Q: There are several inconsistencies in The Urantia Book, such as these from the Wikipedia page on The Urantia Book.
1) The described formation of the solar system is consistent with the Chamberlin-Moulton planetesimal hypothesis. Though popular in the early part of the 20th century, by the early 1940s it was discarded by Henry Russell's argument that it was incompatible with the angular momentum of planets such as Jupiter. The currently accepted scientific explanation for the origin of the solar system is based on the nebular hypothesis.
2) The age of our universe is stated to be more than 1, 000, 000, 000, 000 (one trillion) years old and the universe is said to periodically expand and contract—respire—at 2-billion-year intervals. Current observations, however, suggest that the true age of the universe is approximately 13.7 billion years.
3) The big bang theory is not supported.
4) A fundamental particle called an "ultimaton" is proposed, with an electron being composed of 100 ultimatons. The particle is not known to be described anywhere else and the concept is not supported by modern particle physics.
5) Some species are said to have evolved suddenly from single mutations without transitional species. The theory originated with Dutch botanist Hugo De Vries, but was short-lived and is not now supported.
6) According to The Urantia Book, multi-colored human races originated suddenly in one generation and in one family, producing brothers and sisters that variously turned blue, yellow, red, green, orange, and indigo when exposed to sunlight. Their offspring subsequently favored the parent color. Later, Adam and Eve produced a violet race. In the book's account, the blue, yellow, and red races were considered "primary", and the green, orange, and indigo "secondary". The green and orange races were driven to extinction, and the rest mixed over time. Modern evolutionary theory does not support this account.
7) The book repeats the idea prevalent at the time of its origin that one side of the planet Mercury always faces the sun due to tidal locking. In 1965, radio astronomers discovered that Mercury actually rotates fast enough for all sides to see exposure to the sun. In the same passage, the book states that tidal friction will slow the rotation of a planet or other orbiting body "until axial revolution ceases". However, current understanding is that revolutions do not cease, but stabilize such that the time to complete one revolution will become equal to the time needed to complete an orbit.
8) The book says that a solar eclipse was predicted in 1808 by the Native American prophet Tenskwatawa. The eclipse was actually predicted in late April 1806 and occurred on June 16, 1806."
can these be explained easily?
A: The list you've provided includes many of the discrepancies people bring up in order to discredit the validity of The Urantia Book. You've concluded by asking "Can these be explained easily?" and for the most part, the answer is yes, they can be explained easily.
The simple explanation is that good science is constrained to support hypotheses that can be proven. If it can't be proven then it's not scientifically viable. For that reason scientific discovery is always in a state of adjustment as new facts are learned and hypotheses are upgraded. And as you've indicated in this question, some of these scientific findings of the early 1900s have gone through just such change and redefinition. Are there any scientific explanations today that are 100% correct and will never be altered? Are there any areas in which a scientist of today knows and understands all there is to know so that it can be set aside as a truth forevermore?
One of the fundamental purposes of the Urantia teachings is to make it obvious that science and spiritual truth (what is often thought of as religion) are not at odds... that an intelligent and logical thinker does not have to toss religion to the side in order to embrace science or toss science aside in order to embrace religion. Science and religion might not always agree, but what bridges the gap between them is philosophy. We've found ourselves tending to gather at the poles, saying that it's science that has the answers or that it's religion that is true and we've neglected the need for reconciling those poles through philosophical thought.
Besides corroborating the value of scientific inquiry The Urantia Book demonstrates that spiritual truth is of even more valid since science could not exist were it not for the spiritual underpinnings of creation. But science cannot prove that spirit even exists. Science has its own arena of expertise but that arena at most encompass only half of reality. Spiritual underpinnings permeate all of creation which is comprised of both spiritual and material reality.
Here are my non-scientific answers to the issues you've presented:
For 1) – Today's currently accepted scientific explanation may become tomorrow's discarded hypothesis.
For 2) – Today's currently accepted scientific explanation may become tomorrow's discarded hypothesis.
For 3) – The Big Bang is no longer a popular theory.
For 4) – Yes, this particle is unknown.
For 5) – Today's currently accepted scientific explanation may become tomorrow's discarded hypothesis.
For 6) – Today's currently accepted scientific explanation may become tomorrow's discarded hypothesis.
For 7) – Today's currently accepted scientific explanation may become tomorrow's discarded hypothesis.
For 8) – There are actually two errors in that paragraph; you can read the explanation HERE
I'm sure you're aware that aside from disclosing this undiscovered singular material substance from which all material creation is composed (the ultimaton) the book also gives the enigmatic statement that the center of every ultimaton is the Isle of Paradise. That statement gives matter an unknowable quality which will forever baffle science and will force science to come to terms with the reality of the spiritual underpinning to reality through philosophical insight.
Scientific inquiry is a valuable endeavor but it won't provide the answers people most struggle to discover. Faith is the substance of things hoped for, the evidence of things not seen and it is a necessary element in the evolution of human consciousness and insight.
One additional comment. The Urantia Book claims to be a revelation. It could not justify that claim unless it presented new and previously unknown information, information that is not readily understood, information that is not recognized by current scientific standards. Many of those who study The Urantia Book believe it is exactly what it says it is so disparity between its explanations and current scientific thought are of little concern for alarm. If science is a big issue with your ability to believe you might find the website UBTheNews to be of interest as it focuses on current scientific thought versus the teachings of The Urantia Book The website address is http://www.ubthenews.com/
Best wishes and thank you for the question.