Evan Osnos

In the final years of his life, when former Communist Party Chief Zhao Ziyang lived under house arrest, in Beijing, his aging friends resorted to donning white doctors' coats in order to slip past the guards stationed outside his home.

The jet stream is a very strong force and pushing a balloon into it is like pushing up against a brick wall, but once we got into it, we found that, remarkably, the balloon went whatever speed the wind went.