What is the definition of a googolplex?
The definition of a googolplex is 10 to the power of 10 to the power of 100.
A googol is 1 followed by 100 zeros, and a googolplex is 1, followed by a googol amount of zeros. In a universe which is "a Googolplex meters across", if you would travel far enough, you would expect to eventually begin finding duplicates of yourself.
The reason for this, is because there is finite number of quantum states in the universe which can represent the space in which your body resides.
That volume is roughly one cubic centimetre, and the possible number of states possible for that volume is 10 to the power of 10 to the power of 70.
This is obviously much less than the possible number of quantum states that could be represented within each cubic meter of a Googolplex Universe, and so the idea does make some sense.