:Looking out their windows.<ref>The Sun, and all stars, are examples of nuclear fusion (in this case, fusing hydrogen to form helium and other gases). Scientists are seeking to replicate this at lower temperatures, called "cold fusion."</ref> | :Looking out their windows.<ref>The Sun, and all stars, are examples of nuclear fusion (in this case, fusing hydrogen to form helium and other gases). Scientists are seeking to replicate this at lower temperatures, called "cold fusion."</ref> |