When I heard about this, I thought it was a joke: The Gates Foundation is investing in the development of a urine-powered cellphone.

Frankly, I have always harbored a secret wish that someone would develop a urine-powered engine for automobiles. No one would ever run out of fuel. Now, that would be a wonderful idea and would provide an endless supply of sustainable energy forever!

But a urine-powered cellphone?

Who would have thought of that?

It does make more sense to invest in a urine-powered cellphone than to spend hundreds of millions to persuade school districts to evaluate teachers based on test scores. That dog of an idea went nowhere. It led to false positives, to high error rates, to narrowing the curriculum, cheating, and endless test prep as the stakes got higher and higher.

Last year, the Gates Foundation issued a challenge to reinvent the toilet of the future. An Israeli firm won the grant. There is a theme here but I don’t know if I am the right one to put a name to it.

I admit the idea of a urine-powered cellphone is intriguing. Also somewhat alarming. I am thinking about what will happen in public places, when people find that their cell power is low. But that’s just me worrying about proprieties. Hmm.