Coordinative definition has two major features. The first has to do with coordinating units of length with certain physical objects. This is motivated by the fact that we can never directly apprehend length. Instead we must choose some physical object, say the Standard Metre at the Bureau International des Poids et Mesures (International Bureau of Weights and Measures), or the wavelength of cadmium to stand in as our unit of length. The second feature deals with separated objects. Although we can, presumably, directly test the equality of length of two measuring rods when they are next to one another, we can not find out as much for two rods distant from one another. Even supposing that two rods, whenever brought near to one another are seen to be equal in length, we are not justified in stating that they are always equal in length. This impossibility undermines our ability to decide the equality of length of two distant objects. Sameness of length, to the contrary, must be set by definition.
The first feature of Coordinative definition involves what?
coordinating units of length with certain physical objects

In 1729, Nader Shah, a chieftain and military genius from Khorasan, successfully drove out and conquered the Pashtun invaders. He subsequently took back the annexed Caucasian territories which were divided among the Ottoman and Russian authorities by the ongoing chaos in Iran. During the reign of Nader Shah, Iran reached its greatest extent since the Sassanid Empire, reestablishing the Iranian hegemony all over the Caucasus, as well as other major parts of the west and central Asia, and briefly possessing what was arguably the most powerful empire at the time.
In what year were the Pashtuns defeated and driven out of Iran?
1729

In the 1960s, American and British blues and rock bands began to modify rock and roll by adding harder sounds, heavier guitar riffs, bombastic drumming, and louder vocals, from electric blues. Early forms of hard rock can be heard in the work of Chicago blues musicians Elmore James, Muddy Waters, and Howlin' Wolf, The Kingsmen's version of "Louie Louie" (1963) which made it a garage rock standard, and the songs of rhythm and blues influenced British Invasion acts, including "You Really Got Me" by The Kinks (1964), "My Generation" by The Who (1965), "Shapes of Things" (1966) by The Yardbirds and "(I Can't Get No) Satisfaction" (1965) by The Rolling Stones. From the late 1960s, it became common to divide mainstream rock music that emerged from psychedelia into soft and hard rock. Soft rock was often derived from folk rock, using acoustic instruments and putting more emphasis on melody and harmonies. In contrast, hard rock was most often derived from blues rock and was played louder and with more intensity.
Who were three Chicago blues players who influenced hard rock?
Elmore James, Muddy Waters, and Howlin' Wolf