The past generation has seen major advances in science and technology, and in the preparation of high school students for college. This study investigates changes in the science knowledge of college students, and in their attitudes and belief systems regarding science and technology. Over 12,600 non-science majors at the University of Arizona were surveyed using the same instrument over a period of 27 years. The knowledge-based component of the survey overlaps with questions used by the National Science Foundation over the same interval to measure science literacy in the adult U.S. population. The instrument measuring beliefs and attitudes is original to this study. The central result of this work is that student knowledge shows almost no change, in the aggregate or measured by individual items, over this span of time. This is in contrast to a significant gain in science literacy among the U.S. adults. In terms of beliefs, student susceptibility to pseudoscience ideas is relatively high and stable over time. College students have a positive attitude towards science and technology that is constant over time, except for changes on a few issues of societal importance. Responses for several items indicate the appearance of a strong gender effect in the past decade. This long-term study suggests there is still substantial work to be done in giving non-science undergraduates basic scientific knowledge and in training them how to think critically in world increasingly dominated by science and technology.