You don't have to create a new universe just to write one.

A whole new universe of knowledge had been opened up.

This was a new universe and it turned out to be fun.

The Doctor has to stay outside this new universe in order for that to happen.

"Why did you release the new universe in the first place?"

In the process, you will open the door to a whole new universe of technology.

Nobody but me would know the difference, for my new universe came complete with history?

Moments later he could see clearly again, and they were in a new universe.

Their goal is to create a new universe that they can control.

And, starting there, they would take over the new universe.