Friday, March 25, 2016

Debunking debunking, part 1

Things need to be proven, or disproven. Urban legends need debunking.  But unless you dig into the history and have some context you may be wasting your time.  And if you have the context, you can make your case more convincingly.

Let’s venture into automotive lore for two examples.  First, a simple one- there’s a longstanding belief that you should never place a battery on bare concrete or it will damage the battery, or at least cause it to discharge.  You regularly see shops with batteries on scraps of plywood to this day.  I had this “debunked” at a manufacturer’s tech training many years ago, one of the instructors put a fully charged battery on the bare floor and the beginning of a week of training and it was fully charged at the end of the week.  End of story, right?  Well, not quite. 

First, the school was new and well equipped, it even had infrared heating, so the concrete floors were always warm, as opposed to the cold, damp floors many garages have throughout the winter.  Putting a modern battery on a cold damp floor really won’t hurt the battery- but cold batteries don’t release their power as well as warm ones, so putting a marginal battery on the floor could make it weak enough that it won’t start a car without being charged.

Second, above I said:

“Putting a modern battery on a cold damp floor really won’t hurt the battery”

The word “modern” is key to this legend.  In ye olden days car battery cases were made of “sealed” wood, then of natural rubber- both of which were somewhat porous.  Concrete is very good at wicking moisture, so putting one of these old batteries on concrete could really discharge it and suck water out of the battery.  Knowing this backstory means you can make a more convincing argument when faced with this particular legend.

Later, I’ll dive into one that has been “debunked” on TV and in universities.  By people who apparently don’t get the significance of context.