Jeff Duntemann's Contrapositive Diary Rotating Header Image

August 15th, 2011:

Old Faceful

OldFaceful190Wide.jpgCarol bought a new water bottle the other day. She put some juice in it for our shopping wander this morning, and we set out, with the bottle in the cupholder in the front console. We spent some time at Best Buy, shopping for smartphones, all the while the August sun sweltered down upon the 4Runner. When we got back forty minutes later, the car was an oven. The juice was warm but it was still fluids, and necessary in our land of 20%-or-less humidity. She grabbed the bottle, flipped up the little straw thingie in the lid…

…and got a face full of juice.

On the surface, the design would seem like a good one: With the straw up there’s a vent port that lets air in while you draw fluids out. With the straw down the bottle is sealed, and won’t spill fluids if it’s not dead vertical. However, if you leave the bottle in a hot car, the air above the juice expands, and evidently the pivot mechanism in the lid opens the path to the straw just before it opens the vent port. Whooosh!

Science lesson learned. The bottle is going into the recycle bin, and we’re back to looking for something similar with a slightly better awareness of basic physics.