The principle of length theory

As mentioned earlier, when the rod is only one, we don't know whether the rod is long or short.
To know it, we should relatively compare the rods.

If the rod B is an absolute standard of the rods, then the length of rod A is A/B (A,B: interval of lengthspace)
The Definition of the SI unit is the same.
The Kelvin(k), the Ampere(A), the second(S), Mass(kg) .... are the fundamental units in physics.
But, The SI units don't have any absolute standard. Only physicists decided it by the reasonable condition.

If we don't decide an absolute standard of each unit, then the rod B is equal to one.
In mathematics, If A*B=A, B*A=A , then B=1.
The each unit must have an absolute standard, but if the units don't have it, the denominator must become one.
Until now, mathematicians don't have explained " why the denominator cannot be zero?"
Using the length principle, this problem is easily solved. Physicists have passed over this point.

Therefore, the unconsciousness of the absolute standard must become one.