Universe Expansion

[David Levy]

http://www.space.com/17884-universe-expansion-speed-hubble-constant.html

"The most precise measurement ever made of the speed of the universe's expansion is in, thanks to NASA's Spitzer Space Telescope, and it's a doozy. Space itself is pulling apart at the seams, expanding at a rate of 74.3 plus or minus 2.1 kilometers (46.2 plus or minus 1.3 miles) per second per megaparsec (a megaparsec is roughly 3 million light-years)."

 

So, the expansion rate is about 74 kilometer per second per 3 million LY.

Let's verify if it is correlated with some other evidences.

For example – Andromeda galaxy which is located 2.5 Million LY from Earth:

 

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

"The Andromeda Galaxy (/ænˈdrɒmɨdə/), also known as Messier 31, M31, or NGC 224, is a spiral galaxy approximately 780kiloparsecs (2.5 million light-years) from Earth"

 

Therefore, the expantion rate between the Milky Way and Andromeda (at 2.5 Miilion LY) should be as follow:

74 * 2.5 / 3 = 61.5 kilometer per second.

 

However, it is stated Andromeda is approaching the milky way at 110 Kilometer per second.

"The Andromeda Galaxy is approaching the Milky Way at about 110 kilometres per second (68 mi/s).^[95]It has been measured approaching relative to our Sun at around 300 kilometres per second (190 mi/s)^[1]as the Sun orbits around the center of our galaxy at a speed of approximately 225 kilometres per second (140 mi/s)."

 

Therefore, by adding the expansion rate to the measured approaching speed, it is clear that the real velocity between the two galaxies should be:

110 + 61.5 = 175.5 kilometres per second.

 

Do you agree with this calculation?

Edited January 1, 2016 by David Levy

[Strange]

For example – Andromeda galaxy which is located 2.5 Million LY from Earth:

 

The Andromeda galaxy is in our local cluster, a collection of galaxies which are held together by gravity. Therefore they are not affected by the expansion of the universe (which only occurs in the absence of any force). That is why the Andromeda galaxy is approaching us, rather than receding.

 

Do you agree with this calculation?

 

No.

[David Levy]

 

The Andromeda galaxy is in our local cluster, a collection of galaxies which are held together by gravity. Therefore they are not affected by the expansion of the universe (which only occurs in the absence of any force). That is why the Andromeda galaxy is approaching us, rather than receding.

So do you mean that the gravity eliminates the expansion of the universe?

I assume that at a distance of 2.5 million Ly, the gravity force between the two galaxies is virtually zero.

So, how could it be?

In the same token, as you mention the gravity force, let's look at the Triangulum Galaxy which is located near Andromeda.

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

However, it isn't expected that Andromeda should collide with Triangulum.

Actually it is expected that the Triangulum galaxy should also collide with the milky way.

So how could it be those two galaxies "prefer" to collide with the Milky Way instead of with each other?

Why gravity doesn't work between so closed galaxies?

Edited January 1, 2016 by David Levy

[Strange]

So do you mean that the gravity eliminates the expansion of the universe?

 

Effectively, yes.

 

I assume that at a distance of 2.5 million Ly, the gravity force between the two galaxies is virtually zero.

 

Why don't you work it out?

 

But note that the cluster is held together by the mass of all the galaxies (and gas, and dark matter) in the cluster. So you need to take into account all the galaxies in the local supercluster (which is many thousands, I believe).

So how could it be those two galaxies "prefer" to collide with the Milky Way instead of with each other?

 

The orbits of multiple bodies around one another are very complex.

Edited January 1, 2016 by Strange

[David Levy]

 

Effectively, yes.

 

Thanks

 

Now it is clear that the gravity force eliminates the expansion of the universe in our cluster (at a distance of at least 2.5 Mly).

So what is the real size of our cluster? in other words, until what distance this gravity force eliminates the expansion?

Is it 5 Mly? 10 Mly, above?

In the same token, Do you agree with the following:

There is no expansion in all the clusters in the universe.

The expansion works only in the open space between the clusters.

 

Would you kindly direct me to an article which explains the connection between gravity clusters and universe expansion?

 

Edited January 2, 2016 by David Levy

[Mordred]

It's simply a matter of energy density. The cosmological constant is per cubic metre extremely weak. Roughly 6.0 *10^-10 joules per cubic metre. Local to galaxy clusters gravity can easily overpower this weak influence. The distance where galaxies would remain gravitationally bound would vary with the mass of each galaxy.

However you can do your own calculations. Simply take the mass of the galaxy. Force of gravity falls of at 1/r^2. Find when it's force becomes nearly negligible( roughly 6.0*10^-10 Newtons. Convert Newtons to joules/metre. 1 joule/metre=1 Newton

[Strange]

Would you kindly direct me to an article which explains the connection between gravity clusters and universe expansion?

 

It is worth noting that expansion depends on matter being homogeneously distributed. This is approximately true for the universe as a whole, on very large scales. Where there are concentrations of matter, bound together by electromagnetic forces and/or gravity, then there will be no expansion.

 

These are good introductions:

http://math.ucr.edu/home/baez/einstein/

http://arxiv.org/abs/0707.0380

http://arxiv.org/abs/astro-ph/0310808

[Sorcerer]

But at some point dark energy increases the energy density of expansion to a point where it is on par with gravity at larger scales and further still where it over comes it, right?

 

Since gravity is an inverse square law, but expansion constant, as mass is removed from the edges, and thus combined mass, wouldn't this be sort of like a cascade?

 

Since gravity is inverse square, but the expansion uniform, how does this shape clusters? Are small distant galaxys torn off?

Edited January 2, 2016 by Sorcerer

[David Levy]

 

Where there are concentrations of matter, bound together by electromagnetic forces and/or gravity, then there will be no expansion.

 

O.K.

If that is correct then it might generate some significant distortion in the expansion rate as follow:

Let's assume the following:

Our cluster is like a ball shape with a radius of 3 Mly.

The closest cluster to ours has the same features.

Let's assume that the distance between the centers of those clusters is 9Mly.

The expansion rate is about 74 kilometer per second per 3 million LY.

So, as the clusters are not affected by mutual gravity force, then technically the expansion rate between the centers should be as follow:

74 x 9 / 3 = 222 kilometer per second.

However, the distance between the closest edges of each cluster is only 3 MLY.

Let's assume that at each edge there is a galaxy. (Galaxy A – in our cluster, and Galaxy B in the other cluster)

So, as stated, the expansion rate doesn't affect the whole mass in each cluster due to gravity force.

Therefore, in order to compensate the effect of the gravity force in each cluster, those two galaxies should move away from each other at a speed of 222 kilometer per second.

That set a conflict.

How could it be that two galaxies at a distance of 3 MLY move away from each other at a speed of 222 kilometer per second due to expansion, while the expansion rate is only 74 kilometer per second per 3 million LY?

So, we should see significant distortion in the expansion rate between edges of clusters all over the universe.

Do you agree?

Edited January 2, 2016 by David Levy

[Strange]

Maybe you should learn about this, rather than making up numbers.

Edited January 2, 2016 by Strange

[David Levy]

Maybe you should learn about this, rather than making up numbers.

Why?

What is wrong in my calculation?

[Strange]

Why?

What is wrong in my calculation?

 

Please show the sources for the data you use. I'm not to waste my time doing that research.

[Mordred]

Why?

What is wrong in my calculation?

It's not even the correct method to calculate. You need to compare how much work at a particular point gravity does compared to the cosmological constant in joules/metre. Expansion only occurs when the cosmological constant exceeds gravity in joules/metre. You didn't account for mass in the above.

But at some point dark energy increases the energy density of expansion to a point where it is on par with gravity at larger scales and further still where it over comes it, right?

 

Since gravity is an inverse square law, but expansion constant, as mass is removed from the edges, and thus combined mass, wouldn't this be sort of like a cascade?

 

Since gravity is inverse square, but the expansion uniform, how does this shape clusters? Are small distant galaxys torn off?

Not positive what your asking here, but if your asking if the energy/mass equivalence of DE can accumulate to assist in breaking galaxies from clusters the answer is no.

 

The reason being DE is too evenly distributed. On all sides of a galaxy the energy/mass is the same. So the amount of mass of DE on the left side of a galaxy will be the same on the right side. In effect they will cancel out. Hence why galaxies gain no inertia due to expansion.

[David Levy]

It's not even the correct method to calculate. You need to compare how much work at a particular point gravity does compared to the cosmological constant in joules/metre. Expansion only occurs when the cosmological constant exceeds gravity in joules/metre. You didn't account for mass in the above.

 

Thanks

You might have missed my main point.

So let me ask the following:

 

I assume that the expansion is mainly applicable for long distance.

So, let's start by looking at a galaxy which is located at 90 Mly away from us.

Do you agree that (regardless of all the mass and clusters in between) the expansion rate in space between us should be:

74 x 90 / 3 = 2220 kilometer per second?

Is it correct?

One more question about the size of the Universe.

How long it might take to the Universe to multiply its size due to the Expansion?

Edited January 3, 2016 by David Levy

[Mordred]

Roughly 70 km/sec/Mpc in non gravitational bound voids is the rate of expansion.

 

One Mpc is 3261563.78 light years. You can use the lightcone calculator on my signature to see the expansion history.

Use the formula [latex]v=H_OD[/latex]

 

In the above 70 or 74 depending on dataset your using Hubbles constant varies a bit between them. Lol

 

74*(90,000,000 ly/3261563.78 ly)=km/sec/Mpc

Edited January 3, 2016 by Mordred

[Strange]

How long it might take to the Universe to multiply its size due to the Expansion?

 

Multiply its size by how much?

[David Levy]

Roughly 70 km/sec/Mpc in non gravitational bound voids is the rate of expansion.

 

One Mpc is 3261563.78 light years. You can use the lightcone calculator on my signature to see the expansion history.

Use the formula [latex]v=H_OD[/latex]

 

In the above 70 or 74 depending on dataset your using Hubbles constant varies a bit between them. Lol

 

74*(90,000,000 ly/3261563.78 ly)=km/sec/Mpc

 

Thanks

 

Based on your reply, the expansion is: 70 km/sec/Mpc,

 

So, let's look at a galaxy which is located at 100 Mpc away from the milky way:

- If there are no clusters at all between the two galaxies, do you agree that the expansion rate between the galaxies should be:

70 x 100 = 7,000 km/sec?

 

- However, if there are clusters in between the galaxies, is it going to have any effect on the total expansion speed?

In other words, do we have to eliminate the expansion rate for all the spots were the clusters are located?

For example, if there are two clusters, and each cluster is at size of 10 Mpc, then the real open space is only:

100 - ( 10 x 2) = 80 Mpc.

Therefore, the expansion rate should be:

70 x 80 = 5,600 Km/sec (instead on 7,000 km/sec - without the clusters).

Is it correct? Do I understand it correctly?

 

Multiply its size by how much?

 

Well, the science has some sort of estimation what is the current size of the Universe.

Let's assume that it is 50 Billion Ly from edge to edge.

My question is - how long it might take the universe to multiply its size to 100 Billion Ly?

Edited January 3, 2016 by David Levy

[Strange]

Well, the science has some sort of estimation what is the current size of the Universe.

Let's assume that it is 50 Billion Ly from edge to edge.

My question is - how long it might take the universe to multiply its size to 100 Billion Ly?

 

The rate of expansion is that required to get from zero size(1) to its current size in 13.8 billion years. So to get to twice that size would take another 13.8 billion years(2).

 

(1) Ignoring the fact it was probably never zero size

(2) Ignoring the possible acceleration that has been observed.

[David Levy]

In the following article (from 2008) it is stated that the Universe is not expanding uniformly:

http://www.universetoday.com/19509/the-universe-is-not-expanding-uniformly/

It is also stated:

“We expected the expansion to become more uniform on increasingly larger scales, but that’s not what we found.”

"If the work he and others are doing is confirmed, it will require a major revision in the way we think the universe came into being and how it evolved.”

So, the questions are as follow:

1. After about 8 years, did we find a confirmation for that work?

2. If so, how it could affect the evolvement of the Universe?

Edited February 2, 2016 by David Levy

[swansont]

So, the questions are as follow:

1. After about 8 years, did we find a confirmation for that work?

 

What have your efforts found out about this?

[Strange]

1. After about 8 years, did we find a confirmation for that work?

 

Several related papers have been published:

http://www.willamette.edu/cla/physics/faculty/watkins/

http://tatania.phsx.ku.edu/feldman/cv/cv.html

 

 

You can search for them. For example:

http://arxiv.org/abs/1411.6665

http://arxiv.org/abs/1111.0631

[David Levy]

 

What have your efforts found out about this?

 

My efforts?

 

I was not involved in that research.

 

 

Several related papers have been published:

http://www.willamette.edu/cla/physics/faculty/watkins/

http://tatania.phsx.ku.edu/feldman/cv/cv.html

 

 

You can search for them. For example:

http://arxiv.org/abs/1411.6665

http://arxiv.org/abs/1111.0631

Thanks

 

I couldn't find in those articles if there is a confirmation that the Universe is not expanding uniformly

 

[swansont]

 

My efforts?

 

I was not involved in that research.

 

I was not talking about the research. I was talking about the efforts to find out about the research. e.g. via Google.

[Strange]

I couldn't find in those articles if there is a confirmation that the Universe is not expanding uniformly

 

There are dozens of papers listed. Have your read them all already? I'm impressed.

[David Levy]

One more question:

In our local group cluster there are more than 54 galaxies (For the calculation - Let's assume that there are about 50).

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

"The Local Group comprises more than 54 galaxies"

"The Local Group covers a diameter of 10 Mly (3.1 Mpc)"

 

However, there are about 500 Billion galaxies in our universe:

http://www.dailygalaxy.com/my_weblog/2013/06/500-billion-a-universe-of-galaxies-some-older-than-milky-way.html

"500 Billion --A Universe of Galaxies: Some Older than Milky Way"

 

So, if we use our cluster as a typical one, then we can calculate that there could be about 10 billion clusters in the Universe with a similar diameter of 10 Mly.

500 Billion / 50 = 10 Billion

 

With regards to the expansion:

It is stated that the expansion had started when the size of the Universe was 40 Mly and its temp was 3000K.

It is also stated that the expansion only works in the open space between the clusters.

 

Therefore, as we go back on time, the clusters should be closer to each other.

Eventually, there will be no open space between the clusters and all the clusters will be next to each other.

In this moment, the size of all the clusters (side by side) should be:

10 Billion (Clusters) x 10 Mly (typical cluster size).

Let's call it - Mega Custer.

 

In 40 Mly we can place about 64 typical local group clusters (10Mly for each one).

Just to make it easy – let's assume that we can set up to 100 typical local group clusters in a diameter of in 40 Mly. (I use it as a worst case scenario)

Therefore, we can assume that the size of that mega cluster is almost 100 Million times bigger than the size of the Universe when the expansion had started (40 Mly)

10 Billion / 100 = 100 Million

 

This might contradict the basic idea that the expansion had started when the size of the universe was only 40 Mly.

We know that the expansion can only works on the open space between the clusters. Therefore, technically, there is no way for the expansion to start before all the clusters in the Universe are located side by side.

In other words, the starting point of the expansion should be when the size of the universe was bigger by 100 Million times than the 40Mly.

 

So, how can we explain this contradiction?

How can we claim that the expansion had started when the size of the universe was 40Mly, while we see clearly that the minimum size of the universe without any open space (all the clusters are located side by side) is 100 Million times bigger than that?

Edited February 3, 2016 by David Levy