Sir Charles Parsons invented the modern steam turbine, which converted the thermal energy of pressurized steam into rotary motion much more efficiently than previous reciprocating steam engines. Instead of pushing a piston back and forth, steam was blown across sets of blades to spin a shaft directly. This invention was a monumental leap for electricity generation; even today, nearly all thermal power plants (coal, natural gas, and nuclear) use steam turbines to drive their generators. Parsons also applied his invention to naval warfare, building the 'Turbinia,' the fastest ship in the world at the time. This revolutionized maritime travel and paved the way for the massive ocean liners and warships of the 20th century. The steam turbine remains the invisible backbone of the world's power grid.