Well, that explains a lot about Giratina.

[Zeta]

For a long time, I didn't understand the purpose of Giratina in relation to Dialga and Palkia in relation to the Sinnoh myth of matter being created. I was reading Junichi Masuda's blog, and in an interview he linked to, Masuda said that Giratina is supposed to be the living personification of anti-matter, and that it and the Distortion World are made up of anti-matter.

That pretty much actually explains everything. At first, I thought it was just "reality" or "dimensions", but the latter didn't make sense because Palkia already does that. But anti-matter explains why it changes Formes in the real world and why exactly Arceus had to create it along with Palkia and Dialga.

Too bad nothing said anything about this in the damn games!

I gotta say, now I like Giratina a whole lot more. What other fictional series has a god of anti-matter, of all things?

One thing that always bothered me is if the Distortion World is supposed to be the opposite of the regular Pokemon world, why is it so much smaller? Well a concept called "baryon asymmetry" states there's more matter than antimatter in the world.

 

[Blackjack Gabbiani]

So what about in DP where there's no Distortion World and it just sits around some ruins?

Moreover, what does this mean for those who inhabit Giratina's world?

Spoiler

Gameverse Cyrus (and possibly Mars if she can really get there) and animeverse (so far) Newton

 

[Zeta]

Well in most science fiction, antimatter and matter explode or cease to be when they contact each other, that's obviously not the case here. So I don't know what the effect humans would suffer from by staying in the Distortion World for an extended periods of time - but going back and forth affects Giratina's body, so possibly it would effect theirs as well. Maybe they'd loose their legs and start to float around? : p They'd probably return to normal if they ever came back, though. I suspect Griseous Orb contains some concentrated antimatter from the Distortion World that causes Giratina to change back to its normal form even in the positive matter universe.

So what about in DP where there's no Distortion World and it just sits around some ruins?

I dunno. It seems Junichi Masuda got really into speculative science fiction physics between DP and Platinum.

 

[Zephy]

The physics are sketchy but I don't think that it's much of a problem. I mean Pokémon is in a different universe. It's a quaint explanation that solves some fans problems so I'm happy.
Actually I'm going to spend forever filling a blackboard with physics equations.

 

[spiritsunami]

Yeah, it definitely makes sense. It always seemed as though Giratina had formed a trinity with Dialga and Palkia, just looking at the move set, but until Platinum, there had been no explanation as to its proper place in the mythos. Now, it has its proper place.

 

[Martonimos]

Well in most science fiction, antimatter and matter explode or cease to be when they contact each other, that's obviously not the case here. So I don't know what the effect humans would suffer from by staying in the Distortion World for an extended periods of time - but going back and forth affects Giratina's body, so possibly it would effect theirs as well. Maybe they'd loose their legs and start to float around? : p They'd probably return to normal if they ever came back, though. I suspect Griseous Orb contains some concentrated antimatter from the Distortion World that causes Giratina to change back to its normal form even in the positive matter universe.

It's called annihilation. When a particle meets its antiparticle, both are destroyed and a large amount of energy is released. Like you said, the Altered Forme is probably a method of surviving the matter world; a protective casing, perhaps, or (more likely) a matter version of its body. Of course, it's impossible (as far as I can tell) to change matter to antimatter, but so is a two-foot high turtle being able to walk on its hind legs and spit out enough water to extinguish a burning building, so...

 

[Transfinite]

Since this is the Pokemon universe, matter and antimatter probably don't have to behave the same way. Or maybe moving between universes switches whatever is changing; Giratina's changed Forme is a matter version of its body, and a human who goes to the Distortion World becomes anti-matter. But since they aren't badass like Giratina humans don't get new Formes.

One thing that always bothered me is if the Distortion World is supposed to be the opposite of the regular Pokemon world, why is it so much smaller? Well a concept called "baryon asymmetry" states there's more matter than antimatter in the world.

However, the Distortion World is another universe, isn't it? If Giratina is the personification of antimatter, I'd think its universe would have anti-baryon asymmetry. Personally I figure it's smaller because the game programmers just didn't want to program a whole entire second universe into the games.

 

[Dlakii]

So what about in DP where there's no Distortion World and it just sits around some ruins?

Giratina's Diamond Pokédex entry says hi. =P It actually makes a likely reference to the idea of the Distortion World - particularly as to its method of portrayal in the anime, methinks -, stating that Giratina is "said to live in a world on the reverse side of ours.". Problem solved.

 

[Nekusagi]

So all Zero wanted to do is blow up the Vatican then?

*shot*

 

[Jamesredsilver]

I always figured since Giratina was a Ghost, that it can do whatever it wants and they can make up any physics they want to explain it because it's a Ghost.