Flying mode for Celestia

[Harry]

Except for the problem with cursor-keys (i.e. you need to user other keys instead). it should be possible to write a CELX script which implements this, including simple gravity. This way Fridger won't have to worry about inaccurate calculations

Seb, what are you waiting for?

Harald

[selden]

Seb,

If you haven't already, you should try Martin Schweiger's Orbiter. It does most of what you want, I think. It's designed for accurate simulation of spacecraft control rather than astronomy.

See http://www.medphys.ucl.ac.uk/~martins/orbit/orbit.html

[Seb]

Selden,

Thanks, will have a look, but actually more interested in seeing an accurate representation of space. Think I will have a go at a CELX script that Harry has suggested when I have a little more time (and patients).

I just know there must be someone out there who has already written loads of scripts or done development on Celestia who could probably knock this up in 15mins. So come on guys.. pleaseee.!!

- Seb

[tony873004]

Thanks, will have a look, but actually more interested in seeing an accurate representation of space. - Seb

Orbiter does an impressive job with the 8 planets (Mercury - Neptune) and Earth's Moon. It uses VSOP87 and an additional dll for the Moon. There's tricks you can play to get the other moons and asteroids properly positioned. A fresh set of elements from Horizons is good enough to do a fairly accurate Voyager flyby of Jupiter, etc.

[Guest]

Hmm.. I don't see what the big deal about having a slightly inaccurate gravity simulation is. It would only affect the users viewpoint not the positions of any other objects. I think it would be fun to just give yourself a trajectory going a bit past jupiter, turn gravity on and see what happens. I wouldn't try to use the results for astrogation

[Capt Rooster]

Realistically, whats it going to hurt to try something new huh Fridger? Maybe he is on to something, like creating a new game or community of people. Sounds to me that there are some people on here that are not open to trying new ideas. Quick dismissing of new ideas is what makes people turn to other places or avenues and thus creating unwanted problems and compliations.

Honestly, noone here is an expert at Physics. If that was the case, Celestia would not be as readily available and this person would be working for government agencies that would not allow them to be online here. Anyone on here who claims to be that good needs to have a reality check and pull there head back out of their arse and take a deep breath.

Now lets try this again. Does Seb have a good idea, yes. Maybe he should implement that somehow and create a seperate version of Celestia called 'Celestia: Gravitation' or something like that. Lets allow the creator of this program decide whats going to work and whats not.

[selden]

Celestia is open source.

This means that you can copy it to make your own program which includes whatever features you want to try out. You can't call the result Celestia, of course.

Mostly Harmless is a program based on Celestia which at one point included gravitational effects applied to the observer. Contact its author for details.

Honestly, noone here is an expert at Physics. If that was the case, Celestia would not be as readily available and this person would be working for government agencies that would not allow them to be online here. .

Fortunately you are incorrect about some of your assumptions.

Fridger Schrempp is a professional physicist and knows whereof he writes. Don't take my word for it. Do a Web search.

Not all physicists work for government agencies. Many of them work for educational institutions. Others work for corporations. I know several who work on Wall Street, applying what they've learned to other ends.
None of them are prevented from contributing their free time to publicly available software projects like Celestia.

People working for NASA contribute to Celestia, and have even done it as part of their jobs. Examples of their work are at http://learn.arc.nasa.gov/planets/ and http://exp.arc.nasa.gov/downloads/

Educational institutions have used Celestia's source code as a teaching tool, with students modifying it to run in other environments. One example is at http://www.lsi.usp.br/~paiva/glass/glass.htm
It shows the results of porting Celestia to the Cave envrionment. (The Cave is a room which provides an immersive 3D environment. Quite a few universities have Caves in their graphics facilities.)

However, Chris Laurel is the primary author of Celestia and makes the final decisions on what features get included.

I hope this clarifies things a little.

[Capt Rooster]

You are correct Seldon, Sometimes I do make 'assumptions' when in a hurry or in an unfavorable mood.

The true problem then is that in my experience professionals do not behave in such manners. I take that back, the academic professionals are the ones that behave that way. I know this becaue I have seen it many times while I was teaching at a university. This kind of pretensious attitude is the reason I no longer teach. a professional or a PhD does not necessarily mean expert.

I believe I have wsted enough of this threads time. I appologize.

[t00fri]

You are correct Seldon, Sometimes I do make 'assumptions' when in a hurry or in an unfavorable mood.

The true problem then is that in my experience professionals do not behave in such manners. I take that back, the academic professionals are the ones that behave that way. I know this becaue I have seen it many times while I was teaching at a university. This kind of pretensious attitude is the reason I no longer teach. a professional or a PhD does not necessarily mean expert.

I believe I have wsted enough of this threads time. I appologize.

I should perhaps add that Celesltia follows a certain consistent design concept as to it's core. This is unrelated to your supposition that some of the developers are just 'conservative' minds. The philosophy of implementing only those (astro)physical effects that are under accurate control seems to be very well received after all. The number of Celestia users of varying backgrounds is increasing steadily and big organizations like NASA or ESA also use it on their Web sites. The latter add tremendously to Celestia's reputation. If Celestia was less accurate it would not be where it presently is...

There are other most interesting aspects to be incorporated into Celestia that --unlike "observer gravity effects"-- can very well be modelled accurately: e.g. special relativity including color shifts and spectacular distortions of the field of view.

As Selden emphasized, Celestia is open source, so you or others are free to add in what they please...

Bye Fridger