Ready for anything

So my husband found a video of a person showing how to make a flashlight work with only one battery. He yells to me, "Bring the aluminum foil!" I oblige, no questions asked. He wanted to try it out. It really does work!  Here's what you do...

Assemble supplies: flashlight, one battery, and the foil

Tear off a sheet of foil about "yay" big. 

Fold until it is as wide as the battery. 

Roll it up. It does not matter that it is not as fat as the battery as long as they are the same height. 

The battery touches the bulb end. 

The foil roll goes next. 

Turn it on and Voila! Working flashlight!