Methods for dating the earth Free xxx mobile chatrooms
Like the tree rings, this method can be verified by comparison to historical records for weather, as well as to records of volcanic eruptions around the globe that left thin dust layers on the glaciers.
Scientists have drilled ice cores deep into glaciers and found ice that is 123,000 years old in Greenland In your high school science classroom, you may have seen a large poster of the periodic table hanging on the wall.
Using the known rate of change in radio-active elements (radiometric dating), some Earth rocks have been shown to be billions of years old, while the oldest solar system rocks are dated at 4.6 billion years.
Astronomers use the distance to galaxies and the speed of light to calculate that the light has been traveling for billions of years.
The periodic table shows the types of atoms that make up the world around us.
An element in the periodic table can come in different flavors called isotopes.
Some isotopes have short half-lives of minutes or years, but Potassium-40 has a half-life of 1.3 billion years.This method can even be used on dead trees that fell in a forest long ago.For example, the last 200 rings in the dead tree might match up with 200 rings early in the life of the living tree, so the two trees together can count back many years.This conclusion is not based on just one measurement or one calculation, but on many types of evidence.Here we will describe just two types of evidence for an old Earth and two types of evidence for an old universe; more types can be found under further reading.
It’s hard to find rocks on the surface of the Earth that have not been altered over time.