Investigating undergraduate students’ ideas about the fate of the Universe

As astronomers further develop an understanding of the fate of the Universe, it is essential to study students’ ideas on the fate of the Universe so that instructors can communicate the field’s current status more effectively. In this study, we examine undergraduate students’ preinstruction ideas of the fate of the Universe in ten semester-long introductory astronomy course sections (ASTRO 101) at three institutions. We also examine students’ postinstruction ideas about the fate of the Universe in ASTRO 101 over five semester-long course sections at one institution. The data include precourse surveys given during the first week of instruction ($N=264$), postinstruction exam questions ($N=59$), and interviews. We find that, preinstruction, more than a quarter of ASTRO 101 students either do not respond or respond with “I don’t know” when asked what the long-term fate of the Universe is. We also find that, though the term was not necessarily used, students tend to describe a “big chill” scenario in the preinstruction surveys, among a wide variety of other scenarios. A fraction of students describe the fate of smaller-scale systems, possibly due to confusion of the hierarchical nature of structure in the Universe. Preinstruction, students mention the Universe’s expansion when describing how astronomers know the fate of the Universe but do not discuss how we know the Universe is expanding or the relationship between expansion and the fate of the Universe. Postinstruction, students’ responses shift toward greater degrees of completeness and correctness.

Figure 1

ASTRO 101 preinstruction survey responses, thematic coding—What is the fate of the Universe? The horizontal axis is the number of responses coded under each theme ($N=191$ of 264 students responded to this question). The percentage for each theme (out of the total number of students responding) is listed at the end of each category. The percentages may add up to more than 100% because each response may be coded with more than one theme.

Figure 2

ASTRO 101 preinstruction survey responses, thematic coding—How do we know the fate of the Universe? The horizontal axis is the number of responses coded under each theme ($N=135$ of 264 students responded). The percentage for each theme (out of the total number of students responding) is listed at the end of each category. The percentages may add up to more than 100% because each response may be coded with more than one theme.

Figure 3

ASTRO 101 preinstruction survey responses, coded for degree of correctness for both the fate and how we know combined ($N=264$).

Figure 4

CSU ASTRO 101 postinstruction exam question parts (a) ($N=59$) and (b) ($N=57$), coded for correctness, in comparison with CSU preinstruction results ($N=22$), also coded for correctness.