Movement of Galaxies in relation to each other

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Discussion Overview

The discussion revolves around the movement of galaxies in relation to each other, particularly in the context of cosmic expansion and local gravitational interactions. Participants explore the nature of galaxy motion, including potential rotational movements and the effects of gravitational attraction among nearby galaxies.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants note that while galaxies are generally moving away from each other due to cosmic expansion, local gravitational effects can cause nearby galaxies to move toward one another.
  • One participant mentions the concept of the "great attractor," indicating that the Milky Way and other local galaxies are moving in a specific direction influenced by gravitational forces.
  • There is a repeated inquiry about whether there is any rotational movement between neighboring galaxies in addition to the overall expansion, suggesting uncertainty about the nature of such movements.
  • A participant describes the Milky Way's satellite galaxies and their orbital relationships, providing examples of specific dwarf galaxies that orbit the Milky Way.
  • Another participant acknowledges that while there is movement between galaxies, it may be random and highlights the impending gravitational interaction between the Milky Way and Andromeda galaxies, emphasizing that actual collisions of stars are unlikely due to the vast distances involved.
  • References to external sources, such as Wikipedia articles on Milky Way's satellite galaxies and galactic collisions, are provided to support the discussion but do not resolve the questions raised.

Areas of Agreement / Disagreement

Participants express a range of views regarding the nature of galaxy movement, with some agreeing on the general principles of cosmic expansion and local gravitational interactions, while others raise questions about the specifics of rotational movements and the randomness of galaxy motion. The discussion remains unresolved regarding the detailed mechanics of these movements.

Contextual Notes

Participants express uncertainty about the specifics of galaxy movement, including the nature of rotational dynamics and the influence of gravitational interactions. There are references to external sources that may not fully capture the complexities of the discussion.

GiZeHy
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hi folks, maybe somebody can help me with this:

According to the standard theories of cosmology, the universe started with a "Big Bang" about 14 thousand million years ago and has been expanding ever since. Yet there is no centre to the expansion; it is the same everywhere. The Big Bang should not be visualised as an ordinary explosion. The universe is not expanding out from a centre into space; rather, the whole universe is expanding and it is doing so equally at all places, as far as we can tell.

In 1929 Edwin Hubble announced that he had measured the speed of galaxies at different distances from us, and had discovered that the farther they were, the faster they were receding. This might suggest that we are at the centre of the expanding universe, but in fact if the universe is expanding uniformly according to Hubble's law, then it will appear to do so from any vantage point.

As we know all matter in a galaxy is moving in rotation. But how is the movement of galaxies or even clusters of galaxies to each other? Is there any rotational movement between neighboring galaxies in addition to the expanding?
 
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Please, somebody can answer this question!

As we know all matter in a galaxy is moving in rotation. But how is the movement of galaxies or even clusters of galaxies to each other? Is there any rotational movement between neighboring galaxies in addition to the expanding?
 
Although overall the galaxies are all moving away from each other - as Hubble's law says.
They do have a local gravitational effect on each other, and nearby galaxies are sometimes moving toward each other.

The milky way and a few other local galaxies are all moving in a particular direction - known as the great attractor.
 
Zolaxy said:
Please, somebody can answer this question!

As we know all matter in a galaxy is moving in rotation. But how is the movement of galaxies or even clusters of galaxies to each other? Is there any rotational movement between neighboring galaxies in addition to the expanding?



Our own Milky Way Galaxy has many satellite galaxies which orbit it.
The closest is the Sagittarius Dwarf Galaxy. Prior to its discovery the most familiar ones were the Large and Small; Magellanic Clouds. Here is a list of Milky Way Satellite Galaxies. The ones with question marks are suspected of being satellites but not as yet fully confirmed.

Excerpt:


I Canis Major Dwarf .
II Sagittarius Dwarf .
III LMC .
IV SMC .
V Ursa Major II Dwarf .
VI Ursa Minor Dwarf .
VII Draco Dwarf .
VIII Sculptor Dwarf Galaxy .
IX Sextans Dwarf.
X Carina Dwarf .
XI Ursa Major I Dwarf .
XII Fornax Dwarf .
XIII Leo II .
XIV Leo I .
? Leo IV.
? Boötes .
? Boötes II.
? Boötes III .
? Coma Berenices .
? Segue 2 0.07 35 dG D 2007
? Canes Venatici .
? Canes Venatici II .
? Hercules .
? Pisces II .
.

http://en.wikipedia.org/wiki/List_of_Milky_Way's_satellite_galaxies
 
But how is the movement of galaxies or even clusters of galaxies to each other?

There IS movement but I've never read a summary/synopsis of such movement...likely it's rather random.

Is there any rotational movement between neighboring galaxies in addition to the expanding?

Yes, in general. Our own Milky Way galaxy and the nearby Andromedia galaxy are moving toward a general rotatioonal "collision"...but few stars or planets will actually collide as all galaxies are 99% space...gravitational attraction will shift the orbits of most mass in both galaxies...
I've seen computer simulations of galactic collisions but don't have any references...

Here is one type of movement: http://en.wikipedia.org/wiki/Virgo-centric_flow

and some discussion of collisions here:

http://en.wikipedia.org/wiki/Galactic_collision
 

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