Question: if u could make a world changing invention what would it b

Iain Bethune answered on 25 Jun 2015:

I would like to invent an efficient green energy generation/storage device that could completely end our dependence on fossil fuels. If we can do this, it will make our world a much safer, less polluted, and more sustainable place to live, and having a ‘free’ energy supply will enable lots of other technological applications.

The most likely candidate for this is a highly efficient solar panel, with a high energy density battery. We are heading in this direction, but not quite there yet.