The present often means the single spacetime event being considered.

Is the mass in this spacetime so far away that we can't see it?

Local here means that it all happens at the same spacetime point.

Helps me avoid getting lost in local spacetime or whatever.

A world line is a special type of curve in spacetime.

In the special case the spacetime is said to be static.

Our Earth moves in this bent spacetime, as does light.

These play a role in the causal structure of spacetime.

A world line traces out the path of a single point in spacetime.

In physical reality, both energy and spacetime are secondary features.

The model is defined in a spacetime with an even number of dimensions.

The distance between two different events is called the spacetime interval.

I should imagine we experienced some sort of spacetime slip.

A spacetime diagram of this situation is shown in the figure to the right.

This is referred to as the line element of the spacetime.

Any spacetime may evolve into a time machine, but it never has to do so.

Spacetime points only acquire their physical significance because matter is moving through them.

"It is not made clear where in spacetime a transaction occurs."

Why had he been brought to this point in spacetime and then so casually abandoned?

But what if spacetime does not yield up its absolute so easily?

A black hole is a region of spacetime from which nothing escapes.

The events of spacetime are then no longer a background in which physics happens.

This would leave only the familiar four dimensions of spacetime visible.

The transformations of these functions in spacetime are given below.

The small dots indicate specific (past and future) events in spacetime.