Tin foil hat validity, as the effect of strong radio waves has been documented for quite some time. A well-constructed aluminum foil enclosure would approximate a Faraday cage for parts of the body enclosed by metal, reducing the amount of radio frequency electromagnetic radiation passing through to the parts of the body covered by the foil. Unlike a foil hat, a Faraday cage is a complete enclosure. A foil hat does not protect the face, and other uncovered areas of the body are not protected. A common high school physics demonstration involves placing an AM radio on aluminum foil, and then covering the
Tin-glazing of tin glazes may differ in different sites and periods, the process of the production of tin glazes is similar. Generally speaking, the first step of the production of tin glazes is to mix tin and lead in order to form oxides, which was then added to a glaze matrix (alkali-silicate glaze, for example) and heated. After the mixture cooled, the tin oxide crystallises as what has been mentioned above, therefore generates the so-called white tin-opacified glazes. Besides, the body of tin-opacified wares is generally calcareous clays containing 15-25% CaO, of which the thermal expansion coefficient is close to that