Hot on the range

This is one of those ones that I always assumed I understood-- right up until I started thinking about it.  I suspect there's a lesson in there, somewhere.

On an old electric range (I specify old for a reason), there will be one or more heavy metal coils.  When you turn on a burner, electricity flows through the coil, electrical resistance makes it heat up, and it gets hot, glowing red and cooking your food.  Right?

Well, it suddenly occurred to me, if that were the case, then touching a live burner wouldn't just burn you, it would shock you.  And electricity being what it is, this would still be the case even right when you turned on the burner but it hadn't had time to heat up, and this just doesn't happen.  This is something that you could BUT ABSOLUTELY SHOULDN'T verify at home.  So there must be something else going on somewhere.

It turns out that these classic burners are actually slightly more complicated than that.  Not much-- the basics of that theory are still correct.  But those heavy metal coils are actually hollow tubes, containing a set of wires (usually an alloy of nickel and chrome) that complete the actual circuit, separated from the tube by a ceramic insulator.  The nichrome wires heat up from the electrical resistance, but the heat then moves through the insulator into the heavy coil tubes, while the electrical current stays safely inside.  Er, not that a hot burner is especially safe, but you get the idea.

I specified old ranges, because more and more often these days you see the flat glass-topped stoves, and those often have alternate heat sources underneath the glass surface, such as powerful infrared lamps.  Then there are the induction burners, but those are complicated and generally only professional chefs and really wealthy amateurs have those.