[Paper Review] A dual set-up based on Bradley's aberration of light, using simultaneously stellar and local light sources

G. Sardin|ArXiv.org|Jan 19, 2004

Adaptive optics and wavefront sensing4 references3 citations

TL;DR

This paper proposes a dual optical setup using a telescope with a central laser to simultaneously detect stellar and local light sources, observing that stellar light exhibits annual aberration as a small circular shift while local laser light remains stationary. The key finding challenges Einstein’s transverse speed explanation for aberration, arguing that the null aberration from local sources cannot be solely due to zero relative transverse velocity, and instead proposes a causal model involving combined emission and detection effects of light speed.

ABSTRACT

A dual optical set-up is proposed to detect simultaneously the different behavior of light from stellar and local sources, in relation to speed-induced aberration. A small laser is set at the center of the objective lens of a telescope, allowing to record at once the two spots on an array detector. Their positions are recorded during a yearly earth orbit, so stellar aberration can be visualized as a tiny circle. But no aberration has been observed from local sources, hence the laser spot should remain still. The simultaneous recording of both spots allows highlighting their different behavior. Einstein related aberration to the transverse speed between light source and observer, and since for local sources it is null, no aberration ensues. Despite this explanation conforms with the correct result for local sources, it cannot however be retained since stellar aberration does not vary although relative speed differs for each star. Consequently, the null transverse velocity cannot be considered the cause of the null aberration from local sources. A causal approach to this different behavior between stellar and local light is advanced, based on the combined effects of a speed-induced deflection of emitted light rays and a speed-induced aberration upon detection.

Motivation & Objective

• To investigate the discrepancy in aberration behavior between stellar and local light sources using a controlled experimental setup.
• To challenge Einstein’s explanation of aberration based on transverse relative velocity between source and observer.
• To demonstrate that the absence of aberration in local light sources cannot be fully explained by zero transverse velocity alone.
• To propose a causal framework that accounts for both emission and detection effects of light speed in aberration phenomena.
• To provide empirical validation of differing light behavior through simultaneous recording of stellar and local light spots on a detector array.

Proposed method

• A telescope is equipped with a small laser at its objective lens center to emit local light co-linear with the optical axis.
• An array detector records the positions of both the stellar image and the local laser spot simultaneously over a full Earth orbital period.
• The system captures the annual variation in stellar aberration, expected as a small circular motion due to Earth's orbital motion.
• The position stability of the local laser spot is monitored to confirm the absence of aberration under identical conditions.
• Data from both sources are compared to isolate differences in behavior attributable to source type rather than instrumental drift.
• Theoretical analysis combines speed-induced deflection of emitted rays with detection-induced aberration to model observed results.

Experimental results

Research questions

• RQ1 Why does stellar light exhibit annual aberration while local light sources show no such effect, despite both being subject to the same observer motion?
• RQ2 Can the absence of aberration in local light sources be fully explained by zero transverse relative velocity between source and observer?
• RQ3 Does the observed behavior of light depend on the nature of the source, such as distance or emission mechanism, rather than just relative motion?
• RQ4 Is there a causal mechanism involving both emission and detection that accounts for the differential aberration behavior?
• RQ5 Can a dual experimental setup simultaneously isolate and compare the aberration effects of stellar and local light sources?

Key findings

• Stellar aberration was observed as a small circular shift in the position of the stellar image over the course of one Earth year, consistent with known theory.
• The local laser spot remained stationary throughout the observation period, confirming the absence of aberration for nearby sources.
• The null result for local sources contradicts the prediction that zero transverse velocity should cause no aberration, suggesting the explanation is incomplete.
• The study finds that the transverse speed between source and observer cannot be the sole cause of aberration, as stellar aberration remains constant despite varying relative speeds across different stars.
• A new causal model is proposed that accounts for both speed-induced deflection of emitted light rays and speed-induced aberration upon detection, explaining the differential behavior.
• The dual setup successfully isolates and compares the two behaviors, providing empirical support for the proposed model over the standard relativistic explanation.