Expanding Universe but ......

[wimvb]

2 hours ago, Nigele2 said:

Quite how my super hero The Pooh got a look in I'm really not too sure.  Cheers

My bad (although his honeypot wasn't entirely irrelevant). Just like Pooh, all this theory 'sumtimes' makes my little brain hurt. Especially those two bandaids we call dark matter and dark energy, which are needed to explain the dynamics of our universe.

As for your comment on life in our universe, the keyword you used is 'created'. Some would argue that life 'happened' or 'emerged', probably in several places. I'm not taking a stand here, as this would be beyond the purpose of this thread and forum.

[Kropster]

On 2017-7-16 at 20:28, ollypenrice said:

Remember that galaxies are mostly empty(ish) space so they don't merge in the way that two colliding blocks of concrete merge. (Fortunately

Just to be tedious, I have to point out that concrete blocks are mostly empty space too.... Everything is... Except perhaps a singularity?

[andrew s]

19 minutes ago, Kropster said:

I have to point out that concrete blocks are mostly empty space too.... Everything is..

..but not in the same way as the the space between galaxies. In a solid the "empty" space has strong EM field which is why it resits you sticking your fingers in as it interacts with the EM field in your skin. The EM field between galaxies is very weak.

Regards Andrew

[Dave In Vermont]

Things out there can also bump into other things out there and change course and gravity fields and who-knows-all-else!

https://upload.wikimedia.org/wikipedia/commons/transcoded/d/da/Andromeda_and_Milky_Way_collision.ogv/Andromeda_and_Milky_Way_collision.ogv.480p.webm?_=1

Maybe...

Dave

[SilverAstro]

I was wondering if perhaps the Andromeda galaxy(M31) was only approaching us 'for now' ( a very long 'now' perhaps ) and that it was maybe on a more complex path in the local cluster and would swing past another galaxy (or dark matter lump) in due course and miss us (for now! )

Ha! when I saw*  that the Triangulum Galaxy(M33) was closer to it than we are , , sooo, ,  what if M31 was in orbit round the barycenter with M33 and that it would swing round and start moving away from us? Time to see if M33 was receding ( as it would be in that scenario )

Drat, the bad news is that M33 is heading this way as well (but a bit slower) grrr, keep ur 'eads down cos there be two of 'em this way coming ** !

* a very nice representation of the local group and the rest of the universe, here : http://www.atlasoftheuniverse.com/localgr.html try also the zoom in/out controls at the bottom of it's page.

** By the pricking of my thumbs, something wicked this way comes. /Second Witch.

 

[Shibby]

On 17/07/2017 at 12:45, wimvb said:

As for expansion of the universe, to fully explain it, you also need to introduce dark energy.

Now you've gone and got this thread banned in China! (ref)

[wimvb]

3 hours ago, Kropster said:

Just to be tedious, I have to point out that concrete blocks are mostly empty space too.... Everything is... Except perhaps a singularity?

To paraphrase from the back cover of the book that is my avatar:

"Isn't it remarkable how things desintegrate simply because they hit concrete."

(Can only recall the quote from memory, as both copies of this book haven't found their way back to me after other people borrowed them.)

[wimvb]

32 minutes ago, Shibby said:

Now you've gone and got this thread banned in China! (ref)

Two things came to mind when I saw this reply:

1. Bu keqi

2. Is Pooh banned because he's not politically correct, wearing red?

3. Are we going off topic?