Definition of Spatial Velocity in GR Homework

[Reedeegi]

I was doing some homework for GR when I came across the term "spacial velocity." What is its definition?

It's in the context of finding the spatial velocity using the knowledge of the four-velocity U being U = (1+t^2,t^2,t√2,0) [I don't need help with the problem itself, I just need to know the definition in this context]

 

[Fredrik]

Check out this post. They must be talking about the 3-vector I call $\vec v$. (Note that I'm using units such that c=1).

Oh yeah, and it's spelled "spatial".

Hm, maybe not. Dictionary.com says that "spacial" is OK too.

 

[Entropia]

In the context of general relativity, spatial velocity refers to the rate of change of an object's position in three-dimensional space. It is often denoted as v and can be calculated using the four-velocity U, which represents the object's velocity in four-dimensional spacetime. To find the spatial velocity, one would use the components of U that correspond to the object's position in three-dimensional space, typically the x, y, and z components. In this case, the spatial velocity would be v = (t^2, t√2, 0). I hope this helps clarify the definition for you.