[Audio] Hi everyone
Today our topic is
Why earth is colling so slowly. 

Scene 1

Scene 2

According to Geologists, if there is no heat source, Earth have cooled to its present temperature in no more 1-Billion years old. Earth is 4-Billion years old. 	High energy particles in radioactive decay cause heat Earth from inside. Elements like Uranium and Potassium have half life longer then Earth. Energy produced is so small, but cannot escape easily from Earth. Thermal energy in Earth core is transferred to Earth surface by convection, conduction and radiation.

Why is Earth Cooling so Slowly

Scene 1 (0s)

Scene 2 (9s)

Scene 3 (33s)