By mid-century there will likely be 9 billion people on the planet, consuming ever more resources and leading ever more technologically complex lives.
What will our cities be like? How much will artificial intelligence advance? Will global warming trigger catastrophic changes, or will we be able to engineer our way out of the climate change crisis?
Making predictions is, by nature, a dicey business, but to celebrate the 40th anniversary of Smithsonian magazine Big Think asked top minds from a variety of fields to weigh in on what the future holds 40 years from now.