Infantry in the Middle Ages heavy toll on the English invaders of their lands. Adapted by the English, the longbow was nevertheless a difficult weapon to master, requiring long years of use and practice. Even bow construction was extended, sometimes taking as much as four years for seasoned staves to be prepared and shaped for final deployment. A skilled longbowman could shoot 12 arrows a minute, a rate of fire superior to competing weapons like the crossbow or early gunpowder weapons. The nearest competitor to the longbow was the much more expensive crossbow or Arbalest, used often by urban militias and mercenary forces. It required
Nuclear weapon design built. Most known innovations in nuclear weapon design originated in the United States, although some were later developed independently by other states. In early news accounts, pure fission weapons were called atomic bombs or A-bombs and weapons involving fusion were called hydrogen bombs or H-bombs. Practitioners however favor the terms nuclear and thermonuclear, respectively. Nuclear fission separates or splits heavier atoms to form lighter atoms. Nuclear fusion combines together lighter atoms to form heavier atoms. Both reactions generate roughly a million times more energy than comparable chemical reactions, making nuclear bombs a million times more powerful than non-nuclear bombs, which