water, is not always possible. Another example is from Whorf's experience as a chemical engineer working for an insurance company as a fire inspector. While inspecting a chemical plant he observed that the plant had two storage rooms for gasoline barrels, one for the full barrels and one for the empty ones. He further noticed that while no employees smoked cigarettes in the room for full barrels, no-one minded smoking in the room with empty barrels, although this was potentially much more dangerous because of the highly flammable vapors still in the barrels. He concluded that the use of the word empty in connection to the barrels had led the workers to unconsciously regard them as harmless, although consciously they were probably aware of the risk of explosion. This example was later criticized by Lenneberg as not actually demonstrating causality between the use of the word empty and the action of smoking, but instead was an example of circular reasoning. Pinker in The Language Instinct ridiculed this example, claiming that this was a failing of human insight rather than language. Whorf's most elaborate argument for linguistic relativity regarded what he believed to be a fundamental difference in the understanding of time as a conceptual category among the Hopi. He argued that in contrast to English and other SAE languages, Hopi does not treat the flow of time as a sequence of distinct, countable instances, like "three days" or "five years," but rather as a single process and that consequently it has no nouns referring to units of time as SAE speakers understand them. He proposed that this view of time was fundamental to Hopi culture and explained certain Hopi behavioral patterns. Ekkehart Malotki later claimed that he had found no evidence of Whorf's claims in 1980's era speakers, nor in historical documents dating back to the arrival of Europeans. Malotki used evidence from archaeological data, calendars, historical documents, and modern speech; he concluded that there was no evidence that Hopi conceptualize time in the way Whorf suggested. Universalist scholars such as Pinker often see Malotki's study as a final refutation of Whorf's claim about Hopi, whereas relativist scholars such as Lucy and Penny Lee criticized Malotki's study for mischaracterizing Whorf's claims and for forcing Hopi grammar into a model of analysis that doesn't fit the data. Whorf's argument about Hopi speakers’ conceptualization about time is an example of the structure-centered