Neil B. Christianson, a scientist who believes the center of the Earth is made of a cold hydrogen crystal instead of molten rock, will explain his theory next week at Weber State University.

Christianson, author of "Earth Has a Cold Heart," will give his first public lecture about the book at 10:30 a.m. Thursday, April 25, in Room 126 of the Lind Lecture Hall.Since the early 1600s, scientists have believed that planets begin as molten masses whose surfaces gradually cool while their interiors continue in a hot, liquid state. This theory is used to explain the creation of the universe, star-birth, black holes and plate tectonics.

Christianson contends that the earth's magnetic field could not exist with a hot core. He says planets were created by chemical elements that form a cold hydrogen core. He believes his theory explains the creation of planets, volcanism and the workings of the universe.

His lecture at Weber State is free to the public.