Inspired by what I had seen so far, I opted to squeeze in a last-minute jeep tour of the tiny Nairobi National Park that borders the runways of the domestic Wilson Airport.

BBC: The wildest side of Nairobi

Alternate the charges fast enough and the minute fluttering of the film causes tiny dimples on its surface to push the air at ultrasound frequencies.

FORBES: Technology

This was thought to be caused by the difficulty of achieving an accurate injection of a tiny heart that beats 600 times a minute.

BBC: Stem cells repair heart attack damage