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In 1888, Friedrich Reinitzer discovered liquid crystal, a substance between solid and liquid phases. Liquid crystals have two main phases, nematic and smectic. LCD technology was developed in 1963 and has since surpassed CRT monitors and plasma televisions.
It was once firmly believed that there were three, and only three, states of matter: solid, liquid, and gas. This was the case in 1888, when an Austrian chemist named Friedrich Reinitzer, who worked at the University of Prague, was working on a cholesterol-based substance that did not seem to meet his expectations. While trying to determine the melting point, he discovered that the substance, which was a solid crystal at room temperature, had two distinct melting points at 293.9ºC (145.5ºF) and 353.3ºC (178.5ºF). Between these two spots was a cloudy liquid, and when heated above the second spot, it became clear. Reinitzer consulted Otto Lehmann, an expert in crystal optics, who realized that the cloudy liquid was an unspecified state of matter, for which he coined the name liquid crystal.
A liquid crystal is a substance considered between its solid and liquid phases. Often its molecules are shaped like plates or rods, shapes that tend to line up in a certain direction. The molecular order in liquid crystals can be altered by exposing them to electrical, magnetic or mechanical forces.
There are two main phases to a liquid crystal. In the nematic phase, which is close to the liquid state, the molecules float but remain ordered. In this stage where a liquid crystal is what is called a cholesteric, the crystals can create a twisted structure and reflect visible light in a temperature dependent color pattern. The link between temperature and color allows its use in thermometers.
The other phase is the smectic phase. In this phase the crystal is close to solid, and is arranged in layers. Liquid crystals move within layers, but not between layers.
The liquid crystal display (LCD) was developed in Princeton, New Jersey at the David Sarnoff Research Center in 1963. Monochrome LCD digital watches were first produced in the 1970s, and the first commercial LCD television is was built in 1988. Color LCD computer monitors began to be sold in the 1990s and surpassed CRT monitors for the first time in 2003. As the prices of LCD technology fell, more were sold during the 2007 holiday season. LCD televisions compared to plasma televisions or CRT televisions.
