3-space

A familiar Riemannian manifold is a Euclidean manifold (where one has to add a smoothly varying inner product on the tangent space of the standard Euclidean space), with the familiar Euclidean (distance) metric (our 3-space, for example).

Bad Language: “Riemannian Manifold” 2009

A familiar Riemannian manifold is a Euclidean manifold (where one has to add a smoothly varying inner product on the tangent space of the standard Euclidean space), with the familiar Euclidean (distance) metric (our 3-space, for example).

Bad Language: Metric vs Metric Tensor vs Matrix Form vs Line Element 2009

By moving my head I could change not the 3-space, but the 4-space perspective.

Neurosurgical Intervention For Beginners 2009

The tanks had coalesced, enfolding me in a 3-space tableau.

Neurosurgical Intervention For Beginners 2009

"The Cloud, my - colleague - that's where it pushed you out of 3-space."

Neurosurgical Intervention For Beginners 2009

Again, by extending the analogy by a further dimension, our 3-space bodies may be 'closed' to us, but to someone in 4-space they're open for inspection.

Neurosurgical Intervention For Beginners 2009

To appreciate 3-space you need two flattish retinas stuffed with nerve endings.

Neurosurgical Intervention For Beginners 2009

Think of The Cloud as millions of tiny filaments, hovering ana a scene in 3-space.

Neurosurgical Intervention For Beginners 2009

What is less obvious is that this conflict arises only if we try to retain the notion of an absolute time (or, at least, a preferred 3-space in each Tp).

A Third Choice (ID Hypothesis) 2007

Here is a micron higher than the 3-space you're used to.

Neurosurgical Intervention For Beginners 2009