The article by Neel Roberts in the 5 February 2021 issue of Prairie Post provided an overview on how large the universe is. To comprehend the vastness of space and the number of stars and galaxies can be challenging â€”â€” the numbers are literally astronomical in size.
However, one number provided, the size of the universe at 13.8 billion light-years (a distance), is not correct, and may have been confused with the age of the universe, which is 13.8 billion years old (a time). The distance we can see into the universe is limited by time. Light travels at a fixed speed, albeit a very fast speed. The furthest we can see is 13.8 billion light-years, and because this is true in opposite directions, one may conclude the universe is 27.6 billion light-years across in size. But interestingly, after that light started to travel towards us 13.8 billion years ago the universe has expanded in size, and in fact, observations have shown the expansion is accelerating. Taking the expansion into account, it is estimated that the observable universe â€”â€” and the word observable is key here â€”â€” is about 92 billion light-years in size. And astronomers suggest the unobservable universe is even larger, and Mr. Roberts correctly indicated that we do not know the size of the universe.
One other correction is our solar system has eight planets, not nine planets. The former ninth planet, Pluto, was reclassified as a dwarf planet and is a member of a very large number of icy bodies located in the outer solar system known as the Kuiper Belt. The classification change was made in 2006 after many more Kuiper Belt objects were discovered and it became clear that Pluto is part of this group. I know some folks have sentimental feelings for Pluto as a planet, but what’s important is we have gained new knowledge about the solar system and Pluto is no longer the odd duckling among the planets but rather is a distinguished member (currently the second largest) of this amazing group of faraway objects.
Mr. Roberts described the first four dimensions as being the three dimensions of space and one dimension of time. However, the fifth dimension being of the supernatural has no scientific basis. In fact, physics has determined there may be 10 or 11 dimensions in the universe. These included the four dimensions of space-time, which we are all familiar with from our daily activities. The fifth dimension and the other five or six dimensions are calculated to occur at the very small scale of the sub-atomic level. These higher numbered dimensions are important in understanding string theory, quantum physics, and relativity. All of the dimensions can be represented through mathematics. To gain an understanding of the universe requires study from the very large to the very small.
After this point, the meaning of Mr. Roberts’ article becomes less clear, particular with reference to the word universe. First, evolutionists deal with biology and the evolution of life on Earth during the past 3.7 billion years of which there is a massive amount of evidence. The study of cosmology, which is a branch of astronomy, deals with study of the origin, form, and development of the universe. The Big Bang Theory indicates the universe began about 13.8 billion years ago. To suggest that “evolutionists”, or cosmologists who study the universe, whose “central philosophy is endless progression â€¦ is a faith-based religion” is misguided. The scientific method is a way of rational and innovated thinking, hypothesis testing, observation, and re-assessment. As we study and learn more of the natural world and the cosmos, the better our understanding becomes. It’s quite refreshing and liberating.
Finally, the phrase “In the beginning â€¦” in Genesis has no merit in terms of time. In the beginning, when? Genesis is simply a story in a book of selected, reinterpreted stories and is not a credible document in terms of being a source of evidence. It has been people such as Copernicus, Galilei, Newton, Einstein, Hubble, Rubin, Bell, and Hawking, and many other men and women of science, who have during the past 600 years pieced together the true nature of the cosmos surrounding us. This is arguably humankind’s greatest achievement. This achievement is not done yet, and the quest to further our understanding will continue with the next generation of astronomers. I can hardly wait to see what they will discover.
Retired research scientist and amateur astronomer and space historian