Mr Light wrote:
The other question is, was that the original Eye of Harmony that Omega created? Or does every Tardis have an Eye in it because they can easily replicate the technology?
Does every Tardis have a portal to the same Eye, does every Tardis have its own Eye, or did the Doctor take the Eye at the end of the Time War?
One of the books established that the Eye in the Doctor's TARDIS in the '96 movie was an "aspect" of the original in the Panopticon on Gallifrey ("The Deadly Assassin"). My personal take is this:
Imagine a universe as a flat sheet. A black hole is an infinitely deep "well" extending down from that sheet. TARDIS interiors are pocket universes -- imagine them as separate parallel sheets underneath the main one. Each parallel sheet intersects the "well" of the black hole. Thus, the same single black hole is a part of every separate pocket universe, linking them all.
However, if Gallifrey and all other TARDISes were destroyed, then the Doctor's would be the only one still connected to the Eye, so it might contain the whole thing now.
...The Doctor said in this very episode that the TARDIS is infinite (and has said this in previous stories, if I recall correctly).
Which contradicts what was established in the original series. In "Full Circle," Romana mentioned the TARDIS's total mass, which was about the same as the fully loaded mass of the Titanic
. And in "Castrovalva," the Doctor jettisoned 25% of the TARDIS's interior architecture to burn off enough mass to escape a galactic collapse. So at the time, it was decidedly finite in extent.
Though later books, whose canon status is questionable, suggested an interior size that was comparable to a large city in one book and larger than the volume of Gallifrey in another. It seems to me that the TARDIS's size gets more and more exaggerated by writers over time, much like Superman's powers.
And remember rule one: The Doctor lies. At the very least, he's prone to hyperbole. It's not like there was actually a self-destruct either.