Atmosphere of Earth (see the temperature section, below). Because the general pattern of the temperature/altitude profile is constant and measurable by means of instrumented balloon soundings, the temperature behavior provides a useful metric to distinguish atmospheric layers. In this way, Earth's atmosphere can be divided (called atmospheric stratification) into five main layers. Excluding the exosphere, the atmosphere has four primary layers, which are the troposphere, stratosphere, mesosphere, and thermosphere. From highest to lowest, the five main layers are: The exosphere is the outermost layer of Earth's atmosphere (i.e. the upper limit of the atmosphere). It extends from the exobase, which is located at
What Is a Nation? to the reasons based on race, geography, history and so on. They argue that Renan maintains his intellectual background but subtly, i.e. the arguments he explicitly used in "What is a Nation?" are not consistent with his thinking. The concept of "daily plebiscite" would be ambiguous. They argue that the definition is an opportunist idealization and it should be interpreted within the Franco-Prussian War and in the midst of the dispute concerning the Alsace-Lorraine region. What Is a Nation? "What is a Nation?" ("Qu'est-ce qu'une nation?") is an 1882 lecture by French historian Ernest Renan (1823–1892), known for the statements