We few, we happy few, we band of brothers; For he to-day that sheds his blood with me Shall be my brother; be he ne'er so vile, This day shall gentle his condition; And gentlemen in England now a-bed Shall think themselves accurs'd they were not here, And hold their manhoods cheap whiles any speaks That fought with us upon Saint Crispin's day.
Radiocarbon dating. Using the half-life of a radioactive isotope of carbon to approximate its age based on how much radiation it still gives off.