The Genius of Lemaitre and the Hesitant Universe

Since 1927, theory and observations have shown that the Universe is progressively expanding. Georges Lemaitre, a Belgian and contemporary of Einstein achieved a piece of groundbreaking work. The concept of cosmic repulsion led him to model a universe with accelerated expansion (initial inflation) followed by a stagnation period and then a second expansion starting around 6 billion years ago. His work has now achieved renewed recognition due to it's solution to the age of the universe and associated time taken for galaxies to form. (source: The Wraparound Universe by Luminet, 2008)

Coincidentally, this model is just like my own intuitive version, where gravity from a pre-bigbang build-up of matter & structure has wrapped around the universe to become a force of repulsion. Why isn't this idea mentioned in Luminet's book? It's so simple, logical and elegant.

 

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Here is the result of a Google search on "Wraparound Universe by Luminet". Topology is always an interesting topic and in the links I found I don't see the discussion of the "hesitation". Can you give a recap of what he thinks caused the hesitation and the resumption?

I understand the idea of a pre-big bang build up of matter and structure. I also can understand the concept of gravity warping around the universe if that object contains all of the matter and energy of the universe. But I have trouble with the repulsion concept. Please elaborate.

 

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I'd have to re-read the chapter of the book which is currently at home. But from memory, it's a result from the manipulation of the equations resulting from general relativity. He didn't have an answer as such as to why there was this hesitation and a second inflation, just that Einstein's 'cosmological constant' was obviously a justified necessity and shouldn't be discarded. I'll give a better answer tomorrow.

You're the first person to say this and I'm delighted

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It's so simple it's crazy: draw a circle on a piece of paper to represent the wraparound universe and draw a small dark circle (or dot) at the top to represent an object. Next, draw a dot to the right of the object to represent a gravity particle/wave which is travelling clockwise. Draw an arrow from the gravity partcle/wave back towards the object to represent the direction of force i.e. attracting. Now draw the gravity particle at the bottom of the wraparound universe heading clockwise with the force of attraction still in the direction that it has come from. Finally, draw the gravity particle as it approaches the initial object from the left and draw the direction of force as before. You should now see that the direction of force is AWAY from the initial object. If another similar object were next to it, then the gravity particle would be attracting this away from the initial object i.e. as if it were being repulsed.

I really hope you get to understand this most simple of ideas. I'm sure you will.

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(Remember that I'm not using Einstein's rubber sheet proposal at all, just particles in empty space)

 

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I'd like to see it. If Lemaitre has an idea about the distribution of energy and the point where matter forms and gravity takes effect, then I can see how it would be possible for expansion to have a hesitation.

For example if the early universe was mostly energy and sparse matter, then expansion driven by "dark energy" would greatly exceed the gravitational attraction between particles of matter. This could be exponential and could go on for a period of time. He could have a particular scenario that describes his thinking as to what that timing was. Then there could be a period of significant matter formation, maybe related to the overall energy density of the expanding universe, i.e. when some limit of energy density is reached as a result of expansion, matter could form abundantly. The formation of matter would require that the energy driving the expansion be converted to energy to provide for the formation of matter. The expansion would hesitate as the matter formed. Once the period of matter formation ended the expansion would resume driven by the remaining "dark energy". With the presence of the newly formed matter, gravity would take on the characteristics the we observe. Acceleration of the expansion might occur due to the inverse square rule as the distance between galaxies increased.

I will be interested in what his scenario is.

Don't be too excited because my ideas have been banned from The Cosmology Forum by D H, and my views are disparaged roundly by Prometheus, AlphaNumeric, Ophiolite, and Oli among others. Take what I say for what it is worth to you.

I think I will understand it and I believe if you are willing to discuss it you will see that I can understand it. I hope you are ready to consider some possible flaws in your ideas because I may think there are some as we get into it.

I do understand the idea of a pre-big bang build up of matter and structure. I would call one possible build up a big crunch that precedes the Big Bang. One question. If the matter and energy of the universe is gathered into such a big crunch with its particular gravitation signature, wrapping around if you like, then how does an object get out to point A to be effected by gravity waves in that location?

 

It makes more sense for you to read the book first hand then for me to try and translate I think.

I understand the situation perfectly. No problem.

I'm flexible to new opinions and considerations and open to the possibility of flaws in my arguments.

Were talking in slightly different languages at present. I'm sure this will be resolved when you read Luminet's book which we can use as a common reference point.

btw one point that I wish to make concerns a quote from Luminet:

The idea of a pre-big bang build-up of (spinning) structure and matter means that during this time proto-galaxy formation has already started to take place. Hence the calculated time for galaxy formation may be more relevant to the time needed for star formation only.

 

I will be receiving some scans of certain pages that I selected from the index on Amazon. After I read them we can get into the discussion.

It should be interesting. I am trying to improve my view of cosmology and I am certain that Lemaitre, via Luminet has some slants on the standard cosmology that I will appreciate.

I can see how that could be the case. Personally I am looking for ideas about a first round and a second round of star formation with a thermalization period in between that could explain galaxy formation and separation. As we get into it I hope you will let me bounce my ideas off of you as we discuss what Lemaitre/Luminet has to say and your particular ideas.

 

I'd be delighted.

 

I read the pages related to Cosmic Repulsion, chapter 36. I think you understand the concept of repulsion as it relates to the cosmological constant. Many think of it as negative energy density, dark energy, or the force behind the expansion that we observe.

Correct me if I misinterpret the effect of the concept of "hesitation" but I take it as a topology that results from an initial exponential expansion, a period of slowing, and then a universe where expansion is accelerating. Does it represent a universe where energy density changes over time? And during that period of hesitation, galaxy formation which has been taking shape from before the Big Bang finally completes itself, and once complete, the separation between galaxies begins to accelerate?

 

I haven't got these terms clearly defined in my mind. The way I see it is that there is the expansion of galaxies due to the possible expansion of the 4D shape of the cosmos and also possibly due to the matter contained within it. Because I have started at a different place to everyone else i.e. assuming that Einstein's concept of space-time is wrong, then even the simplest terms need thorough clarification. So, in my mind, there are just two causes of the galactic expansion; (i) force due to matter (ii) 'outside' force acting on 4D topology of the universe.

That's exactly how I read it.

I assume so. What exactly do you mean by 'energy density'? That the amount of energy is fixed but that the amount of space that it fills is increasing??

That's it exactly. I think that this simple idea has enormous potential.

 

Yes, the amount of energy is fixed in a given space at a point in time and the energy density becomes variable as the amount of space changes over time. When I refer to the energy in a given space I am including all forms of energy in that space including matter, electromagnetic radiation, dark energy, dark matter, everything that can be described as energy whether observed or theoretical.

See footnote 7 from the chapter 36 Cosmic Repulsion. Let’s start there in getting a common understanding of terms:

“The cosmological constant is comparable to the inverse of the square of length. For the physicists of the infinitesimally small, this length is interpreted as the distance scale at which the gravitational effects due to the vacuum energy become manifest on the geometry of space-time. They estimate that this scale is Planck length, or 10^-33 centimeters. For astronomers, the cosmological constant is a cosmic repulsive force that effects the rate of expansion on the scale of the radius of the observable universe, or 10^28 centimeters. The ratio between these two lengths is 10^61, which is in fact the square root of 10^122.”

Now go to pages 213 to 216 and read from the perspective of the footnote, i.e. the huge energy difference between the theories at the quantum level and the macro level. Let’s start with vacuum energy: http://www.astro.ucla.edu/~wright/cosmo_constant.html

The cosmological constant is said to represent the force that the vacuum of empty space would have on an expanding universe within it. I’m not saying that there is any empty space or that our universe is expanding into empty space because I have formed my own opinion on that imponderable

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. But the concept is that this empty vacuum which surrounds our finite expanding universe is in effect pulling at the universe causing the expansion. That is vacuum energy density, i.e. a constant force driving the expansion. It is called it the cosmological constant and represents that constant force of expansion that can be explained using the empty space concept.

The force is mysterious if you believe that our observable universe is all there is, i.e. that there is no such empty space surrounding it, but if you look for a way to explain that mysterious “dark energy” driving the expansion and especially the inflationary epoch during the first instant of expansion, then the concept of vacuum energy density is there for you. Vacuum energy density and negative energy density are the same thing.

Next, you use the term 4-D topology. Would you name the 4 dimensions that make up 4-D topology and say a little about it relative to 3-D space plus time? This question is just to be sure we have the same definitions as we discuss things.

And one more question for clarification. You mention the "expansion of galaxies due to the possible expansion of the 4D shape of the cosmos". Are you talking about the observed separation of the galaxies as in chapter 32, The Rate of Expansion?

I assume you don't mind if I make a reference to this thread in my blog because it begins to show the origin of my ideas about the two levels of order. The similarity between quantum action and arena action is the idea I use to solve the energy discrepancy between the two levels. There is a connection between the two levels during the arena expansion when the quantum realm of the arena forms from the energy density of the expanded big crunch core. The core is the “source particle” and the energy of the quantum realm is extracted from the expanding core energy. The extracted energy retains its energy density in the form of matter while the rest of the core energy is devoted to the force of expansion called dark energy. The energy density of the dark energy portion decreases as the space it occupies increases, while the energy density of the matter is locked into the space required for matter to function properly. Matter doesn’t expand as the observable universe expands.

 

Sure you can reference this in your blogspot. I think in pictures and find it difficult to fully appreciate your ideas. Maybe it's because I'm so self-absorbed with my own, I don't know..

 

You just said a mouth full. There is a preoccupation with one's own speculative thinking and it does make the speculations of someone else seem very strange

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. My view is that there is a reality that our speculations are trying to touch and two people can touch on that reality at different points in that reality. Mutual discussion can be beneficial to the personal satisfaction of our own speculations if you follow my reasoning.

 

Nicely put. It'll be good when we get new data from the cutting edge of science discovery. That's what I'm waiting for.

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Any idea can be elegant if you aren't required to give details. What makes a theory elegant is that when you do the details they are short and succinct.

Otherwise, if we went by elegance "God did it" would fit the bill.

 

I recommend you obtain Luminet's 'The Wraparound Universe' and I've just picked up my ordered library book 'Dark Side Of The Universe' by Iain Nicholson (my old university lecturer) which looks to be very good reading with excellent colour piccies. These two should be our points of reference I think.

 

What did you study at university? A quick google has suggested it wasn't physics. Perhaps psychology? veterinary science?

 

You're the person who said "Using your imagination isn't science", right? (lol)

 

Ignorant imagination is worse than unimaginative knowledge, at least the knowledge can be applied to something.

 

What is it about you crackpots that make you unable to read?! I said that the imagination step comes after one has done a rigorous mathematical study to derive some results. For example, much of relativity was known before Einstein via the work of Lorentz and Poincare but Einstein had the vision to interpret the results correctly.

 

The hijacking and trolling begins, there are the "you are wrong" statements, then the "I told you you were wrong and now you are stupid" starts, then the peanut gallery jumps in to support their smart physics and math heroes, and the work of all the self proclaimed expert professionals turns into obnoxious arrogance.