In honor of Blog Action Day, the video here is a six-minute TED talk by William Kamkwamba, author of The Boy Who Harnessed the Wind.
Facing serious food shortages in his native Malawi while still a teenager, William taught himself some science and physics. And using scrap materials, he built the windmill that supplied electric power and pumped water to his family.
He says to others:
Trust yourself, and believe. Whatever happens, don’t give up.
You can watch the video on TED.com.