Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

is it possible to have length, width and time. A 2D or 1D object with the 4th dimension (although then there would not be 4 dimensions so would it b 3D?) .

share|cite|improve this question
I think you are describing sonic the hedgehog videogame. – Dale Jun 15 '11 at 4:27
There is a nice animation about the 10th dimensions which goes through the various dimensions. Check it out: – Yotam Jun 15 '11 at 8:14
up vote 1 down vote accepted

Sure, a 2D object that exists at more than one point in time would have those three dimensions. It'd be called 2+1-dimensional and there are various physical theories that could be adapted to describe it.

In our own universe, of course, all actual objects are 3+1-dimensional, because as far as we know, the universe itself is 3+1-dimensional (3 dimensions of space and one of time).

share|cite|improve this answer
In theoretical mechanics you can have for the 2D object in time 5 dimension. 2 for position, 2 for velocities and one for time. – Crowley Jun 15 '11 at 7:31
@Crowley: that's phase space, though, not configuration space (a.k.a. real space). Velocity is a degree of freedom, sure, but it's not an actual spatial dimension. – David Z Jun 15 '11 at 18:45
but if there was a universe "in the 5th dimension" we wouldnt be able to observe it would we? It seems like the dimensions of our universe really pertain to how we perceive things – luca590 Jun 16 '11 at 20:16
@luca590: what do you mean by "in the 5th dimension"? That statement doesn't make sense as it is. – David Z Jun 16 '11 at 20:18
ok i see. The 5th dimension (all possible paths of a point in time and space), is not really observed by us. Our universe has length, width, depth, and time. However we cannot see, hear, touch, etc the 5th. So how would we observe every possible path in the first 4 dimensions at once? – luca590 Jun 16 '11 at 20:37

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.