This was previously in the FAQ proper, but because of the detail that this could possess, I'm moving it to its own threadmark. Also because there are a couple of things I want people to keep in mind.
With the Dimensional Transfer spell, Taylor can head off to other worlds to see what is there. According to the Enforcers, there are between fifteen and eighteen worlds in the "Earth Bet cluster world", named as such because the TSAB names cluster worlds by the first world with which contact is established.
You as players can do one of two things when you want Taylor to go world-hopping. First, you can explore a world you and she already know about. Second, you can look at one of the worlds that has yet to be explored, in which case I will create it at random. Be advised that not all worlds are fit for humanity, and most of them are in a different technologic age than Earth Bet.
The worlds Taylor knows about are:
EARTH ALEPH, AKA "Earth Bet-4", was the first alternate Earth that was ever discovered. Thanks to Professor Haywire's portal, there is communication between Earth Aleph and Earth Bet, though the portal in question is only large enough and stable enough to permit wireless data transfer. Physical objects cannot move between worlds. Like Earth Bet, Aleph is in the Digital Age.
EARTH BET (Earth Bet-12) is Taylor's home dimension.
EARTH GIMEL (Earth Bet-1) is the alternate Earth where the Enforcers crash-landed. Humanity never developed on this world because dinosaurs did not become extinct. The Sojourner is currently in orbit around this planet.
EARTH DALET (Earth Bet-10) is where Contessa was born, Eden crashed, and Cauldron's base was built. Taylor, Tim, and Dragon explored the base to some extent, and she returned with Legend and Alexandria to recover the remaining power vials. Unlike the base, which was built with methods and materials from Earth Bet, the rest of this world has a technology level more consistent with the Early Modern Age or very early Industrial Revolution.
EARTH HE (Earth Bet-2) could best be described as a volcanic hell-world. Taylor has not explored it at all, merely landed there for a few seconds before moving on. Nonetheless that brief glance indicates that there may be ruins of a fallen civilization close by.
EARTH VAV (Earth Bet-5). This alternate Earth is still in the Bronze Age. Capes are worshiped as gods. Taylor and Missy explored long enough to find a bug-controlling villain and defeated her and her retinue, which seems to have made Taylor the primary god of that village.
EARTH ZAYIN (Earth Bet-16) is in a dimension that even the Enforcers could not see clearly. When Taylor, the Triumvirate, and the Arcana as a whole visited, they discovered a seemingly abandoned planet whose previous inhabitants had a technological base centuries ahead of Earth Bet's.