Celestia Forums

Hi fellow celestians,

I am new to the celestia universe. I have posted one or two questions before and here are some new technical questions:

1.) When I move away from the sun and look back at our galaxy the Milky-Way it is represented as a barred galaxy. However most literature depicts it as a spiral galaxy and it seems the commonly accepted view is that it is a spiral galaxy. Can this be corrected with an appropriate add-on?

2.) Has anyone ever attempted to model relativistic perspective / distortion effects for travel at speeds close to the speed of light ( i.e. 0.8c - 0.99 c )?

3.) I can follow the orbital motion of planets around their sun in distant solar systems. However I can't seem to be able to observe the motion of binary star systems around their shared center of gravity. Again is this modelled or not?

Since I am new to Celestia I would like to know if 1.) & 3.) are due to misconfiguration, incorrect settings or due features currently missing from Celestia.

In case these are due to incorrect usage and/or misconfiguration, what steps should I take to remedy these issues.

Regards

Reza Mostafid

dar_beh_dar wrote:1.) When I move away from the sun and look back at our galaxy the Milky-Way it is represented as a barred galaxy. However most literature depicts it as a spiral galaxy and it seems the commonly accepted view is that it is a spiral galaxy. Can this be corrected with an appropriate add-on?

Fixed in 1.5.0

dar_beh_dar wrote:2.) Has anyone ever attempted to model relativistic perspective / distortion effects for travel at speeds close to the speed of light ( i.e. 0.8c - 0.99 c )?

No idea...

dar_beh_dar wrote:3.) I can follow the orbital motion of planets around their sun in distant solar systems. However I can't seem to be able to observe the motion of binary star systems around their shared center of gravity. Again is this modelled or not?

Fixed in 1.5.0

A (working, but still with a few bugs) prerelease of Celestia 1.5.0 can be found at http://shatters.net/forum/viewtopic.php?t=10473

dar_beh_dar wrote:1.) When I move away from the sun and look back at our galaxy the Milky-Way it is represented as a barred galaxy. However most literature depicts it as a spiral galaxy and it seems the commonly accepted view is that it is a spiral galaxy. Can this be corrected with an appropriate add-on?

Observations made since the mid 1980s have concluded that the Milky Way is an SBbc barred galaxy. Documents describing it as a spiral are obsolete. See http://en.wikipedia.org/wiki/Milky_Way

The Milky Way's model in Celestia v1.5.0 has been updated to represent current theories (4 arms, etc) rather than showing a generic two-armed barred spiral.

dar_beh_dar wrote:2.) Has anyone ever attempted to model relativistic perspective / distortion effects for travel at speeds close to the speed of light ( i.e. 0.8c - 0.99 c )?

Not in Celestia. There is an ongoing discussion of how that might be done, though. A Web search will locate several attempts using speciailzed software.

dar_beh_dar wrote:3.) I can follow the orbital motion of planets around their sun in distant solar systems. However I can't seem to be able to observe the motion of binary star systems around their shared center of gravity. Again is this modelled or not?

Fixed in 1.4.0, actually, but only for ~200 binaries with well measured orbits. Look in the Data folder for the visualbins and specbins STC catalogs. No changes have been made for v1.5.0.

selden wrote:

dar_beh_dar wrote:3.) I can follow the orbital motion of planets around their sun in distant solar systems. However I can't seem to be able to observe the motion of binary star systems around their shared center of gravity. Again is this modelled or not?

Fixed in 1.4.0, actually, but only for ~200 binaries with well measured orbits. Look in the Data folder for the visualbins and specbins STC catalogs. No changes have been made for v1.5.0.

Actually, looking into it a bit further, it seems that in 1.4.1 the binaries do orbit eachother, but they don't show the orbit lines. The orbit lines do show in 1.5.0, though.

Selden and Johaen,

thanks a lot for the information guys. Also thanks for the information about the shape of the Milky Way....that is very exciting to find out we might be living in a barred galaxy instead of a plain vanilla spiral one.

Also Johaen congrats on your new Athlon 'spaceship'....sounds like you won't need add-ons to check out relativistic effects at the speed of light....your hardware will take there.


Regards


dar_beh_dar

dar_beh_dar wrote:Also Johaen congrats on your new Athlon 'spaceship'....sounds like you won't need add-ons to check out relativistic effects at the speed of light....your hardware will take there.

lol. Thanks. I've recently been fiddling with overclocking the videocard.

Default 7900GT:
GPU: 450MHz
Memory: 1320 MHz

My video card with manufacturer overclock:
GPU: 550 MHz
Mem: 1550 MHz

My overclocking, after putting a new heatsink on it:
GPU: 650 MHz
Mem: 1600 MHz

That effectively turns it into a 7900GTX.
I've also been able to overclock my CPU from it's default 2.22 GHz up to 2.44 GHz. I <3 my new PC.

I <3 my new PC

???

I think that's supposed to be a heart lying on its side. A heart is often used as a graphic representation of the word "love". So CC's choice of red to highlight it was most appropriate!

selden wrote:I think that's supposed to be a heart lying on its side. A heart is often used as a graphic representation of the word "love". So CC's choice of red to highlight it was most appropriate!

Correct. Hehe. Sorry, it's something I picked up back when I played Final Fantasy XI.

I thought that might be it, but when I googled internet abbreviations, nothing seemed to mention this particular one.

The choice of colour was serendipitous Selden.

It is hard to search words which has mathematical characters (like +, * , $, of cource < and >, etc.) in Google or other search engine...