#calorie
The #SI system of #units is based on very precise measurement of universal constants like the speed of light or Planck's constant and no longer on prototypes kept in #Paris, or wherever. However, for more mundane everyday use, many of the units are also linked closely to #water in the #MetricSystem. For examples, 1 #kg of liquid water at room termperature has 1 #litre of #volume. Therefore, 1 #tonne of water fits into a cube with sides of 1 #m. One #calorie is the amount of #heat or #energy required to raise the #temperature of 1 #gram (or 1 #cc or #CubicCentimetre) of water by 1 #degreeCelsius or 1 #K.