How come that Bilbo sang songs to the spiders when he was wearing the ring in "The Hobbit"?
Bilbo sang songs to the spiders while he was invisible in order to frustrate and provoke them into chasing after him. Meanwhile, the dwarves were able to continue freeing themselves and each other.
Recommended textbook solutions
Scientists can determine the age of ancient objects by the method of radiocarbon dating. The bombardment of the upper atmosphere by cosmic rays converts nitrogen to a radioactive isotope of carbon, 14C, with a half-life of about 5730 years. Vegetation absorbs carbon dioxide through the atmosphere and animal life assimilates 14C through food chains. When a plant or animal dies, it stops replacing its carbon and the amount of C begins to decrease through radioactive decay. Therefore the level of radioactivity must also decay exponentially. A parchment fragment was discovered that had about 74% as much 14C radioactivity as does plant material on the earth today. Estimate the age of the parchment.