Why asking people to turn up the heat is a bad motivational analogy

With boiling water comes steam, and bad motivational analogies. After two of them it perhaps is time to contact the Analogy Police, for a warning that next time they will take away your poetic license.

On December 30, 2009 I blogged about how the inspirational book 212 Degrees: The Extra Degree was where inspirational vapor clashes with reality. That book confused temperature and the amount of heat required to boil water. At 2:54 in their accompanying video there also is a call to action which says that:

“You are responsible for your results. And it’s time to turn up the heat.”

That statement may seem obvious if your experience with heat transfer is limited to watching pots or teakettles boiling on your kitchen stove. But, it is not how the boiling heat transfer process always works. Chemical engineers, mechanical engineers, and metallurgists all know better.

When you look at the section on boiling heat transfer in the Wikipedia entry under heat transfer you will see that there are two very different types of boiling. The more familiar one is called nucleate boiling, but there also is another one called film boiling.

If you keep turning up the heat in an industrial boiler you eventually change over to film boiling. During film boiling there is a blanket of vapor covering the surface which insulates it from the liquid and greatly reduces heat transfer. You can see film boiling on your stove at home if you put a drop of water on a hot pancake griddle. When it is hot enough for the drop to dance around without evaporating quickly, then you are watching film boiling. Film boiling also is discussed in the Wikipedia entry under the Leidenfrost Effect. A more technical discussion appears in one section of the Wolverine Tube Handbook. So, once again inspirational vapor clashes with reality.

My father taught chemical engineering for twenty years. When I was a teenager he told me a story about how film boiling could seem completely counterintuitive. Back in the 1930s he was hired by a glue company who wanted to cut costs and increase production. He looked at their process, and told them to turn DOWN the heat. They were skeptical until he told them why that would help. After they did their glue production soared. Their warehouse began to fill up until their salesmen managed to get more customers.

















Asking people to turn up the heat sounds pretty silly when peak daytime temperatures currently are hitting above 100 degrees. Maybe it is time for a big glass of iced tea instead.

212 Degrees – Where inspirational vapor clashes with reality

 

212 Degrees: The Extra Degree is an inspirational book by Samuel L. Parker and Mac Anderson. Of course there is a web site too (and an inspirational two-minute video).

The video has several comparisons showing that in sports there are very small differences between winning big and losing. Those comparisons are real, and perhaps relevant to the rest of us. If they had stopped there, then they would have been fine.

Unfortunately the book instead begins with the following:

“At 211 degrees water is hot. At 212 degrees it boils. And with boiling water comes steam. And steam can power a locomotive.”

“….Raising the temperature of water by one extra degree means the difference between something that is simply very hot and something that generates enough force to power a machine – a beautiful, uncomplicated metaphor that ideally should feed our every endeavor – consistently pushing us to make the extra effort in every task we undertake. 212 degrees serves as a forceful drill sergeant with its motivating and focused message while adhering to a scientific law – a natural law. It reminds us that seemingly small things can make tremendous differences. So simple is the analogy that you can stop reading right now, walk away with the opening thought firmly planted in your mind, and benefit from it the rest of your life.”

To many people that sounds very inspiring. Just a little more effort can bring huge results! The web site also has the catch-phrase: “One extra degree = exponential results.”

Don’t try telling the stuff about steam to engineers or scientists. At best they just will giggle. At worst they will scald you with their derision. For them it is a horribly bad analogy, an incomplete one that does not really add up. Instead it clashes with what they know about thermodynamics, and how water actually behaves.

That metaphor and “scientific law” confuses temperature and heat. How much added heat it does it really take to both bring a gram of water from 211 degrees to 212 degrees, and then to make it all boil away – to turn it from liquid to vapor?

Heating the liquid from 211 to 212 degrees takes only 2.342 Joules (the specific heat times the temperature difference). One degree F is 0.555 degree C, and the specific heat is 4.2159 Joules per gram degree C.

But, boiling it away takes adding another 2257 Joules (the heat of vaporization). You need to add another 964 times as much heat before you can turn it all into steam. Although it’s only one degree more, it takes adding much more heat to finish the job. And heat is equivalent to work. There really is no huge difference achieved with just a little more effort.

If instead you begin with the water at room temperature, 68 F, and heat it to 212 F, it only takes 335 Joules. Then you just need to add about another 6.74 times more heat to turn it all into steam. Tom Lambert pointed this out last year in a scalding blog post.

So the uncomplicated metaphor in the 212 degree book left out a huge part of the effort required to reach the goal. It is simply…wrong. The video says that: “…sometimes we need to sweat the small stuff.” Wrong! We always need to sweat the small stuff.

Boil some water, sit back, and have cup of nice hot tea. Consider the huge gap between an incomplete analogy and physical reality.

Mr. Parker since has written another motivational book called Smile & Move. If you do motivational speaking, then I strongly suggest you consider that one. You are now aware. Don’t steam people up by repeating a bad analogy!

Speaking of bad, there also is a much briefer (and only slightly obscene) parody video called 32 Degrees – the Extra Degree. Happy New Year!