4-dimensional

(There are also issues with using 2-dimensional images to help us think about 4-dimensional spaces, but that can be for later).

Objections to Kaku and Liu’s “How to Time Travel?” 2009

He steps through into a network of alternate pathways through 4-dimensional space.

A Pantry of Unusual Sounds stephen hastings-king 2011

He steps through into a network of alternate pathways through 4-dimensional space.

A Pantry of Unusual Sounds stephen hastings-king 2011

(There are also issues with using 2-dimensional images to help us think about 4-dimensional spaces, but that can be for later).

Objections to Kaku and Liu’s “How to Time Travel?” 2009

For example, it has been proven that there is no general means of proving whether or not a pair of 'triangulated' 4-dimensional manifolds are homeomorphic (topologically identical).

Theories of Everything and Godel's theorem Gordon McCabe 2009

We can retain the general relativistic representation of physical space-time as a 4-dimensional manifold, equipped with a metric tensor of Lorentzian signature, but for each worldline & #947 representing a physical system with a mind supervening upon it, we can introduce a subjective time tensor.

Archive 2009-01-01 Gordon McCabe 2009

For example, in general relativity, the structure is that of a 4-dimensional Lorentzian manifold, the Einstein field equations select a sub-class of all the possible 4-dimensional Lorentzian manifolds, and the choice of boundary conditions or initial conditions selects a particular 4-dimensional Lorentzian manifold within that sub-class.

Archive 2009-06-01 Gordon McCabe 2009

(There are also issues with using 2-dimensional images to help us think about 4-dimensional spaces, but that can be for later).

Objections to Kaku and Liu’s “How to Time Travel?” 2009

For example, it has been proven that there is no general means of proving whether or not a pair of 'triangulated' 4-dimensional manifolds are homeomorphic (topologically identical).

Archive 2009-06-01 Gordon McCabe 2009

For example, in general relativity, the structure is that of a 4-dimensional Lorentzian manifold, the Einstein field equations select a sub-class of all the possible 4-dimensional Lorentzian manifolds, and the choice of boundary conditions or initial conditions selects a particular 4-dimensional Lorentzian manifold within that sub-class.

Lee Smolin and the multiverse Gordon McCabe 2009