Sessions' work states that Earth is filled with water and not molten rock, including a core of solid ice, and that fossilization, petrification and the planet's land forms are the result of a recent worldwide flood and not millennia of geological development.
"Students and the BYU community are reminded that organic evolution, anthropogenic climate change, radiometric dating and a 4.56 billion-year-old age of the Earth are all seriously taught on campus by professors, who are in good standing with the church, in fields directly relating to these subjects," the letter states, signed by BYU Associate Dean Bart Kowallis, eight faculty members and 24 students.
The letter was submitted in response to a Firm Foundation Expo advertisement that ran in The Daily Universe. Kowallis did not respond to a request for comment, but the letter states that Sessions' assertions are contradicted by empirical evidence and would not pass peer review by subject experts.
"We are concerned that the presence of the aforementioned advertisement in The Universe may legitimize Dean Sessions' 'Universal Model' in the eyes of some within the community," the geologists wrote.
A similar ad ran in the student newspaper of Utah Valley University, where the conference will be held between Thursday and Saturday. UVU physics and astronomy professor Joseph Jensen said he too was concerned about Sessions' assertions being legitimized through an event on a university campus.
"This is pseudoscience," Jensen said. "It's people trying to make money on something that sounds scientific but has no basis in observation or reality, for that matter."
Rian Nelson, an organizer of the Firm Foundation Expo, said Sessions is one of 88 speakers participating in the event, which covers topics ranging from holistic health practices to evidence of the historicity of the Book of Mormon, the LDS Church's foundational scripture, which tells of pre-Columbian Christians in the Western Hemisphere.
Firm Foundation is an acronym for Foundation for Indigenous Research and Mormonism.
"We include science and Book of Mormon study and gardening and emergency preparedness," Nelson said. "We're all, solidly, members of the LDS Church and believe in it with all of our heart."
Nelson said he wasn't concerned with the criticism of the "Universal Model," even from scientists who are members of his own faith. The creation and timeline of the Earth, Nelson said, are areas of study in which faithful Mormons can disagree.
"There are many BYU faculty members that disagree with our theory about the heartland of North America being where the Book of Mormon was," he said. "We both have strong testimonies of the gospel. We're just looking at different theories in different directions."
But Jensen, who is also LDS, said his concerns with the "Universal Model" go beyond a disagreement over theories.
Sessions calculates the mass of his water-filled Earth to be about a third of the scientific consensus, Jensen said. And the "Universal Model" is designed to justify a personal viewpoint, he said, rather than respond to empirical evidence.
"We have a really good idea of how much mass the Earth has," Jensen said. "There's nothing about the model that Mr. Sessions is proposing that is consistent with any of the observations."
In a prepared statement, "Universal Model" spokesman Jarom Sessions said that he expects lively feedback from students and professors in response to the incredible discoveries and extraordinary assertions included in the model. But, he added, inquirers should set aside their emotions and examine the evidence.
"Just because a theory is taught for 'generations' as fact," Jarom Sessions wrote, "that alone does not make it credible or true when the observable evidence shows otherwise."
Other presentations at the Firm Foundation Expo include "Noah's Flood and Lake Bonneville," "Relieve Pain with Brain Techniques," "Prophets and the Women Who Loved Them" and "Reconciling Science and Mormonism."