Newton, faced in May 1686 with Hooke's claim on the inverse square law, denied that Hooke was to be credited as author of the idea. Among the reasons, Newton recalled that the idea had been discussed with Sir Christopher Wren previous to Hooke's 1679 letter.
Gettysburg is a borough and the county seat of Adams County in the U.S. state of Pennsylvania. The Battle of Gettysburg (1863) and President Abraham Lincoln 's Gettysburg Address are named for this town.
Bradford County is the largest of the four counties of the Endless Mountains region of Pennsylvania and is rich in history. The area is also rich in native American history. Exhibits of native American lore can be found at the Bradford County Museum, in Towanda, and the Tioga Point Museum, in Athens.