The document discusses the hyperloop transportation system proposed by Elon Musk in 2012. It describes hyperloop as a fifth mode of transportation that is faster than air travel and has less environmental impact than other modes. Pods carrying 28 passengers each would travel inside low pressure tubes at speeds up to 1200 km/hr, propelled by linear accelerators along the tube. Solar panels on the tube would provide power. Hyperloop aims to be safer, less expensive, and more sustainable than existing high-speed transportation options.