Hitting the Books: What if 'Up' but pigeons?

We all have those thoughts, the ones that come to us in the small hours of the night. Who am I? Why are we here? What if my cellphone ran on vacuum tubes instead? Randall Munroe has the answer to, well, only one of those questions, but also the answers to a whole bunch of others collected together into What If? 2: Additional Serious Scientific Answers to Absurd Hypothetical Questions. Yes, that is a T-Rex eating an airplane. In the excerpt below Munroe examines what it would take to haul an average sized human in a chair over Australia's tallest skyscraper, using only the power of pigeons. Lots and lots of pigeons.