Starlight problem

The Starlight problem or Distant Starlight problem is an objection frequently proposed to Young Earth creationists, who maintain that the total age of the universe is only 6,000–10,000 years. If this age is correct, it should not be possible to see light coming from stars and galaxies that are millions or even billions of light-years distant. For example, one of the most distant galaxies ever discovered, Abell 1835 IR1916, is measured to be 13.23 billion light-years away from Earth. This implies that the universe is at least 13.23 billion years old; otherwise the light from this galaxy would not have been able to reach us yet (see particle horizon). This is a fundamental impetus for many creationists who have created alternative creationist cosmologies to accommodate the size of the universe. Mainstream physical cosmology rejects these alternative models as pseudoscience.

In-transit creation

According to some creationists, one explanation used for seeing galaxies that are billions of light-years away is that God created the light "in-transit." This "aged-earth" line of reasoning suggests that, while created relatively recently, the universe has much greater "apparent age." This is part of a broader sweep of arguments used by some creationists, known as the Omphalos hypothesis, and has parallels with views about the creation of Adam and Eve. Had they been created as newborns or children, it is less likely that they would have survived, so it is suggested that they were created as fully formed adults (or at least teenagers). This latter argument was famously articulated by Philip Gosse in his 1857 book Omphalos.

1987A supernova remnant near the center

The central problem with the "in-transit" idea is that, if it is true, then events that astronomers are now observing and interpreting as having happened at vast distances away from the Earth never actually happened. For example, in 1987 astronomers observed a supernova (an exploding star) approximately 170,000 light-years away from the earth (SN 1987A). Alongside the visible light from this explosion, they also observed gamma rays and x-rays as predicted by theory, all strongly indicative that they were observing an actual event.

However, if the universe is only 6,000–12,000 years old, what the astronomers observed did not actually happen as the data suggested. Instead, it would imply that all of the radiation from this "event" was carefully arranged in space approximately 10,000 light-years away from the Earth, such that when the Earth reached 1987, this radiation would reach it and give the impression of a supernova event which never actually happened. Consequently, the in-transit theory is often rejected for theological reasons, as it suggests that God created a "false history" of events that never took place.

Another counterargument constructs a reductio ad absurdum; if the universe were created with a false history, it becomes difficult to claim that it took place at any particular time. It could even have been created last week. (This thought experiment is sometimes referred to as Last Tuesdayism, Last Thursdayism, etc.)

c-decay

Main article: c-decay

This image is a Galaxy Evolution Explorer observation of the large galaxy in Andromeda, Messier 31.

In 1981, Australian creationist Barry Setterfield suggested that the speed of light is not constant, and was much higher ten thousand years ago than it is currently. This would enable light from very distant galaxies to reach Earth in the few thousand years available in young earth cosmologies. According to Setterfield, Rømer's measurement results in a speed of 301,300 km/s, implying that the speed of light has slowed by about 1,300 km/s over the last 300 years. However it was later pointed out that Setterfield's own source for this information directly contradicts this claim, and in fact demonstrates that the speed he measured is identical to the modern value.

This is only one of a number of criticisms that have been made. For instance, the speed of light is ingrained into most of modern physics, meaning that changes to this value would have wide-reaching and sometimes non-obvious effects, none of which have been observed. Another more recent line of reasoning uses a purely geometric argument to demonstrate that the speed of light when Supernova 1987A exploded is the same as it is today. Due to the way the argument is constructed it is possible to change this speed, but only if one makes the universe larger (or smaller), thereby erasing the effect of changing the speed.

This idea has also fallen out of favor, as measurements of the speed of light have been made accurately enough to show that there has been no noticeable variation over the time that it has been measurable. Answers in Genesis (AiG), a leading creationist organization, says that this hypothesis has a number of problems that have not been satisfactorily answered.

This idea is independent of the variable speed of light found in present models of the earliest moments of the Big Bang, though various creationists, including Setterfield, have exploited the explanation as a confirmation of their own ideas (despite the fact that the speed of light has remained constant to at least one part in 10¹⁰ over the last 13 billion years according to observations of distant quasars). Other creationists have warned against reading too much into such claims.

Humphreys model

Russell Humphreys, a young Earth creationist and a nuclear physicist, wrote a book called Starlight and Time, which attempts to explain the starlight problem with his ideas of how a young earth and universe can fit in with the distant starlight problem. The first starting point for Humphreys' model is the original cosmic material, while the second concerns the state in which that matter was in, which Humphreys believes to have been a massive black hole. Humphreys argues at great length to the effect that the Big Bang theory does not and cannot begin with a black hole (due to the assumption of the cosmological principle). The model also suggests that the universe has a distinct physical "edge", and that the Earth lies in the middle, something Humphreys believes is supported by claims of quantized redshifts.

This model is criticized by scientists and some creationists. This includes a long rebuttal by Old Earth creationists Hugh Ross, an astronomer, and Samuel R. Conner, the authors of The Unraveling of Starlight and Time. Humphreys has since written New Vistas of Spacetime Rebut the Critics to answer some of his critics.

See also

• Creationism
• Creationist cosmologies
• c-decay
• Horizon Problem
• Old Earth creationism
• Young Earth creationism
• Naturalism (philosophy)
• Natural science

External links

• Does the Speed of Light Slow Down Over Time?, Ronald Ebert (Rep. NCSE 17, 1997)