As self-driving cars move from fiction to reality, a philosophical problem has become the focus of fierce debate. The “trolley problem” describes a runaway mine cart, hurtling down tracks towards a group of five oblivious people.
With no time to warn them, your only option is to pull a switch and divert the cart on to a different track, which only has one person standing on it. You will save five lives, but at the cost of actively killing one person. What do you do?
All kinds of tweaks can be made to the basic problem. What if you stop the mine cart by pushing one particularly large person in its way? What if the five people are all over the age of 80 and the one person is under 20?