There are a variety of different ways to figure out how old an object is.
Of course, the best method is to check the account of a reliable eyewitness, if one is available. Since it is the written Word of God, we can trust it to tell us the truth about the past.
When scientists chipped the Iceman out of the block of ice he was found in, they tested his body to see how many carbon-14 atoms were remaining, which told them his age.
The New Zealand curve is representative for the Southern Hemisphere, the Austrian curve is representative for the Northern Hemisphere. This makes it possible to tell the age of substances that contain carbon. Dates obtained are usually written as before present ('present' is 1950).
The method was developed by Willard Libby and his colleagues at the University of Chicago in 1949.
In 1960, he was awarded the Nobel Prize in Chemistry for this work.
While on a hike, a couple from Germany found what is now referred to as the Iceman.
To determine the relative age of different rocks, geologists start with the assumption that unless something has happened, in a sequence of sedimentary rock layers, the newer rock layers will be on top of older ones. This rule is common sense, but it serves as a powerful reference point.
Yet, you’ve heard the news: Earth is 4.6 billion years old. That corn cob found in an ancient Native American fire pit is 1,000 years old. Geologic age dating—assigning an age to materials—is an entire discipline of its own.
In a way this field, called geochronology, is some of the purest detective work earth scientists do.
Scientists in the fields of geology, climatology, anthropology, and archaeology can answer many questions about the past through a technique called radiocarbon, or carbon-14, dating.
One key to understanding how and why something happened is to pinpoint when it happened.