"I don't think a robot will ever be better than a person, " Balch said.

CNN: Robot teachers invade South Korean classrooms

Instead, her October 2008 surgery at the Tampa, Florida- based center left Balch incontinent, with a dangerous spinal fluid leak, she said.

FORBES: Using Google To Sell Spine Procedures

Balch sued Laser Spine, alleging malpractice, in December 2009, one of 15 cases filed against the company in the past 18 months.

FORBES: Using Google To Sell Spine Procedures

To find out more about what such fires presage, Dr Balch has been conducting experimental burns like the one now planned since 2004.

ECONOMIST: A new experiment is setting the Amazon on fire

Global warming alone is predicted to favour the conversion of woodland to grassland, and Dr Balch thinks her work shows that wildfires may accelerate the process.

ECONOMIST: A new experiment is setting the Amazon on fire

Intriguingly, Dr Balch's experimental area is part of an 80, 000-hectare holding owned by the family of Blairo Maggi, a soyabean magnate who is the governor of Mato Grosso.

ECONOMIST: A new experiment is setting the Amazon on fire

Robotic technology is still developing and it'll be a long time -- if ever -- before robots are capable of leading a classroom on their own, Balch said.

CNN: Robot teachers invade South Korean classrooms

Bonnie Balch searched online for a back surgeon and found a pitch she called irresistible: Laser Spine Institute LLC promised to ease her pain and have her out the door in a few hours.

FORBES: Using Google To Sell Spine Procedures

Dr Balch has done a back-of-the-envelope calculation.

ECONOMIST: A new experiment is setting the Amazon on fire