During the 1600's, the exotic tulip became a nationwide sensation; some single bulbs even sold for ten times the yearly salary of a skilled craftsman. Suddenly, though, the demand completely plummeted, leaving the tulip market in a depression. What happened? Prateek Singh explains the peak of a business cycle, commonly referred to as a mania. [D...

View full lesson: http://ed.ted.com/lessons/what-causes... During the 1600s, the exotic tulip became a nationwide sensation; some single bulbs even sold for ten times the yearly salary of a skilled craftsman. Suddenly, though, the demand completely plummeted, leaving the tulip market in a depression. What happened? Prateek Singh explains the pe...

Pratik Saini is a twenty years old boy who has been in an inherent disease called “Scoliosis”. He has recently been awarded by ministry of skill development and entrepreneurship for creating World’s first rap song to learn English Language. He shares his heart-melting but very inspiring journey of overcoming the disability and making it his stre...