
Time, Length, and Mass Are Derived QuantitiesDOI: 10.4236/jmp.2016.710108, PP. 11921199 Keywords: Fundamental Units, Fundamental Quantities, Derived Units, Derived Quantities, Special Relativity, Constant Velocity of Light, ThreeDimensional SpaceTime Frame Abstract: Fundamental units of measurements are kilograms, meters, and seconds—in regards to mass length, and time. All other measurements in mechanical quantities including kinetic quantities and dynamic quantities are called derived units. These derived units can be expressed in terms of fundamental units, such as acceleration, area, energy, force, power, velocity and volume. Derived quantities will be referred to as time, length, and mass. In order to explain that fundamental units are not equivalent with fundamental quantities, we need to understand the contraction of time and length in Special Relativity. If we choose the velocity of light as fundamental quantity and length and time as derived quantities, then we are able to construct threedimensional spacetime frames. Threedimensional spacetime frames representing time with polar coordination, time contraction and length contraction can be shown graphically.
