The terms "plain science" and "general science" are not commonly used or recognized scientific terms. However, based on the context you provided, I can offer some interpretations:
Plain Science: It is possible that "plain science" refers to the fundamental or basic principles and concepts of science. This could encompass the foundational knowledge and theories in various scientific disciplines, such as physics, chemistry, biology, and so on. "Plain science" might refer to the core principles that form the basis of scientific understanding without delving into specialized or advanced topics within specific fields.
General Science: "General science" typically refers to a broad, interdisciplinary approach to scientific knowledge that covers multiple scientific disciplines. It often includes basic concepts and principles from various branches of science, including physics, chemistry, biology, geology, astronomy, and more. General science seeks to provide a comprehensive understanding of the natural world without going into the specifics of any particular scientific discipline. It is often taught at the elementary or introductory level to provide a well-rounded scientific education.
It's important to note that these interpretations are based on the context you provided, as the terms themselves are not widely recognized within scientific discourse. The field of science is vast and diverse, encompassing numerous specialized disciplines, and its terminology tends to be specific and precise.