![Image](http://library.thinkquest.org/12909/media/periodic1.gif)
was assembled to arrange the known chemical elements by their physical and chemical properties.
A century later, the Standard Model
![Image](http://upload.wikimedia.org/wikipedia/commons/thumb/0/00/Standard_Model_of_Elementary_Particles.svg/544px-Standard_Model_of_Elementary_Particles.svg.png)
did the same for subatomic particles.
Recently, M-Theory has come about as the apparent culmination of Quantum Mechanics/ Relativity grand unification.
4-d Gravity...
![Image](http://www.wbabin.net/physics/Image14.gif)
...plus one dimension, as per Kaluza-Klein, yields Gravity PLUS Electromagnetism.
Add dimensions 6 and 7 gets you the Weak Nuclear Force, and adding up to 11 dimensions produces the Strong Nuclear Force.
![Image](http://universe-review.ca/I15-74-nd.jpg)
...a periodic table of forces.
Perhaps we can have a periodic table of dimensions?
For that we must define the characteristics of the dimensions themselves.
We have all been taught that Time is the fourth dimension...an integral part of the spacetime fabric of reality.
We 3-d humans trace out a wormlike 4-d worldline starting at our birth and ending with our death.
A 2-d tv picture over the course of a broadcast of course changes shapes and colors.
a 1-d line on an oscilloscope traces out a curve over the course of an interval.
Even a 0-d geometric point like a quantum singularity does not exist for only an instant, but has a past and future.
Time measures change.
Time is not the fourth dimension...time is the first dimension!
So...we have a unique uni-directional dimension,
three basically identical bi-directional dimensions(length, width,depth).
and seven microscopically curled-up dimensions.
Graphically, they seem to naturally go together when arranged like this:
![Image](http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Hexagonal_close-packed_unit_cell.jpg/648px-Hexagonal_close-packed_unit_cell.jpg)
...a geometry which seems to bear a resemblance to Quantum Chromodynamics:
![Image](http://wpcontent.answcdn.com/wikipedia/en/thumb/9/98/Baryon_octet_w_mass.png/280px-Baryon_octet_w_mass.png)
![Image](http://wpcontent.answcdn.com/wikipedia/en/thumb/c/c1/Baryon_decuplet_w_mass.png/290px-Baryon_decuplet_w_mass.png)
Am I onto something?