Andromeda, Great Attractor: when do we collide?

ColoradoSky · Post by **ColoradoSky** » Fri Dec 23, 2005 5:34 pm

Thank you for the beautiful shot of Andromeda on APOD 12/22/05.

I have recently learned that the Milky Way will collide with Andromeda in 4 billion years or so. And that our whole "local group" is speeding toward the Great Attractor black hole.

Does anyone know how long until we fall into the Great Attractor?

harry · Post by **harry** » Fri Dec 23, 2005 11:10 pm

Start packing your bags

If the distance is about 2.3 Million light years

and if we are travelling at ?????????????

How long will it take?

Have to find how fast we are at.

Can someone help

Merry Xmas

harry · Post by **harry** » Fri Dec 23, 2005 11:12 pm

Start packing your bags

If the distance is about 2.3 Million light years

and if we are travelling at ?????????????

How long will it take?

Have to find how fast we are at.

Can someone help

Merry Xmas

S. Bilderback · Post by **S. Bilderback** » Sat Dec 24, 2005 3:36 am

That would be 3.67^17 / 1.1^19*π . . . ah . . . DUCK AND COVER!!!!!!!!!

Just kidding, our Sun will be a long passed faded memory by then.

A Merry Christmas to all!

And I wish for you all a prosperous new year.

Salute.

harry · Post by **harry** » Sat Dec 24, 2005 7:58 am

Ok
I have estimated the time for our milky way travelling at 600kms/sec
would reach M31 Andromeda by about 1,1000,000,000 years.
I like some to double check this.

Now the earth has been evolving for the last 5 Billion Years or so.
Life evolved about 3 Billion Years
Dinosaurs end about 100,000 yrs ago

By the time we reach M31 I think man would have found a way to travel elswhere.

William Roeder · Post by **William Roeder** » Sat Dec 24, 2005 4:47 pm

about 1,1000,000,000 years

I assume you meant 1.1 Billion which is what I remember being the start of the collision

harry · Post by **harry** » Sat Dec 24, 2005 9:53 pm

Hello William

Before we even collide the galaxies will start to unwind extend themselves due to the gravity and than the fun starts.

http://antwrp.gsfc.nasa.gov/apod/ap951218.html

http://antwrp.gsfc.nasa.gov/apod/ap951228.html

http://antwrp.gsfc.nasa.gov/apod/ap971022.html

http://antwrp.gsfc.nasa.gov/apod/ap040612.html

http://antwrp.gsfc.nasa.gov/apod/ap001113.html

and there is much more.

and they say the universe is exapnding

Merry Xmas

orin stepanek · Post by **orin stepanek** » Sun Dec 25, 2005 5:58 pm

http://www.daviddarling.info/encycloped ... actor.html
Maybe we do collide; maybe we don't. We wouldn't feel a thing.
Orin

harry · Post by **harry** » Mon Dec 26, 2005 12:12 am

Its only a matter of time before it ends.

Its part of the never ending story

Happy New Year

ColoradoSky · Post by **ColoradoSky** » Tue Dec 27, 2005 11:55 pm

Hi Harry, thank you for the great images of collisions. I found a nice animation of Milky Way colliding with Andromeda here:

http://www.cita.utoronto.ca/~dubinski/t ... hosis.html

Many thanks to mr. orin stepanek for that great link. I did not realize that we are still testing the Attractor as a theory. So 150 million light years is the hypothesized distance to what could be a black hole or center of mass of galaxies.

I found a site that our local group is moving toward Hydra at 600 kilometers per second. http://hypertextbook.com/facts/1999/PatriciaKong.shtml

So does that work out to be 75 B years? Harry is indeed correct it is only a matter of time, but a long time.

Happy New Year.

orin stepanek · Post by **orin stepanek** » Wed Dec 28, 2005 1:40 am

Hi ColoradoSky! You found a good link also. 300,000 kph seems awful fast. Makes one wonder just how fast we really are moving. What with moving toward Andromeda and toward the Great Attractor and toward who knows where with the expansion of space and all. And yet we feel no sense of motion at all. Happy New Year.
Orin

S. Bilderback · Post by **S. Bilderback** » Wed Dec 28, 2005 2:30 am

And yet we feel no sense of motion at all.

That means it time to go to the frig and find another cold one.

So what impact do you think these high velocities have on our relative time compared to the source of origin?

harry · Post by **harry** » Wed Dec 28, 2005 2:39 am

Thanks to colaradosky link
http://hypertextbook.com/facts/1999/PatriciaKong.shtml

I will make a few corrections to the previous post I made by 'Harry'

quote:

"In conclusion, galaxies experience neutral attractions on one other. Due to relativity, the speed of the Milky Way varies when compared with different objects in space. For example, I have learned from my research that the Milky Way and Andromeda galaxy are approaching each other with a speed of about 130 km/s, however the collision of these two galaxies will not occur for about 5 billion years (AstroFile). Another result I found was that our galaxy and neighbors are moving at 600 km/s in the direction of the constellation Hydra (Scientific American). Finally, I found that the Milky Way moves through space within the cluster of galaxies it is a member of, and this cluster in turn moves through space towards yet another larger cluster of galaxies off in the direction of the constellation Virgo. This speed is approximately 300 km/s (Ask the Space Scientist). Therefore, the speed of the Milky Way galaxy is not a single number, its value is relative to the speed of other objects".

I have estimated the time for our milky way travelling at 600kms/sec
would reach M31 Andromeda by about 1,1000,000,000 years.
times this by 4.55 gives us 5,005,000,000 ie 5.5 billion years.Out by a few billion here or there. Aint so bad.Smile

Now the earth has been evolving for the last 5 Billion Years or so.
Life evolved about 3 Billion Years
Dinosaurs end about 100,000,000 yrs ago
So in the scale of things we are not too far away.

orin stepanek · Post by **orin stepanek** » Wed Dec 28, 2005 5:58 pm

I really don't know; but don't you think that the closer that Andromeda and the Milky way came together that the speed toward each other would become greater being that the gravitational pull would become greater. I think I'll have that cold one.
Orin

harry · Post by **harry** » Wed Dec 28, 2005 10:57 pm

Yes the speed will increase as we get closer to M31.

Our Galaxy is heading towards M31 and also to the centre m87 of our local cluster of galaxies. Which is moving towards the centre of a larger cluster Hydra. Which itself is moving towards a larger cluster.

They keep on telling me that the universe is expanding.

I cannot work it out. What part is expanding.

Happy New Year

ColoradoSky · Post by **ColoradoSky** » Thu Dec 29, 2005 9:48 pm

harry wrote:
They keep on telling me that the universe is expanding.

I cannot work it out. What part is expanding.

I too have been puzzled about the universe expanding yet things falling into local black holes. I found an article "The Universe Might Last Forever, Astronomers Say, but Life Might Not" which discusses how dark energy may be pushing the universe apart. The whole article is well worth a read, but I'll quote a bit regarding the acceleration of this expansion that fits this thread...

"If the present trend of acceleration continues this is the forecast:

In about two billion years Earth will become uninhabitable as a gradually warming Sun produces a runaway greenhouse effect. In five billion years the Sun will swell up and die, burning the Earth to a crisp in the process. At about the same time the Milky Way will collide with its twin the Andromeda galaxy, now about two million light- years away and closing fast, spewing stars, gas and planets across intergalactic space.

Any civilization that managed to survive these events would face a future of increasing ignorance and darkness as the accelerating cosmic expansion rushes most of the universe away from us. "Our ability to know about the universe will decrease with time," said Dr. Krauss. "The longer you wait, the less you see, the opposite of what we always thought.

...

"At present all possibilities are open," [Dr. Freeman Dyson] wrote. "The recent observations are important, not because they answer the big questions about the history of the universe, but because they give us new tools with which to explore the history."

Even in an accelerating universe, Dr. Dyson said, humans or their descendants might one day be able to rearrange the galaxies and save more of them from disappearing.

http://www.phys.cwru.edu/~krauss/01ENDrev.html

harry · Post by **harry** » Thu Dec 29, 2005 10:29 pm

Hello Coloradosky

When i said:
They keep on telling me that the universe is expanding.
I cannot work it out. What part is expanding?

I was just joking.
I do know, that's in my thinking what is happening out there.

I do not think the universe is expanding.
Parts of the universe do expand and parts contract.

As for the age of the universe. It is infinite no age , no start , no end.

Yes the sun one day will destroy planet earth and we hope before that, man will find a way to survive and live to fight another day.

Black holes are a normal part of the recyling process of the universe. Blackholes become active and eject matter back into space with new energy, like a rebirth.

Acceleration has been used in lose way.

The process of the sun will take its path. It could even be sooner for our sun to shed its skin. Normally its Iron content.

Happy New Year

S. Bilderback · Post by **S. Bilderback** » Fri Dec 30, 2005 12:50 am

It is the space between the galactic clusters that seems to have the greatest rate of expansion. It could be all space is expanding at the same rate and the distances between galactic clusters is a much greater distance so there would be more expansion over the larger area. It could also be that matter repels Dark Matter so Dark Matter collects between the galactic clusters pushing them apart.

Yet another possibility is that Relative Earth Time is slowing at a greater rate than the early universe so what appears to be expansion may not be that at all. Stronger gravity fields can affect the Red Shift as well as change in relative time and relative speed. Any one or any mix of these options have validity.

harry · Post by **harry** » Fri Dec 30, 2005 1:23 am

Hello Bilderback

Which cluster of galaxies

Local cluster.

Local cluster that our local cluster is part of.

Super clusters.

If you have evidence, i'd love to see it.

I think the universe is infinite and is in a never ending process of recycling.

The Big Bang theories are at their tail end.

If the universe is "all". Than "all" cannot expand unless you bring in diffferent time dimension, which i cannot see to work.

orin stepanek · Post by **orin stepanek** » Fri Dec 30, 2005 2:46 am

What about antimatter; Would matter and antimatter attract? Maybe we are going toward and wouldn't see A universe made of antimatter because anti light couldn't be seen. What is left over when antimatter and matter collide? Total annihilation I know but There has to be something. I think I'll pass on the next cold one.
Orin

harry · Post by **harry** » Fri Dec 30, 2005 4:35 am

Good question
I have my ideas.

I'm going to look it up

Happy New Year

Empeda2 · Post by **Empeda2** » Sat Dec 31, 2005 1:08 pm

What's expanding? The space - though we've been through that one elsewhere....!

I suspect the human race will be gone when we collide - though if we're not I wouldn't worry too much - stars very very rarely collide in galactic collisions - should be more concerned about the shock waves producing new stars and effecting galactic orbits.....

(65M years since the end of the creataceous period). We've only been around 2/3M. The average for a species is not that long at all in the scale of things.....

orin stepanek · Post by **orin stepanek** » Sat Dec 31, 2005 6:15 pm

If the human race is still around at the time that Andromeda and Milky way collide; than I am sure man will have evolved to where he has colonized planets around other stars within the galaxy. Surely most of these will survive such an event. What a great opportunity this will be for Astronomers so study the forces of nature going on at the time when it is happening.
Actually this would probably be more of a merger than a collusion.
Orin

harry · Post by **harry** » Sun Jan 01, 2006 8:13 am

The Expanding universe is a subject that will be discussed in detail with all the recent observations.

Some say it is expanding others say it is not.

The funny thing is that our conclusions of an expanding universe are not founded on solid foundations. This makes the theory wobble.

--------------------------------------------------------------------------------
In my opinion the universe is not exapnding but! going through cycles.
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The other point when galaxies collide there is an opinion that the stars rearly collide.

That is not true: What happens is that the frequency of collision increases and although it takes along time, the stars will collide onto other stars and blackholes that are distributed throughout both galaxies and also the central blackholes will dance for sometime before they merge with each other.

I hope the New Year brings good luck to all

FieryIce · Post by **FieryIce** » Sun Jan 01, 2006 3:07 pm

If collide was the process then there would be continual colliding ending in rubble, otherwise what would be the purpose in “repel”. Merge does not necessarily mean the destruction of both for the end result of one.