Scientists like using models because they are often than the real thing.

Cheaper and easier to work with

creative diagnostics provides a protocol for total protein extraction based on ripa which is widely used.

this age may represent the age of the earth's accretion, of core formation, or of the material from which the earth formed. this dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.