How does the doctor go back to Gallifrey if it is in another universe?

Question

After the events of The Day of the Doctor, we know that Gallifrey is in another universe. However, in Hell Bent, the Doctor is trapped in the confession dial by the Time Lords. The Veil makes him confess in order to survive. The Doctor refuses to give the secret of the hybrid and breaks through the Byzantium Wall in 4.5 billion years. When he breaks through he is on Gallifrey.

My question is, how is he able to go to Gallifrey if it is in another universe? If the transporter that Me puts on him transports him to another universe, why hasn't the doctor used the same technology to return?

Answer 1

It's no longer in another universe.

In The Time of the Doctor, the Doctor receives a signal from Gallifrey trying to exit out of their alternate pocket dimension. At that point, Gallifrey didn't come out, because their enemies were waiting for them and the Doctor did not provide them an all clear. The point is, it's implied they can get themselves out of the dimension, and will so long as they could do so safely.

The full sequence of events isn't covered, but it's presumed Gallifrey found their own way out of the pocket dimension at some later point in time, and by the time of Heaven Sent and Hell Bent deliberately positioned the planet near the end of the universe (end of time, that is, the heat death that current science expects) to avoid detection. This was foreshadowed earlier by the reappearance of the Master in Dark Water, who was last known to be on Gallifrey.