If certain things are known, it is possible to calculate the amount of time since the parent isotope began to decay.For example, if you began with 1 gram of carbon-14, after 5,730 years you would be left with 0.50 g and only 0.25 g after 11,460 years.There is also a difference in the timescale used to explain the layers.Determining the relative age of a rock layer is based on the assumption that you know the ages of the rocks surrounding it.The reason this age may not be a true age—even though it is commonly called an absolute age—is that it is based on several crucial assumptions.Most radiometric dating techniques must make three assumptions: The major problem with the first assumption is that there is no way to prove that the decay rate was not different at some point in the past.If any of these three conditions is not accurately known, the hourglass will give an inaccurate measure of time.Radiometric dating is based on the fact that radioactive isotopes decay to form isotopes of different elements.

You can use the hourglass to tell time if you know several things: the amount of sand in the top of the hourglass when it started flowing, the rate that the sand flows through the hole in the middle, and that the quantity of sand in each chamber has not been tampered with.

There are three main assumptions that must be made to accept radiometric dating methods.

These must be accepted on faith in uniformitarian and naturalistic frameworks.

Some of the common isotope pairs used are K-Ar, Rb-Sr, Pb-Pb, and U-Pb.

Carbon-14 dating is another common technique, but it can only be used on carbon-containing things that were once alive.

You can use the hourglass to tell time if you know several things: the amount of sand in the top of the hourglass when it started flowing, the rate that the sand flows through the hole in the middle, and that the quantity of sand in each chamber has not been tampered with.There are three main assumptions that must be made to accept radiometric dating methods.These must be accepted on faith in uniformitarian and naturalistic frameworks.Some of the common isotope pairs used are K-Ar, Rb-Sr, Pb-Pb, and U-Pb.Carbon-14 dating is another common technique, but it can only be used on carbon-containing things that were once alive.Despite the fact that there are many scientific problems with radiometric dating, there is a more significant problem.