Starlight problem

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The starlight problem, or starlight travel-time problem is an objection against the young-Earth creationist argument that the universe is only 6,000 years old, in which the age of the universe is based primarily on the Genesis narrative. The problem is that if the universe is only 6,000 years old, one has to explain how light from stars more than 6,000 light years from Earth has reached us in the time available.

Despite this frequently being put as an argument against young-Earth creationism, light travel time is also a problem for the Big Bang theory.

Creationists have proposed a number of solutions. The currently-favoured solutions involve time dilation, in which time passed slower on Earth than in other parts of the universe.

The Crab nebula, a supernova remnant
The Crab nebula, a supernova remnant

Contents

The size of the universe

Using parallax calculations, the Milky Way galaxy alone can be directly observed to have a diameter of approximately 80-100,000 light years. Calculations based on the observed brightness of supernovae of known energy output can determine the distance to more distant objects. The most distant object known is a galaxy cluster approximately thirteen billion light-years away from Earth, observed by the Hubble Telescope using gravitational lensing.[1]

Although creationists have at times disputed the size of the universe, virtually none propose that it is less than 12,000 light years across.[2]

Suggested solutions to the problem

Several solutions have been proposed by creationists to explain how a young universe may be reconciled with these observations.

They also point out that there is a logical fallacy in the argument, as the observation that many stars are millions of light years away is one of distance, not time. No matter how reasonable, it is a deduction, not an observation, that the starlight from stars millions of light years away would have required millions of years to reach Earth.

Light created in transit

Some creationists have proposed that the light we see from stars more than 6,000 light years away was not emitted by those stars, but was created 'in transit' by God. However, most creationists reject this explanation, as the light contains images of events that would therefore never have actually happened, including supernovae, meaning that we are seeing an image of a star exploding, even though the star never existed. This would make the creator a deceiver.[3]

Moon-Spencer theory

Some creationists promoted an idea by Parry Moon and Domina Spencer that light somehow takes a shortcut through "Riemannian Space", taking no more than 15 years to reach Earth from the outer limits of the universe. However, this idea never really caught on and appears to no longer have adherents.[4]

Decrease in the speed of light

Barry Setterfield
Barry Setterfield

Creationist Barry Setterfield has proposed that the speed of light was faster in the past. [5] This idea initially found wide acceptance by creationists, but is now widely rejected, although some still hold to the idea.

One criticism of it by anticreationists was that if the speed of light had changed, we should see the difference in the Fine Structure Constant as measured by nearby stars versus distant stars, but this was not observed. Yet in 1999, John Webb, a professor at the University of New South Wales in Sydney, Australia, and his colleagues reported astronomical observations suggesting that the value of the fine-structure constant may indeed have changed. They subsequently published this in Physical Review Letters.[6][7] However, although this showed that mainstream scientists are prepared to entertain the idea of a change in the speed of light when it suits them, the size of the change did not provide specific support for Setterfield's idea.

In addition, there were other problems with the theory, leading most creationists to drop the idea, although some credit it with stimulating further research.[8]

Humphreys' model

In 1994 Dr. Russell Humphreys proposed a new cosmology[9] that includes a bounded universe with a center and an edge, that God had created 6,000 years ago as a much smaller body than today, then stretched it out, making it much larger. In Humphreys' model, because the universe has a center and an edge (unlike the unbounded model of the Big Bang universe), the center of the universe is also the center of a gravity well, meaning that gravity is stronger at the center of the universe than at the edge.

As gravity can affect the rate at which time passes, he calculated that while the six days of creation week were passing on Earth, billions of years' of time was passing at the edge of the universe. According to this idea, the Biblical references to time are according to an observer (real or imaginary) on Earth, so ages are given in "Earth time".

This model receives cautious but wide support among creationists.

Time dilation field

Dr. John Hartnett, a creationist physicist, spurred by Humphreys' model, has proposed an alternative time dilation model, by theorizing the Earth was in a time-dilation field during the first few days of creation, from Earth's point of view, while billions of years passed for the rest of the universe. According to the Bible, God "stretched out"[10] the heavens (space), and this movement during creation week caused time to travel faster for those objects, in accordance with Einstein's Special Theory of Relativity, adding to the time dilation caused by gravity, per Humphreys, in accordance with Einstein's General Theory of Relativity.[11]

Starlight Problem for the Big Bang Theory

Despite the use of the Starlight Problem in arguing against young-Earth creationism, the Big Bang theory has its own light travel problem, known as the horizon problem.

The Big Bang model proposes that the temperature of the Cosmic Microwave Background (CMB) would have varied considerably from place to place early in the universe, yet because the speed at which this radiation can disperse from hotter to colder parts of the universe is limited by the speed of light, there has not been enough time for the radiation to even out, yet observations today show it to be extremely uniform[12] (with fluctuations at the part-per-million level[13]).

The problem is this: even assuming the big bang timescale, there has not been enough time for light to travel between widely separated regions of space. So, how can the different regions of the current CMB have such precisely uniform temperatures if they have never communicated with each other? This is a light-travel–time problem.[12]

A number of solutions to this problem have been proposed, including several versions of an "inflationary model", in which space itself expanded faster than the speed of light early in the Big Bang, but after different areas exchanged radiation to even out the temperature. However, there is no consensus on which explanation is correct, and each of the proposed solutions have their own problems.[12]

Bibliography

Notes

  1. ↑ Amos, 2004
  2. ↑ Fangrad, Richard, 2007.
  3. ↑ Humphreys, 1994, p.43-46.
  4. ↑ Humphreys, 1994, p. 46.
  5. ↑ Norman and Setterfield, 1986
  6. ↑ Physical Review Letters 091301, 2001
  7. ↑ Sarfati, 2001
  8. ↑ Humphreys, 1994, p.128
  9. ↑ Batten et. al., 2007, p.90, Humphreys, 1994
  10. ↑ For example, Isaiah 40:22
  11. ↑ Hartnett, 2003, Hartnett 2007
  12. ↑ 12.0 12.1 12.2 Lisle, 2003
  13. ↑ Fluctuations in the Cosmic Microwave Background
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