Fantastic Friday: Latent Heat of Fusion

20160322_081447Yes, I’m still an English teacher. I haven’t moved into physics or anything. But I was tutoring a student, who had to write an essay on Latent Heat of Fusion. My coursework in science is several years old and a bit rusty, and when I started Googling the term, I came upon frightening things like the term enthalpy and formulas that use characters that are neither letters nor numbers recognizable in common life.

But once the terminology became familiar, I remembered having studied the concept back in the day. And researching latent heat of fusion and its practical applications/importance made me appreciate it.

Water, a huge percentage of our planet, has a high latent heat of fusion. This means that before it changes state—from solid to liquid (or, in vaporization, from liquid to gas), it has to absorb lots of energy to break bonds. This means water loses lots of energy before it turns into ice—without actually lowering its temperature any.

I never realized how important this concept was. I’d heard that farmers in Florida spray their oranges with water before an overnight freeze to protect them, but I never understood that the energy transfer happening during a transition from water to ice is at play.

Because our oceans cover most of the Earth’s surface, latent heat of fusion/vaporization comes into play in regulating our climate and keeping it relatively moderate (compared to, for instance, Venus). Water provides a buffer so that temperature change happens slowly.

Most substances require much less energy to change state.

In similar ways, water (inside our bodies) helps us stay warm and cool, both in the form of sweating and in the form of blood circulating around the body.

Whether we understand it or not, the special properties of water help us to thrive on our planet and make our atmosphere unique enough to support us. And even on a bad day, it makes me feel lucky to think that a very special coincidence of circumstances created just the right mix of conditions to provide life for all of us.

Conditions have converged to give us this particular day. Now, what amazing things will you do with that opportunity?


Don’t miss my class “Storytelling for Kids,” helping writers who want to write for children or young adults. It’s in progress now, but it’s not too late to join! https://valmuller.com/2019/05/21/storytelling-for-kids/  The class is less than $50 and comes with a free two-chapter critique!

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