Elon Musk and Jack Ma floated some radical ideas last week. Two of the most powerful men in the world, both have invested heavily in AI. Ma, who is the Alibaba Group cofounder and a huge advocate for the 12-hour a day six-day Chinese work week in tech, indicated that he believed AI would reduce the work week from 72 hours, where it now is in China, to 12 hours -- that is, three 4-hour workdays.