Most people probably don't spend a lot of time thinking about their toilets, but they are both a modern marvel while also being somewhat of a failure of systems design. On the one hand, it has created a vast sanitation system that has helped add decades to human lifespan by reducing disease. But on the other hand, less than half of the world’s population can access a toilet that safely manages bodily waste, including many right here in the United States. We use about 100 trillion gallons of water for toilets every year at a time when water is becoming more scarce. While we see radical technological change in almost every other aspect of our lives, we remain stuck in a sanitation status quo—in part because the topic of toilets is taboo.