stbenge schrieb:

> It's good to know that some people are taking the idea of a fourth 
> spatial dimension seriously. A lot of people argue that time is the 
> "true" 4th dimension, but that idea just doesn't sit well with me, even 
> though I don't have a lot of knowledge in this area.

Just one stupid question: What is there to be taken serious about - I 
mean, if not considering time to be the 4th dimension (which it actually 
is)?

The main point is that /if/ such a 4th ("space-like") dimension /does/ 
exist, then our 3 dimensions /already are/ embedded in that 4D world - 
the 4th dimension will not just suddenly appear out of thin air to 
entertain us.

There is no room for "serious" speculation about "what would it be like 
if there /was/ a 4th dimension" - either a 4th (space-like) dimension 
/does/ exist, in which case the natural laws in this 4D world /must/ 
result in the effects we observe in "our" 3D "slice" - or such a 4th 
dimension does /not/ exist, in which case there's no room for 
speculation left.

In any case we cannot in any way "leave 3D and enter 4D" - all we can do 
is act within our 3D world, and (possibly) find that the resulting 
effects can only (or best) be explained by assuming that our 3D world is 
just a "slice" embedded in a 4D world.

Scientists are, by the way, seriously discussing models according to 
which the universe does indeed have more than three space-like 
dimensions (quite a lot actually), but they appear to agree that in this 
case those extra dimensions must be quite small (think of the surface of 
a thin wire, with the length corresponding to our known three space-like 
dimensions, and the circumfence corresponding to the extra dimensions).

Post a reply to this message