MADISON, Wis. - The sun set on this bustling state capital shortly before 7 o'clock. Long before that, though, darkness had fallen on Penn State's hopes of taking a step back toward respectability in the Big Ten Conference.
  The shadow was cast by Erasmus James, the swift, fierce Wisconsin defensive end who devastated the Nittany Lions' offense by knocking out quarterbacks Zack Mills and Michael Robinson before the first quarter ended.
  For Penn State, that meant getting into the Wisconsin end zone would be darn near impossible, and the Nittany Lions didn't as the 20th-ranked Badgers scored a 16-3 victory at raucous Camp Randall Stadium last night.
  The loss was the fifth straight in a conference opener for Penn State, which dropped to 2-2 overall. Wisconsin improved to 4-0 overall.
  In a frightening scene with 1 minute, 43 seconds remaining in the opening quarter, Robinson lay unconscious for several minutes. His neck stabilized and his body strapped to a stretcher, he was taken by ambulance to University of Wisconsin Hospital and Clinics, where he was diagnosed as having a concussion. He was held overnight for observation. A team spokesman said he was able to move his extremities.
  "It was pretty scary," said Mills, who watched Robinson being tended to while he himself was nursing a separated joint in his right shoulder.
  "He was knocked out, and he just went limp. But I hear he's OK. He's probably going to have a bad headache."
  Mills left the game after the second play. He said he would play Saturday at Minnesota.
  After the game, coach Joe Paterno was quickly rushed back to State College after being notified that his son-in-law, Chris Hort, had suffered a severe injury in a bicycle accident yesterday. Hort, husband of Paterno's daughter, Mary Kay, was in intensive care after being airlifted to Altoona Hospital. Paterno was not available for comment.
  "There were tears in his eyes," defensive coordinator Tom Bradley said. "It's a sad occurrence."
  The hit on Robinson was delivered by the 6-foot-4, 263-pound James, who spent most of the game having his way with Penn State's offensive line. It appeared to be a helmet-on-helmet collision. As Robinson was falling backward, Jason Jefferson, a 306-pound Wisconsin tackle, landed on top of him.
  The rest of the game was in the hands of third-string quarterback Chris Ganter, a redshirt junior who had played sparingly, mostly in mop-up roles.
  "We had to adjust our game plan a lot, because Michael Robinson obviously factors into our game plan a great deal," Bradley said. "Not only as a quarterback but as a wide receiver. So our offense became very limited.
  "We lost Zack, so Mike has to play quarterback, and that's going to chop your offense a little bit because of our wide-receiver situation. Chris - you can't run some of the things. He's not a running threat like Michael is. When you lose your two offensive weapons, you're limited in what you can do."