Einstein eqns for a Constant-Curvature space. There are only 3 possibilities - already mentioned in your discussion. Anything else is not a solution of FLRW. To accommodate your 4th option requires a new metric, perhaps a time/space-dependent curvature solution. I have not yet found such a solution of the Einstein eqn.

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I might add that my paper on a "Bipolar Model"...of hyperbolic space was rejected by Physics journals as being too mathematical and by Mathematics journals as being too physical. It primarily raises the question of what coordinates are "physical". This is not easy to answer. For example rotating coordinates are considered non-physical, but if you are in them, they are real and there is physics associated with them. As mentioned above, one needs to consider the matter distribution to make sense of them.

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What is the cosmological impact of "The Radcliffe Wave" for understanding our galaxy's formation?

Discussion

6 replies

- Asked 9th Jan, 2020

- Gloria Lee Mcmillan

Dear Colleagues,

I am a liaison (informal) at my university between science and the arts. I have family in planetary astronomy but this is far afield.

LINK to VIDEO: https://news.harvard.edu/gazette/story/2020/01/largest-gaseous-structure-ever-seen-in-our-galaxy-is-discovered/

A question or two:

What does this newly-reported Radcliffe Wave of gaseous proto-stars tell us about how our galaxy originated?

Is there any chance that this wave will make some difference in our own sun's behavior?

Are Dr. Hans-Otto Carmesin Models supported by the Supernova Observations?

Discussion

4 replies

- Asked 27th Apr, 2021

- Marco Pereira

Dr. Hans-Otto Carmesin is a prolific theoretician who wrote among other things, these two books:

Modeling SN1a data:

Data H0_20210424.pdf

That said, he leads a field where a lot of unsupported claims are tossed around without anything to support it. That is why they are unsupported..:)

As Dr. Carmesin professed, scientists should follow the teachings of Aristotle and always use the simplest possible model that is consistent with Reality.

Dr. Carmesin's model has nonlocality, dimensional transitions, the usual suspects (Dark Matter and Dark Energy), and an epoch-dependent Dark Energy (figure 8.15 on the first book above).

It is a fantastic work and from my point of view, unnecessary and incorrect.

Unnecessary because there is HU which is capable to explain everything Dr. Carmesin explained without the need for a Big Bang, Dark Energy, Dark Matter, epoch-dependent Dark Matter, Polychromatic Vacuum. Because of that, Aristotle and Occam's Razor would support HU and rebut Dr. Carmesin's work.

Attached is my summary of the problems I found on Dr. Carmesin's claims that SN1a distances support his work.

This is an ongoing discussion.

Dr. Carmesin provided a reply to my objections and **confirmed that he is not sure if his model can predict the SN1a distances**.

In fact, he said: **"My theory does not fail to predict these distances. I just did not calculate these distances yet for a good reason: I tested my full theory by calculating the measured Hubble constants of the Hubble tension."**

My plot of his model showcases that the model fails to predict the observed distances.

I also drive home the fact that Dr. Carmesin's model modifies the meaning of H0 (the Hubble Constant). Because of that comparison of results are not straightforward and seems to not have been considered before.

The plots also show that HU model predicts the observed distances without any parameters.

Hawking's legacy? What is it?

Question

164 answers

- Asked 18th Mar, 2018

- Stephen Crothers

Black hole thermodynamics and the Zeroth Law [1,2].

(a) black hole temperature: **T**_{H} = hc^{3}/16π^{2}GkM

The LHS is intensive but the RHS is not intensive; therefore a violation of thermodynamics [1,2].

(b) black hole entropy: **S = πkc**^{3}A/2hG

The LHS is extensive but the RHS is neither intensive nor extensive; therefore a violation of thermodynamics [1,2].

(c) Black holes do not exist [1-3].

Hawking leaves nothing of value to science.

[1] Robitaille, P.-M., Hawking Radiation: A Violation of the Zeroth Law of Thermodynamics, *American Physical Society* (ABSTRACT), March, 2018, http://meetings.aps.org/Meeting/NES18/Session/D01.3

[2] Robitaille, P.-M., Hawking Radiation: A Violation of the Zeroth Law of Thermodynamics, *American Physical Society *(SLIDE PRESENTATION), March, 2018, http://vixra.org/pdf/1803.0264v1.pdf

[3] Crothers, S.J., A Critical Analysis of LIGO's Recent Detection of Gravitational Waves Caused by Merging Black Holes, *Hadronic Journal*, n.3, Vol. 39, 2016, pp.271-302, http://vixra.org/pdf/1603.0127v5.pdf

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