Hoping to build on their win over Tampa Bay, the Saints stayed at home for a Week 6 fight with the Philadelphia Eagles.  In the first quarter, New Orleans jumped out to an early lead with kicker John Carney kicking a 39-yard field goal and quarterback Drew Brees completing a 14-yard touchdown pass to WR Joe Horn.  In the second quarter, Philadelphia would get on the board with kicker David Akers kicking a 47-yard field goal.  Fortunately, the Saints managed to further themselves, as Brees completed a 7-yard touchdown pass to WR Marques Colston.  However, in the third quarter, the Eagles started to get back into the game, as quarterback Donovan McNabb completed two touchdown passes (a 60-yarder to WR Reggie Brown and a 4-yard to TE L.J. Smith).  In the fourth quarter, Philadelphia took the lead on a 15-yard touchdown run by Brown.  Fortunately, after Brees completed a 48-yard touchdown pass to Horn, Carney helped give New Orleans the win as he kicked a 31-yard field goal as time ran out on the game.  With the win, the Saints maintained their lead in the NFC South with a 5-1 record going into their bye week.
Question: How many yards shorter was John Carney's second field goal compared to his first?
Answer: 8