Understanding the Speed of Light in an Expanding Universe: A Comparative Analysis

Introduction
In the field of cosmology, one of the most fascinating puzzles is the relationship between the speed of light and the expansion of the universe. Given the constancy of the speed of light as established by physics, how does it coexist with the expansion of spacetime? This article explores the mechanics behind the speed of light, its constancy in the context of an expanding universe, and the theories that attempt to reconcile these two phenomena.

The Constancy of Light

The speed of light in a vacuum is considered a fundamental constant of nature. This is enshrined in the SI definition of the meter adopted by the Bureau International des Poids et Mesures (BIPM) in 2019. One meter is now defined as the distance light travels in 1/299792458 of a second. This definition underscores the robustness of the speed of light as a constant, independent of the expansion of spacetime.

Expanding Spacetime and Redshift

The expansion of the universe, as observed by the redshift of distant galaxies, presents a complex challenge to understanding the speed of light. While the wavelength of light can change due to redshift, the speed of light itself remains constant. The Microwave Background Radiation (MBR) provides a cosmic yardstick, indicating that the expansion of the universe is a consequence of the stretch of spacetime, rather than a mechanical movement of matter.

A New Perspective: my Spherical Dimensional Model

The traditional explanation for redshift is the velocity of galaxies moving away from each other. However, the spherical dimensional model proposes an alternative: the direction of time. According to this model, a variation in the direction of time can cause redshift without necessitating the expansion of space. In this context, light travels at a rate that, from our perspective, appears to increase with distance from the center of the universe due to increased speed through time.

Theoretical Challenges in Current Models

Many current theories, notably the Lorentz transformation and the concept of covariant invariance, face significant theoretical and experimental challenges. The Micahelson-Morley experiment and stellar aberration provide evidence against the non-linear speed behavior suggested by the Lorentz transformation. The classical Doppler effect offers a simpler, more consistent model for understanding the propagation of light.

Possible Explanations and Future Research

Revisiting the original conundrums presented by experiments like the Michelson-Morley and stellar aberration might provide insights. The persistent evidence of a 'dragging' effect by the Sun on the speed of electromagnetic waves suggests a deeper, possibly environmental factor influencing light speed. Future research could explore the roles of gravitational fields, quantum effects, and other environmental factors in shaping our understanding of the speed of light.

Conclusion

The constancy of the speed of light in an expanding universe is a profoundly complex issue. While the expansion of the universe increases the observed wavelength of light, the speed remains a fundamental constant. By exploring new models like the spherical dimensional perspective and reconsidering the classical Doppler effect, we can enhance our comprehension of the true nature of spacetime. Further research is needed to reconcile these phenomena and deepen our understanding of the fabric of the universe.