Earth is the planet from which humankind originates. On Earth, it is currently the mid-to-late 2000s.
Many Unstable Portals have been popping up in the world's oceans: most commonly in the Pacific, but also the Atlantic and Indian oceans. These portals sometimes bring over people who get caught in them, as well as their ships and their tech. A lot of this Terran Technology gets found by scavengers or washed up on beaches, where it is studied and sometimes repaired.