Conductivity for Dummies

How ions move in an electrical conductor

Have you heard about Tom Nichols' book, The Death of Expertise yet? Well, you will... simply put, Nichols' thesis is that people who read about some topic in a blog will "lecture" those with education and experience in the field as if the latter know nothing. It happens all the time... In our humble opinion, expertise is dying by a million little cuts -- and today's DotD nominee is responsible for a lot of them, especially when it comes to science. She's 24-time winner of the award Joan Whetzel, who we brought back to tell us "Why Is Conductivity Important?" for eHow, now appearing at Sciencing.com¹.

As contributors to eHow often do, Whetzel begins by attempting to define conductivity... well, actually, she doesn't: her lede is,

"Numerous materials (like copper) and liquids (like water) can conduct electricity. However, impurities can lower this ability to keep electricity moving, which creates resistance..."

...which is, actually wrong. The whole idea of "electricity moving" is hilarious to begin with, and Whetzel immediately sticks her scientific foot in her mouth with that "impurities... [create] resistance" business. Why? Because she mentioned water, which doesn't conduct electricity unless "impurities" are present. But that's just Joan being Joan...

Some of Whetzel's other goofiness includes "Micro-mhos (µmhos/cm) are the basic measurement for conductivity for liquids." "If minerals and metals are suspended in [water], ions form. These can be measured as conductivity." "Copper atoms are one electron short, making them positive ions." "Determining the correct conductivity reading depends on the type of water (fresh, salt or distilled) or the metal/alloy..." "Conductivity and insolation in solid substances is important for electrical purposes. "

...to which we add the following comments

1. Micromhos (note lack of hyphen) are not µmhos/cm. The micromho is a unit of conductivity, while micromho/cm is conductivity per distance.
2. Ions are not the result of suspension. Ions are the result of solution.
3. Copper atoms aren't "one electron short"; the reason copper conducts so well is that the electrons in the atom's outer shell can easily be freed.
4. Determining the conductivity doesn't depend on those things; the conductivity itself depends on those attributes.
5. Insolation refers to the quantity of sunlight that falls on an area. It's not the opposite of conductivity (and neither is "insulation".)

As usual, Whetzel reworded a few sites and, confused, changed around a few words. The result? misinformation and misinterpretation -- as usual -- and also as usual, Joan so impressed an equally uninformed eHow content editor with her erudition that the rubbish was allowed to stand. Another Dumbass of the Day trophy bites the dust!

¹ Joan's version has been sent to Leaf Group's cleanup team for rewrite. We'll be checking that one out, but if you're interested in seeing her her original, you can use the Wayback Machine at archive.org. The URL in question was   sciencing.com/conductivity-important-6524603.html

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