Speleology to cave science in the world. The growth of speleology is directly linked with that of the sport of caving, both because of the stimulation of public interest and awareness, and the fact that most speleological field-work has been conducted by sport cavers. The creation of an accurate, detailed map is one of the most common technical activities undertaken within a cave. Cave maps, called "surveys", can be used to compare caves to each other by length, depth and volume, may reveal clues on speleogenesis, provide a spatial reference for further scientific study, and assist visitors with route-finding. Caves provide
Exploration Earth: The Time Machine BBC Radio 4. "Exploration Earth: The Time Machine" was released on CD, paired with "Genesis of the Daleks", in 2001. It was also given away on its own as a free CD with the 28 April 2010 edition of "The Daily Telegraph" newspaper via WHSmith. It was re-released on CD in The BBC Radio Episodes but this time paired with What Happened to...Susan?, a 1994 spoof from the radio comedy series What Happened to...? Exploration Earth: The Time Machine "Exploration Earth: The Time Machine" is an episode of the BBC Schools radio drama series "Exploration Earth", a series exploring geography.