Ghideon

48 minutes ago, László Hajós said:

The "void" is not expanding if "staff" has to be pushed away or not.

Ok!

More images showing why the model has some strange geometry.

1: This is how the 1D version looks like in 2D in a naive version where a second dimension is added. There are two voids separated by a universe. I am sure this is not what is intended but I include this one as reference to show how easy it is to misinterpret how the 1D description applies to a 2D geometry. 

Top: 1D
Bottom: naive 2D version.

2: Picture with the naive and incorrect version with expanding universe. This shows that it is easy to maintain the angles and measurements of the void when the universe expands. But the void is broken into two pieces. This is probably not what the model says. But I think the measurements of each void piece is according to the description; area is not changed, and anything at, or in, the void would not need to be moved to make room for the expanding universe.

Left: original universe
Right: an expanded universe.  

Next picture shows how I interpretative that the void should look like, in surrounds the universe on all sides. The void is continuous, you can travel around the universe and measure the distance. The proportions are not important, the important part is that it is one void surrounding a universe. This is not a new image, we agreed on this on in an early post. It is just included as a reference.

Now lets try to create an image that complies to the rules I think the model states 
-The void has room for an expanding universe
-The void does not expand
-Use 2 dimensions since 1D fails to show the issues
-The same distances must be measured from edge of the universe to a given point in the void even after universe has expanded.
-Void area is not changed
-Possibility to travel around the universe and measure the distance.

Case I shows the starting position as a reference, defining distances to given points in the void, nothing new in this image.
Case II is a failed attempt; you can travel around the universe and measure that the universe has expanded, the distances to the points in the void are the same but the area is larger. The points in the void, at or near the edge of the universe, is changed. 
Case III has correct measurements of X and correct area but is not continuous. Also the edges, seen from the void, ar not the same radius som some posts are moved or stretched/compressed.
Case IV has correct X values and correct area and also no edge defects of the void. But now the void is not continuous, travel around the universe is not possible.

Note: this is not meant to make fun of the model, it is my serious attempts at making sense of the descriptions of the model.

Properties you have used to describe the void does not apply to a void that is geometrically possible under the circumstances given. So again, what kind of geometry does the void have? Can you show the math? 

40 minutes ago, László Hajós said:

in real world you could go around ( or even acces the edge of the unierse if the edge is not expanding with the speed of light), altough that lenght of travel would be bigger as well if expansion still goe's on.

So the path, in the void, along the outside of the universe, will be longer and longer as the universe expands. That means that the void expands, otherwise stuff would have to be pushed away by force (accelerated).

Please note that you said that if another universe located at point A stays at the same distance from B when the universe between B and C expands:

On 2018-10-02 at 10:31 PM, László Hajós said:

There would be no acceleration measured. It is the same like our universe expands faster than speed of light. We on earth right now expanding more than the speed of light away from an other far away point in our universe but we dont feel any acceleration.

You could imagine as follows: if only these two universes and the space between them would exist in the whole world. The line between the universes is in the middle. The line will not move, only X universe growing (from our point of view the closest edge will stay in place and every furthest point in the universe would accelerate faster and faster. The same would we see on the other side in the other universe

1 hour ago, László Hajós said:

But the area of void has to stay the same

No, that is not true unless you break the void apart*. Now it is your turn. If all of your statements so far are true, draw a 2D image where there is no expansion of the void, universes separated by distance X are still separated as they expand, the area of the void is unchanged and a traveler has to travel longer and longer distances to travel, in the void, along the edge of a universe. If it is not possible then your explanations are missing important properties, the geometry is non standard or, quite possible, the model just is not correct. 

*) If hard to understand I'll create a few pictures showing this.

I do not get this. 

5 minutes ago, László Hajós said:

 But the area of void has to stay the same, this means that in this 2 dimension as a sheet, AB and CD is smaller than in case I. Only the area of "voi"d stays the same. 

Then my simplified picture failed to show the issue. Did you understand the part where the 1D model you used requires the void to be split in two parts that are not accessible without passing through the universe? 

I'll try to add a new picture later.

3 minutes ago, László Hajós said:

X would be minimum half the circle of the universe in case III

Ok! Distance in the void, around the universe, gets longer and longer as the universe expands. So the void expands, correct?

Fail! The letters are mixed up. Too late to edit ... 

Image is correct; 

A/B/C was wrong in descriptions, correct versions of Case I,II,III:

1 hour ago, Ghideon said:

Case I: A and D are points in the void, B and C are located at the edge on one universe.

Case II: The universe has expanded so that the distance BC inside the universe is twice as long as in case I. As a consequence, according to the model, lines AB and CD are moved further apart. Distances AB and CD are unchanged. A traveler inside the universe travels from B to C and measures the distance, distance BC is X.

Case III: Same as case II but we take into account that the void is continuous. The universe is still 1D but it has to be surrounded by void. The void must allow for travel between B and C without passing through the universe.  The traveler is now in the void and travels from B to C in the void, represented by the dashed line along the universe. What distance will the traveler measure in the void in Case III? Is it X?

The points B  and C  in the void are exactly the same in all three cases. Either the void has expanded or objects at B and C would experience acceleration? There may be other explanations, I can't figure out how the geometry of the void works.

I believe I have found one more reason for confusion in the discussion. The explanations you post are simplified versions containing one physical dimension. In the general case I think this is absolutely fine, removing unnecessary complexity while addressing some specific aspect is a good thing. But in the case with a 1D line in the model, the simplification removes important issues of the model. When you use 1D line you have universe that has a void at both ends. There is no void along the part of the 1D line that is represents the universe. The void is not continuous, it is actually two different voids separated by a 1D universe. In this case you can, as you stated, probably have an expanding universe that increases the distance between two pieces of non-changing voids, just as we can observe increasing distance between galaxies in the universe.

But the above simplification seems to hide the geometrical issues I try to address. The universe(s) are surrounded by the void on all sides.

Below is a new picture.

Case I: A and D are points in the void, B and C are located at the edge on one universe.

Case II: The universe has expanded so that the distance BC inside the universe is twice as long as in case I. As a consequence, according to the model, lines AB and CD are moved further apart. Distances AB and CD are unchanged. A traveler inside the universe travels from A to B and measures the distance, distance AB is X.

Case III: Same as case II but we take into account that the void is continuous. The universe is still 1D but it has to be surrounded by void. The void must allow for travel between A and B without passing through the universe.  The traveler is now in the void and travels from A to B in the void, represented by the dashed line along the universe. What distance will the traveler measure in the void in Case III? Is it X?

The points A and B in the void exactly the same in all three cases. Either the void has expanded or objects at A and B would experience acceleration? There may be other explanations, I can't figure out how the geometry of the void works.

Side note: once you manage to explain the geometry of the void there are a huge number of issues inside the universe that will be addressed. 

15 hours ago, László Hajós said:

y=gravity or dark energy

This will require some thought to untangle. I'll do that in a later post if the tread remains open.

2 hours ago, László Hajós said:

Maybe, you can call it an extra dimension.

Ok! If one or more additional new "dimensions" are needed, it is not surprising that my attempts at explaining or drawing pictures of the situation fails. I need an exact definition, in whatever mathematical detail that is required, describing all about this new concept and how it is related to the space time. It changes how the geometry behaves and I'm simply not clever enough to figure out how. I use "dimension" because at this point I'm not sure if the model uses mainstream definitions.

One thing that just hit me, I haven't verified:

Question 1: how many spatial and temporal dimensions does the universe(s) have in your model?
Question 2: how many spatial and temporal dimensions does the void have in your model?

Please also explain in detail how the following is possible:

On 2018-10-01 at 10:22 AM, László Hajós said:

In my model general relativity is not changed, it would be the same

2 hours ago, László Hajós said:

Okay, this is the last time I will try to explain.

Ok! Then this thread can be closed.

2 hours ago, László Hajós said:

So the lenght of the whole line is: AB(1) + BC(1+10) + CD(1) = 13

You need to define a coordinate system, dimensions, distance, lines and length. If "distance" in a "dimension" the universe is different to the "distance" in a "dimension" the void you will have some really strange geometrical effects along the edge of the universe. I deliberately use "distance" because at this point it is not clear what it is. 

2 hours ago, László Hajós said:

We are talking about the same thing again and again.

No, we are talking about new stuff you keep adding.

2 hours ago, László Hajós said:

It is not so difficult to understand

It is quite possible that your model of spacetime is intuitive to many forum members. But to me it would be easier if you present the complete definitions of all new concepts you need. 

49 minutes ago, László Hajós said:

That is why I used 1 dimensonal lines for simplicty. Only in 1D stays 1ly a 1ly. In 2D is different, and 3 D is different.

Yes but the 1D simple model seems to fail to explain the geometry you seems to suggest. You say there is no expansion of the void and no acceleration of stuff that needs to be moved out of the way. Yet there seems to be room in the void for expaning universes, without moving stuff from the universe and into the void. I added a second dimension to try to show one, out of many possible, situations where I could not understand how the distances and angles are supposed to behave in the model.

17 minutes ago, László Hajós said:

This 1 cm peak is slowly getting smaller and "creating" more distance.

But then the dip is in another dimension compared to the 1D line you are drawing? This is confusing. 

I think your reply confirms that the geometry you suggest may not be possible to explain using pictures. Now when I look at the peaks and dips I get the impression that a 1 Ly distance in the universe is not always a 1 Ly distance in the void. 

1 hour ago, László Hajós said:

space  would be exactly the same density.

What is space density? 

I realise that my picture and description failed to describe the issue, sorry for the confusion! 
I’ll try a more detailed version, the initial situation is the same but I have out labels on more points. Hope this one is better

Case I:

A is a point in the void, B is one edge of the universe, C is the other edge, D is a point in the void. Points E and F are in the void, located so that line EF is 5 Ly (Light year). Lines EF and AD are parallel and separated by a distance of 2 Ly.  Lines AE and DF are 2 Ly, parallel and separated by distance of 5 Ly. A 1 Ly universe is located between B and C. Angles at A, D, E and F are 90 degrees.

Case II: The universe has expanded to 2 Ly, according to your model the result is that the solid AB and CD are pushed away. Line AD is now 6 Ly. How long is line EF according to your model?

Case II is where I fail to understand the geometry of the void. If distance EF is increasing then there is metric expansion of space between E and F? How are other universes in the void affected?

I have also tried to re-read the thread, at this point it is very confusing to make out what your model tries to explain. I suggest you try to define, in detail, each of the concept you use and how they behave. Also please provide the math, it may not be possible to continue the discussion with pictures only. A few issues:

11 hours ago, László Hajós said:

If I count the distance between AD, it grows from 5 ly to 6 ly. But if I would measure the line with all the dips and peaks, I would get the same result in booth pictures.

I cant figure out what this means.

16 hours ago, László Hajós said:

The area closer to the edge of our universe would expand slightly faster than the area inside the universe. But these external forces dont cause any space time expansion, it would be only like a gravitational pulling force. Space time expansion is caused only by the internal "pushing" force.

Please explain area and how distance can increase without metric expansion or moving of objects.

On 2018-10-01 at 1:04 PM, László Hajós said:

In local scale the lenght of the x axis, or space can get longer (expansion, big bang) or shorter (supermassive black hole).

What is a local scale? 

Here are some examples where I believe you state that the void, the space between universes, does not expand:

13 hours ago, László Hajós said:

It is the same space like in our universe which is not expanding and could contain some huge black holes

12 hours ago, László Hajós said:

The "void" or space between expanding universes stays the same.

12 hours ago, László Hajós said:

The void, the space between the universes doesnt need to expand, only the space inside the universe expands.

12 hours ago, László Hajós said:

Space outside of the universe wont expand it will be "pushed away" by the expanding universe.

On 2018-10-02 at 2:06 AM, László Hajós said:

from a huge distance (lets say 10^12 light years) from eachother in a space time which is not expanding between them will pull eachother until they collide an merge?

12 hours ago, László Hajós said:

And as I said before, in this model the line (or fabric in 2D) would always stay the same lenght in global scale. It can be pulled down (and then straighten) or pushed up (and then straighten), the total lenght is always the same.

4 minutes ago, László Hajós said:

The answer is very simple, 6

Then how can a 5 Ly distance become 6 Ly? So far you have, as far as I can tell, denied metric expansion of the void and acceleration of stuff that needs to be moved. What mechanism is responsible for the geometry of the void?

2 minutes ago, László Hajós said:

You could imagine as follows: if only these two universes and the space between them would exist in the whole world. The line between the universes is in the middle. The line will not move, onnly X universe growing (from our point of view the closest edge will stay in place and every furtest pointin the universe would accelerate faster and faster. The same would we see on the other side in the other unierse

Thanks, but I can't see how the geometry works. I'll try a picture, ugly but hopefully correct.

I reuse the notations from the quote below, and add a point D.

50 minutes ago, László Hajós said:

A is a point in the void, B is one edge of the universe, C is the other edge.

Case I: A 1 Ly (light year) universe. We have the same points A,B and C as in your case and an additional point D. The line AD is 5 Ly.

Case II: The universe has expanded to 2 Ly pushing the solid AB and CD away. How long is line AD according to your model? 

.

28 minutes ago, László Hajós said:

A is a point in the void, B is one edge of the universe, C is the other edge. AB is example 5 ly. AB is a solid straight line. BC distance is 1 ly first, the line between BC is not straight and not solid. It has dips and peaks. The total of the dips will always stay the same  (energy or mass) but the peaks slowly push down straightening. BC grows to 2 ly, and pushes AB solid line away

Ok! Then the following apply? Lets have the same setup as above but let A be a point on the edge of another universe "X". When AB is pushed away when BC grows. AB is solid so universe X is pushed away. What kind of acceleration will be measured inside universe X? 

23 minutes ago, László Hajós said:

The void, the space between the universes doesnt need to expand, only the space inside the universe expands.

Ok! Lets say a universe has a circumference of 1 Ly (Light year) when measured along the edge from inside the universe. Along the outside, seen from the void, the same universe has a circumference of 1 Ly. Space in the universe expands so circumference measured inside is now 2 Ly. Space outside the universe, in the void, does not expand. The circumference in the void is still 1 Ly. Please explain how this works.

1 hour ago, László Hajós said:

I don't know why you think that in my model space is not expanding.

Sorry, my bad! I assumed that because I couldn't figure out how the geometry is working, maybe you can explain?

3 hours ago, László Hajós said:

The area closer to the edge of our universe would expand slightly faster than the area inside the universe. But these external forces dont cause any space time expansion, it would be only like a gravitational pulling force. Space time expansion is caused only by the internal "pushing" force.

Assumptions:
1: Space inside the many universes* is expanding, just like in the mainstream model of big bang. 
2: Galaxies at the edge of the universes may be pulled out into an empty void, while also getting further and further form the centre due to the expanding space*

If above assumptions about the model are correct, what mechanism allows for the following two things:
A: The void between universes allows for a smaller and smaller distance between universes, so the universes can eventually collide.
B: The void must, at the same time, expand to make room for expanding universes. 

I can't figure out how the void between universes behaves, I think you need to provide a mathematic model. 

*) Standard disclaimer: This is not my understanding of the generally accepted model, its my understanding of the proposed model in this topic

1 hour ago, László Hajós said:

Expansion could be an external force (if there is one) + the "pushing" force inside the universe. The force pushing is only expansion in large scale  (+ could be other phenomena in small scale)

Follow up to make sure I understand; space is not expanding in your model? Expansion is instead always the result from various speculative forces that acts on matter? Matter is dragged and/or pushed into empty space surrounding "a universe"? 

With all these forces like negative* gravity etc acting on matter, wouldn't a large number of galaxies be deformed? 

*) non-existing in mainstream models but part of previous posts.

9 hours ago, László Hajós said:

it would be almost if not totally impossible to find any starting point of the early universe which would end up so close to the edge that you can see almost nothing on one side and our universe on the other side

Thanks for the clarification! That was the thing I was looking for.

Lets move on, I have some trouble with some references to "expansion" and "force"; examples: 

20 hours ago, László Hajós said:

but the expansion stops after a long time

and

13 hours ago, László Hajós said:

because all the mass is pushed away from eachother with about the same amount of force

Is some movement in your model is caused by expansion of space and other movement caused by pushing forces? 

1 hour ago, László Hajós said:

The astronomer can only start in the universe, first as particles, or pure energy in the singularity. Like forus on the earth, if would start right on the edge of the expansion, one edge of the observable universe would be almost always maximum on the edge of the whole universe and not further because all the mass is pushed away from eachother with about the same amount of force

Ok! But I still do not understand why an observer close to the edge does not observe the empty void on one side and "lots of starts and galaxies" on the other side. What prevents the observer from being at a location that is closer to the edge than half the size of the observable universe? 
 

24 minutes ago, László Hajós said:

Then why would it cause expansion in the universe?

Probably just my english, but what is "it" in this context. None of the things mentioned by @Strange is supposed to cause expansion as far as I can tell. (bold by me)

There are several issues raised, for now I focus on one I posted. 

4 hours ago, László Hajós said:

Yes, exactly like that picture. The empty void is also space, with almost nothing, or nothing in it. You may call it overlap, but the expansion stops after a long time, and only the black holes  remain from that universe. Than you can't even really call it universe any more. Then an other universe edge could "overlap" these black holes and feed them with more mass or merge one universe black hole with a black hole from a different universe.

8 hours ago, László Hajós said:

This astronomer you mention would think from any point inside the universe that he is in the centre from his point of view (if he wouldnt know better)

The two explainations above seems to contradict each other. How can an observer near the edge of the expanding sphere believe that he is in the centre from his point of view? 

1 hour ago, László Hajós said:

No, I am not saying that we are in the centre. This astronomer you mention would think from any point inside the universe that he is in the centre from his point of view (if he wouldnt know better).

Ok.

1 hour ago, László Hajós said:

But if he would observe the whole universe (with our observable universe in it) from outside of it - and lets say that the speed of light is infinite - than he would see the universe as a sphere, with our observable universe in it, also a sphere.

Please clarify, does your hypothesis state that the universe exists in an empty void? Something like the attached image? This void, yellow in the image, may contain other universes (green area). In the future one or many green universes will have expanded enough to overlap?

13 minutes ago, Strange said:

The characteristics of the expanding universe (isotropic expansion meaning that every galaxy is moving away from every other, distribution of red-shift/velocity with distance, etc) does not match an explosion. Fir example, you would need to explain how an explosion can cause objects to recede with velocity greater than the speed of light.

Yes I know, I tried to create a thought experiment with one thing out of many that the speculative idea fails to explain. Now that we have a list of issues maybe the OP can address them all in one go?

21 minutes ago, Strange said:

you need to explain why GR is wrong.

Do not expect that me to do that, I prefer to try to explain why GR seems correct . Hopefully you refer to anyone proposing or believing in ideas similar to the OP?  (Bold by me).  

27 minutes ago, Strange said:

We are in the centre of the observable universe but we have a very slight motion relative to the CMB.

Correct, I failed to express myself clearly. Thanks for pointing it out! Maybe this is better: The earth is not in a central position in some expanding sphere caused by an explosion. 
 

Other members have already pointed at problems with your statements. But I find it interesting to try to understand how your idea is supposed to work* in comparison to the generally accepted big bang model. 

15 hours ago, László Hajós said:

I am not sure what you mean by everywhere. As far as I know, the hot dense state is in an almost perfect sphere. And by now, after 13.8 billion years if we could see our universe from outside, it would be still more or less a sphere shape expanding. As time goes on, the sphere is less and less perfect. 

Are we, according to your idea, located at a unique position near a centre of an explosion?  As far as I know the cooling of cosmic microwave shows that, on a cosmological scale, the Earth is not in a central position.  Thought experiment: imagine an astronomer, located at some large distance from us, observing the expansion of the universe. Would that astronomer, according to you, draw the conclusion that he is not in the centre but between the centre and the edge of an expanding sphere? @beecee posted descriptive images, do you have images of your model as a comparison?

*) I obviously do not believe the model you describe is working or supported by observations. My questions are intended to allow you to see why. 

2 minutes ago, DannyTR said:

Actual Infinity is difficult to define because it does not exist exist mathematically or in nature; just exists in our heads as a (flawed) concept.

Something that we cannot cleanly define and is not a rational concept, does not have a place in scientific theories IMO. 

I'm no math expert but above seems like a sound statement about Actual Infinity. Maybe that is why Actual Infinity is somewhat outdated and replaced by newer definitions?

Hello, I might be able to hint you in the right direction; 
-What have you tried so far?
-Are you familiar with some other basic triangle theorems that you may start from?