Friday, September 16, 2011

Firewater Friday . . . Mmmm, Daddy!

You know the old wives’ tale that says a watched pot never boils? Well, I’m thinking too many old wives spent too much time in the kitchen and had nothing better to do than make sh!t up to mess with our minds.   Of course a pot will boil even if you’re staring at it.  It just feels like it takes longer because you are concentrating on the water and nothing else.

In order to distract you from all this water watching, someone invented a device so that you don't have to . . . it's call the Boil Buoy.  It's a little device goes into your pot of boilables and will chime when the water is ready to go.  How cool is that!!

Then there’s the claim that cold water boils faster than hot water does or that hot water freezes faster than cold water does . . . tell me how much sense that makes . . . but it must be true because I’ve been hearing it all my life.  Right??

Lets start with the first one . . . it’s true that cold water gains heat more rapidly than water that is already hot but that doesn’t mean it will boil faster.  Once it gets up to the temperature of hot water, the heating rate slows down and from there it takes just as long to bring it to a boil as the water that was hot to begin with. So, obviously, because it takes cold water takes some time to reach the temperature of hot water, cold water clearly takes longer to boil than hot water does.  DUH!  No brainer . . . right?

Sort of . . . there’s a caveat: water that has been boiled once and allowed to cool will boil faster than hot water straight from the tap. Seriously!  How can this be so you wonder just before your head explodes.  The reason is actually quite elemental, literally.  It’s because boiling gets rid of the dissolved oxygen usually found in water, making it easier for the water to boil the second time around.

Now the second claim, believe it or not, is actually true . . . under the right conditions.  Hot water can actually freeze faster than cold water . . . well not cold water, actually, but lukewarm water.  But how is this possible you are asking dubiously right at this very moment.  Physics, my dear Watson, physics.  Hotter water loses mass to evaporation.  Less mass equals less water to freeze . . . therefore, it freezes faster.  Ta-da!

On a side note . . . where did the term lukewarm come from?  It’s actually a biblical reference.  Matthew, Mark, Luke and John were walking down the street of Jerusalem. Three of them said they were cool, but Mark said, "Luke warm”.  Okay, okay . . . I made that up.  The word lukewarm is a centuries old word.  The adjective luke is thought to be an alternative form of lew, an Old English word meaning tepid.  There was a time when the word luke stood alone and meant the same thing as lukewarm.  Saying lukewarm is pretty much the same thing as saying ATM Machine. 

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