Dimensions

[Daecon]

What about if atoms already are 4-dimensional?

 

Because they already exist in time - electrons orbit them, etc. which couldn't happen if there was no time for it to happen in.

[DQW]

What about if atoms already are[/i'] 4-dimensional? Because they already exist in time - electrons orbit them, etc. which couldn't happen if there was no time for it to happen in.

Yes, if you choose, you can represent atoms (as well as cans of soup or lampshades) as 4-dimensional objects in 4-d space-time. The choice of the number of dimensions you want to use is entirely yours. These dimensions are your own creation, and you use as many dimensions as you need to fully describe the system of interest.

 

However, the electrons have very little to do with the need for a time co-ordinate, in the case of an stable, isolated atom. For one thing, according to QM, electrons do not really "revolve" around the nucleus. Electrons exist in probability clouds that are described by a quantity called the wavefunction, whose square (actually the square of its length) tells you the probability of finding the electron at a particular location and a particular time. Now, the wavefunction of an electron in a stable atom is known to be "time-independent", meaning that the probablity of finding an electron at a certain place is always the same, and does not change with time. While this does not mean that there are no effects of revolution, it does mean that you will not find any property of the stable atom changing with time (sort of making the time co-ordinate useless).

 

It is only when you have interacting atoms that you begin to see time-dependence.

[LCD]

my take on the question:

 

3 dimensional atoms have their length width and height, but are basically still life models of an atom, where nothing moves or changes. you add in the dimension of time, the axis on which change occurs... and you have atoms as they are commonly observed in 4d.

 

think of observable 3d space as sort of a cut of time, like the "visible man" program, where you could display a portion of a corpse, as it moves down the length (reclining, head to foot) you see all the insides of him within the boundries of his width and heigth. A constant movement along the length makes his insides appear to expand and flow as if they are moving, shrinking, growing, along the two visible axes.

 

time is the same, but the cut is moving down the axis of time and we are observing the axes of length width and heigth of the frozen corpse of the universe one slide at a time. one should then question weather or not the future is malleable or if it is set in stone (as the past is) and we just lack enough data about the current state of the world and possible changes to determine which route in that "future cone" that is going to be followed.