1. According to astronomical observation, galaxies like our own experience about one supernova every 25 years. The gas and dust from such explosions expand rapidly and should remain visble for over a million years. However only about 200 supernova remnants are seen in our galaxy. 200*25=5,000 years...that is quite off of the 3 billion year estimate of the age of the Earth. Even if you double the amount of time between supernovas, that is still only 10,000 years...a very wide gap.
2. The total energy stored in the Earth's magnetic field is decreasing with a half-life of about 1465+/-165 years. At that rate the field couldn't be more than 20,000 years old at the most.
3. Natural radioactivity, mutations, and decay degrade DNA and other biological material rapidly. DNA in a NATURAL ENVIOROMENT cannot last more than 10,000 years, yet intact strands of DNA apear to have been recovered from fossils much older.
-The recent discovery of the intact flesh of a Tyrannosaurus Rex with its "blood vessels, still flexible and elastic after a supposed 68 million years, and apparently intact cells" is a case in and of itself.
4. Radioactive elements generate Helium atoms as they decay to lead. Newly measured rates of Helium loss, have been calculated, and the results say that they couln't have been decaying for more than 6000+/-2000 years.
(This is enough evidence for now...if the topic gets active i'll add more.)
-Lithuania