Universal 'Now' at Time-Zero

[tar]

StringJunky,

 

Understood. But if for instance, I have a question about the evolution of the voids, I cannot tell, since relativistic effects are not modeled, whether the distant voids are the size and shape they actually would be, at 13.8 billion years old, or if the distant strings pictured at a distance if 1 billion lys are actually the size and shape they were at 12.8 billion years old, since that would correspond to the data received from the telescopes. So the size of the model matters, and the depth of the model matters, and there is not a realistic way to consider the whole volume as existing at once. You either have the way you know it could be, or the way it looks, and if you have a "purpose" for showing the thing, you have obscured some information from the actual that would be good to include, so that people looking to learn, or figure something out, are not misinformed.

 

Regards, TAR

Edited August 21, 2016 by tar

[StringJunky]

Some info about that universe-in-a-box-simulation. This video puts you in amongst the filaments.

 

 

The Millennium Simulation featured in this clip was run in 2005 by the Virgo Consortium, an international group of astrophysicists from Germany, the United Kingdom, Canada, Japan and the United States. A virtual cube of 2 billion light years on a side was "filled" with 10 billion "particles" whose evolution was computed using the physical laws expected to hold in the currently known cosmologies. The initial distribution of matter, that resembled the conditions present when the cosmic microwave background radiation was emitted (about 379,000 years after the universe began) was allowed to evolve, and the formation of galaxies and black holes in the simulation were recorded. After all the computing work was done (28 days, at a rate of 200 billion calculations per second) 20 million galaxies were formed in the initial space. These galaxies and the dark matter around them formed web-like structures that resemble the shapes observed by the most recent data available in cosmic surveys, such as the Sloan Digital Sky Survey. Also very importantly: the simulation provided support for our current "standard model" of cosmology, the so called: Lambda Cold Dark Matter Model.

 

Edited August 21, 2016 by StringJunky

[Mordred]

the size of this model is 130 Mpc if I recall correctly

[tar]

StringJunky,

 

Nice video, but it is after all a simulation, and it is VERY unrealistic to then navigate through the simulation as is done at the end. Exciting, but not very useful. It makes one think they can see the whole thing at once. I am thinking mostly about the fact that the navigation was at superluminal speeds. Just for instance, at that speed, as you approached an item you should see it moving backward and devolving, which does not occur in the simulation. As a matter of fact you would not "see" it at all, as the electromagnetic waves hitting your eyes would be at such high frequencies as to be considered gamma rays or cosmic rays. It establishes a model in one's head that does not correspond with the huge nature of actual universe. I am thinking you make the same mistake when considering the early universe while in a hot dense state, as some one thing, with no dimensions.

 

Regards, TAR

[StringJunky]

StringJunky,

 

Nice video, but it is after all a simulation, and it is VERY unrealistic to then navigate through the simulation as is done at the end. Exciting, but not very useful. It makes one think they can see the whole thing at once. I am thinking mostly about the fact that the navigation was at superluminal speeds. Just for instance, at that speed, as you approached an item you should see it moving backward and devolving, which does not occur in the simulation. As a matter of fact you would not "see" it at all, as the electromagnetic waves hitting your eyes would be at such high frequencies as to be considered gamma rays or cosmic rays. It establishes a model in one's head that does not correspond with the huge nature of actual universe. I am thinking you make the same mistake when considering the early universe while in a hot dense state, as some one thing, with no dimensions.

 

Regards, TAR

The simulations are not trying to show relativistic viewpoints, as I said before. I'm only interested in the current view, not my imagination or whether it concurs with it; you should do the same too. That is the state of the current art. You fuss about irrelevances and minutiae too much. I don't want that to come across as ill-tempered, it's a sincere observation.

Edited August 21, 2016 by StringJunky

[tar]

I understand the idea of a simulation, and appreciate its value, but there are aspects of reality that are ignored that might be very important. You say that on a large scale the place is homogeneous and isotropic, but yet we do have large scale structures in the place, walls of galaxies, voids and great attractors, to where identity can be viewed, where looking in one direction looks different then looking in the other. That is, when thinking about the evolution of the voids, are there areas of space, where the voids are of different sizes or density, like a fractal type situation, where there is character to the landscape, at every level?

Don't we need to care both about our current model and the current actual empirical view? You need the one, to comprehend the other.

And without taking relativistic considerations into account you lose the reality of the situation. After all, we are talking about the genesis of the universe, which has already happened. We can only consider such in our imaginations, guided by what we see, and the implications thereof.

[Strange]

Nice video, but it is after all a simulation, and it is VERY unrealistic to then navigate through the simulation as is done at the end. Exciting, but not very useful.

 

 

It is useful because it confirms that that the model produces results consistent with what we observe. The simulations only produce the correct results when the right amount of cold dark matter is included, for example. This helps confirm our models of the universe.

[tar]

Strange,

 

Yes, very impressive, and indeed with the right inputs and programming the model can approach reality, and as you say confirm the model is correct. But there is the slight chance, that a different correction to a different program would also result in a simulation, that looked like our empirical view of the place. It is reverence to the state of the art that is what I am playing devil's advocate against. The program is already fixed and decided upon, before it is run. Corrections are made and the thing is reprogrammed to end up more closely approximating reality. The equation is tweeked to accommodate some additional terms. So how much can you learn from a program that is already set. It is like doing a Sudoku that is already designed. Yes it is going to wind up with all the columns and all the rows and all the boxes with the numbers 1,2,3,4,5,6,7,8,9...but it was supposed to.

 

So my cudos to the state of the art, but the model is not as interesting to me as the place that is being modeled. The place holds more surprises and beautiful relationships just the way it appears, than do the equations, that are already static and prone to human error, simplification, and omission, and misinterpretation.

 

The point, in terms of this thread is to question StringJunky's concept of a hot/dense state, with no dimensions. You perhaps can write an equation, but what does it mean in terms of reality? How do I design the thought experiment, without the use of time and space?

 

Regards, TAR

Edited August 21, 2016 by tar

[michel123456]

Yeah, that's what seems to happen in the universe-in-a-box simulations. Mass-density won't be even along the filaments.

Then that means that there exist an interaction between the expanding voids and the filaments. The filaments are thus stretched by some kind of hypothetical force that expands the bubbles of voids.

But we know that there is no such kind of interaction: we know that expansion is occurring without a force being required. Which makes me think that this kind of model is not easily compatible with the space expanding theory.

[Strange]

The program is already fixed and decided upon, before it is run. Corrections are made and the thing is reprogrammed to end up more closely approximating reality. The equation is tweeked to accommodate some additional terms. So how much can you learn from a program that is already set. It is like doing a Sudoku that is already designed. Yes it is going to wind up with all the columns and all the rows and all the boxes with the numbers 1,2,3,4,5,6,7,8,9...but it was supposed to.

 

Simulations like this are used all the time to check our models. The reason you can have a low cost phone with more processing power and memory than all the computers in the world a few decades ago is because we can simulate. The reason we have quieter, more efficient and safer airplanes than in the past is because of simulation. So your doubts are unfounded and, to be honest, a little silly.

 

 

 

The point, in terms of this thread is to question your concept of a hot/dense state, with no dimensions.

 

If it is hot and dense, then it must have dimensions. The idea of a state with no dimensions is pretty meaningless, if you ask me.

But we know that there is no such kind of interaction: we know that expansion is occurring without a force being required. Which makes me think that this kind of model is not easily compatible with the space expanding theory.

 

As the model is based on exactly that theory, I don't see how it can be incompatible.

[michel123456]

 

As the model is based on exactly that theory, I don't see how it can be incompatible.

You don't see that if the voids get larger the filaments are stretched?

Ultimately, the filaments will get ripped apart. Just as if there was an interaction between the voids and the filaments.

This structured model is not what a thinking mind would expect from an expanding universe that follows the rules imposed by the space expanding paradigm.

If there were an interaction between the space expanding and the filaments, a regular force, then yes, maybe. But without any interaction, no. In this last case, the voids should remain roughly the same sizes.

Edited August 21, 2016 by michel123456

[tar]

Strange,

 

Point taken about the usefulness of simulations...but simulation of a complete process and arrangement from start to finish, with all important variables included is one thing, because you have the starting conditions, interactions and ending conditions, all understandable and checkable. It is something quite different to simulate the rotation of a galaxy, being the one side is happening 100,000 years away, in terms of information travel time, from the other end.

 

Regards, TAR

[StringJunky]

If it is hot and dense, then it must have dimensions. The idea of a state with no dimensions is pretty meaningless, if you ask me.

I was referring to spatial dimensions, not dimensions of other parameters. When I was referring to 'space', I meant that which photons, or other things, can travel through and relay information to other areas that they may travel to..

Edited August 21, 2016 by StringJunky

[Strange]

It is something quite different to simulate the rotation of a galaxy, being the one side is happening 100,000 years away, in terms of information travel time, from the other end.

 

 

I can't imagine why that would be a problem. The simulation will account for the time it takes for matter of light to travel between points being simulated. At each "tick" of the simulation clock each point can only be affected by things which are within the distance that light travels in that period.

 

We do the same when we simulate microprocessors: we have to account for the delay from one side to the other. And that might be many times longer than the steps in the simulation.

I was referring to spatial dimensions, not dimensions of other parameters. When I was referring to 'space', I meant that which photons, or other things, can travel through and relay information to other areas that they may travel to..

 

Me too.

[tar]

StringJunky,

 

But before the place became transparent to photons, there were electrons and protons, and these things existed over here and over there, and gravity and vibrations and energy gradients were certainly possible, creating a difference between over here and over there. That there could be something that happened everywhere at once would require both time and space to talk about. And if we are not talking about the three dimensions of space and the one of time that define spacetime, what dimensions are we talking about?

 

Regards, TAR

Strange,

 

I don't see a problem either, if the time it takes various forces and energies to propagate are built into the simulation...but the simulation posted here had us navigating through the web in a manner completely ignoring the size of the place and the effects that traveling that fast would have on what was being seen.

 

Regards, TAR

[StringJunky]

StringJunky,

 

But before the place became transparent to photons, there were electrons and protons, and these things existed over here and over there, and gravity and vibrations and energy gradients were certainly possible, creating a difference between over here and over there. That there could be something that happened everywhere at once would require both time and space to talk about. And if we are not talking about the three dimensions of space and the one of time that define spacetime, what dimensions are we talking about?

 

Regards, TAR

Whatever preceded spacetime; dimensions relate to any parameters, not just spatial ones. Nothing is required, it is required by your commosense and that has been proven many times to be false; speaking generally and not personally.

Edited August 21, 2016 by StringJunky

[tar]

StringJunky,

 

I will have to leave you with that thought. I have no reply because it makes no sense to me. I do not comprehend what you are talking about. You are making something up, and not relating it to the waking world, where I can experience the things we are referring to as dimensions. Are you saying that any variable I can imagine is a dimension? Like would it make a difference if I was standing to your left or right or if I had my eyes closed, or if I was spinning on my heel? What is on your list of parameters that qualify as dimensions?

 

Regards, TAR

(Good luck with the smoking cessation by the way. Read the nicotine tapering method thread in Medical, Phi for All has some good advice...helped me quit for good.)

Edited August 21, 2016 by tar

[Mordred]

Tar that simulation tests more than just expansion. In excellent agreement it also tests our knowledge of nucleosynthesis in the metalicity details. Also it generated all known galaxy types.

 

How expansion works with regards to gravity is a rather tricky process to fully appreciate. With somewhat surprising results.

 

First off the range from gravitationally bound objects where the cosmological constant takes over, though this isn't only cause of expansion.

 

To calculate the distance has to do with relative field strength per cubic metre.

 

Gravity locally is far stronger than the cosmological constant.

[tar]

Mordred,

Did it generate any galaxy types we don't know about?

 

What I mean, is did it show us what to look for, or just verify what we already guess is true?

 

On the strings stretching around the voids, I would suggest in an analogy type of way, that you can stretch a piece of gum into a very long and thin string, without requiring space to expand in some unexplainable fashion.

 

Regards, TAR

Edited August 21, 2016 by tar

[StringJunky]

StringJunky,

 

I will have to leave you with that thought. I have no reply because it makes no sense to me. I do not comprehend what you are talking about. You are making something up, and not relating it to the waking world, where I can experience the things we are referring to as dimensions. Are you saying that any variable I can imagine is a dimension? Like would it make a difference if I was standing to your left or right or if I had my eyes closed, or if I was spinning on my heel? What is on your list of parameters that qualify as dimensions?

 

Regards, TAR

(Good luck with the smoking cessation by the way. Read the nicotine tapering method thread in Medical, Phi for All has some good advice...helped me quit for good.)

Anything that can be measured has dimensions. A dimension is a variable.

 

Thanks.

Edited August 21, 2016 by StringJunky

[Strange]

I don't see a problem either, if the time it takes various forces and energies to propagate are built into the simulation...but the simulation posted here had us navigating through the web in a manner completely ignoring the size of the place and the effects that traveling that fast would have on what was being seen.

 

You can look at the results of the simulation at any speed, direction, etc that you want. That says nothing about the validity of the simulation.

[Mordred]

Mordred,

Did it generate any galaxy types we don't know about?

 

What I mean, is did it show us what to look for, or just verify what we already guess is true?

 

On the strings stretching around the voids, I would suggest in an analogy type of way, that you can stretch a piece of gum into a very long and thin string, without requiring space to expand in some unexplainable fashion.

 

Regards, TAR

No other types of galaxies weren't generated afiak. It is an immensely huge dataset.

 

Funny I don't find expansion unimaginable. Of course I've spent years studying expansion. Quite frankly nothing is more natural than the development of those strands and expansion.

 

It follows the rules of an adiabatic and isentropic fluid and particle physics in exquisite detail.

 

If your intetsted in the math I can provide several key formulas to large scale structure formation later on.

Edited August 21, 2016 by Mordred

[StringJunky]

It follows the rules of an adiabatic and isentropic fluid and particle physics in exquisite detail.

Only one new word at a time, please, Mordred; don't make me consult a dictionary twice in a day.

[geordief]

Anything that can be measured has dimensions. A dimension is a variable.

 

Thanks.

That seems very interesting. So before EM got going there were other ways the universe "talked " to itself?

 

Imbalances or asymmetries of any kind perhaps that redressed themselves?

 

I have never heard that expression " a dimension is a variable" before (although I may have thought along those lines).

 

Would that be a mathematical concept that may or may not have "physical applications" in the very early universe ?

 

Am I talking rubbish again?

[StringJunky]

That seems very interesting. So before EM got going there were other ways the universe "talked " to itself?

 

Imbalances or asymmetries of any kind perhaps that redressed themselves?

 

I have never heard that expression " a dimension is a variable" before (although I may have thought along those lines).

 

Would that be a mathematical concept that may or may not have "physical applications" in the very early universe ?

 

Am I talking rubbish again?

Dimension - a measurable extent of a particular kind, such as length, breadth, depth, or height. (My bolding; it is only using volume as an example). It could also be force which has the dimensions of mass and acceleration.

Edited August 21, 2016 by StringJunky