Rethink

  1. Health & Medicine

    How much water should you drink a day? It depends on several factors.

    A study of more than 5,000 people in 23 countries finds that individual water need varies widely depending on physical and environmental factors.

    By Allison Gasparini
  2. Space

    A proposed space telescope would use Earth’s atmosphere as a lens

    One astronomer has a bold solution to the high cost of building big telescopes.

    By Emily Conover
  3. Health & Medicine

    Thick calluses don’t make feet any less sensitive

    Bare feet that develop thick calluses are just as sensitive as shoe-clad feet, a study in Kenya finds.

    By Aimee Cunningham
  4. Animals

    Nearly 200 Great Barrier Reef coral species also live in the deep sea

    There are more coral species lurking in the deep ocean that previously thought.