Readers ask about the moon’s slow escape from Earth and more

Feel the burn

The discovery of a protein receptor in nerve cells that detects heat and capsaicin — the compound that makes chili peppers spicy — was one of the 2021 Nobel Prize winners in physiology or medicine, Tina Hesman Saey and Freda Kreier reported in “This year’s Nobel Prizes awarded” (SN: 11/6/21, p.