Cities are not static objects to be feared or admired, but are instead a living process that residents are changing all the time.

People who gentrify are usually new transplants to a city, changing it to suit their particular cultural needs and whims.

There can be problems with extended families, and it can get a little close for comfort. But for the younger generations, it's clear that this option is becoming almost as appealing as living alone.

Cities might become biological entities, walls hung with curtains of algae that glow at night and sequester carbon, and floors made from tweaked cellular material that strengthens like bones as we walk on it.

In the 1970s, as historians became enchanted with microhistories, economists were expanding the reach of their discipline. Nations, states and cities began to plan for the future by consulting with economists whose prognostications were shaped by investment cycles rather than historical ones.

Using predictive models from engineering and public health, designers will plan safer, healthier cities that could allow us to survive natural disasters, pandemics, and even a radiation calamity that drives us underground.