If we use simple dendrochronology (a foolproof method involving counting tree rings -- we've all done it!), the earth has to be at least 12,000 years old. If you prefer not to count tree rings and to compare overlap among various ancient trees, you could head to the caves and study the formation of stalagmites. That method yields an age of at least 40,000 years. Using glacial core ice samples, again where every year is represented by a thin layer, the earth has to be at least 100,000 years old. These methods are rock-solid, and the ages beyond dispute. If you use radiometric dating, which depends on the decay rates of radioactive isotopes (like Potassium to Argon, or Uranium 238 to Uranium 236), you end up with an age in the billions of years. I think this method is also accurate.For more on this specific subject, see Alan Hayward's book helpful book, Creation and Evolution. And if you read my book Genesis, Science & History, you may appreciate my view on how to interpret the first book of the Bible.
According to your findings, how old is our earth?