Steam

Steam is water in the gas phase, which is formed when water boils. Steam is invisible; however, "steam" often refers to wet steam, the visible mist or aerosol of water droplets formed as this water vapor condenses. At lower pressures, such as in the upper atmosphere or at the top of high mountains, water boils at a lower temperature than the nominal 100 °C (212 °F) at standard temperature and pressure. If heated further it becomes superheated steam.

The enthalpy of vaporization is the energy required to turn water into the gaseous form when it increases in volume by 1,700 times at standard temperature and pressure; this change in volume can be converted into mechanical work by steam engines such as reciprocating piston type engines and steam turbines, which are a sub-group of steam engines. Piston type steam engines played a central role to the Industrial Revolution and modern steam turbines are used to generate more than 80% of the world's electricity. If liquid water comes in contact with a very hot surface or depressurizes quickly below its vapor pressure, it can create a steam explosion. Steam explosions have been responsible for many foundry accidents, and may also have been responsible for much of the damage to the plant in the Chernobyl disaster.

Critical Role (web series)

Critical Role is an American web series produced by Geek and Sundry in which a group of professional voice actors play Dungeons & Dragons. The series is broadcast live on Thursdays on the Geek and Sundry Twitch.tv, with episodes made available the following Monday on Geek and Sundry's official website. Matthew Mercer serves as the show's Dungeon Master, running the ongoing campaign that is the basis for the show. The campaign began two years prior to the series as a one-time Pathfinder game at a birthday party for Liam O'Brien, after Liam and Sam Riegel discussed the idea on their podcast AllWorkNoPlay. The group enjoyed this initial game so much that they continued to play privately until they were approached by Felicia Day's Geek and Sundry network. In order to streamline gameplay for the live show, the game's characters were converted from Pathfinder to Dungeons & Dragons 5th Edition before the web series began airing on 13 March 2015. Each stream also serves as a donation drive to support nonprofit organizations such as St Jude's, 826LA, Extra Life, and Doctors Without Borders.