How does anyone know that the supposed age of the archaeopteryx is 100 or more million years old since no dating methods are accurate or effective?

Answer 1

Although no one can determine the EXACT date for anything prehistoric, there are still dating techniques that effectively tell the general lifespan of a given species. Although the range may vary many thousands of years in extreme cases, in comparison to the age of the world (which is about 4.5 billion years old) it is actually pretty good error range for our level of technology. The archaeopteryx is estimated to have lived about 150 million years ago, during the Jurassic period and is evidence of the first feathered prehistoric creature. The dating technique used for this was certainly not carbon-14 dating, because the half life of carbon-14 is only 5730 years, and therefore cannot be used on materials older than 70,000 years old. The method used to date the fossil of the archaeopteryx was probably radiometric dating. with this form of dating, sets of isotopes are examined such as potassium/argon, rubidium/stronium, thorium/lead, argon/argon or uranium/lead. Slight proportionate differences in the isotope levels in whichever isotope set was chosen determines the age of the object. Because the half life of each set of isotopes is so long, they can be used to date objects as old as as the earth, but cannot be used for anything more recent than .7 billion years old. First, a sample is taken from a several rocks and materials around the fossil and excavation site. After the isotope levels have been determined from the objects surrounding the fossil, it is safe to say that the fossil itself must have been approximately the age of the objects it was discovered with. Also, dating methods are tested many times and cross tested between different labs and techniques until there is a consistent result and date range given, to ensure the most accurate result possible. And as always, younger specimens will always have more accurate results than older ones.