Context

A friend passed this image on today and I think it does a great job of contextualizing these different scales. For more context consider today’s high temperature: 84⁰F, 29⁰C or 302K

So why K? The Kelvin scale is the ultimate at contextualizing temperature. K references where temperature is actually, or better said, absolutely zero.  Temperature is a measurement of the average energy of the molecules in an object where heat is the total energy in an object.  When K = 0 there is no energy and therefore absolutely no temperature.

Wait a minute what was that thinkgyou said about the molecules and the energy and the thing?

Context can help. I read a nice example that illustrates the difference.  Imagine a small cup of water and a bath tub. Both are filled with water of the same temperature. However the bathtub has much more heat because there is far more total energy because there are a lot more molecules in the tub than in the cup.

Okayyyyyy……?

As another example let’s take two more containers of water. Container A has 10 total molecules and container B has 50 total molecules.

Each molecule’s energy is represented by the numbers in the table.

<><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><> <><>

Container A				Container B
	6				6	7	4	9	6
	7				7	4	8	6	7
	3				3	8	6	7	3
	4				4	6	6	4	4
	9				9	6	7	8	9
	6				6	7	3	6	6
	7				9	3	4	6	7
	4				6	4	9	7	4
	8				8	7	6	3	8
	6				4	6	7	4	6
Average energy	6			Average energy	6
Total energy	60			Total energy	300

The average energy, or temperature, of the two containers is 6. However because container B has so many more molecules its total temperature is much higher.

The Kelvin temperature scale starts where there is no energy in the molecules which is why zero K is known as absolute zero.