The big science stories this week included a viral post on how a dropped bag of Cheetos transformed a cave's ecosystem. And yesterday's first all-civilian spacewalk was a big success.

UNPOPULAR OPINIONS: "If people need your seat on public transport, they should ask for it"
00:56

UNPOPULAR OPINIONS: "We should stop telling people they have time to figure out their lives"
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UNPOPULAR OPINION: "Errands should be done on weekdays, not weekends"
01:03