The size of the Star Wars Galaxy

[Eternal_Freedom]

• I do not have the time to reply to all that was said - especially as most posts did not contributed to the thread.
  
  In my last post I complained that the source that Eternal_Freedom gave for his claim that most dwarf galaxies are low surface brightness galaxies didn't support that claim.
  
  He wrote:
  

  • • • • Well dwarf spiral galaxies can be that small (indeed they are often categorised as being low-luminosity spirals of 5kpc/15kly diameter). They are considered a subset of low surface brightness galaxies.

  Following the link to Wikipedia, there it is written:
  
  • • • • [quote="Wikipedia about "Low-surface-brightness galaxy""]Most LSBs are dwarf galaxies, [...]

The source Eternal_Freedom gave did not support his claim.

Responding to my complain, Eternal_Freedom provided another source which seemed to confirmed his claim:

• • • • [quote="Wikipedia about "Dwarf spiral galaxies""]A dwarf spiral galaxy is the dwarf version of a spiral galaxy. Dwarf galaxies are galaxies are characterized as having low luminosities, small diameters (less than 5 kpc), low surface brightnesses, and low hydrogen masses." and that they "may be considered a subclass of low-surface-brightness galaxies[/quote]

I admit that in the Wikipedia entry about "Dwarf spiral galaxies" it is written that such "galaxies are characterized as having low luminosities, small diameters (less than 5 kpc), low surface brightnesses, and low hydrogen masses." and that they "may be considered a subclass of low-surface-brightness galaxies".

But what does that mean?

Dwarf spiral galaxies only may be considered a subclass of low-surface-brightness galaxies. That's more than vague.

It does not mean that they are low-surface-brightness galaxies.

It does not mean that they are a subclass of low-surface-brightness galaxies.

It does not mean that they are considered to be a subclass of low-surface-brightness galaxies.

It does mean that they only may be considered a subclass of low-surface-brightness galaxies.

Are they or are they not low-surface-brightness galaxies?

And how different are dwarf spiral galaxies from normal low-surface-brightness galaxies?

How much of what Wikipedia writes about low-surface-brightness galaxies applies to dwarf spiral galaxies?

There have to be difference enough to put into question if dwarf spiral galaxies are low-surface-brightness galaxies.

I could address the other arguments of Eternal_Freedom too.

But as they are mostly depending on the assumption that dwarf spiral galaxies are low-surface-brightness galaxies and that all typical characteristics of low-surface-brightness galaxies can be found in dwarf spiral galaxies, I think it makes more sense to wait until Eternal_Freedom addressed the uncertainty his given sources have left.

[/list][/quote]

You're really going to nitpick the wording on Wikipedia now? Jesus christ.

Nope, sorry, I will not respond, Queue has stated that the evidence I posted is acceptable. Unless and until you can provide evidence that counteracts this, we're done here.

[Lord Revan]

Well he is nothing if not consistent.

I've asked him to provide evidence for his claims already on this thread, though I'll admit he hasn't posted after the second time I asked for it but still I shouldn't have to ask for it multiple times and I'm a nobody, unlike Queue who asked more or less the same thing.

[WATCH-MAN]

• Watch-man seeing how certain you are that the SW galaxy is a dense dwarf galaxy, surely you have a wealth of evidence to support that claim right? so would you kindly share some of that evidence with us?
  
  that's all I ask, surely that can't be so hard?

  • Would you kindly refer to any post in which I have claimed that the Star Wars galaxy is a dense dwarf galaxy.
    
    You may have the impression that this is my objective.
    
    But do you know why that is your impression?
    
    Because you want to prove that it is not - although I have not asked what the Star Wars galaxy is not.
    
    Even if I would admit that the Star Wars galaxy is not a dwarf spiral galaxy - it wouldn't really help us. Because that only means that it is bigger then 5kpc/15kly.
    
    But that means it could still be as small as 16kly or it could be as big as 650kpc. That's the approximate diameter of the largest known spiral galaxy - Malin 1 - which happen to be a low-surface-brightness galaxy.

[WATCH-MAN]

• Does it matter that certain characters in the new EU novels have actually thought or stated that it's a large galaxy?

  • If they are considered canon - it would be evidence.
    
    Where it leads - we have to see.
    
    Insofar: Please show us what your characters have thought or stated.

[WATCH-MAN]

• Well I'd say that depends on the context of where that was said. even a 3 kly galaxy is huge when you're trying to find someone or something hidden.

  • I totally agree.

  That said I'm still waiting for the evidence for the assertion that the SW galaxy is a dense dwarf galaxy, I've asked it twice already, if Watch-man has time to play semantics with everything someone else then him writes surely he has time to provide evidence for his assertions.

  • Please show me where anyone has made the assertion that the SW galaxy is a dense dwarf galaxy.
    
    Please show me where I have made such an assertion.
    
    You want to prove that it is not - although I have not asked what the Star Wars galaxy is not.
    
    Even if I would admit that the Star Wars galaxy is not a dwarf spiral galaxy - it wouldn't really help us. Because that only means that it is bigger then 5kpc/15kly.
    
    But that means it could still be as small as 16kly or it could be as big as 650kpc. That's the approximate diameter of the largest known spiral galaxy - Malin 1 - which happen to be a low-surface-brightness galaxy.

[Eternal_Freedom]

You do understand the idea of a lower limit don't you? The SW galaxy not being a dwarf spiral (or a dwarf galaxy in general) gives us a lower limit. Now we explore to see if there is an upper limit. Malin 1 (thank you for the link, by the way, I had not heard of that object before) gives us an upper limit, though frankly I would be astonished in the SW galaxy is that size, simply because Malin 1 is peculiar and very odd indeed.

While there are other extremely large spiral galaxies like NGC 6872 (link available from that article on Malin-1) that are 500kly diameters or more, they have extremely distended spiral arms that we do not see in the SW galaxy.

The SW galaxy appears to be a roughly circular spiral without a central bar. A quick search through some of the more well-known galaxies like this (M51/Whirlpool, M101/Pinwheel, M63/Sunflower, M33/Triangulum and M31/Andromeda) gives us a bracket of 60kly (M63/Triangulum) to 120-220kly (M31/Andromeda). The Andromeda number is a bit difficult, as the 220kly size includes a large tenuous disc of stars around the main galactic disc, which is about 120 kly in size. M101/Pinwheel is a better upper estimate, being ~170kly in diamter.

So it's most likely somewhere in the region of 60-170 kly diameter.

[WATCH-MAN]

• You're really going to nitpick the wording on Wikipedia now? Jesus christ.
  
  Nope, sorry, I will not respond, Queue has stated that the evidence I posted is acceptable. Unless and until you can provide evidence that counteracts this, we're done here.

  • That may be the difference between you and me.
    
    If you refer to a source, I try to read it. And I try to understand what it says. I do not try to find only what I want to find, what supports my preconceived opinion.
    
    And when I read in Wikipedia that something "may be considered", I wonder why there is such a speculative statement.
    
    Such a statement is unusual for a encyclopedia.
    
    Either it is or it is not.
    
    Or it is considered or it is not considered.
    
    Why writing something that is so vague?
    
    That has to have a reason.
    
    If there is a dispute about it in the scientific community, one would expect that this dispute is described.
    
    But there is nothing but the vague "may be considered".
    
    Maybe it seems only to me so peculiar as English isn't my mother tongue and maybe it is a phrase in English that conveys total conviction. But somehow I doubt that this is case.
    
    
    
    I totally understand that you do not question this - as the answer could put into question your preconceived opinion.
    
    And you do not seem to me to be someone who is ready to question yourself. You have your opinion and all that contradicts this opinion is ignored.
    
    But that is the difference between you and me.
    
    I try to be open to all evidence. And I try to scrutinize all evidence - regardless in which direction it leads.
    
    
    
    And you will excuse that I do not think that Queue's opinion has any merit.
    
    I wonder e.g. if he knew that your account on what Wikipedia has stated was wrong. You wrote that Wikipedia says that "dwarf spiral galaxies [...] are considered a subset of low surface brightness galaxies. But Wikipedia only said that dwarf spiral galaxies may be considered a subset of low surface brightness galaxies. That's a not insignificant difference and one easily could get the idea that you wanted to lie by citing Wikipedia wrongly.
    
    I think that the questions I have asked are justified.
    
    There have to be differences enough to put into question if dwarf spiral galaxies are low-surface-brightness galaxies. Otherwise Wikipedia would say that they are low-surface-brightness galaxies.
    
    And that puts into question how much of what Wikipedia wrote about low-surface-brightness galaxies applies to dwarf spiral galaxies.
    
    But your whole arguments hinges on your assumption that all all typical characteristics of low-surface-brightness galaxies can be found in dwarf spiral galaxies as you want to show that the Star Wars galaxy can not be a dwarf spiral galaxy as we are not seeing the typical characteristics of a low-surface-brightness galaxy.
    
    Please provide evidence for this assumption - or withdraw the claim.

[WATCH-MAN]

• You do understand the idea of a lower limit don't you? The SW galaxy not being a dwarf spiral (or a dwarf galaxy in general) gives us a lower limit. Now we explore to see if there is an upper limit.

  • I understand the idea of a lower limit.
    
    But you failed to provide evidence that this is a lower limit for the Star Wars galaxy.

  Malin 1 (thank you for the link, by the way, I had not heard of that object before) gives us an upper limit, though frankly I would be astonished in the SW galaxy is that size, simply because Malin 1 is peculiar and very odd indeed.

  • And that is what lets me doubt that you have any scientific background.
    
    The galaxy Malin 1 was mentioned in the entry of the Wikipedia entry about low-surface-brightness galaxies.
    
    The whole entry does not have even 450 words. It has five paragraphs.
    
    The galaxy Malin 1 is mentioned in the fifth paragraph that consists of 50 words and only describes the Malin 1 galaxy.
    
    How could you have overseen it if you had read the whole entry about low-surface-brightness galaxies?
    
    That only confirms my impression that you are looking only for things that confirms your preconceived opinions - but not for real evidence - regardless where it leads.

  While there are other extremely large spiral galaxies like NGC 6872 (link available from that article on Malin-1) that are 500kly diameters or more, they have extremely distended spiral arms that we do not see in the SW galaxy.
  
  The SW galaxy appears to be a roughly circular spiral without a central bar. A quick search through some of the more well-known galaxies like this (M51/Whirlpool, M101/Pinwheel, M63/Sunflower, M33/Triangulum and M31/Andromeda) gives us a bracket of 60kly (M63/Triangulum) to 120-220kly (M31/Andromeda). The Andromeda number is a bit difficult, as the 220kly size includes a large tenuous disc of stars around the main galactic disc, which is about 120 kly in size. M101/Pinwheel is a better upper estimate, being ~170kly in diamter.
  
  So it's most likely somewhere in the region of 60-170 kly diameter.

  • You have taken five spiral galaxies and now you are claiming that the size of these five galaxies is representative for the size of all spiral galaxies? That's stupid - if not outright ludicrous.
    
    There could be billions of spiral galaxies in the universe. To take five and claim that these are representative for all is as if I would arbitrary take five persons and would claim that these are representative for the whole mankind.

[Chris Parr]

Has anyone mentioned Han Solo's Kessel Run yet? The one he made in the Millenium Falcon in less than twelve parsecs?

Let's see, twelve parsecs would be thirty nine point twelve light years. So less than twelve parsecs would be about thirty nine light years. If the Kessel Run is a round trip between systems, call it thirty eight light years, or nineteen light years one way. Which seems to me to be consistent with an average sized galaxy like ours, not a dwarf galaxy. Because the distance between systems would be much less in a dense dwarf galaxy, seems to me.

Then again, what do I know?

[Elheru Aran]

And you will excuse that I do not think that Queue's opinion has any merit.

One, stop using list.

Two, Queue is a board administrator. Whether or not you think his opinion has any merit, you are obligated by the terms of your membership here to abide by his (or her) directives. If an administrator says that side A's evidence is acceptable, then either accept it, or present evidence that contradicts it. You have failed to do so in a convincing manner.

[Lord Revan]

Watch-man the assertion of a dense dwarf galaxy is comes from pretty much everything you've posted so far, starting from the OP, You've assumed that the SW galaxy is dense dwarf galaxy though you've yet to show single evidence to support that claim, not a single thing.

basically your argument and don't try to pretend you didn't make one, has no evidence to back it up. And as Elheru Aran pointed out Queue's opinion matters alot as it repesents the opinion of the board staff. like it or not but you've been called to back your claims.

EDIT:I'm not trying to play backseat mod here but rather I'm trying to advice Watch-man how to get past this with honor, whether he takes my advice or not is up to him.

[Lord Revan]

Has anyone mentioned Han Solo's Kessel Run yet? The one he made in the Millenium Falcon in less than twelve parsecs?

Let's see, twelve parsecs would be thirty nine point twelve light years. So less than twelve parsecs would be about thirty nine light years. If the Kessel Run is a round trip between systems, call it thirty eight light years, or nineteen light years one way. Which seems to me to be consistent with an average sized galaxy like ours, not a dwarf galaxy. Because the distance between systems would be much less in a dense dwarf galaxy, seems to me.

Then again, what do I know?

too many variables we don't know to really get anything usefull out of it.

[Eternal_Freedom]

Indeed, it's an interesting avenue to approach it from though. We'd have to assume that the "run" is actually between two systems and that 11-12 parsecs is actually the shortest distance between the two. We'd further have to assume that this does in fact represent an average stellar separation and not, for instance, between two stars which are on the fringes of two nearby star clusters.

The biggest limitation though is that (IIRC) the ANH shooting script indicates Han is bullshitting to impress the yokel farmboys. Since the EU explanation of how he was being honest is out the window, I'm sticking to that.

[Chris Parr]

Well, if he's boasting as you say, wouldn't that indicate the distance between those systems is even greater?

[Elheru Aran]

Well, if he's boasting as you say, wouldn't that indicate the distance between those systems is even greater?

No, he's bullshitting because he thinks they won't know that parsecs are a unit of distance rather than time as he's presenting it (though by a stretch of the imagination you can see how it could be presented as distance).

[Batman]

No, it would indicate that he's just throwing out random spacy-sounding stuff to impress the farmboy and the old man (which is almost inevitably what that scene was meant to be about).

[Elheru Aran]

No, it would indicate that he's just throwing out random spacy-sounding stuff to impress the farmboy and the old man (which is almost inevitably what that scene was meant to be about).

Well, it amounts to the same thing-- the 'Kessel Run in less than 12 parsecs' bit is bollocks, however you try to read it. It doesn't really mean much of anything towards the size of the galaxy.

[Batman]

Sorry. You're right, that was directed at Chris Parr, not you.

[Chris Parr]

All right.

[Esquire]

And when I read in Wikipedia that something "may be considered", I wonder why there is such a speculative statement.

Such a statement is unusual for a encyclopedia.

Either it is or it is not.

Or it is considered or it is not considered.

Why writing something that is so vague?

That has to have a reason.

Right, look. We did this last year, and you clearly haven't learned anything since - stop making semantics arguments based on your understanding of the English language. You're not perfectly proficient in it; specifically, you are flat-out wrong about how scientific statements are made.

We (the scientific community) do not have perfect knowledge of everything. Definitive statements are never made by scientists; that's why gravity is technically a theory, and always will be. Similarly, it is unacceptable to say that smoking causes lung cancer, although only an idiot or a tobacco lobbyist would dispute the clear link between them. All we can do is say things like "according to the balance of the evidence," "research suggests," and, yes, "it may be considered." The absence of a definitive statement is not evidence for the alternative hypothesis, it's a tacit admission that we don't know everything yet. In this case, Wikipedia is simply following the rules of scientific writing. In this specific case, the sentence "dwarf spiral galaxies... may be considered a subset of low-surface-brightness galaxies" is equivalent to "the astronomical community currently considers dwarf spiral galaxies to be a subset of low-surface-brightness galaxies." As an example, a paper on current political theory might read something like "the Tea Party may be considered a spinoff of the larger Republican Party in the United States."

Moreover - and I can't believe I have to explain this again, in a different thread no less - you are explicitly not, as you claim, "trying to scrutinize all evidence." You are demanding increasingly ridiculous levels of proof while offering precisely no contradictory evidence. Your wall-of-ignorance tactics begin to run thin; either provide a reason to discount the existing balance of evidence or concede the point.

Also, why are all of your posts in list format? Everybody else can express their ideas in full paragraphs with logically-coherent arguments and supporting evidence, why can't you?

[Eternal_Freedom]

That's a good point Watch-Man, you freely admit English isn't your native language, so why are you trying to nitpick semantics in said language to people who are native speakers (such as myself).

[Lagmonster]

No, it would indicate that he's just throwing out random spacy-sounding stuff to impress the farmboy and the old man (which is almost inevitably what that scene was meant to be about).

Well, it amounts to the same thing-- the 'Kessel Run in less than 12 parsecs' bit is bollocks, however you try to read it. It doesn't really mean much of anything towards the size of the galaxy.

Distance could be noteworthy if the "kessel run", whatever it is, turned out to be significant because of dangerous obstacles.

Imagine, for example, that to get from point A to point B, you had to go through a field of lit torches, with the torches more densely packed in the middle than on the outside. You could get to point B by going around, where the torches are thinly packed, or you could take a more dangerous, but much shorter route, through the middle where the torches are densely packed. Obviously, the shorter route gets you there quicker, but to pass through the heat unharmed, you need to move much, much faster than if you were weaving carefully around the obstacles.

It requires a bit of imagination, but you can imagine Han's boast as something that makes sense.

[biostem]

No, it would indicate that he's just throwing out random spacy-sounding stuff to impress the farmboy and the old man (which is almost inevitably what that scene was meant to be about).

Well, it amounts to the same thing-- the 'Kessel Run in less than 12 parsecs' bit is bollocks, however you try to read it. It doesn't really mean much of anything towards the size of the galaxy.

Distance could be noteworthy if the "kessel run", whatever it is, turned out to be significant because of dangerous obstacles.

Imagine, for example, that to get from point A to point B, you had to go through a field of lit torches, with the torches more densely packed in the middle than on the outside. You could get to point B by going around, where the torches are thinly packed, or you could take a more dangerous, but much shorter route, through the middle where the torches are densely packed. Obviously, the shorter route gets you there quicker, but to pass through the heat unharmed, you need to move much, much faster than if you were weaving carefully around the obstacles.

It requires a bit of imagination, but you can imagine Han's boast as something that makes sense.

Well, isn't that basically the EU explanation, regarding "The Maw" and its black holes?

[Terralthra]

I'm on the side of the script, which says in the pre-shooting draft, "Ben reacts to Solo's stupid attempt to impress them with obvious misinformation.", and other drafts, says, "[Han] is obviously lying."

Sorry, don't buy any other explanation. He's bragging trying to impress the yokels with bullshit, and Ben's look in response sells understated disbelief well, in my opinion. He goes from leaning a bit forward, with a politely curious look, on "No, should I have?":


To leaning a bit back, lowering his eyebrows, and smiling faintly. He's throwing perfect Jedi shade after "twelve parsecs":

[Techno_Union]

Not looking to jump in the middle of this debate, but I recalled a few mentions of the galaxy's size in the ANH novel and thought I'd share. I grabbed these from the PDF version, which unfortunately lacks corresponding page numbers:

The tridimensional solid screen filled one wall of the vast chamber from floor to ceiling. It showed
a million star systems. A tiny portion of the galaxy, but an impressive display nonetheless when
exhibited in such a fashion.

This is written right before the Death Star sets course for Alderaan.

Vader stared at the motley array of stars displayed on the conference-room map while Tarkin and
Admiral Motti conferred nearby. Interestingly, the first use of the most powerful destructive machine
ever constructed had seemingly had no influence at all on that map, which in itself represented only a
tiny fraction of this section of one modest-sized galaxy.

Written right after the Falcon was captured by the Death Star's tractor beam.

Happy to provide additional quotes if necessary.