1) The document discusses a student who had doubts about the young earth based on seeing stalactites in caves, but the author addresses this by showing him stalactites growing rapidly under buildings. 2) It provides examples of stalactites found growing in just 59 years under the Shrine of Remembrance in Melbourne, disproving the notion that stalactites require thousands of years to form. 3) The author concludes that stalactites can form rapidly in many locations like buildings, shopping centers, and cars parks, not just caves, challenging the idea that their presence indicates an old earth.