Simplify the following text for a Grade 13 native English-speaking person.
Original: Opponents to the hypothesis contested the implications of the geological evidence for global glaciation , the geophysical feasibility of an ice - or slush-covered ocean , and the difficulty of escaping an all-frozen condition .
Simplified: Opponents do not draw the same inferences from the geological evidence , and doubt the geophysical feasibility of an ice or slush-covered ocean .