Aberration of starlight and the one-way speed of light

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“Simple stellar aberration diagram” by BlankAxolotl – inkscape. Licensed under CC BY-SA 3.0 via Wikipedia

The aberration of starlight (also called stellar aberration) is an astronomical phenomenon which produces an apparent motion of stars about their locations dependent on the velocity of the observer. Aberration causes objects to appear to be angled or tilted towards the direction of motion of the observer compared to when the observer is stationary. The change in angle is very small, and specified by the ratio of v/c where c is the canonical speed of light and v the velocity of the observer. With annual stellar aberration, the apparent change in the position of a star varies as observed by an Earth observer periodically over a year as the Earth’s velocity changes as it revolves around the Sun, with a maximum angle of about 20 arc-seconds in right ascension or declination. It traces a small ellipse on the sky over that time.

The fact of stellar aberration, which has been explained by a constant speed of light c, has been used by some to “refute” the idea of an infinite one-way speed of light in Lisle’s ASC model. The claim is that aberration would not occur at all if the one-way incoming speed of light was infinite, thus v/c = 0, here.  Dr Jason Lisle responds to this claim.


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A biblical creationist cosmogony

Abstract: According to the Bible the Universe is about six thousand years old. It follows from all standard assumptions that we have a starlight-travel-time problem. With the Universe being billions of light-years in extent how does light travel across the Universe to Earth within the timescale of only about six thousand years as laid out by summing up the years represented by the genealogies in Genesis 5 and 11? This problem has been a stumbling block to many simply to believe the inerrant Word of God. Others have attempted to re-interpret the Scriptures to force them to fit in with so-called modern scientific dating of the age of the Universe.  But is this really necessary? I take another look at the problem and ask the following questions: What is absolutely non-negotiable? What can we say for sure? What defines our universe? And is that consistent from a biblical creationist perspective?  The cosmogony I propose involves Lisle’s ASC (Anisotropic Synchrony Convention) model in a static universe with added features and a mechanism for cosmological redshifts, which is consistent with all creationist understandings of the biblical texts, and no light-travel time problem. Article first published by Answers Research Journal 8 (2015):13–20. PDF available here.

Introduction

What do we know from science about the size and nature (the physics) of the Universe? In the following I list what I believe we know, but there are some necessary, and I think reasonable, assumptions included. Continue reading