The Arrow and the Bong

I shot an arrow into the sky It fell to earth, I knew not why The year was sixteen-forty-three Before Isaac's discovery Yet had that arrow fallen where The infant slept, yet unaware That arrows, just like apples, fall The 'why' might have remained unsolved My point fell safe fortunately So Isaac gave us gravity Now you will have to wonder why This rhyming archer has not died Perhaps the title does mislead A cheap trick to increase the reads At least it rhymes with Henry's 'song' (But, unlike me) Both he and Isaac are long gone