A new business model could help people in poor countries light their homes cheaply using solar power

Credit: Eight19

Consumers get safer, cheaper lighting, their mobile phones charged, & the atmosphere gets less carbon dioxide. An energy distribution system where everyone wins.

http://www.economist.com/node/21548482#sthash.nZKYbjZq.dpbs

http://eight19.com/overview/indigo-pay-you-go-solar / Sun sunny sunshine countries often poor photovoltaic photo voltaic PV solar power expensive getting cheaper cheap competitive other forms of energy attached electricity grids large potential market solar energy sunlight solar cell upfront cost equipment loan lend loan money buy finance Eight19 British company Cambridge University deposit $10 supply supplying poor families Kenya solar cell generate 2.5 watts electricity battery 3 Amp current store electricity lamp energy efficient light emitting diode LED battery fully charged system light two small rooms power mobile phone charger scratch card reference number printed reference serial number household solar unit text message Eight19 company's server access code hourly rate for their electricity paying off the cost the user will own it trade trading it in bigger model driven 10 Watt solar cell upgraded kit increase electricity supply consumer user customer Kenyan trial charitable loan its roll out Kenya Malawi Zambia /

Mathematics explains why your earphones are always tangled

All bad news on the tangling front — if headphones are shaken, as in a pocket or bag while you are walking, the cords will tangle. Shorter, stiffer cords may help a little, but the only thing known to work is a pair of wireless earbuds.

http://www.dvice.com/2014-6-19/math-explains-why-your-earphones-are-always-tangled / pocket earphone earphones ear phone jumbled mess of cords untangle untangling group of physicists study studying earphones tangle maths math several factors knots cords shake shaking agitation cords pocket box factor physics physicists box full of string shake shook complex knots string knot knots 120 different types of prime knots up to seven crossings mathematical theory each type of knot probability length of each string agitation time shake strings longer length longer time more knots stiffness diameter length and agitation time strings shorter than 18 inches knotted less probability knotting increasing longer lengths long flexible cord getting tangled earphone cords getting tangled shorter and stiffer slightly fewer number of knots wireless earbuds /