Minkowskian Spacetime Viewed Through Systemic Functional Linguistics

Penrose (2004: 404, 406-7):

To complete Minkowski’s viewpoint with regard to the geometry underlying special relativity, and thereby define Minkowskian spacetime 𝕄, we must fix the scaling of g, so that it provides a measure of ‘length’ along world lines. This applies to curves in 𝕄 that we refer to as timelike which means that their tangents always lie within the null cones (Fig. 17.15a) and, according to the theory, are possible world lines for ordinary massive particles. This ‘length’ is actually a time and it measures the actual time 𝜏 that an (ideal) clock would register, between two points A and B on the curve … Photons have world lines that are called null (or lightlike), having tangents that are on the null cones (Fig. 17.15b). Accordingly the ‘time’ that a photon experiences (if a photon could actually have experiences) has to be zero!

Blogger Comments:

From the perspective of Systemic Functional Linguistic Theory, the null cones of Minkowskian spacetime represent processes (all possible trajectories) in spacetime, not spacetime. 

To be clear, the time that a photon "experiences" is the time measured by a clock that is travelling at the speed of light. If the time measured is zero, then the clock does not tick. In other words, processes do not unfold for a body travelling at the speed of light. In terms of the Special Theory of Relativity, viewed through Systemic Functional Linguistic Theory, this means that time intervals expand to infinity for a body moving at the speed of light.