Inflatable latex rubber balloon, (the most common balloon) was Michael Faraday in 1824, via experiments with air and various gases. Inflatable castles and similar structures are temporary inflatable buildings and structures that are rented for functions, school and church festivals and village fetes and used for recreational purposes, mainly used by children. The growth in popularity of moonwalks has led to an inflatable rental industry which includes inflatable slides, obstacle courses, games, and more. Inflatables are ideal for portable amusements because they are easy to transport and store. The name given to such structures varies. They have been marketed with such
Physicist the early-to-mid 20th century. New knowledge in the early 21st century includes a large increase in understanding physical cosmology. The broad and general study of nature, natural philosophy, was divided into several fields in the 19th century, when the concept of "science" received its modern shape. Specific categories emerged, such as "biology" and "biologist", "physics" and "physicist", "chemistry" and "chemist", among other technical fields and titles. The term "physicist" was coined by William Whewell (also the originator of the term "scientist") in his 1840 book "The Philosophy of the Inductive Sciences". A standard undergraduate physics curriculum consists of classical mechanics,