Here they are. https://www.nationalgeographic.org/article/how-did-scientists-calculate-age-earth/ Now tell us how they are wrong.
The 6000 years was determined by Bishop Ussher using the bible and his guesses. Now that is not scientific.
radiometric dating is flawed!
Most scientists today believe that life has existed on the earth for billions of years. This belief in long ages for the earth and the existence of life is derived largely from radiometric dating. These long time periods are computed by measuring the ratio of daughter to parent substance in a rock and inferring an age based on this ratio. This age is computed under the assumption that the parent substance (say, uranium) gradually decays to the daughter substance (say, lead), so the higher the ratio of lead to uranium, the older the rock must be. Of course, there are many problems with such dating methods, such as parent or daughter substances entering or leaving the rock, as well as daughter product being present at the beginning.

