why didn't the early geologic time scale include the number of years ago that events happened?
i have
The early geologic time scale did not include the number of years ago that events happened because the concept of deep time, which refers to the vastness of geological time, was not fully understood or accepted at that time. In the 19th century, when the geologic time scale was being developed, there was limited knowledge about the actual age of the Earth. Additionally, techniques for absolute dating, such as radiometric dating, had not yet been developed. Instead, geologists relied on relative dating methods, such as the order and characteristics of rock layers and the fossils found within them, to determine the sequence of events in Earth's history. It wasn't until the 20th century, with advancements in dating techniques, that scientists were able to assign numerical ages to specific geologic events and include them in the geologic time scale.
The early geologic time scale did not include the number of years ago that events happened because at that time, scientists had not yet developed the technology or methods to accurately determine the age of the Earth or the various geological events that occurred in the past. They did not have access to radiometric dating techniques or other forms of absolute dating, which are used today to precisely determine the age of rocks and geological events.
Instead, the early geologic time scale was based primarily on relative dating methods, which involved determining the sequence of events and the relative ages of rocks and fossils. Scientists observed the different layers of sedimentary rocks and the order in which they occurred, as well as the presence of certain fossils in specific layers. By comparing these rock layers and fossils found in different locations, they were able to establish a relative chronological order of events.
It was not until the early 20th century that scientists began to develop techniques such as radiometric dating, which allowed them to assign numerical ages to rocks and geological events. With the advent of radiometric dating, scientists could measure the decay of radioactive isotopes in rocks and minerals, thus providing a more precise estimate of their age in years.
The incorporation of numerical ages into the geologic time scale was a significant advancement that provided a more accurate understanding of Earth's history. Today, the geologic time scale includes both relative ages and numerical age estimates for major events, giving us a better understanding of the timeline of Earth's history.
The early geological time scale I believe did include the number of years ago that events happened. The timeline, however based on carbon dating is approximate.
hope that helped!