Gravitational redshift revisited: Inertia, geometry, and charge

Area of Science:

• Physics
• General Relativity
• Special Relativity

Background:

• Gravitational redshift, famously demonstrated by the Pound-Rebka experiment, is a well-established phenomenon.
• Existing literature presents confusion regarding the precise implications and theoretical underpinnings of gravitational redshift experiments.

Purpose of the Study:

• To clarify the theoretical interpretations of gravitational redshift experiments.
• To demonstrate that special relativity and alternative frameworks can explain observed effects.
• To challenge the assumption that the absence of gravitational redshift implies a flat spacetime.

Main Methods:

• Analysis of experimental outcomes of gravitational redshift setups, including the Pound-Rebka experiment.
• Application of principles from special relativity, particularly accelerating frames and Rindler spacetime.
• Investigation of alternative theoretical frameworks, including the 'geometric trinity' of gravity.
• Examination of the Reissner-Nordström metric to explore the role of charge in gravitational phenomena.

Main Results:

• The outcomes of less sensitive gravitational redshift experiments, like the original Pound-Rebka setup, are adequately explained by special relativity's accelerating frames.
• More sensitive gravitational redshift experiments require additional theoretical considerations beyond basic special relativity.
• Spacetime curvature, while often invoked, is not strictly necessary for explaining gravitational redshift; alternative relativistic frameworks suffice.
• The presence of electric charge, as described by the Reissner-Nordström metric, can cancel or even reverse gravitational redshift and attractive forces, demonstrating that absence of redshift does not necessitate a Minkowskian spacetime.

Conclusions:

• Gravitational redshift phenomena can be understood within the framework of special relativity, even in advanced scenarios.
• General relativity's spacetime curvature is not the sole explanation for gravitational redshift.
• The interplay of charge and gravity, as seen in the Reissner-Nordström metric, offers a more nuanced view of gravitational effects and spacetime properties.