In the case of rubidium, the twin ruby red lines farther into the red part of the spectrum than Bunsen and Kirchoff had ever seen before indicated the presence of a new element.
Rubidium was discovered in 1861, in Heidelberg, Germany, by Robert Bunsen and Gustav Kirchhoff using spectroscopy, the method the pair had invented and developed in the previous two years.
Bunsen and Kirchoff had discovered cesium in 1860 when they analyzed the spectrum of mineral water.
The age of the fossil must be determined so it can be compared to other fossil species from the same time period.
Understanding the ages of related fossil species helps scientists piece together the evolutionary history of a group of organisms.
At the heart of the spectroscope lay a glass prism, which split light coming from a flame into a spectrum – much in the same way that raindrops can split sunlight into a rainbow.
The spectroscope magnified the spectrum to allow it to be studied in detail.