Age of universe

We have told about 4 billion years ago the big bang occurs in the universe and the earth came into the existence. That means the universe is older than the earth but the question is how old the universe is? The scientists said that the universe is 13.7 billion years old fro the earth time that means that for the 10 year the earth was the part of the universe as a big ball and after that big band occur and our galaxy is form and the solar system also. 

Elbert Einstein says that time is not constant in universe and his give proof of it so the question arises which time they have took it as standard to calculate the universe age.  The age of the universe is calculated by the Lambda CMD concordance model. It is calculated by the linear time expansion but there is variation in it. The changes in the expansion are both negative and the positive.  According to the cosmological parameter the age of the universe is about six day now the question is that  which age is correct the cosmological or the linear expansion and answer is quite simple that both are correct but the parameter are different.