Prior to the late 1700's, the accepted method of belief in earth's history was based on a concept called catastrophism.
Catastrophism says that the earth is very young, about 6,000 to 10,000 years old.
In the geologic column at right, the oldest layers of rock are at the bottom, and the youngest layer of rocks is at the top.
The first person to challenge catastrophism was James Hutton, who is considered the father of modern geology.
These young earth creationists are forced to interpret rock formation so that it fits within their short time frame.
This forcing of time scales upon observed scientific data leads young earth creationists to commit many scientific errors.
It also states that what we see in the rock record is the result of many catastrophic events that were quick in duration, such as volcanic events, or in the case of young earth creationism, the year-long global flood.
In the late 1700's, the first geologists started to question this interpretation.
Because of this, we tend to think that 80 years is a very long time. 2 Peter 3:8 says that a thousand years to God is like a day.