What the hell is a video? I couldn't resist.

A 2D slice of a 3D object.

Projection, not slice.

An image of a video is a slice of it for some constant time coordinate.

If you instead fix a spatial coordinate you get images as the two left and center images in

> http://electronicimaging.spiedigitallibrary.org/data/Journal...

I think it's not a slice. If you sliced reality in half you'd see the cross-section of whatever you sliced in half, as opposed to that multi-planer cow standing over there beyond the slice point. Our 2D version of the 3D world we perceive to inhabit is projecting (and mixing) light that falls on the back of our eye. It's a highly dynamic and contextual environment backed by the absolutely best encryption known anywhere. Other simulations, while cost effective, can't compete with our reality's reliability. Call today for your free trial!

You changed the assertion because you're including time.

The parent said "A 2D slice of a 3D object."

And that's wrong, it's a 2D projection of a 3D object.

If you include time then it's a slice in the time component, right, but that wasn't being discussed.

The third dimension is time.

Videos can also be generated without using projections (though cameras use this method).

Time is a different type of dimension than the spatial dimensions. If you're really going to bring time into it, you need to use a dimensional signature, wherein one number represents dimensions that square to a positive number, another represents dimensions that square to a negative number, and another represents dimensions that square to zero.

A video is either {2,1,0}-D or {1,2,0}-D, depending on the mathematical sign convention you chose for your spacelike dimensions.

When people use a single number, they invariably mean spacelike dimensions, as null dimensions and multiple timelike dimensions tend to give people the screaming jibblies when they try to visualize them.