Coming off their road win over the Chiefs, the Chargers went home, donned their alternate uniforms, and played a Week 8 divisional rematch with the Oakland Raiders.  In the first quarter, San Diego struck first as running back LaDainian Tomlinson got a 6-yard touchdown run.  The Raiders would answer in the second quarter with a 3-yard touchdown run by running back Justin Fargas, yet the Chargers stormed on as quarterback Philip Rivers hooked up wide receiver Vincent Jackson on an 8-yard touchdown pass, followed by Tomlinson getting a 10-yard touchdown run.  Oakland would close out the half with a 48-yard field goal by kicker Sebastian Janikowski. In the second half, the Raiders would slowly try to rally as Janikowski nailed a 41-yard field goal in the third quarter and a 41-yard field goal in the fourth.  Afterwards, San Diego pulled away as kicker Nate Kaeding booted a 28-yard field goal. With their 13th-straight win over Oakland, the Chargers improved to 4-3.
Question: How many yards shorter was Sebastian Janikowski's second field goal compared to his first?
Answer: 7