I've got a theory

[Ana-Ris Kevar]

Why do some Jedi disappear and not others?
We've all seen Obi-Wan and Yoda disappear, but not Qui-Gon Jin. In the NJO books, the same happens: we 'see' Daesha'cor disappear, but not Anakin Solo. My theory is that the Jedi that do disappear aren't really there. Think about it. We know that Obi-Wan and Yoda were out of touch, so maybe they made a copy of themselves. These copies aren't clones, but they are similar. These copies contain the memories and emotions of the original. May be that this could be in Ep. 3.
What do you think? What theories do you have?

[JMK]

I think it's too late for a development like that to happen personally.

[MasterPewter]

I think the Jedi that dissapear are the ones truely in center with themselfs at the time of death. When they come to expect it as did Master Yoda and Ob1. The same was not true with Quigon or Anakin they were both in the middle of a fight not using the force for ballance. Thats my Thought!

[Amara Skywalker]

But Anakin was with the Force. He was in the middle of a fight true, but Anakin knew that he was dying anyway. He fought so that the others could get to, and kill, the Voxyn queen. He embraced the Force for what it was.
For all we know perhaps Obi-Wan and Yoda found a way to do as Ana-Ris said and could make an identical copy of themselves.

[Jedi_Psyche]

perhaps the jedi that disappear are the ones that at the moment of death, accept it and are ready. in a way, obi-wan willed himself to die, and yoda also was aware that his time was running out. Qui-gon and Vader, however, were not ready to die.. Qui-gon had the unfinished business of training Anakin.... and Vader had just reunited with his son. i dunno.. very puzzling this is lol.

[Jedieb]

I believe that EP3 is going to shed some light on this. Forget the EU, EP3 will give us the scoop. I think we're going to see that disappearing is a technique that has to be mastered. The AOTC novelization made it seem as if Qui-Gon had discovered something about the Force which had previously been unknown to most Force users. That you could somehow retain your identity after you died. Throw in Obi-Wan's taunt in ANH "I shall become more powerful than you can possibly imagine." and you've got some weight behind that idea. I think Yoda and Obi-Wan will learn of this technique and that's why they'll be able to disappear. I think MasterPewter's idea is pretty solid. Part of this disappearing technique requires a Jedi to know that his death is emminent.

[JMK]

For sure, you had to only look at Obi Wan's and Yoda's situation. They both knew they were goners. I do wonder though if Qui Gon truly thought that he was going to die? Did he have time to prepare himself? I mean, how did he do what he did after he was killed? And at what point does Anakin learn this technique?

[Jedi Master Carr]

I don't think Anakin learns it most likely Obi-Wan and Yoda bring his spirt back to comfort Luke. As for Qui-Gon he could have known something or else the force sends him back to guide Yoda and Obi-Wan, it will be interesting to see what is revealed about this in Ep 3.

[Doc Milo]

The AotC novelization, at least in my reading of it, seemed to say that the emotion behind Anakin's slaughtering of the Tuskens was so powerful, it brought Qui-Gon back. Yoda hears Qui-Gon's voice, and is surprised by it, for a Jedi is not supposed to be able to keep his identity once he becomes one with the Force.

I believe that the emotion behind Anakin's fall is enough to bring Qui-Gon's spirit back, enable him to keep some semblance of his identity, and because of this, Yoda, who becomes aware of it, learns that this is possible through the Force, and develops a technique to do it. He then teaches this technique to Obi-Wan, at some point....

[J'hrea Alsac'lynol]

I believe it is when someone is slaughtered that he can not return. Dying when you didn't want to, or hadn't became one with the force are all collected as reasons why they aren't spirits that move through the force.

Obi-Wan you may say was slaughtered by at the time he was one with the Force, and did this with the intent of dying in the first place. He accepted his death and that is why I think he became one with the Force.

Then there was Yoda, who you know died with his own mind already seeing it. He was not slaughtered, he simply died of age. Accepting this, and as he is a Master, being balanced with the power of the Force, he became one with it during his death.

That is my theory, but that's about it..

[CMJ]

I think you may be onto something Doc.

[JMK]

But I'm left to wonder how one Jedi's emotions can be so strong as to bring back a departed Jedi's identity....

[J'hrea Alsac'lynol]

I dont think it's souly their emotions, though it is apart of it. I think it's their emotions intertwining with the Force, and their stability with both. Where they are unwavered in emotion by darkness, and unwavered in their one-ness (huh, what the hell is oneness) in the Force.

[Evil Hobgoblin]

The period between TPM and AOTC was turbulent at best, chaotic at worst. Anakin Skywalker was a focal point of all that chaos. I don't think it a stretch to say that Qui-Gon Jinn, who died in battle and whose spirit did not leave his body as we've seen Yoda and Obi-Wan's, never found the true peace of the Force and his spirit was attached to the young Anakin in some unknown and complex way. So long as Anakin walks the path of the Light, Qui-Gon remains passive. When trouble starts brewing, so too does Qui-Gon's essence become semi-aware.

Also, I believe that the transmutation of Jedi to Force spirit takes more than a split-second of mental preparation, which is all Qui-Gon had at the time he faced Darth Maul.

[Jedi Master Carr]

That is an interesting theory that could be very possible explanation.

[Doc Milo]

But I'm left to wonder how one Jedi's emotions can be so strong as to bring back a departed Jedi's identity....

Anakin is more than just "one man." Qui-Gon says about him, to the Council: "I've encountered a vergence in the Force." Anakin is some kind of focal point -- a centering point of some sort. Him being the chosen one is tied up with this, perhaps what happens with Anakin sends ripples through the Force with greater intensity than any other Jedi because of this connection he has with the Force.

[JediRaver]

It's cause Qui Gon is really a dark sider.>D

[Sage Hazzard]

I actually think it might have to do with the balance of the Force. Now I don't quite know what that means, and maybe the Jedi don't either. They just know of a prophecy, not nessecarily how to interpet it. So maybe it means having equal Dark Side and Light Side. Equal good and evil? I don't know. I'm not sure what the balancing of the Force means, etc. But if perhaps in that anger, Anikin slipping to the Darkside, Qui-Gon was able to come through because of some kind of... I don't know, better Force? I mean, it might be an explaination. Obi-Wan and Yoda do the dissapearing act while Anikin is Vader, a Dark Sider. Qui-Gon comes through while Anikin gives into Anger and Aggression. Also, don't the spirits of Yoda, Obi-Wan, and Vader fade out at the end of ROTJ. Appearing then slowly fading out? As if to cue that they're gone for good, because the big guns of the Dark Side are dead and the Force isn't in that kind of balance anymore... Also, Obi-Wan appears as a voice in Luke's head when he's just a star pilot, not heavily trained in the Force. Then Luke can see a full bodied spirit of Obi-Wan, after getting some training by Yoda. So maybe he evened the score a little more, by learning the Force and giving some power back to the Light Side, now that the only Jedi left was Yoda and the Dark Side had Vader and Palpy.

Probably wrong but might have some sanity mixed in there. :)