I was talking with some friends recently, and it occurred to me that there is a hole in the middle of the GSR's chest, and the hole is surrounded by water. So why exactly is the entire GSR not filled with water? Theres obviously no barrier keeping things out of Karda Nui while Voya Nui's not attached to the GSR, as a little water did enter the island and became the swamp. also, there's obviously a passageway between Karda Nui and the rest of the robot, as the Toa Mata couldn't leave the robot to travel to Karda Nui. So why exactly didn't the robot flood?
Karda Nui is really, really big. It took 1,000years to fill up about halfway. Presumably, any passages leading out would've been above where the water line was in the 2008 story.
Maybe, but with the size of Voya Nui, a lot more water should have flooded in than the small amount that made up the swamp
It wasn't a small amount, though. Karda Nui is a gigantic sphere, and it was halfway filled with water after 1,000 years. Maybe it's a bit of a stretch, but not so much of one that it can't be written off as "Bionicle physics."
Greg Farshtey has even stated that BIONICLE can't always use science to explain things.
If I am submerged in the bathtub, with my feet, stomach and head all sticking out of the water, and I manage to rupture my stomach, my face will not inexplicably be covered with water. Nor will my brain be completely submerged as my nostrils are still above water.
If I'm missing any details, let me know.
It didn't flood because Voya Nui returned to its original position after the Matoran Universe was repaired with the Staff of Artakha.
Well, your insides are also not made up of a series of domes. And if your brain is below water in that case, and so is your stomach, the water will try to balance its level both outside and inside your body. And as far as I know, there was no landmass above water aside from Mata and Voya Nui.
@Rando after a thousand years of having a submerged island shaped hole in it.
There was a gateway to Metru Nui that was "locked" by Teridax prior to the cataclysm.
But that barrier obviously didn't work, as the Visorak kind of got in after the cataclysm
Water did get in and did start filling up the robot, this is what formed that massive waterfall in Karda Nui and essentially created the Swamp of Secrets. But the GSR is huuuuuuge, standing at a height of 40 million feet high according to BS01.
The predicted body weight of a person can be calculated using this formula (using this because of the GSR's humanoid shape):1
PBW (kg) = 50 + 2.3 (height (in) – 60)
Inputting the value of 40 million feet we get 1,103,999,912 kg, which is ridiculous. Obviously this is just for a human calculations, which are not made of metal. As you said, the GSR's insides are basically a series of domes, which messes up the calculation even more. So these figures will be pretty rough and are probably a gross underestimation, but you get the idea.
I couldn't find any good formulae for calculating volume of a humanoid shape, but as you can see the figure is ridiculous. Based on that alone I can say with confidence that it would take over 1,000 years to fill up the GSR with water. I refer you to this for more information about the GSR's height.
Another possible answer to this question is that when trying to apply a logical explanation to a lot of BIONICLE lore, you'll often draw a blank. This is definitely one of the cases, because anything being 40 million feet tall just doesn't make sense, which is the reason I linked the BZP topic.
At least it's better than having those fake Spongebob Muscles.