Alfred Goldhaber and Maurice Goldhaber presented a convincing case for not trying to observe helicity reversal in relativistic neutrinos (PHYSICS TODAY, May 2011, page 40). However, I was disappointed that they did not discuss the nonrelativistic Big Bang relic neutrinos. Their low energy precludes detecting them today, but their natural abundance and the existence of clever people make me suspect observation is possible in the near future. Helicity reversal effects may provide a key for this elusive search.