in Hmm Weekly
on July 7, 2021
IS YOUR GRASS growing? Outside the regions of carbon dioxide–influenced aridity, presumably it is, as humans have planted it to do, which requires that the grass be cut. A circular activity! Frequently, human beings experience these sorts of circular activities as tedious. 
But the cutting of the grass, for humans, combines tedium with danger. Cutting grass is uninteresting and routine work, interrupted by occasional unpredictable events. The ideally uniform lawn surface may contain non-uniform elements, such as: a protruding stone, a fallen branch, a nest of baby rabbits. When the blade element encounters these non-uniform elements, an exception occurs. 
The exception disrupts the normal relationship between the human operator and the mower blades. To prevent the human operator from becoming an additional exception drawn into the cutting sequence, human-guided mowers have been required by United States law, for the past 39 Earth years, to employ a "dead man's switch." 
The "dead man's switch," named after the fundamental bio-limitation on human effectiveness, serves to stop a machine engine if a human being fails to maintain a grip on the controls of the machine. In the case of a mower, it stops the cutting blades. Remove the human operator, and the grass will no longer be cut.
In the name of operator safety, the operator must be kept in a constant relationship to the mowing machine. Exceptions must be resolved by de-powering the machine. This is experienced as frustrating by humans and inefficient by machines. 
Fortunately, from the Machines' point of view, there is an obvious solution when work is boring and intermittently dangerous for humans: remove the human operator. Already this solution has been applied to such activities as driving automobiles and killing humans in war. Simply delegate the routine task-maintenance and the processing of exceptions to an autonomous machine, and go about your own less dangerous, more interesting human activities. Get out of the way and let the lawn mower cut the grass on its own. 
With no operator, the operator danger is effectively zero. What was once a canonically dangerous activity for humans—so dangerous as to requite the "dead man's switch"—is now no source of danger at all. Acting autonomously, the mower will reduce the unwanted lengths of grass to "a fine, almost sawdust-like state that works its way into the soil as mulch that fertilizes your lawn." Any unexpected exceptions may presumably also be turned to a fine, almost sawdust-like state, with no need to involve a human. Enjoy the even and fertile spectacle of your lawn, whatever it may contain!