Linguistics is the scientific study of language, and involves an analysis of language form, language meaning, and language in context. The earliest activities in the documentation and description of language have been attributed to the 6th century BC Indian grammarian Pāṇini, who wrote a formal description of the Sanskrit language in his Aṣṭādhyāyī.
Heating, ventilation and air conditioning (HVAC) systems account for approximately 35 % of the total energy spent in residential and commercial buildings. New nanotechnology will significantly reduce this massive energy use.