newbie qsn, what do u define universe as?

Hi,
am new to astronomy, and was wondering, what do you define universe
as?

thanks,
asger

"asger" wrote in message ...
Hi,
am new to astronomy, and was wondering, what do you define universe
as?

thanks,
asger

'Lo Asger --

I define our Universe as being unimaginably huge and
chock full of interesting mysteries and puzzles!

For most of human history people defined the Universe
as a place where Earth was at its center and everything
in the sky traveled around the Earth. It's easy to see why
because anything else seems counter-intuitive.

Almost 2 thousand years ago a guy named Ptolemy
even proved the above using mathematics!

Then about 450 years ago a man who is called "The
Founder of Modern Astronomy," Nikolas Copernicus,
used mathematics to show that Ptolemy had been
wrong for all those many years. Copernicus was able
to show that the Sun was the center of the Universe...
that Earth and everything else revolved around our Sun.
Yet it would be an average lifetime before this idea
would even begin to "catch on!"

So for a little less than 300 years, the Universe was
defined as "heliocentric" or "Sun-centered." In the year
1920, an astronomer named Harlow Shapley was able
to begin convincing people that, while some of the
objects in the sky went around the Sun, many of them
did not. Shapley believed that our Sun along with many
other stars traveled around the center of the Universe.
In fact, up until about the mid-1920s, everything in the
sky was believed to be inside our Milky Way Galaxy.
And Shapley showed that our Sun was very far away
from the center of the galaxy.

A word i like to use to describe this is "galaxocentric"
(although Shapley's mental picture of the Universe did
not last long enough to even be officially named). So
it went something like this...

Aristotle/Ptolemy_____"geocentric" or Earth-centered
Copernicus_________"heliocentric" or Sun-centered
Shapley________"galaxocentric" or Galaxy-centered

Then another great astronomer, Edwin Hubble, was
able to show in the mid-1920s that our Milky Way
Galaxy was just one of many galaxies, each galaxy
home to a great many stars!

To continue your journey and to see why i define the
Universe as i do, check out the speed of light. As you
may already know, the light from the stars and other
objects in the sky travels to our eyes at a finite speed
of about 300 million meters per second. Or if you like,
about 186 thousand miles per second.

This means that the reflected light from our Moon takes
about a second-and-a-half to reach us. The planet Mars
also reflects the Sun's light, yet even when it's closest to
us (like it was recently) the light from Mars takes a little
over 3 minutes to get to Earth.

And the light from our Sun reaches us in a little more
than 8 minutes. It takes over 4 years for the light from
the next nearest star to reach us. And if light could get
through the great dust cloud, it would take it around 30
thousand years to get to us from the center of our
galaxy!

Our galaxy is so large that it takes about 100 thousand
years for light to travel from one edge, through the
middle, and back out to the other edge.

The *nearest* big galaxy to ours, the Andromeda Galaxy,
is so far away that it takes more than 2 million years for
the light from its stars to reach us. And some of the
objects that scientists have seen with telescopes are so
far away that their light rays zoom through space for many
billions of years before we see them!

Since pictures can say it even better than words, you are
invited to go to the following website to get a better idea
about how astronomers presently define the Universe...

http://www.anzwers.org/free/universe/index.html

And most important of all... always remember, Asger, that
YOU ARE WHO YOU ARE! While sometimes the Universe
can make a person feel smaller than a pea, a growing love
for astronomy can make you feel larger than life!

happy days and...
starry starry nights!

--
A smidgeon of fear and a sprinkle of strife
And a whole lotta love till your cold...
Most everyone here wants to live a long life,
Ah! but nobody wants to get old.

Paine Ellsworth

Thank you for the wonderful explanation Painius.

From what i understood, does it mean that the universe is everything that
the space is (including all other galaxies etc), or is there something
larger than that? What does cosmos mean then? Can there be more than one
universe?

Asger

"Painius" wrote in message
...
"asger" wrote in message
...
Hi,
am new to astronomy, and was wondering, what do you define universe
as?

thanks,
asger

'Lo Asger --

I define our Universe as being unimaginably huge and
chock full of interesting mysteries and puzzles!

For most of human history people defined the Universe
as a place where Earth was at its center and everything
in the sky traveled around the Earth. It's easy to see why
because anything else seems counter-intuitive.

Almost 2 thousand years ago a guy named Ptolemy
even proved the above using mathematics!

Then about 450 years ago a man who is called "The
Founder of Modern Astronomy," Nikolas Copernicus,
used mathematics to show that Ptolemy had been
wrong for all those many years. Copernicus was able
to show that the Sun was the center of the Universe...
that Earth and everything else revolved around our Sun.
Yet it would be an average lifetime before this idea
would even begin to "catch on!"

So for a little less than 300 years, the Universe was
defined as "heliocentric" or "Sun-centered." In the year
1920, an astronomer named Harlow Shapley was able
to begin convincing people that, while some of the
objects in the sky went around the Sun, many of them
did not. Shapley believed that our Sun along with many
other stars traveled around the center of the Universe.
In fact, up until about the mid-1920s, everything in the
sky was believed to be inside our Milky Way Galaxy.
And Shapley showed that our Sun was very far away
from the center of the galaxy.

A word i like to use to describe this is "galaxocentric"
(although Shapley's mental picture of the Universe did
not last long enough to even be officially named). So
it went something like this...

Aristotle/Ptolemy_____"geocentric" or Earth-centered
Copernicus_________"heliocentric" or Sun-centered
Shapley________"galaxocentric" or Galaxy-centered

Then another great astronomer, Edwin Hubble, was
able to show in the mid-1920s that our Milky Way
Galaxy was just one of many galaxies, each galaxy
home to a great many stars!

To continue your journey and to see why i define the
Universe as i do, check out the speed of light. As you
may already know, the light from the stars and other
objects in the sky travels to our eyes at a finite speed
of about 300 million meters per second. Or if you like,
about 186 thousand miles per second.

This means that the reflected light from our Moon takes
about a second-and-a-half to reach us. The planet Mars
also reflects the Sun's light, yet even when it's closest to
us (like it was recently) the light from Mars takes a little
over 3 minutes to get to Earth.

And the light from our Sun reaches us in a little more
than 8 minutes. It takes over 4 years for the light from
the next nearest star to reach us. And if light could get
through the great dust cloud, it would take it around 30
thousand years to get to us from the center of our
galaxy!

Our galaxy is so large that it takes about 100 thousand
years for light to travel from one edge, through the
middle, and back out to the other edge.

The *nearest* big galaxy to ours, the Andromeda Galaxy,
is so far away that it takes more than 2 million years for
the light from its stars to reach us. And some of the
objects that scientists have seen with telescopes are so
far away that their light rays zoom through space for many
billions of years before we see them!

Since pictures can say it even better than words, you are
invited to go to the following website to get a better idea
about how astronomers presently define the Universe...

http://www.anzwers.org/free/universe/index.html

And most important of all... always remember, Asger, that
YOU ARE WHO YOU ARE! While sometimes the Universe
can make a person feel smaller than a pea, a growing love
for astronomy can make you feel larger than life!

happy days and...
starry starry nights!

--
A smidgeon of fear and a sprinkle of strife
And a whole lotta love till your cold...
Most everyone here wants to live a long life,
Ah! but nobody wants to get old.

Paine Ellsworth

On Mon, 8 Sep 2003 12:38:29 -0400, "Asger" wrote:

Thank you for the wonderful explanation Painius.

From what i understood, does it mean that the universe is everything that
the space is (including all other galaxies etc), or is there something
larger than that? What does cosmos mean then? Can there be more than one
universe?

Asger

The word "Cosmos" comes from the ancient Greek and mean: Order; it is opposed to
the word Chaos (disorder). I agree with that: the Universe is a well ordered
place!

But during the last twenty years, some scientists began to believe that the
Universe might be MUCH bigger that the one we see using our biggest telescope.
Here is the idea: The Universe is (about) 15 billions years old. Because of the
speed of light, all the instruments we can create cannot "see" further away than
15 bilions light-years away. We have instruments much more sensitive than that
but all we can see is a big wall: the initial "flash" of the Big Bang. We will
never know what is beyond his wall until we discover something that can goes
faster than light.

When we look at those distance with the Hubble Space Telescope, all what we see
are a few sparse Quasars and very young galaxies. But there are people out
there, they too have evolved for 15 billions years just like us. And when they
look at us with their "Zxdbdltg Space Astroscope", they see a very young galaxy
only a few millions years old unable to harbor any life at all. That is the
problem with light, it is too slow to show us what is "actualy" happenig at the
other end of the Universe.

Shortly after the Big Bang, our Universe entered a phase of "inflation". The
first computations described that phase as "The Universe is the size of an atom
and it grows suddenly to the size of a football in less than a billionth af a
second". Now, many people think the the inflation might have been much more
stupendous than that, placing much of the Universe outside of the boundary of
the "Big Flash", unreachable for us forever...

Now what is the Universe: is it "everything that exist" or "everything that can
be observed"?

I go for the latter.

P.S. According to some theories on quantum fluctuations and the Higgs's boson,
there are litteraly billions of Big Bangs happening under our noses every
seconds all of them leading to another "Universe". We cannot detect them
because they are not part of "our" Universe. Choose your religion...

Benoît Morrissette

On Sat, 06 Sep 2003 21:53:34 GMT, "Painius" wrote:

"asger" wrote in message ...
Hi,
am new to astronomy, and was wondering, what do you define universe
as?

thanks,
asger

'Lo Asger --

I define our Universe as being unimaginably huge and
chock full of interesting mysteries and puzzles!
snip...

And most important of all... always remember, Asger, that
YOU ARE WHO YOU ARE! While sometimes the Universe
can make a person feel smaller than a pea, a growing love
for astronomy can make you feel larger than life!

From a pea, knowlege of the Universe makes me feel smaller than a neutrino, but
a very very happy neutrino!!

happy days and...
starry starry nights!

To you too!

Benoît Morrissette

"Asger" wrote in message...
...

Thank you for the wonderful explanation Painius.

From what i understood, does it mean that the universe is everything that
the space is (including all other galaxies etc), or is there something
larger than that? What does cosmos mean then? Can there be more than one
universe?

Asger

You're welcome, Asger, it's a pleasure!

Had to be away for a few days... so here we are again!

The Universe is usually taken to be "everything," whether
we can see and observe it or not. So sometimes when
we read about astronomy and cosmology, we have to find
out what the author really means. I find it interesting and
even a little bit funny that we now have the term...

observable universe

....which means all of the Universe that we can see that has
not expanded out beyond the limits of our observation.
And the funny part is that Earth is at the very center of this
"observable universe." So we are officially back to seeing
the Universe--at least this *kind*, the observable one--to be
"geocentric" or "Earth-centered.

Morrissette gave you the derivation of "cosmos" to be from
the Greek and meaning "order." And in astronomy when
this term is used, it's usually to describe the observation of
the physical structure and origins of the Universe. As an
example, the science of "cosmology"--which is also called
"cosmogony"--is a branch of astrophysics that studies this.

As for more than one Universe?...there is very little evidence
that supports this possibility. However there are many who
do speculate about it...

http://www.sciam.com/article.cfm?art...A5809EC5880000

....and typing "multiple universes" into any good search engine
will reveal even more. Such ideas-at least in my neck of the
woods--are considered highly speculative and more along
the lines of philosophy rather than science.

Will we ever know? Probably not, but it's damn fun looking
and talking about it!

happy days and...
starry starry nights!

--
"Oh give me please the Universe keys
That unlock all those mysteries!"
You pay your fees, you find some keys,
That keeps you always groping.

"Oh give me please the Happiness keys
That ease the pain of biting fleas!"
Today you seize you need no keys,
That door is always open.

Paine Ellsworth

"Asger" wrote in message...
...

Thank you for the wonderful explanation Painius.

From what i understood, does it mean that the universe is everything that
the space is (including all other galaxies etc), or is there something
larger than that? What does cosmos mean then? Can there be more than one
universe?

Asger

You're welcome, Asger, it's a pleasure!

Had to be away for a few days... so here we are again!

The Universe is usually taken to be "everything," whether
we can see and observe it or not. So sometimes when
we read about astronomy and cosmology, we have to find
out what the author really means. I find it interesting and
even a little bit funny that we now have the term...

observable universe

....which means all of the Universe that we can see that has
not expanded out beyond the limits of our observation.
And the funny part is that Earth is at the very center of this
"observable universe." So we are officially back to seeing
the Universe--at least this *kind*, the observable one--to be
"geocentric" or "Earth-centered.

Morrissette gave you the derivation of "cosmos" to be from
the Greek and meaning "order." And in astronomy when
this term is used, it's usually to describe the observation of
the physical structure and origins of the Universe. As an
example, the science of "cosmology"--which is also called
"cosmogony"--is a branch of astrophysics that studies this.

As for more than one Universe?...there is very little evidence
that supports this possibility. However there are many who
do speculate about it...

http://www.sciam.com/article.cfm?art...A5809EC5880000

....and typing "multiple universes" into any good search engine
will reveal even more. Such ideas-at least in my neck of the
woods--are considered highly speculative and more along
the lines of philosophy rather than science.

Will we ever know? Probably not, but it's damn fun looking
and talking about it!

happy days and...
starry starry nights!

--
"Oh give me please the Universe keys
That unlock all those mysteries!"
You pay your fees, you find some keys,
That keeps you always groping.

"Oh give me please the Happiness keys
That ease the pain of biting fleas!"
Today you seize you need no keys,
That door is always open.

Paine Ellsworth

Painius wrote,

And the funny part is that Earth is at the
very center of this "observable universe." So we are officially back
to seeing the
Universe--at least this *kind*, the
observable one--to be "geocentric" or
"Earth-centered.

Heh. It's geocentrism resurrected in a big, big way. Hilarious indeed.
oc

Anti-spam address: oldcoot88atwebtv.net
Change 'at' to@

Painius wrote,

And the funny part is that Earth is at the
very center of this "observable universe." So we are officially back
to seeing the
Universe--at least this *kind*, the
observable one--to be "geocentric" or
"Earth-centered.

Heh. It's geocentrism resurrected in a big, big way. Hilarious indeed.
oc

Anti-spam address: oldcoot88atwebtv.net
Change 'at' to@

asger:


asger wrote:
Hi,
am new to astronomy, and was wondering, what do you define universe
as?

thanks,
asger


One starting place in your quest for knowledge could be the universe.
The universe is everything that exists. More particularly, one could
ask, is the universe one thing, that is, is it a 'singularity'?, or is
the universe many things or a 'plurality' of existents?

To review some philosophical commentaries on that subject you could do
some research on the discussion groups that are hosted and archived on
www.google.com . Go to 'Groups', and select 'humanities', 'philosophy',
and 'Objectivism'. Search for the following keywords and keyword
combinations:

+universe +plurality
+universe +singularity
+existence +plurality
+existence +singularity
universe
existence
plurality
singularity

Note that a singularity that is claimed to be the universe, as is
claimed by most religionists, has never been observed, however, a
plurality of existents that is the universe has been observed everywhere
in science and by every person. Searches of other groups and keywords
may be helpful.

Ralph Hertle