What is one of the questions that chapter 3 Alan The World Without Us tries to answer?

Chapter 3 of "The World Without Us" explores the impact of human absence on the built environment. It delves into the question of how long various structures and objects would last without human intervention.

Specifically, chapter 3 focuses on:

* The fate of buildings: How would concrete structures, steel skyscrapers, and wooden houses fare in the absence of regular maintenance?

* The decay of infrastructure: How would roads, bridges, and power lines crumble without repair?

* The fate of objects: How would everyday items like cars, furniture, and appliances deteriorate over time?

By examining these aspects, the chapter seeks to answer the question: What would become of the physical world we have built if humans disappeared?