OSLO (AP).- Polar adventurers, scientists and the prime minister of Norway gathered at the bottom of the world Wednesday to mark the 100th anniversary of explorer Roald Amundsen becoming the first to reach the South Pole. Under a crystal blue sky and temperatures of minus 40 F (minus 40 C), the group remembered the Norwegian explorer’s achievement on the spot where he placed his flag on Dec. 14, 1911. “We are here to celebrate one of the greatest feats in human history,” Prime Minister Jens Stoltenberg said as he unveiled an ice sculpture of Amundsen. Several expeditions skied across Antarctica to attend the ceremony, which was broadcast on Norway’s NRK television. Many were delayed and had to be flown the last stretch. “Our respect for Amundsen’s feat 100 years ago grew as we traveled in his ski tracks, and felt the physical challenges he experienced,” said Jan-Gunnar Winther, director of the Norwegian Polar Institute. Wint