Short answers, pulled from the story.
Shen Kuo was a Chinese polymath, scientist, and statesman of the Northern Song dynasty who lived from 1031 to 1095. He served as a finance minister, state inspector, and head official of the Bureau of Astronomy, and wrote the Dream Pool Essays of 1088. Joseph Needham called him one of the greatest scientific minds in Chinese history.
Shen Kuo made the first known explicit reference to the magnetic compass-needle and the concept of true north, describing magnetic declination. He wrote that magnetized needles are always displaced slightly east rather than pointing due south. This concept may have been unknown in Europe for another four hundred years.
The Dream Pool Essays, or Mengxi Bitan, is Shen Kuo's major written work, completed in 1088 and named after his Dream Brook garden estate near modern Zhenjiang. It consists of some 507 separate essays covering physics, astronomy, mathematics, medicine, and more. It was originally 30 chapters before a 1166 edition reorganized it into 26.
Shen Kuo formed a hypothesis of land formation after finding marine fossil shells in a mountain cliff hundreds of miles from the ocean while visiting the Taihang Mountains in 1074. He reasoned the land was reshaped by erosion, uplift, and silt deposition over an enormous span of time. After finding petrified bamboos underground near Yanzhou around 1080, where bamboo no longer grew, he deduced the climate there had once been very different.
Shen Kuo wrote extensively about Bi Sheng, an obscure commoner who invented ceramic movable type printing and lived from 990 to 1051. Because Shen recorded it in the Dream Pool Essays, the legacy of Bi Sheng and the earliest movable type was handed down to later generations. Nothing else is known of Bi Sheng's life beyond Shen's account.
Shen Kuo's career ended after a military disaster in 1081 near Yanzhou, where an arrogant officer ignored his plan and led forces to ruin with a death toll of 60,000. The new Chancellor Cai Que held Shen responsible and ousted him from office. Shen was placed under probation for six years, then retired to his Dream Brook estate, where he died in 1095.