Bootes Void

[Yash4astronomy]

Hey Everyone. I believe almost everyone of us would be aware about the Bootes Void. If not then I'll explain. Bootes Void is a point in universe of massive volume and almost completely empty space. It's about 750 million light years from us and stretches for about a billion of light years. It definitely is huge but is also just that empty because such large space only contains about sixty galaxies.

Now what's special about this place is that it is more mysterious than black holes, even more than primordial black holes. So there definitely are many possibilities and hypothesis, like expansion caused by alien species or merger of two voids. But I've a different speculation, based on my hypothesis, this void is probably the center of expansion of our universe. What if big bang actually took place there?!!! It probably may have....

What makes me think so is that the void is not empty at all, it probably is full of more dark matter in many parts of the universe and also a centre of Dark energy in universe which makes it expand like that.

I guess almost everyone of us would be knowing of comparison of our universe' expansion with inflation (not the inflation in the beginning of expansion of our universe) of a balloon, then, yes it's true that if we mark any point  on the balloon then it would look like it's expanding in every direction and the same is happening with our universe, wherever we observe, we find anything around it to going away from themselves, but we also know that a balloon has the centre of expansion from which we blows in it,  similarly universe is also supposed to have an actual point of  expansion and it probably is the bootes void! 

It is or not?

Thank you.

-Yash Tomar

Edited June 20, 2019 by Yash4astronomy
Checking spelling mistakes.

[Demonperformer]

The balloon analogy refers to the surface of the balloon expanding, rather than the volume of the balloon. There is no centre of the surface, it is just expanding into something which is outside it. So the thing outside it may have a centre, but not the surface itself. Remember, this analogy is losing a dimension - it is a 2D surface expanding into a 3D space.

[michael.h.f.wilkinson]

There are many more voids than the Bootes void. Many simulations of cosmic expansion throw up any number of voids, walls, filaments, and super clusters.  

[ollypenrice]

As Demonperformer says, the expansion of the universe always applied to all parts of the universe so it does not have a centre. In an explosion there is a central point away from which everything races. This is entirely different from the expansion of the universe because in this case every point is racing away from every other point.

Olly

[gorann]

2 hours ago, ollypenrice said:

every point is racing away from every other point.

I assume that this may be true for very big "points" like whole gaxies moving apart, but within a galaxy gravitation may bring "every point" closer over time. And galaxies may even move closer to each other due to gravitational pull. I even read somewhere that we may crash with M31 one day......

Edited June 20, 2019 by gorann

[ollypenrice]

1 hour ago, gorann said:

I assume that this may be true for very big "points" like whole gaxies moving apart, but within a galaxy gravitation may bring "every point" closer over time. And galaxies may even move closer to each other due to gravitational pull. I even read somewhere that we may crash with M31 one day......

You're right, the expansion doesn't affect gravitationally bound systems like galaxies. Even on larger scales there are 'local' gravitational attractors which cause galaxies to 'beat against the current' of the Hubble Flow.

Olly

Edited June 20, 2019 by ollypenrice

[Yash4astronomy]

8 hours ago, Demonperformer said:

The balloon analogy refers to the surface of the balloon expanding, rather than the volume of the balloon. There is no centre of the surface, it is just expanding into something which is outside it. So the thing outside it may have a centre, but not the surface itself. Remember, this analogy is losing a dimension - it is a 2D surface expanding into a 3D space.

Yes I do agree to it but that was for reference to relate the expansion of a 3-d or probably a 4-d space in form of 2-d 

[Yash4astronomy]

1 hour ago, gorann said:

I assume that this may be true for very big "points" like whole gaxies moving apart, but within a galaxy gravitation may bring "every point" closer over time. And galaxies may even move closer to each other due to gravitational pull. I even read somewhere that we may crash with M31 one day......

But that void is most probably expanding, there are still observations going on, so yes we can't be certain

[Yash4astronomy]

15 minutes ago, ollypenrice said:

You're right, the expansion doesn't affect gravitationally bound systems like galaxies. Even on larger scales there are 'local' gravitational attractors which cause galaxies to 'beat against the current' of the Hubble Flow.

Olly

Experiments are still going on, so if it results in expansion of void then there is definitely a certainty in my speculation.

Either way, we can't say anything yet

[Yash4astronomy]

4 hours ago, michael.h.f.wilkinson said:

There are many more voids than the Bootes void. Many simulations of cosmic expansion throw up any number of voids, walls, filaments, and super clusters.  

 well I guess it's one of the biggest of them

[vlaiv]

16 minutes ago, Yash4astronomy said:

But that void is most probably expanding, there are still observations going on, so yes we can't be certain

There is a simple explanation why any void is expanding.

Just think what happens in uniformly dense universe (with or without dark energy pushing things apart) - observe single galaxy - it has some galaxies to the left and to the right, and up and down, front and aft. They on average have same gravitational pull and there is no density change.

Now imagine you have the same galaxy but there is nothing to one side of it, just empty space. Gravitational pull is there from above/below, front/behind, left - but no right pull - overall galaxy will tend to slightly drift towards the left - away from area there is nothing, simply because on other side there is something that is gravitationally pulling it.

Same thing happens with liquids - molecules interact with each other (attract) keeping liquid together except on surface of the liquid - there you have surface tension as a result because there are no molecules on the other side equally pulling it. This is why liquids tend to form spheres in low g environments - surface tension is "compressing" liquid into shape and most even shape where there is "compression" from all sides is sphere.

Once you have couple of voids - there will be a structure between them - as each will "expand", but in effect, a wall or filament between them will behave much like water does - it will contract / collapse in volume and it will just look like voids are expanding - but it is the same process as walls / filaments collapsing under their own gravity.

If we had perfectly uniformly dense universe - there would be no voids, but look at CMB map - things were not 100% uniform - there were small quantum mechanical fluctuations in the temperature / density at the beginning and these grew over time with exact same mechanism to form nowadays voids.

[Yash4astronomy]

48 minutes ago, vlaiv said:

There is a simple explanation why any void is expanding.

Just think what happens in uniformly dense universe (with or without dark energy pushing things apart) - observe single galaxy - it has some galaxies to the left and to the right, and up and down, front and aft. They on average have same gravitational pull and there is no density change.

Now imagine you have the same galaxy but there is nothing to one side of it, just empty space. Gravitational pull is there from above/below, front/behind, left - but no right pull - overall galaxy will tend to slightly drift towards the left - away from area there is nothing, simply because on other side there is something that is gravitationally pulling it.

Same thing happens with liquids - molecules interact with each other (attract) keeping liquid together except on surface of the liquid - there you have surface tension as a result because there are no molecules on the other side equally pulling it. This is why liquids tend to form spheres in low g environments - surface tension is "compressing" liquid into shape and most even shape where there is "compression" from all sides is sphere.

Once you have couple of voids - there will be a structure between them - as each will "expand", but in effect, a wall or filament between them will behave much like water does - it will contract / collapse in volume and it will just look like voids are expanding - but it is the same process as walls / filaments collapsing under their own gravity.

If we had perfectly uniformly dense universe - there would be no voids, but look at CMB map - things were not 100% uniform - there were small quantum mechanical fluctuations in the temperature / density at the beginning and these grew over time with exact same mechanism to form nowadays voids.

Well that's the most logical explanation

 

5 hours ago, michael.h.f.wilkinson said:

There are many more voids than the Bootes void. Many simulations of cosmic expansion throw up any number of voids, walls, filaments, and super clusters.  

 well I guess it's one of the biggest of them

[vlaiv]

2 minutes ago, Yash4astronomy said:

Well that's the most logical explanation

 

 well I guess it's one of the biggest of them

Depends how you look at it. Have a read on wiki page that lists voids:

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

KBC void is about x6 as large as Bootes Void by diameter (that would be 6^3 or about x200 in volume)

[andrew s]

8 minutes ago, vlaiv said:

Depends how you look at it. Have a read on wiki page that lists voids:

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

KBC void is about x6 as large as Bootes Void by diameter (that would be 6^3 or about x200 in volume)

Funny what a little research can uncover. But pure speculation is somehow more fun!

Regards Andrew