Hi Everynolds, great questions and I cannot add any further to Jack’s answer except that if we have a dancing room then that tapping and moving will create good energy t maybe charge one device or more 😉 So get moving and grooving guys 😀
Here’s somewhere that apparently “useless” movement is useful. When we get cold we shiver. This repeated and rapid contraction and relaxation of muscles causes them to generate heat (just as we get hot when we do lots of physical exercise for instance). This warms up the body and fights against cold, stopping us from cooling down so that we eventually die. Of course, this is only a short term measure. Sooner or later we need to get warm again as shivering can only cope with so much temperature drop and for so long before we need to replenish out energy supplies by eating.
I like your thinking – sometimes idle thoughts like this are the birthplace of the best inventions …. the story goes that Isaac Newton discovered gravity when an apple fell from a tree and hit him on the head…….