Dear Robert A. Phillips,
Thank you for your thoughtful question. My paper maintains that light is not subject to time dilation, and this is a consistent stance given that time dilation applies to objects or systems experiencing either relative velocity or differences in gravitational potential, both of which apply to masses moving at speeds less than the speed of light. Time dilation, as understood in relativistic terms, does not apply to light itself.
For time dilation to occur, one needs two clocks—one stationary and one in motion. When the moving clock reaches the speed of light, it ceases to function as a clock since time, in that frame, would no longer progress in a measurable way. Hence, time dilation is not applicable to light, which always travels at a constant speed, unaffected by these considerations.
The consideration of light's redshift or blueshift due to gravitational effects is important, but it's critical to differentiate between these phenomena and time dilation. Redshift or blueshift causes a change in the frequency and wavelength of light, which results in time delay or distortion, not dilation. A standard clock would measure time distortion or delay (a deviation in the measured time due to the change in wavelength) but not the enlargement of time associated with time dilation.
Regarding your point on the Planck length, this unit is derived from fundamental constants such as c, G, ħ, and kB and thus naturally includes gravitational consequences. The Planck length, defined long before the introduction of general relativity and the concept of spacetime warpage, remains consistent within the relativistic framework, although it represents a scale at which classical interpretations of spacetime break down, and quantum gravitational effects must be considered.
Thus, while Planck length is a vital concept, it does not directly tie into the observable warpage of spacetime in the way time dilation is often described.
In Summary:
In my paper, I maintain that light is not subject to time dilation, as time dilation arises from relative motion or gravitational potential differences between two clocks, which are constrained by velocities below the speed of light. Since light always travels at the speed of light, it cannot experience time dilation like matter does. If a clock were to reach the speed of light, it would no longer function, as it would lose its capacity to measure time.
Redshift and blueshift result from changes in wavelength and frequency, which I define as time distortions, not time dilation. The equation c = f⋅λ ensures that frequency and wavelength changes are inversely related, and these variations cause time distortions Δt = 1/T, distinct from time dilation (t' > t), which involves the relative expansion of time.
Regarding Planck length, it belongs to the Planck unit system, based on constants c, G, ħ, and kB. Planck length includes gravitational effects and was formulated before the concept of spacetime warpage in general relativity. While gravitational lensing results from spacetime warping, it does not alter the Planck units themselves. Near the Planck scale, quantum gravity effects dominate, rendering classical relativity inapplicable.
Best regards,
Soumendra Nath Thakur
