Is the light coming from distant stars proof that the universe is very old?
Some stars are thousands and even millions of light years away from us. Does this actually mean that the light we receive from these stars took thousands of years to reach us?
Currently, there are no satisfactory answers accepted by the majority of scientists, so we will propose a number of hypotheses.
What we observe is not an old universe, but rather some facts from which we can try to deduce the age of the universe starting from certain preliminary hypotheses. Even if our hypotheses seem reasonable, they are still "beliefs". We must therefore carefully look at each of these hypotheses one at a time, always remembering that we must approach them with great humility as we do not have access to infinite knowledge. The history of science shows that what seems certain in one generation can be totally dethroned by new information in the next generation.
The hypotheses that have been used in the past to estimate the age of the universe by the observation of the light coming from distant stars are the following:
Hypothesis I: the great distances attributed to the stars are real
The further we go, the more indirect the measurement methods are. However, although there is a large margin of error for very distant stars, it is not truly revelatory, since the biblical time structure does not allow for more than 6-10,000 years. Our galaxy "the Milky Way" is also estimated to be about 100,000 light-years in diameter. The universe must be immense, taking into account the considerable number of visible galaxies.
However physicist Russel Humphreys suggests a real question: how far away were the galaxies when the light started moving towards us?
The Bible indicates three times (using 3 different Hebrew verbs) that God has "Stretched out or spread out the heavens" (for example: Isaiah 42, 5/ 45: 12/ 51: 13/ Jeremiah 10: 12).
Since the heavens were created before the stars and planets, this unfolding likely refers to the creation of the celestial bodies.
According to Dr. Humphreys, there is a solution to Einstein's gravitational field equation that can allow a very rapid expansion of space and, consequently, of all the things it contains. This could give the universe the chance to swell to its current size in less than 6,000 years. As a result, light began its journey when galaxies were closer (and also smaller and less energetic) than today. Such an expansion would symmetrically incorporate all matter and would not be identifiable from that of the "inside". Conversely, this could explain the red shift in the wavelengths of starlight.
Hypothesis II: We know for sure how light travels in deep space
In 1953, Moon and Spencer proposed that starlight traveled along curved paths in a mathematical structure known as "Riemannian space." In this case, they declared, the most distant light would reach the earth in less than 20 years.
Such hypothesis is difficult to prove, and has been criticized on the observational level. V. Bounds argued that, if this hypothesis were true, multiple images of celestial objects would be seen. As far as we know, so far there have been no attempts to rebut this criticism.
Hypothesis III: Light has always traveled at the same speed throughout the history of the universe
Clearly this hypothesis is impossible to prove, although, at first glance, it seems reasonable.
If light was faster in the past, then it would be possible for stars to be both very distant and very young. This could be accomplished either by a direct change in the speed of light, at a given time after creation, or by an as yet unknown physical principle that caused the speed of light to slow down. The light we currently receive from distant stars, while traveling at today's speed, would have covered a greater distance in the years following creation.
Considering this point of view, it is interesting to note that the Russian professor Troitskii published a study in the journal "Astrophysique et science de l'espace" in which he declared that the observations detected by cosmology, such as the red shift in light of the stars and the background radiation (used as "evidence" of the big bang), were in fact better understood as being the result of a change in the speed of the light. He proposed that the speed of the light began at a nearly infinite value, then decreased to its present value.
Unfortunately, the idea of the Big Bang (although it has an increasing number of critics) has such an impact on the imagination of cosmologists that no other explanation for these phenomena attracts their attention. Troistkii's work is done in a 2 billion year framework, but the main point to mention is that the change in the speed of the light does not violate any established physical principles.
Another interesting hypothesis is the monograph published by Norman and Setterfied in 1987. They collected all known measurements of the speed of the light for the last 300 years and stated that the tabulation showed that this value is not constant during this period, but always declines reaching a constant level in the 1960s. They cite a number of statistical tests that contradict the constancy of the speed of the lightduring that period.
Such a radical hypothesis raises a number of questions and potential problems in numerous domains of science. Some questions have found satisfactory answers from supporters of this hypothesis, others have not.
Fortunately, future work will certainly clarify this topic but, in the meantime, we are cautious before accepting this proposition prematurely.
Hypothesis IV: The universe could not have been created "ready to work" with people on earth seeing starlight
This assumes that God is not omnipotent. Biblical creation is a miracle that used processes that are no longer in operation. God is not dependent on the physical laws that we observe, since He established them.
To say that God could not create a universe that is both very large and very young challenges the very nature of God as revealed in his Word.
The universe was created as a fully functioning entity. The stars created on the 4th day were for man like "signs to mark the times, the days and the years" (Genesis 1, 14). There is no reason to believe that Adam and Eve had to wait 4 years for the first star to light up (the closest star from us is about 4 light years away).
Likewise, we do not see new stars "flashing" as if their light had finally reached the earth.
The example that was mentioned above by Doctor Humphreys can lead us to a better understanding of how light was originally created "on its path". In a sense, this may actually include an (apparent) change in the speed of the light (the stars move away rapidly, the light beam remains intact), although this would not be detectable in measurements that have been made in the past.
Conclusion
We hope that these discussions have been sufficient to enable the reader to understand that the apparent problem of a young and large universe has multiple possible solutions. Has the speed of light changed? If so, did it become constant thousands of years ago?
Is there a solution in the "relaxation" of space that is implied in the Holy Scriptures? Could it be a combination of these factors? Or was it an entirely different method that God used during Creation Week to create an adult, functioning universe, a method that may never be clarified?
Whatever the answer is, faith in the Creator's revealed Word is the only reasonable starting point for any inquiry.
