Yup. See the concept of a non-orientable wormhole and Alice universe: https://en.wikipedia.org/wiki/Non-orientable_wormhole#Alice_universe https://en.wikipedia.

Yup. See the concept of a non-orientable wormhole and Alice universe: https://en.wikipedia.org/wiki/Non-orientable_wormhole#Alice_universe https://en.wikipedia.org/wiki/Non-orientable_wormhole#Alice_... An interesting consequence is that two particles may attract if brought together along one route, and repel if brought together along another.