8. New Reference Unit for Measure of Energy
The standard unit for the measure and comparison of energy (including work and quantity of heat) should be a new unit (though still could be called a ‘calorie’) which is equal to the amount of energy required to raise the temperature of one liter of water 1˚ Celsius. Such a standard unit of energy would be much simpler to visualize than the current standard because a much more common volume of liquid is used (1 liter) as the basis for determining this unit.
Another option may be to define this new unit according to the energy required to raise the temperature from 0˚ C to 100˚, but this is a relatively large amount of energy and may result too often, perhaps, in the uncomfortable use of centi-, milli-, etc., in the laboratory and when measuring the energy/calories in foods, among other things. Also, defining the new unit as a measure of a 100˚ C change, even though it’s from the freezing point to boiling point of water, may not be as logical as a one-degree change because everything related to the standard would be at the single unit level.
David: September 29, 2016 at 12:34 am
Disagree. There already is a unit of energy in the SI system: the Joule. It is the energy required to move one metre against a force of one Newton. It ties in nicely with other units. Calories are not part of the SI system, and a Calorie will always require a “fudge factor”. For example, it takes more energy to raise the temperature of water from 3.5C to 4.5C than it does to raise it from 19.5C to 20.5C.
Furthermore, the word calorie, with a lower case C, means a different thing than a Calorie, with an upper case C. (A calorie is the energy required to raise a gram of water by one degree Celcius, and a Calorie (sometimes called a kilocalorie) is the energy required to raise a kilogram of water by one degree Celsius.). This dual meaning differentiated by the capitalization of the first letter is confusing, and both terms should be done away with.
Policy Proposals Moderator: November 10, 2018 at 12:49 pm
Yes, you are correct. The Joule is the standard unit of energy. I was more trying to advocate for the use of a larger unit standard so that it would be easier to use in everyday life without using prefixes so often. Since 4184 Joules are equivalent to one calorie, we would, too often in my opinion, need to use prefixes to communicate common energy amounts using Joules. For example, it would be nice to redefine one Joule as the energy required to raise the temperature of some unit of water (like a liter) from 0 degree C to 100 degrees C. But it is understandable that this change would be very disruptive. The BTU is a more graspable unit of energy whereas the Joule is so small that is is not as easily visualized. Describing a Joule as the work required to produce 1 watt of power for one second is probably the most visual way to grasp the concept, but I feel that it is still too small of a unit of energy.