A Physics forum. Physics Banter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » Physics Banter forum » Physics Newsgroups » The Theory of Relativity
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Tags: , , , ,

How do Scientists differentiate between Stars & Galaxies?



 
 
Thread Tools Display Modes
  #11  
Old 1 Week Ago posted to sci.physics,alt.philosophy,alt.astronomy,sci.physics.relativity
xxein[_3_]
external usenet poster
 
Posts: 38
Default How do Scientists differentiate between Stars & Galaxies?

On May 9, 4:39*pm, Tom Roberts wrote:
Sanny wrote:
[...]


I think that 5 minutes using Google will teach you more about this than
any amount of discussion in these newsgroups.

Tom Roberts


xxein: I don't really want to get into an argument here but Google
can probably give support to any thought you may have. It is not an
authoritative document or physic.

If you mean looking at web pages that support your view, there are
plenty. There are plenty without rhyme or reason also. It becomes a
matter of belief.

I know and you know that 'systems' of scale have behavioral qualities
and quantities that are supposed to have a 'definable physic'. Are
you saying we have achieved this understanding of the physic?

I don't think so. We may get results for the applications we seek to
apply, but are they the 'direct' consequence of a physic, or just our
understanding and use of it? We can make Jello anytime without
understanding how it gels.

So, this is the point of consideration. We give reason for physics
through repeatability. This is what we have developed as our
physics. Do we really understand it yet? I doubt it.

We thought we knew physics from Archimedes to Newton. So now we have
Einstein. What's the difference for tomorrow? We were relatively
stupid then, and now we think we know it all? Give us a break.

I have studied this physics situation for a very long time. I can
start to draw pointed suggestions and solutions. They do work, but
just not in the context of the physics you may have in mind. I can't
and won't try to change your belief/mind here. Just be aware that a
consensus will advocate (bandwagon) a change of the understanding of
the physics in the tomorrow.

It may never achieve the physic (itself), but it will get closer.

In the meantime, don't act like a sorcerer who can make a magic fire,
at will, to try and stupify us into believing you command the
universe. You and I can agree that neither one of us can make that
happen (even though a vast majority will be fooled). I'll agree that
there are the so-called 'kooks' that want us to believe their way.
But there is a logic to be found. It is not temporary any more than
this universe. The logic is the juxtaposition of this universe within
itself.

Maybe, some day, we can realise that there are other universes out
there. We have no evidence of that but we can hardly examine an
evidence at hand and make a logic with it that does not have a better
explanation with a logic either.

We are stuck with the temporary logic at hand. And that really sucks
to me. I've put 23 years into understanding the generalities of the
physic presented to us by this universe as the physic to which it
abides. These generalities differ significantly from the physics
currently accepted as belief.

Yeah, SR math works (in it's own context). So does GR (likewise). So
does a billion buyer computer game. What is real anymore? Can we
find out the source code? Or do we just say that if it is not of our
codec, it can't be true?

Smarten up, Tom. There's a whole universe beyond your coffee cup and
the same alligator clips used day after day within a monotonous closed
system.
Ads
  #12  
Old 1 Week Ago posted to sci.physics,alt.philosophy,alt.astronomy,sci.physics.relativity
Eric Gisse
external usenet poster
 
Posts: 15,283
Default How do Scientists differentiate between Stars & Galaxies?

On May 9, 5:48*pm, xxein wrote:
On May 9, 4:39*pm, Tom Roberts wrote:

Sanny wrote:
[...]


I think that 5 minutes using Google will teach you more about this than
any amount of discussion in these newsgroups.


Tom Roberts


xxein: *I don't really want to get into an argument here but Google
can probably give support to any thought you may have. *It is not an
authoritative document or physic.

If you mean looking at web pages that support your view, there are
plenty. *There are plenty without rhyme or reason also. *It becomes a
matter of belief.

I know and you know that 'systems' of scale have behavioral qualities
and quantities that are supposed to have a 'definable physic'. *Are
you saying we have achieved this understanding of the physic?

I don't think so. *We may get results for the applications we seek to
apply, but are they the 'direct' consequence of a physic, or just our
understanding and use of it? *We can make Jello anytime without
understanding how it gels.

So, this is the point of consideration. *We give reason for physics
through repeatability. *This is what we have developed as our
physics. *Do we really understand it yet? *I doubt it.

We thought we knew physics from Archimedes to Newton. *So now we have
Einstein. *What's the difference for tomorrow? *We were relatively
stupid then, and now we think we know it all? *Give us a break.


Particle accelerators, computers, and GPS are good arguments in
counterpoint.

[snip remaining]
  #13  
Old 1 Week Ago posted to sci.physics,alt.philosophy,alt.astronomy,sci.physics.relativity
jonathan
external usenet poster
 
Posts: 2
Default How do Scientists differentiate between Stars & Galaxies?


"Sanny" wrote in message
...
When I see sky I only see small stars twinkling at night.

Now When I see sky with a large telescope I will again see many stars.

How do I know whether a twinkling Object is a Star from our Galxy or
it is some other Galaxy.

How do scientist see the very far away Galaxies and see Billions of
Stars in it.



You know how big the full moon is in the sky? It's about half a degree.
The closest galaxy to us is 2 degress across...four times the size
of the full moon. The first time you see it in a wide angle telescope
or binoculars, it looks like the finest mist you've ever seen.
With the mist being countless stars of that galaxy.

Look at this picture below. Near the very bottom center is a speck of light
within a 'cross' of light. Another near the center. Those are stars within our
galaxy, all the ..rest are galaxies. Look at the full size image for awhile, and
gaze over all the galaxies, it's the most spectacular view of the deep universe
ever made. And this image is just a tiny speck of the night sky.
http://en.wikipedia.org/wiki/Image:H...deep_field.jpg


Can they really see each star in the Galaxy and how do they count that
there are 100 Billion stars in that galaxy.

It may happen That is just a Star with a Billions of small planet
sized things.

And when we are living inside the Galaxy how do astronomers descide
that our galaxy is spiral.

As far as I know whichever direction I see I can see infinite number
of stars.

So what are they basis of these assumption?

What I bilieve is stars are randomly distributed throughout the
Universe.

And Universe is Finite or Infinite is again a Question.

Say Universe is Finite then it must have some Shape.

Lets assume it has a Shape of a Sphere.

Then That sphere must have some radius.

What happens about the place outside that sphere.

Say our Universe Radius is "r"

What are the things ar a distance 2r, 3r, 100r, 1000r. Why do we not
consider the things at a distance 1000r as part of our Universe?

Why we confine our Universe to be a Sphere of radius r ????

Bye
Sanny



  #14  
Old 6 Days Ago posted to sci.physics,alt.philosophy,alt.astronomy,sci.physics.relativity
Immortalist
external usenet poster
 
Posts: 540
Default How do Scientists differentiate between Stars & Galaxies?

On May 9, 10:12*am, Sanny wrote:
When I see sky I only see small stars twinkling at night.

Now When I see sky with a large telescope I will again see many stars.

How do I know whether a twinkling Object is a Star from our Galxy or
it is some other Galaxy.

How do scientist see the very far away Galaxies and see Billions of
Stars in it.

Can they really see each star in the Galaxy and how do they count that
there are 100 Billion stars in that galaxy.


The Official Story;

Toward the end of the 18th century, Charles Messier compiled a catalog
containing the 109 brightest nebulae (celestial objects with a
nebulous appearance), later followed by a larger catalog of 5,000
nebulae assembled by William Herschel. In 1845, Lord Rosse constructed
a new telescope and was able to distinguish between elliptical and
spiral nebulae. He also managed to make out individual point sources
in some of these nebulae, lending credence to Kant's earlier
conjecture.

In 1917, Heber Curtis had observed the nova S Andromedae within the
"Great Andromeda Nebula" (Messier object M31). Searching the
photographic record, he found 11 more novae. Curtis noticed that these
novae were, on average, 10 magnitudes fainter than those that occurred
within our galaxy. As a result he was able to come up with a distance
estimate of 150,000 parsecs. He became a proponent of the so-called
"island universes" hypothesis, which holds that spiral nebulae are
actually independent galaxies.

In 1920 the so-called Great Debate took place between Harlow Shapley
and Heber Curtis, concerning the nature of the Milky Way, spiral
nebulae, and the dimensions of the universe. To support his claim that
the Great Andromeda Nebula was an external galaxy, Curtis noted the
appearance of dark lanes resembling the dust clouds in the Milky Way,
as well as the significant Doppler shift.

The matter was conclusively settled by Edwin Hubble in the early 1920s
using a new telescope. He was able to resolve the outer parts of some
spiral nebulae as collections of individual stars and identified some
Cepheid variables, thus allowing him to estimate the distance to the
nebulae: they were far too distant to be part of the Milky Way. In
1936 Hubble produced a classification system for galaxies that is used
to this day, the Hubble sequence.

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

A Cepheid variable or Cepheid is a member of a particular class of
variable stars, notable for a fairly tight correlation between their
period of variability and absolute luminosity. The namesake and
prototype of these variables is the star Delta Cephei, discovered to
be variable by John Goodricke in 1784.

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

The Hubble sequence is a morphological classification scheme for
galaxies invented by Edwin Hubble in 1936. It is often known
colloquially as the Hubble tuning-fork because of the shape in which
it is traditionally represented.

Hubble’s scheme divides regular galaxies into 3 broad classes -
ellipticals, lenticulars and spirals - based on their visual
appearance (originally on photographic plates). A fourth class
contains galaxies with an irregular appearance. To this day, the
Hubble sequence is the most commonly used system for classifying
galaxies, both in professional astronomical research and in amateur
astronomy.

http://en.wikipedia.org/wiki/Hubble_sequence
  #15  
Old 6 Days Ago posted to sci.physics,alt.philosophy,alt.astronomy,sci.physics.relativity
Sanny
external usenet poster
 
Posts: 143
Default How do Scientists differentiate between Stars & Galaxies?

Thanks that was useful.

Bye
Sanny

  #17  
Old 6 Days Ago posted to sci.physics,alt.philosophy,alt.astronomy,sci.physics.relativity
Yousuf Khan
external usenet poster
 
Posts: 76
Default How do Scientists differentiate between Stars & Galaxies?

Sanny wrote:
When I see sky I only see small stars twinkling at night.

Now When I see sky with a large telescope I will again see many stars.

How do I know whether a twinkling Object is a Star from our Galxy or
it is some other Galaxy.


Some of them are easy, the Andromeda galaxy, and the two Magellanic
Clouds, are both nearby independent galaxies, none of which we can see
from Earth's northern hemisphere, but you can see them from the south.
They look quite different from stars, they look like a spread out cloudy
smear to the naked eye. Andromeda looks bigger than the full moon,
though much fainter.

How do scientist see the very far away Galaxies and see Billions of
Stars in it.

Can they really see each star in the Galaxy and how do they count that
there are 100 Billion stars in that galaxy.


They don't, they just see the smear, and they estimate the number of
stars in it. They may be able to distinguish specific individual stars
inside it, if one of those stars go supernova, or they are large
variable (blinking) stars.

The galaxies that are further away, wouldn't be visible to our naked
eyes anyways. But if they were naked-eye visible, they would be just
pinpricks to us.

The 100 billion star estimate might have to be revised to more like 500
billion per galaxy. As our telescopes get better we're discovering
within our own galaxy that the vast majority of stars are really red
dwarf stars, almost 80% of it in fact. We had previously thought that
stars around the size of our Sun were the majority, but we couldn't see
the faint little red dwarves until now. So the estimates are going up.

It may happen That is just a Star with a Billions of small planet
sized things.


They can tell it's not within our galaxy by the faintness of it. They
can tell it's not a star with many glowing planet-like things because
they wouldn't be nearly as bright as their own star.

And when we are living inside the Galaxy how do astronomers descide
that our galaxy is spiral.


We're not in the main disk of our galaxy, we're slightly higher off the
plane and looking down at it from an angle. Again, most of this is not
visible to us from the northern hemisphere, the people in the southern
hemisphere are much luckier than us in this respect.

As far as I know whichever direction I see I can see infinite number
of stars.


Using just your naked eye, all you are seeing are just stars that are
part of our own galaxy. I don't think there are any particularly
noticeable nearby galaxies visible from the northern hemisphere.

All galaxies we see from the north are only noticeable through telescopes.

So what are they basis of these assumption?

What I bilieve is stars are randomly distributed throughout the
Universe.


Sort of, stars are mostly distributed inside galaxies, and the galaxies
look quite randomly distributed. In actual fact, the galaxies are
distributed in a chaotic tangled spiderweb shape across the universe, so
it's not truly random just merely complex.

As a side note, where there isn't any galaxies, the universe is infused
with intergalactic gas. There's nearly ten times as much mass in the
intergalactic gas as there are in the galaxies. The gas could have
clumped together to form ten times as many galaxies, except that the
existing galaxies often capture some of this gas and incorporate them
into their own internal structures. Other times the jets, winds and
radiation emanating from the existing galaxies blow this gas away, so
they cannot form into new galaxies. There has been some instances of
stars observed that were not part of a galaxy, but floating around in
intergalactic space. Some of these stars may have been part of a galaxy
once, but during a galactic merger, they got tossed out. While others
seem like they may have been born right in the intergalactic gas; some
intergalactic stars were even large enough to go supernova, so they must
have gathered enough intergalactic gas to become truly colossal in size.

And Universe is Finite or Infinite is again a Question.

Say Universe is Finite then it must have some Shape.


There is no definitive answer for that, just theories. Even if the
Universe is finite, the part that we see right now is only a small part
of it. It is generally agreed that there might be some parts of the
universe that are expanding away from us *faster* than the speed of
light, due to the inflation of the universe. This doesn't violate the
laws of relativity because those laws only govern how fast matter and
energy inside the universe can travel through the universe, but not now
how fast space can travel in relation to itself. So space itself is
carrying away parts of the universe faster than light speed, and the
light from that part of the universe will never reach us. The Cosmic
Microwave Background is considered to be the sheath behind which the
rest of the Universe is.

It's all sort of like what happened when our universe was just the
Earth. And in fact, the Earth was merely everything we could see to its
horizons. Eventually we discovered that if we kept walking the horizon
always remained just as far away, except we were seeing new things. We
then eventually discovered that the Earth was not flat, but round. We
are in the same position now within the Universe, we are only seeing to
its horizons, but not beyond.

Lets assume it has a Shape of a Sphere.

Then That sphere must have some radius.

What happens about the place outside that sphere.

Say our Universe Radius is "r"

What are the things ar a distance 2r, 3r, 100r, 1000r. Why do we not
consider the things at a distance 1000r as part of our Universe?

Why we confine our Universe to be a Sphere of radius r ????



Anything outside our point of view cannot be observed, so there is no
way to make any measurements or take any readings. We can only consider
that which we can see. The stuff outside the horizon, whether it exists
or not, whether it is 2 times larger, or 10 times larger, 100 times
larger or 1000 times larger is irrelevant, we cannot even begin to guess
at its size.

Yousuf Khan
  #19  
Old 5 Days Ago posted to sci.physics,alt.philosophy,alt.astronomy,sci.physics.relativity
YKhan
external usenet poster
 
Posts: 18
Default How do Scientists differentiate between Stars & Galaxies?

On May 10, 10:45 am, wrote:
Have you read his other posts?

He's either a babbling twit unable to do a simple Google search or
a troll.

And, if you had bothered to read all my post, I gave links where all
his questions and more were answered.

It took me all of about a minute to find all those pages.


He only sounds like a babbling troll because he doesn't know as much
as you. A lot of people come in knowing a little bit of something, but
they have some holes and/or misconceptions in their knowledge that
they need filled in. Some people come in thinking one thing is similar
to something else they understand, but it's a misconception, and it
has to be explained why it's misconception to them.

And since when is Usenet simply the proxy for Wikipedia and the Web in
general? Nobody wants to discuss anything anymore, just send them to a
webpage? Much of the stuff in Wikipedia is becoming textbook-like in
appearance, these days. Instead of cramming through a whole Wikipedia
article, it's often much quicker to just ask a specific question and
get it answered quickly.

Just see how much more value he got out of Immortalist's reply to him
than yours. Immortalist basically linked to a bunch of Wikipedia pages
too, but he also took the time to explain stuff in his own words. Now
Sanny can go read the Wikipedia articles knowing a bit more about the
background from it. If you don't have the patience to be a teacher,
then don't bother replying to posts that require you to suffer from
fools.

Yousuf Khan
  #20  
Old 5 Days Ago posted to sci.physics,alt.philosophy,alt.astronomy,sci.physics.relativity
ZerkonX[_2_]
external usenet poster
 
Posts: 32
Default How do Scientists differentiate between Stars & Galaxies?

On Fri, 09 May 2008 10:12:07 -0700, Sanny wrote:

How do I know whether a twinkling Object is a Star from our Galxy or it
is some other Galaxy.


reading?
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
How do Scientists differentiate between Stars & Galaxies? Sanny Physics - General Discussion 20 4 Days Ago 11:02 PM
I have already justified the origin of the whole world (including galaxies, planets, stars, etc...) tsabooteh@gmail.com Physics - General Discussion 0 March 15th 07 03:00 PM
Scientist says neutron stars, not black holes, at center of galaxies (Forwarded) Lloyd Parker The Theory of Relativity 45 December 21st 05 11:50 PM
Scientist says neutron stars, not black holes, at center of galaxies (Forwarded) Lloyd Parker Particle Physics 43 December 21st 05 11:50 PM
How stars and galaxies form - Pioneer 10/11 Anomaly's Message Jack Sarfatti Physics - General Discussion 0 October 16th 04 04:52 PM


All times are GMT +1. The time now is 07:22 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2008, Jelsoft Enterprises Ltd.Search Engine Friendly URLs by vBSEO 2.4.0
Copyright ©2004-2008 Physics Banter, part of the NewsgroupBanter project.
The comments are property of their posters.
Loan news - Myspace Images - Loan - McDonalds - Loan