books.google.com - Are there other dimensions beyond our own? Is time travel possible? Can we change the past? Are there gateways to parallel universes? All of us have pondered such questions, but there was a time when scientists dismissed these notions as outlandish speculations. Not any more. Today, they are the focus...https://books.google.com/books/about/Hyperspace.html?id=_HBtAHuG6dwC&q=metric+tensor&utm_source=gb-gplus-shareHyperspace
