The Luftmenschen of Planet Birobidzhan is a work of speculative fiction, a future history of social and science fiction. This is a story of displacement, exile, and entrapment by fate. This is also the saga of the few that strive to break free from those entanglements.
Kabbalists have spoken of traveling great distances in a troika or on foot or in a meditative state through divine intervention. The Baal Shem Tov, for instance, was famous for such feats. So, the rabbis found the idea of folding space/time to be quite plausible. After all, isn't that exactly what the great sages of blessed memory had done?
Wormholes were theorized for a very long time. The first time one was discovered was in the middle of the 21st Century. The scientists were blown away. The rabbis shrugged.
The wormhole opened the option to settle new worlds. When the tenuous connection to the Home Planet was severed, those who had emigrated to Planet Birobidzhan were then on their own.