The age of the universe is about 10^(10) years whereas the mean life for human existance is 10^(6) years. Find the physical meaning of the time interval which is approximately half way between these two on a lagarithmic scale.

The age of the universe is about 10^(10) years whereas the mean life f

1.	The age of the universe is about 10^(10) years whereas the mean life for human existance is 10^(6) years. Find the physical meaning of the time interval which is approximately half way between these two on a lagarithmic scale.
Answer» Solution :Mean life of HUMAN existance `t_(1)= 10^(6)` YEARS Mean life of universe, `t_(2)= 10^(10)` years It is the time INTERVAL, which is half way between `t_(1) " and "t_(2)`, then `log t =(1)/(2) [log t_(1)+log t_(2)]` `=(1)/(2)[log 10^(6)+log 10^(10)]` `=(1)/(2)[6+10]=8` `t= 10^(8)` years which is equal to the travel time for light from the NEAREST star.