A galaxy far, far away?

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Tuefish
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A galaxy far, far away?

Post #1by Tuefish » 06.03.2007, 19:42

Has anyone thought of doing stars in a diferent galaxy?
"Over Seventy earths spinnin' round in the galaxy, and the meek have inherited not a one."
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selden
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Post #2by selden » 06.03.2007, 19:51

Many times.

Unfortunately, Celestia cannot draw stars reliably if they're more than 16KLY from the Sun.

Maybe someday that restriction will be removed...
Selden

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Hungry4info
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Post #3by Hungry4info » 09.03.2007, 23:30

What prevents this restriction from being removed for the final release of Celestia 1.5.0?
Current Setup:
Windows 7 64 bit. Celestia 1.6.0.
AMD Athlon Processor, 1.6 Ghz, 3 Gb RAM
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chris
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Post #4by chris » 10.03.2007, 02:10

Hungry4info wrote:What prevents this restriction from being removed for the final release of Celestia 1.5.0?


Time. Some significant development work is required.

--Chris

peter_89
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Post #5by peter_89 » 30.03.2007, 00:59

True.
Something of this scale is a tremendous challenge to undertake, especially using what is essentially volunteer work. Anyone who is familiar with large-scale development projects will tell you that the only way to successfully undertake such things is with employment.
Besides that, the only "stars" that we are able to actually register in different galaxies with current technologies are those that have undergone supernovas -- in other words, even if such development were possible, it would be comprised of entirely fictional star data.
It is a dream we all have here, but it is simply not yet feasible and is not likely to become so for quite some time.

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Post #6by Dollan » 30.03.2007, 02:55

peter_89 wrote:True.
Something of this scale is a tremendous challenge to undertake, especially using what is essentially volunteer work. Anyone who is familiar with large-scale development projects will tell you that the only way to successfully undertake such things is with employment.
Besides that, the only "stars" that we are able to actually register in different galaxies with current technologies are those that have undergone supernovas -- in other words, even if such development were possible, it would be comprised of entirely fictional star data.
It is a dream we all have here, but it is simply not yet feasible and is not likely to become so for quite some time.


Not at all. While Sol-like stars haven't been resolved, others have been discovered. In 2005, for example, a group of astornomers discovered an eclipsing binary system with a period of some three and a half days. Never mind, of course, various Cepheid variables.

But your point is well taken. The primary use of such a capability at present would be for fictional data. On the other hand, there are plenty of fascinating stellar examples within THIS galaxy which lay beyond the distance limit, and which would be fine additions. Still, there is plenty *within* the stellar limit that needs to be developed...

So, yeah. It would be a nice thing to have, but we should be patient.

...John...
"To make an apple pie from scratch, you must first create the universe..."
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t00fri
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Post #7by t00fri » 30.03.2007, 08:03

peter_89 wrote:True.
Something of this scale is a tremendous challenge to undertake, especially using what is essentially volunteer work. Anyone who is familiar with large-scale development projects will tell you that the only way to successfully undertake such things is with employment.


This is totally incorrect, of course. I don't know what ideas you have about the Celestia development team. ;-) Most of us are software engineers or scientists by profession and are certainly familiar with large-scale development projects (professionally (!) and within Celestia)

After we managed to implement entire standard catalogs of 10000+ galaxies including their correct spacial orientation and morphological types, we certainly could also address to resolve galaxies into stars. But this is entirely besides the point, to emphasize this once more: Celestia is based on /scientific/ data. Since there are NO starmaps of remote galaxies, we are simply NOT in charge here! There are very up-to-date catalogs of (extra galactic) Supernovae which I could easily implement using particular kinds of sprites for example...

Bye Fridger
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ElChristou
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Post #8by ElChristou » 30.03.2007, 10:57

t00fri wrote:...There are very up-to-date catalogs of (extra galactic) Supernovae which I could easily implement using particular kinds of sprites for example...

Bye Fridger


ppff... one more work to add to your to do list... it would be nice to have such catalogue...
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Robertbobby91
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Post #9by Robertbobby91 » 01.05.2007, 20:02

I would think that making an option to switch between Galaxies would make it possibe. Someone said it's too far away from the sun? then make an option to make a "second sun" to move to. It would have to be that you essentially delete allt he milky way galaxy starts and load other ones though. A sacrifice yes, but how much well would it be? Perhapse and auto-switcher so that when you get near a galaxy it moves the sun there. Complicated? yes, but feasible

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Chuft-Captain
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Post #10by Chuft-Captain » 02.05.2007, 11:15

Hungry4info wrote:What prevents this restriction from being removed for the final release of Celestia 1.5.0?


I haven't examined the code, but I assume the fundamental reason for this restriction is the numerical precision of the data-types cuurently used within Celestia to represent distances. As Celestia is able to define distance scales from thousands of LY's right down to meters or less, then I would guess that the 16K limit exists because it represents the distance at which the #units of the smallest measure available to STC objects (whether that be AU's, km's, meters, mm's or nanometers :) ) exceeds the numerical precision of a float or double.

Like I said, I haven't looked at the code, so perhaps there is some other historical reason in the code.....in any case one of the developers is sure to be able to elaborate (or correct me) on this subject.
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t00fri
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Post #11by t00fri » 02.05.2007, 11:25

Chuft-Captain wrote:...
Like I said, I haven't looked at the code, so perhaps there is some other historical reason in the code.....in any case one of the developers is sure to be able to elaborate (or correct me) on this subject.


...all developers I would say ;-) .

Beyond what you wrote, there is a further much tighter /physical/ limitation that however only concerns those who care about scientific correctness of Celestia's data.

The distance measurements get increasingly bad with increasing distances, since the parallaxes tend to become unmeasurably small.
Just like in case of galaxies, for the stars also the main effort is to come up with accurate distance values. If you examine the HIPPARCOS data wrto the inherent distance uncertainties you will be surprised. Also the HIP catalog makes clear statements until which distances the data remain reasonably accurate.

Bye Fridger
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