- Time represents the idea of motion, and is defined as the fastest known motion -- according to the Speed of Light Definition of Time.
- Electrical field strength would be defined by the electrical charge of a rest mass electron.
- The defining physical object for length is still tough. Currently, length is defined using the atomic second, which may seem, to some scientists, a done deal. So why change it? Well, using the atomic second -- a sublight definition of time -- requires retaining Einstein's Relativity. To avoid this, an actual physical object's length is again required as in the good old days of physics. Perhaps the wavelength of a rest mass electron could be used. Whatever choice is used, it will be the weakest link in these units. It will be the toughest of the 3 Basic Units to define and will have the greatest error.
- Electric Charge can be used to derive mass -- using the unifying equation in the Ball of Light Particle Model therefore the Basic Unit of mass can be dropped. Mass would become a Derived Unit.
- Current can be derived from a moving charge, therefore it would also become a Derived Unit.
- Temperature can be derived as a statistical average of moving particles of mass, therefore it would also become a Derived Unit.
- The mole is just a number -- it is not a physical property of matter, or energy.
- Electric charge, length, and motion can be used to describe the photon. Using the description of the photon and length, luminous intensity can be described, therefore it would also become a Derived Unit.

### A new Constant?

The exact equations for deriving SI Basic Units from these 3 Basic Units are not yet worked out. The scientific community -- as a group -- should debate what the exact derivations should be, due to the potential range of the constants that could be chosen. For example, in some systems of physics, scientists define the speed of light to be 1 (unity). While in SI Basic Units the speed of light is given the magnitude: 299,792,458. Which choice is made makes a tremendous difference. As another example, current physics gives the electrical charge a value of plus or minus one. However, some scientists have suggested it would be more convenient to work with charges expressed in thirds (1/3) of the charge now used. While making the transition to a new set of Basic Units, it might make sense to also improve the values of some constants, such as these. Are we now at the crossroads in history where a final set of Basic Units can be chosen for all time? Maybe...