Expanding universe?

On Thu, 7 Oct 2004 10:36:03 -0400, "Benign Vanilla"
wrote:


"Chuck Farley" wrote in message
news snip
Odd how astronomers tell us the universe is EXPANDING, i.e. almost all
the other galaxies/stars are moving AWAY FROM us and EACH OTHER, yet
they often invoke "colliding galaxies" as explanations for various
astrophysical phenomenon!
How DO objects that are flying AWAY FROM each other manage to get in
collisions?
Are we being lied to?

No. The universe is expanding and as such everything in it is being moved
along with the expansion.

Of course, Edwin Hubble, who postulated this expansion based on his
redshift observations, later recanted. And now, we have confirmation
that redshift is quantized. So, explain how the expansion occurs in
quantum leaps! Chuckle.

On Wed, 6 Oct 2004 23:39:49 +0100, Jonathan Silverlight
wrote:

[....]
" The 1913 paper measured the blueshift of Andromeda to be 300 km/s.

1913? GUFFAW!

On Wed, 6 Oct 2004 22:43:45 +0100, Jonathan Silverlight
wrote:

In message , Luigi Caselli
writes
"Chuck Farley" ha scritto nel messaggio
. ..

I"If we take the Hubble constant equal to 60 Km/sec/Mpc, we find that
M31 should run away from us at a speed of only 40 Km/sec that is
equivalent to a red shift of 0,7 Å."
http://www.astrogeo.va.it/astronom/s...galassieen.htm

Gee - sounds like M31 IS moving AWAY from us - so where's the
collision?
GUFFAW!

Sorry but I'm totally confused...
I have read that M31 has a blue shift and not a red one and for this reason
is moving toward us.
Or not?


It does and it is. Its heliocentric radial velocity is about
300km/second, measured at both radio and optical wavelengths. Chuck
doesn't know what he is TALKING about.

Chuck QUOTED the G. V. Schiaperelli Observatory in Italy. Are you
claiming THEY don't know what they are talking about?
Oh, and BTW the web page has the spectrum to back up what they say.

On Wed, 6 Oct 2004 22:43:45 +0100, Jonathan Silverlight
wrote:

In message , Luigi Caselli
writes
"Chuck Farley" ha scritto nel messaggio
. ..

I"If we take the Hubble constant equal to 60 Km/sec/Mpc, we find that
M31 should run away from us at a speed of only 40 Km/sec that is
equivalent to a red shift of 0,7 Å."
http://www.astrogeo.va.it/astronom/s...galassieen.htm

Gee - sounds like M31 IS moving AWAY from us - so where's the
collision?
GUFFAW!

Sorry but I'm totally confused...
I have read that M31 has a blue shift and not a red one and for this reason
is moving toward us.
Or not?


It does and it is. Its heliocentric radial velocity is about
300km/second, measured at both radio and optical wavelengths. Chuck
doesn't know what he is TALKING about.


Perhaps you should actually READ the Schiaperelli Observatory web
page, where it says, "M31 is too close to be able to appreciate its
red shift with our instrument. "

On Fri, 8 Oct 2004 18:28:58 +0100, Jonathan Silverlight
wrote:

In message , Chuck Farley
writes
On Thu, 07 Oct 2004 05:02:05 GMT, "Painius"
wrote:

The 250 km/sec is merely the radial component of
Andromeda's velocity and motion. We have no idea what
Andromeda's lateral motion, direction or speed happens
to be. It may very well be that both galaxies revolve about
a common center of gravity, and that at some parts of the
orbit, Andromeda would show a red shift, at other parts
show a blue shift. And we may just happen be in the part
of the mutual orbit where Andromeda shows a blue shift.

There really is no way of telling, however astronomers
are working on ways to close this gap in our knowledge.

IOW, there are so many "ifs, ands, buts, and maybes" that, to quote
your own words, " We have no idea what
Andromeda's lateral motion, direction or speed happens
to be."
Yet, that's the basis for a projected "collision". Chuckle.

You just don't get it, do you? The collision is hype. No-one's sure if
it will happen. But the evidence for such collisions having happened is
unshakeable, unless you can show an alternative explanation for galaxies
shaped like the Mice (NGC 4676-1) and the Cartwheel (among others).
The evidence for the Milky Way and M31 is also unshakeable, unless you
can show an alternative explanation for the blue shift.

what blue shift?The "apparent" blue shift? Read the Schiapeelli
Observatory page, where they state, "M31 is too close to be able to
appreciate its red shift with our instrument. "

If you do a search for "transverse velocity" and M31, you'll find that
astronomers hope to use missions like SIM and GAIA to look at M31, to
see if it really will hit us.

Hit us? What a laugh. If the sun were scaled as a tennis bal in
Toronto, then the nearest star to us in our local group would be
another tennis ball located in Florida. Sounds like a real collision
risk!

On Thu, 7 Oct 2004 00:47:49 +0100, "OG"
wrote:


"Chuck Farley" wrote in message
.. .
On Tue, 05 Oct 2004 12:45:19 GMT, "Painius"
wrote:
Odd how astronomers tell us the universe is EXPANDING, i.e. almost all
the other galaxies/stars are moving AWAY FROM us and EACH OTHER, yet
they often invoke "colliding galaxies" as explanations for various
astrophysical phenomenon!
How DO objects that are flying AWAY FROM each other manage to get in
collisions?
Are we being lied to?

There's no mystery.
Let us suppose that galaxies may have 'random' speeds of say 200 km/s.
Hubble expansion is measured to be something like 70km/s Mpc, so for
galaxies at distances up to 3Mpc, the 'random' speed of individual
galaxies may be more significant than the overall expansion of the
universe. Above this distance, the expansion will predominate.

Well then, if you observe M31 and the Milky way from a distance of 10
billion light years, the expansion will be close to c, and the
expansion will predominate. So, which is correct, the local view, or
the view from 10 billion light years away?

On Thu, 7 Oct 2004 16:49:51 +0100, Jonathan Silverlight
wrote:

In message , Ira McTavish
writes
On Thu, 07 Oct 2004 04:13:08 GMT, "Painius"
wrote:

"Chuck Farley" wrote in message...
...

[....]
You just brought my error to my attention. I meant to say
that, out of all the galaxies we can see, only a few are moving
"toward" Earth exhibiting a blue shift.

We are not being lied to. There are still many controversial
areas of cosmology. The existing idea is that, while space
itself is expanding, on local levels this expansion is not the
least bit noticeable. So at the level of galaxy groups or
clusters, some galaxies are bound to each other by gravity.
This may mean that they revolve around a common CG
somewhere between them. Or it could mean that some are
satellite galaxies of larger galaxies.

And it can and sometimes does mean that two galaxies are
on a collision course. So keep in mind that the expansion
of space tends to separate matter on an extremely large
scale, while gravity tends to bring matter together on the
smaller scales.

"In an expanding universe, everybody moves away from everybody else."

http://zebu.uoregon.edu/~js/ast123/lectures/lec14.html



You're late :-) That isn't true for bound systems like clusters of
galaxies, according to current ideas.
It's customary to put quotation marks around direct quotations from your
source.

Yeah - that's why they are there. Have you seen your optometrist
lately?

"SunDancingGuy" ha scritto nel messaggio
...

If you do a search for "transverse velocity" and M31, you'll find that
astronomers hope to use missions like SIM and GAIA to look at M31, to
see if it really will hit us.

Hit us? What a laugh. If the sun were scaled as a tennis bal in
Toronto, then the nearest star to us in our local group would be
another tennis ball located in Florida. Sounds like a real collision
risk!

It seems almost impossible to see so many galaxy collisions with distances
like these...
But I know that computer simulations shows that's possible.
We trust a lot in computer nowadays...

Luigi Caselli

In message , SunDancingGuy
writes
On Fri, 8 Oct 2004 18:28:58 +0100, Jonathan Silverlight
wrote:

In message , Chuck Farley
writes
On Thu, 07 Oct 2004 05:02:05 GMT, "Painius"
wrote:

The 250 km/sec is merely the radial component of
Andromeda's velocity and motion. We have no idea what
Andromeda's lateral motion, direction or speed happens
to be. It may very well be that both galaxies revolve about
a common center of gravity, and that at some parts of the
orbit, Andromeda would show a red shift, at other parts
show a blue shift. And we may just happen be in the part
of the mutual orbit where Andromeda shows a blue shift.

There really is no way of telling, however astronomers
are working on ways to close this gap in our knowledge.

IOW, there are so many "ifs, ands, buts, and maybes" that, to quote
your own words, " We have no idea what
Andromeda's lateral motion, direction or speed happens
to be."
Yet, that's the basis for a projected "collision". Chuckle.

You just don't get it, do you? The collision is hype. No-one's sure if
it will happen. But the evidence for such collisions having happened is
unshakeable, unless you can show an alternative explanation for galaxies
shaped like the Mice (NGC 4676-1) and the Cartwheel (among others).
The evidence for the Milky Way and M31 is also unshakeable, unless you
can show an alternative explanation for the blue shift.

what blue shift?The "apparent" blue shift? Read the Schiapeelli
Observatory page, where they state, "M31 is too close to be able to
appreciate its red shift with our instrument. "

Presumably the professionals who have been measuring its red shift for
90 years are in error.


If you do a search for "transverse velocity" and M31, you'll find that
astronomers hope to use missions like SIM and GAIA to look at M31, to
see if it really will hit us.

Hit us? What a laugh. If the sun were scaled as a tennis bal in
Toronto, then the nearest star to us in our local group would be
another tennis ball located in Florida. Sounds like a real collision
risk!

Looks like another idiot's joined the discussion. I wasn't talking about
individual stars colliding, but the galaxies as a whole.

In message , SunDancingGuy
writes
On Wed, 6 Oct 2004 23:39:49 +0100, Jonathan Silverlight
wrote:

[....]
" The 1913 paper measured the blueshift of Andromeda to be 300 km/s.

1913? GUFFAW!



Chuck? Is that you? Just what is your problem with that?